# iBasso PB-2 Pelican fully balanced portable, DB-2 Dac . . HiFlight recommended op amps page 16. .



## jamato8

The information I have gathered on this amp is that it has sockets for changing out op amps and buffers, can use up to 15 IC's and puts out a little over 2.4 watts per channel. It is a quad design (all channels are separated) with a layered board having copper traces that are gold plated. The size is about the same as the iRiver H140 or 100mm long. 
  
 The PB2 is 12.6V when single ended, and it is 25.2V when balanced (swing). Run time is around 15 hours but varies widely depending upon what op amps are chosen and if the buffers are bypassed or not. There are many choices. The volume control is a custom ordered Alps for extremely close matching and is further checked to insure a extremely close tolerance with rejects being tossed.


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## debitsohn

sigh... lol i barely understood all that technical stuff but i already know im goan be very interested in it.  for those who havent tried ibasso, they should.  for the size and price, its very good stuff.


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## brendon

And the guys manning their sales desk are very courteous and quick to respond to any requests or questions that you have which is not too common with a Chinese based company. Win win situation I say  !


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## ztsen

PB1 owners shake there head now..  coz PB2 is coming. 
	

	
	
		
		

		
			




  With the opamp option definitely is a plus.


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## Xan7hos

Good stuff 
	

	
	
		
		

		
		
	


	




 Now we just need to advance 10 years into the future where these things can fit in thinner chassis


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## gtoviper

Inevitably, definitely waiting for someone to pit this against the RSA SR-71B when it's released.


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## flashy

I did kept montior to this amp for 1 month.
  The information show that this is very pwoerful with change of OP Amp features.
  I like it.


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## paulybatz

Yippee!


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## jamato8

With 15 IC's that can be changed and 2.4 watts of output and 26 volts of swing this should be another nice compliment to the portable balanced amplifiers. 
   
  It is supposed to be released around the 5th or 6th of January.


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## pekingduck

^ Does that mean the DB2 is around the corner as well?


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## debitsohn

Quote: 





pekingduck said:


> ^ Does that mean the DB2 is around the corner as well?


 


  yes it is. price is still being decided last time i emailed them but it will be north of 300.


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## kargi

I got my pb1&db1 one month ago... Do they make a special offer when we return them


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## trentino

Will there be a DB2 this january also?


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## jamato8

Quote: 





trentino said:


> Will there be a DB2 this january also?


 

 Most likely a little later.


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## estreeter

Quote: 





kargi said:


> I got my pb1&db1 one month ago... Do they make a special offer when we return them


 


  Just enjoy what you have. First rule here is that there will ALWAYS be something new just around the corner. Always.


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## grokit

How does this compare to the Toucan in its stock form?


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## jamato8

The Pelican isn't out yet. It is supposed to be released around the 5th or 6th of January. Looking forward. I already have some ideas on opamps I want to try and some I am going to order.


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## kargi

Quote: 





estreeter said:


> Quote:
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  I am enjoying them well, they are awesome. Also they are cheaper and smaller. But if PB2 has a "silent" volume knob, I will be sad again because of my early buy


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## wolfen68

It seems the PB2/DB2 are aspiring to a different sub-market segment.  The larger bodies, additional cost and opamp rolling will appeal to the more hard core crowd which is probably a minority of potential ibasso amp buyers.  At it's size and pricepoint, the Toucan will still have it's place unless it's sound quality is significantly subpar to the PB2....which I would not expect as ibasso has done a good job selecting stock opamps on their recent releases.


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## Jalo

Sure Ibasso makes good products, but if they want to be competitive in the portable market, they still have work to do.  I like their pricing, their customer service and the way they turn out new products.  But their design and look and feel need to improve significantly.  For instance, their unit is a little bit too large, they could shrink it down a little especially the thickness.  The matted finish on their amps and dac leaves little to be desired (The Pico amps always have beautiful finish).  I like the Hirose connector as it feels pretty solid, but it stick out almost a 1/4 of an inch from the faceplate, and by the time you connect another hirose connector to it, it is almost half the length of the amp/dac itself.  Now I can see the wisdom of the RSA Protector/SR71B connectors, it flushes even with the faceplate and leaves at an right angle and it hardly adds any bulk to it.  I hope by giving constructive feedback to Ibasso, we could get better products in the future.


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## Gorthon

I to like the feel/security of the Hirose connector, but I do wish there was a 90 degree option like the protector male connector.  That extra length makes it hard to fit into a mall case.  On the same token, I do with there was a stright male option for the protector adapter.


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## jamato8

On the PB-2 it would be hard to make it thinner and have interchangeable op amps. On the the finish, I have had the Pico Slim and I prefer a matt finish. I get tired of the fingerprints, which was also true of some of the earlier finishes of the iBasso amps. I find that the matt finish holds up much better and doesn't scratch as easily and since this is a portable amp, and for me, something I don't carry around in an individual case, I want a tough finish. 
   
  I wish Hirose made a 90 degree connector as well. I have made some connectors shorter and they turn in a short radius but that is something I did. I also have some straight Protector type connectors but again, I customized them.


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## GeorgeGoodman

I am looking forward to the release of this! It is in my consideration, as I have some Cardas balanced 250 ohm DT880s that I would like to hear close to their fullest potential. They are balanced by the 2X3 pin configuration, and I don't really want to buy an adapter from Ibasso for $42. Would it be easier and more efficient just to buy a Hirose pin from them and have a head-fier convert them to the Hiriose pin? It makes sense to me, as it would me my only amp. Anyway, this is pretty exciting. 
   
  BTW, since the most obvious competitor to this is the RSA SR71B, the voltage swing for that amp is about 26-30 volts, about the same as this, but the rated power is 1.2wpc. I think that means the PB2 has twice the power at 2.4wpc, for what its worth.


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## paulybatz

AWESOME!


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## GeorgeGoodman

Quote: 





wolfen68 said:


> It seems the PB2/DB2 are aspiring to a different sub-market segment.  The larger bodies, additional cost and opamp rolling will appeal to the more hard core crowd which is probably a minority of potential ibasso amp buyers.  At it's size and pricepoint, the Toucan will still have it's place unless it's sound quality is significantly subpar to the PB2....which I would not expect as ibasso has done a good job selecting stock opamps on their recent releases.


 
  Quote: 





jalo said:


> Sure Ibasso makes good products, but if they want to be competitive in the portable market, they still have work to do.  I like their pricing, their customer service and the way they turn out new products.  But their design and look and feel need to improve significantly.  For instance, their unit is a little bit too large, they could shrink it down a little especially the thickness.  The matted finish on their amps and dac leaves little to be desired (The Pico amps always have beautiful finish).  I like the Hirose connector as it feels pretty solid, but it stick out almost a 1/4 of an inch from the faceplate, and by the time you connect another hirose connector to it, it is almost half the length of the amp/dac itself.  Now I can see the wisdom of the RSA Protector/SR71B connectors, it flushes even with the faceplate and leaves at an right angle and it hardly adds any bulk to it.  I hope by giving constructive feedback to Ibasso, we could get better products in the future.


 

 IMO, these guys are all about value. If you want the collest new toy or the samllest amp, you might be turned off. If you want very good sound for a reasonable price, I think Ibasso whould be on your shortlist.
  
  Tomorrow or the next day it is being released!


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## trentino

I'd only buy the pb2 if it would suit hifiman he6 better than the pb1. Would it? From would i read it seems they are equal in power? Is the only difference the op amp rolling?

Edit: Hm feels as if I've already asked this question. Man I'm tired.


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## Xan7hos

Quote: 





trentino said:


> I'd only buy the pb2 if it would suit hifiman he6 better than the pb1. Would it? From would i read it seems they are equal in power? Is the only difference the op amp rolling?
> 
> Edit: Hm feels as if I've already asked this question. Man I'm tired.


 

 2.4w output and the ability to fine tune the sound signature to your liking seems plenty enough reasons to upgrade 
   
  These things are getting ridiculously powerful, I might pick one up to see if they can run my desktop full range speakers


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## GeorgeGoodman

Quote: 





trentino said:


> I'd only buy the pb2 if it would suit hifiman he6 better than the pb1. Would it? From would i read it seems they are equal in power? Is the only difference the op amp rolling?
> 
> Edit: Hm feels as if I've already asked this question. Man I'm tired.


 
  I think the original Toucan only had 1.4wpc, and this one pushes 2.4. The rollable opamps are a plus too. Ibasso made the PB2 so they could be the leader in portable balanced sound, so I would think it is a significant or at least very notable improvement from the PB1. I am just waiting for the SR71B versus PB2 smackdown from Jamato, with pics.


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## paulybatz

I think Ibasso is unbeatable, you cannot match the price performance ratio here..with any of their products from the D4 forward...fit, finish and internals are just top notch, high quality resistors and pots...and not just high quality, they are pre-screened for tolerances before being used in the amps!
   
  I cant wait to try that Pelican!


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## jamato8

The Pelican has very high grade SMD film caps and you can use two buf634 per channel for a total of 8. I would guess you could use and over and under adapter with 2 buffers and another one like that per channel but there is a diminishing return and a big current drain. Running one in high C could be the ticket, per channel.


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## GeorgeGoodman

When exactly is this coming out? I thought it was this week, now I see it is next week in the D6 thread. No matter, I just wants pics and impressions when someone gets it.
   
  Jamato, you know I am counting on you for a SR71B vs PB2 battle!
	

	
	
		
		

		
			





 This should be epic. One thing the SR71B has the PB2 doesn't is the panning control, useful on my imbalanced phones. The SR71B is far out of my reach though, the PB2 may not be.


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## jamato8

[size=medium]It looks like it will release at the end of this week. A couple of changes were made. The power output is 2 watts per channel (I believe this is into 32ohms) and a few refinements were made. There can be a total of 14 op amps with 8 that are in sockets. It also uses SMD film caps for bypass. ​[/size]


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## GeorgeGoodman

Thanks for the info. That is significantly more powerful than the SR71B, which has 1.2WPC. I am looking forward to this!


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## GeorgeGoodman

It is finally here!
	

	
	
		
		

		
		
	


	







 http://www.ibasso.com/en/products/show.asp?ID=70
   
  Hey Jamato and Hiflgiht, can I get some impressions? $325 is kind of a lot, until you realize that you can roll the opamps, drive almost any headphone, and have a ton of fun. A three setting gain switch sounds useful too.


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## paulybatz

PB2 available for order and I just ordered mine!!!!
  Sexy Black!


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## GeorgeGoodman

Quote: 





paulybatz said:


> PB2 available for order and I just ordered mine!!!!
> Sexy Black!


 
  Congratulations!
	

	
	
		
		

		
		
	


	




 Waiting for impressions!


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## Vault101

Will ibasso provide uprades to PB1s sold previously?


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## jamato8

Output power was revised again. 2.5 watts per channel.


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## GeorgeGoodman

BOOM!!!
	

	
	
		
		

		
		
	


	















   
  Can you drive the K1000 and HE-6 with authority now, Hiflight? This amp is for people who want a portable that has more power than many desktop amps. I want impressions bad now.


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## wolfen68

Quote: 





vault101 said:


> Will ibasso provide uprades to PB1s sold previously?


 

 Wishful thinking.  Your upgrade will be when you click the PB-2 "Buy Now" button


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## debitsohn

Quote: 





wolfen68 said:


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 +1. wouldnt even bother asking lol


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## HiFlight

My PB2 and D6 are enroute, so I should have some impressions fairly soon.  I, too, really look forward to determining the ultimate performance of the PB2 with regard to these two very hard-to-drive phones.  I am now driving my K1000, HE-6 and K340 directly from the speaker terminals of my Virtue 2.2. 
   
  As these are all balanced phones, the  Virtue does a superb job of allowing all 3 phones to reach their full potential.   I will have a very good basis for comparison when the PB2 arrives. 

  
  Quote: 





georgegoodman said:


> BOOM!!!
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## GeorgeGoodman

Great! I look forward to it. Do you plan on assembling a topkit or different opamp combos? 
  Quote: 





hiflight said:


> My PB2 and D6 are enroute, so I should have some impressions fairly soon.  I, too, really look forward to determining the ultimate performance of the PB2 with regard to these two very hard-to-drive phones.  I am now driving my K1000, HE-6 and K340 directly from the speaker terminals of my Virtue 2.2.
> 
> As these are all balanced phones, the  Virtue does a superb job of allowing all 3 phones to reach their full potential.   I will have a very good basis for comparison when the PB2 arrives.
> 
> ...


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## GeorgeGoodman

I checked the website and it now says 32 volts of swing are available. This is a potent little power pack (couldn't resist a little alliteration.)


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## HiFlight

I will probably be offering some custom L/R modules but not the buffers, as iBasso is including a very nice selection.  My main concern is with the cost of rolling opamps in the PB2, as there will need to be 4 modules instead of 2 for each channel.  The current D12 L/R modules will work very nicely, except for needing twice as many. 
  
  Quote: 





georgegoodman said:


> Great! I look forward to it. Do you plan on assembling a topkit or different opamp combos?
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## GeorgeGoodman

I see. You don't want the cost to be prohibitive. It is good Ibasso is including some buffers. I look forward to your impressions.
  
  Quote: 





hiflight said:


> I will probably be offering some custom L/R modules but not the buffers, as iBasso is including a very nice selection.  My main concern is with the cost of rolling opamps in the PB2, as there will need to be 4 modules instead of 2 for each channel.  The current D12 L/R modules will work very nicely, except for needing twice as many.
> 
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## blitz-dice

im patiently waiting for the PB2 to buy my 1st high end portable amp 
	

	
	
		
		

		
		
	


	




 and yes sorry for my wallet


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## GeorgeGoodman

Any word on the sound yet?
	

	
	
		
		

		
		
	


	




 I am waiting patiently...


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## HiFlight

I am also waiting (im)patiently until tomorrow when my PB2 and D6 are scheduled for delivery!   It will be like Christmas all over again!
   
  Quote: 





georgegoodman said:


> Any word on the sound yet?
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## GeorgeGoodman

Cool. 
  
  Quote: 





hiflight said:


> I am also waiting (im)patiently until tomorrow when my PB2 and D6 are scheduled for delivery!   It will be like Christmas all over again!
> 
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## paulybatz

Looks like my set should arrive tomorrow as well!


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## HiFlight

I received both my D6 and PB2 today, and of course had to immediately try both. First was the PB2, as I wanted to see if it is capable of adequate output to drive the notoriously difficult HE-6 planar. I am pleased to state that it does drive them effortlessly.  It also drives my K1000 very nicely. There seems to be enough power to drive anything short of electrostatics. So far most of my evaluations have been with balanced phones, but I did try a short listen from the SE output using my Sony Z1000.
   
  As can be expected, soundstage and imaging are at their best when using the balanced output. Tonally, the PB2 in its stock configuration is similar to that of PB1, but does reach a bit deeper into the lower octaves. This amp will be an opamp-rollers delight, as can be seen from the 8 sockets: 4 L/R and 4 buffers!!
   
  I have not had time as yet to pair with the Boomslang, but that is next on my list of pairings to try.
   
  So many amps....so little time!!
   
  Ron


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## GeorgeGoodman

Thanks for the initial impressions! I love the picture. It sounds like it is extremely powerful. Tell me, on low gain with something sensitive like the Z1000s, is channel imbalance much of an issue? Looking forward to more impressions...
	

	
	
		
		

		
		
	


	




 Good lower octaves are always welcome around here!


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## Vault101

Awesome picture! I am looking forward to your impression between PB1 and PB2.


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## jamato8

Very nice Ron. The battery looks like a beast. I know the PB2 needs a little time to settle in but how are the highs?


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## paulybatz

Got mine today too!
  But no time today...tomorrow night will be a music night!


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## HiFlight

I haven't yet tried low gain, but with my Z1000 on high gain, the volume knob barely needs to be turned for a reasonable volume level and there is no channel imbalance whatsoever even at the very lowest levels. 
   
  I have tried using both the SE input and the Boomslang for a fully balanced input and the fully-balanced input provides a noticeably more open and 3-dimensional soundstage than does the SE input.  In this regard, I think this difference is more apparent with the PB2 than with the PB1 even when using the SE output. 
  
  Quote: 





georgegoodman said:


> Thanks for the initial impressions! I love the picture. It sounds like it is extremely powerful. Tell me, on low gain with something sensitive like the Z1000s, is channel imbalance much of an issue? Looking forward to more impressions...
> 
> 
> 
> ...


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## GeorgeGoodman

No channel imbalance at high gain! That is great! I can definitely understand how little you need to turn the knob on the Z1000s with 20dbs of gain. That is interesting about the sound improving more over the PB1 from balanced in, I guess it means this amp is more revealing and capable. I have a balanced DAC, so if I get the PB2 I can run it balanced. It would require another of those lovely priced adapters...
	

	
	
		
		

		
		
	


	




 But will probably be worth it. I plan to mod the DAC, an M-audio SuperDAC 2496. Better PS, Caps, and maybe even opamp. 
   
  Nice pic of the PB2 there. Battery is a beast, as expected for 16 volts. All the opamps and buffers look really cool. Does Ibasso give you extra opamps and buffers to play around with, or do they just give you enough to run it?


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## maik

I've always been curious to why iBasso's are priced significantly higher than other portable amps. What about it maeks it so much better?


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## qusp

very cool!! I tell you what, the height needed by that battery has left a nice little area there for stacking opamps and other stuff. I would be trying out making up a little adapter with stick on heatsink for LME49600TS in place of the BUF634. nothing wrong with the BUFs, but they are somewhat limited WRT the current capability due to the package they come in (thus people stack them). I know they used to make an SMD TO263 package the same as the LME but you dont see it much. its one thing to have voltage swing for driving planar fullsize cans, but lowZ IEMs need CURRENT.
   
  nice to see them using SMD PPS films, glad to see a manufacturer finally using them, ive been loving them for well over a year in the FiQ and now use them in every build I make. also use them in LODs to bypass electros
   
  just one LME49600TS per channel would give up to 1A of output current (+/-250ma per channel) and no need for wide band mode, as standard they are 110mhz, so if anything they may need bandwidth limiting. do the math guys.by ohms law, 1 amp channel has 16v swing so 16v x 250ma = 4W x 4 = 16W if i've got that right. haha you could indeed run some small efficient speakers quite well, for a little while
   
   
   
  Quote:maik 





> I've always been curious to why iBasso's are priced significantly higher than other portable amps. What about it maeks it so much better?


 
   
  ermm you dont get around much do you? you sure you didnt mean to say 'priced significantly lower'? the ibassos are probably some of the better value amps around; only things cheaper are actually cheap amps, where the ibassos tebnd to be high value for money amps for what you get. if you cant see that from the above pics then this possibly isnt the amp for you.


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## qusp

also a tip for Ron and all you keen opamp rolers; if you havent tried them yet the LME46990 is SUPERB!! has taken the place of AD797 as my favorite opamp cheaper too.


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## madwolf

Something like this qusp ?
   
  Have you tried the newer LME49610 which is a direct replacement to this the LME49600 
  The 49610 has 120Mhz BW in low current mode compared to LME49600 110Mhz
  and at high C mode it is 200Mhz instead of the LME49600/Buf634 180Mhz 
   
  The one with the crazy spec is LME49990 PSRR 144db CMRR 137db input noise 0.9nV/rootHz THD + N 0.00001%
  Never seen anything like that  
   
  Can't seem to find the  LME46990. One thing I get annoyed by National is that they have so many closely spec parts


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## HiFlight

I have some of the 49990's  and will give them a try in my PB2. I hadn't gotten around to trying them yet. Should also work nicely in the P4. Is that where you are using them?
  Quote: 





qusp said:


> also a tip for Ron and all you keen opamp rolers; if you havent tried them yet the LME46990 is SUPERB!! has taken the place of AD797 as my favorite opamp cheaper too.


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## jamato8

I wondered about the 32 volts of swing since the battery is 12.6. You can maintain a full 32 volts while using the adapter. So since it is running from the adapter, I would think the better the adapter, the better the sound but 32 volts from a portable and 2.5 watts is more than I though a portable is moving some power.


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## GeorgeGoodman

Quote: 





jamato8 said:


> I wondered about the 32 volts of swing since the battery is 12.6. You can maintain a full 32 volts while using the adapter. So since it is running from the adapter, I would think the better the adapter, the better the sound but 32 volts from a portable and 2.5 watts is more than I though a portable is moving some power.


 


  Actually, I am pretty sure the battery is 16 volts, but Hiflight can probably confirm this. That would make sense. The charging jack on the back says 16 volts, while the one on the PB1 is only 12.6 volts. So 16 volts seems consistent. Also, the battery is definitely bigger than the PB1's.


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## HiFlight

Yes, the battery in both the PB2 and P4 is a 16v lithium.  The chargers are identical.  My experience with opamp rolling in the PB2 today has convinced me that there is no non-electrostatic headphone that the PB2 cannot drive with authority.  The PB2 seems to show more sonic differences with different opamps than I have experienced with other amps.  Many of the differences are not subtle.


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## GeorgeGoodman

Sounds awesome! What about the K1000? I know you posted your rig of the Boomslang and PB1 with the K1000s a while back, and mentioned it lacked some authority in the bass but you loved it because you could take it around. I think I am going to get this amp sometime, it is just a matter of when.
   
  BTW, how do balanced KSC75s sound out of this? If you no longer have a pair, can you mention the improvements to balancing them? I just got a pair and really love them, and am going to really mod them in the future.


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## jamato8

Quote: 





hiflight said:


> Yes, the battery in both the PB2 and P4 is a 16v lithium.  The chargers are identical.  My experience with opamp rolling in the PB2 today has convinced me that there is no non-electrostatic headphone that the PB2 cannot drive with authority.  The PB2 seems to show more sonic differences with different opamps than I have experienced with other amps.  Many of the differences are not subtle.


 

 I had understood it was 16 with the adapter. With battery also is crazy. A portable with 32 volts of swing and 2.5 watts at 32 ohms? And stack the buffers to give just a tiny bit more current. Wow. 
   
  I will have to try my balanced PortaPros when I get the PB2.


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## GeorgeGoodman

> I will have to try my balanced PortaPros when I get the PB2.


 


 Thanks. Just curious, how did you terminate them?


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## jamato8

Quote: 





georgegoodman said:


> > I will have to try my balanced PortaPros when I get the PB2.
> 
> 
> 
> ...


 
  With a HiRose. I would like to use Twag on them, I think the PortaPros are that good but I have limits. :^)


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## HiFlight

I don't have my KSC75's balanced, but I do have a set of balanced KSC35's with TWag cable and they sound superb, more like multi-hundred dollar phones. The PB2 drives my K1000s much better than the PB1 did. Bass is now very satisfactory. Not much different than my desktop. I must say, though, that I have changed opamps MANY times today searching for what will ultimately become the PB2 Topkit. I am also using the stacked BUF634's in Hi-C mode.
   
  Most of the improvements that I noticed as a result of balancing my KSC35's were related to imaging and stability of soundstage. Tonally, I don't notice a great deal of difference.
   
  I have been too lazy to keep changing gains, as this is accomplished by internal jumpers. Even at high gain which is what the PB2 comes with as default, the channel balance is perfect even at the very low settings necessary with the high gain and KSC35s. I can also turn down the input from my source if I need to as that is easier than changing jumpers. .  BTW, all of my IEMs and smaller phones I terminated with mini-XLR connectors, then made up a Hi-Rose to Mini XLR pigtail that I can use with all of my smaller phones.  For the larger cans, I made up a Hi-Rose to standard XLR 4-pin pigtail.  
  
  Quote: 





georgegoodman said:


> Sounds awesome! What about the K1000? I know you posted your rig of the Boomslang and PB1 with the K1000s a while back, and mentioned it lacked some authority in the bass but you loved it because you could take it around. I think I am going to get this amp sometime, it is just a matter of when.
> 
> BTW, how do balanced KSC75s sound out of this? If you no longer have a pair, can you mention the improvements to balancing them? I just got a pair and really love them, and am going to really mod them in the future.


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## qusp

Quote: 





madwolf said:


> Something like this qusp ?
> 
> Have you tried the newer LME49610 which is a direct replacement to this the LME49600
> The 49610 has 120Mhz BW in low current mode compared to LME49600 110Mhz
> ...


 

  
  aha I knew I hadnt got that model right it didnt look right.(didnt have enough 9's) its the LME49990 that I meant. I have some I got for 'the wire' project on DIYA and I tried them out in the FiQ just for kicks and whoa!! they are there to stay and i'll have to get some more. I'll try the LME49610TS but in all honesty if you ever go to HiC mode they will oscillate in RF any time your mobile phone rings. 110 is already too much unless the layout and cct are designed for it, needs bandwidth LIMITING, not to be put into HiC mode without bandwidth limiting (~20pf in the feedback loop) IMO and if the leads arent damped and no compensation it wont look good on the scope, so 200mhz is a pointless spec for audio IMO.
   
  kinda like you have, but if you look there is quite a bit of room, so I had in mind a useful amount of heatsinking to take advantage of the better dissipation package, rather than just an adapter. with your setup there you wouldnt be able to get anywhere near the full 250ma current output specified, certainly not at this voltage
   
  right OK well Jamato: 16V is more like it, but where are people getting these output swing (voltage) numbers from? unless there is some sort of charge pump it seems too high to me. of course there is probably something tricky going on i'm unaware of


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## qusp

and yeah you're right national has too many chips that all have almost the same model number, thats why I put that 6 in there because almost all up till now started with 496 or 497, so I guess they really busted out with this one


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## estreeter

Quote: 





hiflight said:


> I don't have my KSC75's balanced, but I do have a set of balanced KSC35's with TWag cable and they sound superb, more like multi-hundred dollar phones.


 

 Ron, I'm always up for a challenge, but is it seriously worth the cost to have a pair of KSC-75s balanced ? I have a pair on the way, but they cost me $39 delivered - I guess its different if you can do this stuff yourself, but for me it would be serious overcapitalisation


----------



## HiFlight

The Hi-C as provided by iBasso is not the maximum wideband, but rather about halfway between low and high bandwidth.  The does have the effect of lowering the input impedance of the buffer stage and providing better square-wave response of low-signal inputs.  This arguably can result in improvement of low-level detail while the lower impedance allows an increased, albeit farly small, current flow from the LR opamps.. 
   
  When driving my HE-6 to my normal listening level using high gain,  the stacked buffers running Hi-C get only slight warm to the touch.  Although my cellphone is in fairly close proximity to my PB2, I have not experienced any RF interference while using the Hi-C configuration. 
   
  I do have some of the LME49990 opamps that I will try.   The specs do look very good, but I have been somewhat unimpressed by some of the other LME49xxx opamps, so they kind of gotten placed on the back burner. 
   
  I will say that my current configuration is really making my HE-6 sing sweetly!


----------



## HiFlight

I don't know if I would say that the cost of recabling with an expensive cable is worthwhile, but it is very easy to balance the stock cable by just adding the appropriate connector.   That only costs a few dollars.   As the HiRose connector is not real easy to work with, I would just buy the iBasso pigtail connector and use a standard XLR 4-pin connector on your KSC75. 
   
  I can't answer if it is worth it though.  I like mine balanced but I have lots of time to tinker and play with wires and gadgets.  The TWag cable on my KSC35's was a joint experiment between myself and Craig with the wire first was introduced. 
  
  Quote: 





estreeter said:


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> 
> 
> 
> ...


----------



## qusp

Quote: 





hiflight said:


> The Hi-C as provided by iBasso is not the maximum wideband, but rather about halfway between low and high bandwidth.  The does have the effect of lowering the input impedance of the buffer stage and providing better square-wave response of low-signal inputs.  This arguably can result in improvement of low-level detail while the lower impedance allows an increased, albeit farly small, current flow from the LR opamps..
> 
> When driving my HE-6 to my normal listening level using high gain,  the stacked buffers running Hi-C get only slight warm to the touch.  Although my cellphone is in fairly close proximity to my PB2, I have not experienced any RF interference while using the Hi-C configuration.
> 
> ...


 

 erm Ron, the point of RF oscillation (notice I didnt say interference) is that its in the RF, we cannot hear RF so you cannot 'experience it' to do that it would have to be down in the audio band which is a factor of 3 lower bandwidth (kHz vs MHz) what you hear with mobile phone interference is sidebands of the main signal that exist down in lower frequencies. it may instead manifest itself in oscillation,
   
  opamps are designed to drive MASSIVE impedances like other opamps, which generally have extremely high inputZ so they are capable of driving a wide range of loads. I cannot see how this better dealing with low level will effect anything much audio related, except a chance of a phono preamp or something with really massive gain on very low level signals, not on a 4-5v output from a balanced dac which is then amplified by in this case how many opamps?
   
  the buffers are inside the feedback loop so outputZ of the circuit should be close to nil. thing is though and this is why I recommended the national chip (only if heatsinked) instead of stacked buffers, that these DIP8 and SOIC8 packages are designed to use the PCB for heatsinking, using stacked dip8 packages in a socket...well you should see where i'm going. if they are only just warm, you are not using high current
   
  dont get me wrong the BUF634 can and does often sound very good, i've used them for years and have been very happy with them, but a single heatsinked package like the LME49600 or even a to220 buf634T is IMO a much better choice, shorter feedback paths, better dissipation specs, lower inductance etc etc. so if possible I would try it and this amp provides enough room for it.
   
   
  oh and I totally agree re the sound of most of their chips until now, to use a term I hate; they sound too 'HiFi' technically brilliant, but boring as hell and lacking any substance.
   
  not this one so try it LME49990 I mean


----------



## ztsen

Hi Ron, How is the PB2 compare with P4 for the SE part? Is the PB2 also have a G/V channel to roll?


----------



## qusp

there is no ground channel in a balanced amp. in fact there is no signal ground at all in a properly balanced amp, Vground or not. the only connections to 'ground' are in the power supply. so the only way they would possibly have a signal ground channel amp would be if they installed this specifically to drive the single ended outputs


----------



## paulybatz

Not only is this thing sexy (I really like this matte black finish!), but sounds fantastic right out of the box...Ill have to wait for A/B comparisons but WOW!
  I love balanced amps now, the HD-650s never sounded this good before I got the PB1/2


----------



## GeorgeGoodman

Quote: 





jamato8 said:


> Quote:
> 
> 
> 
> ...


 

 Thanks, Jamato. I will probably do what Ron says below, are send it to somebody to do it.
    
  Quote:


hiflight said:


> I don't have my KSC75's balanced, but I do have a set of balanced KSC35's with TWag cable and they sound superb, more like multi-hundred dollar phones. The PB2 drives my K1000s much better than the PB1 did. Bass is now very satisfactory. Not much different than my desktop. I must say, though, that I have changed opamps MANY times today searching for what will ultimately become the PB2 Topkit. I am also using the stacked BUF634's in Hi-C mode.
> 
> Most of the improvements that I noticed as a result of balancing my KSC35's were related to imaging and stability of soundstage. Tonally, I don't notice a great deal of difference.
> 
> ...


 
   
  Thanks for the reply. Sounds really amazing. I am still getting my mind around how much the various adapters cost. Do you think it would be economical to just get the 4 pin to Hirose adapter and then have all the phones I want balanced balanced in a four pin? It would make them easy to run out of a receiver and one connector instead of two would be less cumbersome. Of course, none of this is going to happen until I get the PB-2, which might be a while. I am actually going to run an equalizer in the middle of my balanced setup, as I have always wanted one and it has level control for both channels, useful for my unbalanced phones and any others I get. I find myself adjusting the bass between songs on my H120, as well as the pan balance, so this would make it easy. This or a JH3A or SR71B, both of which are out of my reach
	

	
	
		
		

		
			





!


----------



## jamato8

The balanced voltage swing of the PB2 with the adapter is 32  volts or 16 pos and 16 negative. With the battery, it is 25.2  as the battery is 12.6 not 16 volts. With  a 16 volt charger, unless you stepped it up, you couldn't have a 16 volt battery, the adapter would have to be of higher voltage. iBasso confirms that the battery is 12.6 and the same battery as the other 12.6 amps they have. So to maximize everything on the desk top, it would be run from the adapter, giving it 32 volts of swing.


----------



## GeorgeGoodman

I see. However, there is still more power than the PB1 obviously, even without the adapter.
   
  How much of a difference do the people who have it hear with adapter and with the batteries?


----------



## madwolf

Hi qusp, 
   
   
  For prototyping the possibility of your mod
  I could not find 4 unused LME49600 instead I used 4 TO220 with an possible (Still need to cut the bottom) heatsink that may fit into the PB-2. 
  One thing I notice on the PB-2 is that the position of the buffers are between the OPA and the vol pot 3.5mm connectors 
   
  That leaves a few option.
  1) Leave the cover open all the time.
   
  2) Take the battery outside the box and leave the heatsink with LME49600 at the space occupied by the battery
  (This will open up the options of having a bigger battery and maybe a higher voltage)
   
  3) Reverse mount the 4* LME49600 on the cover of the PB2 using the cover as a heatsink maybe with the LME49600 pin wired into a 8 pin socket. 
  Either that or some precision positioning so that when the cover is close the leads will slot into the 8pin sockets nicely. 
   
  Option 2 and 3 require some wire which might not be a very good idea if you are concern of high freq osc. 
   
  But anyway it certainly sound like a very interesting and fun mod, just for the hack of it.


----------



## saggett

I'm planning to buy a balanced portable amp for use at home and work with balanced HD650s and balanced DT770/600s - can anyone tell me how the PB1 and PB2 compare in terms of SQ when used with either of these headphones? Also, if there is an audible difference do you think it's worth the extra $96? I won't be rolling the opamps.


----------



## qusp

haha madwolf yeah thats the ticket 
	

	
	
		
		

		
		
	


	




 . option 3 sounds best to me, but add some small damping resistors to help with the lead inductance in case of oscillation; with such a wideband device could be a problem. this trick seem to work with offboard mounting of wideband power transistors in power amps, though not ideal. I had in mind a PCB with 2oz or 4oz copper with the national LME46900/10 and use some silver epoxy to glue some little CPU heatsinks either directly to the package, or to the underside of the PCB with a heap of thermal vias to suck the heat through. the PCB will have a fair bit of copper and surface area on its own if you use 2 or even 4oz FR4 double side, leave one side solid copper with only connections for the dip pins or whatever surrounded by copper pour and the other with just some local SMD bypass caps on the power pins and the rest coper with vias to connect to the other side. you could even use the 2 or 4oz without the sink and just tin it with a crapload of solder to add mass. the sink would be ideal though of course, PC tweaking extremist sites should have something suitable
   
  haha even a little waterhblock lol now i'm just being silly
   
   
  i'll do up a rough so you see what I mean. 
   
  indeed looks/sounds like fun!! good luck!!


----------



## madwolf

Warning !!!!! qusp
   
  The Tab or what you call it on the LME49600 is connected to Vee, might need to check if there is anything connected to the case before using silver epoxy. 
  Otherwise I assume all 4 chip should be connect to the same Vee and Vcc but not sure if there would be any ground loop problem later on. 
   
  Unlike the To220 the T263 case does not come with a screw mount. so I am a bit worried of the mounting. maybe silver epoxy with individual islands of heat sink
   
  Notice the Mica sheet on the photo.


----------



## qusp

sorry I assumed you knew the tab would be live, it usually is, need to use an isolation pad. keratherm red is my fave, but a silpad will do. I dont have this amp mate, I just dropped in to have a look and saw you here so thought I would throw some suggestions around and egg you on as I kniow you are usually up for some extreme mods 
   
  thats why i've been talking about a PCB for the heatsink primarily, so it could be easily thermally coupled but not electrically, but even with the LME49600 you could do it no problem with one heatsink with silver epoxy sticking it to the isolation pad and silver epoxy to bond it there from the other side. separate sinks would work too, but my favorite is TO263 with a heavy copper PCB, have you made PCBs before?
   
  it would be extremely unlikely to get a ground loop with such a small build with elements that all draw their power supply 'ground' from the same reference, but for power I would check VCC to see if there is continuity already. I wouldnt personally as this amp probably has 4 regulators and 4 discrete power supplies, I wouldnt waste that by connecting them all together. thermally coupling them is ideal because they will all track thermally and CMRR will be better that way as the performance changes with temperature, but probably best to keep them all electrically isolated


----------



## qusp

you can also leave out the epoxy and use a hole drilled on either side of the tab/body and screw down a small bar or piece of copper over the plastic molded body part to pinch them against the sink with an isolation pad underneath. ive used this method before with the fiddly little LU1014D TO251 (IPAK) power jfet package


----------



## GeorgeGoodman

Quote: 





saggett said:


> I'm planning to buy a balanced portable amp for use at home and work with balanced HD650s and balanced DT770/600s - can anyone tell me how the PB1 and PB2 compare in terms of SQ when used with either of these headphones? Also, if there is an audible difference do you think it's worth the extra $96? I won't be rolling the opamps.


 
   
  I think the difference is worth it. The PB2 sounds better, and is more powerful. Besides, you may decide want to roll opamps later. Hiflight usually makes up a topkit that includes everything you need to make the amps sound better, so it is not hard. Also, if you decide to get another headphone or get a deal that you can't resist, especially on one that is hard to drive, the PB2 can probably drive it.


----------



## trentino

Does the stock PB2 have the same sound sig as PB1?


----------



## madwolf

What!!! Are you telling me you don't have this amp and you are thinking of all this mod already ?
Actually I do not have it as well ...... 





   
  Ibasso's stuff are so mod-able. Every time I look at one I could hear it coxing me "Mod me, mod me ....."
  Open up an RSA and the feeling is totally opposite. You hear it says "Leave me alone!!!" 
   
  And yes I do etch board at home. 

  
  Quote: 





qusp said:


> I dont have this amp mate, I just dropped in to have a look and saw you here so thought I would throw some suggestions around and egg you on as I kniow you are usually up for some extreme mods


----------



## GeorgeGoodman

Madwolf, I want to see you mod this thing.
	

	
	
		
		

		
		
	


	




 That would be awesome. There are pretty much no cans it can't drive already with the exception of maybe the K1000, but maybe you could improve the sound, power, or some other aspect and make it even better. You obviously know much more about this stuff than me. I just like to marvel and listen.


----------



## Racio

I'm eyeing this amp like a hawk, so, I'd appreciate it if anyone here could please give their impression on this headamp (stock and the supplied alternative op-amps) with the Audez'e LCD-2. I used to own the PB1 and I felt that particular amp had a tendency to become a bit overly-sibilant, specially when used with silver cabling. Now, I'm wondering if it's the same case with the newer PB2 with different op-amps. Thanks in advance.


----------



## flashy

Here is LME49600 that coverted to DIP8.
  Sounds good more detail as buffer inside the PB2.


----------



## paulybatz

Quote: 





trentino said:


> Does the stock PB2 have the same sound sig as PB1?


 


  Ill be doing some A/B comparisons over the weekend.
  This amp sounds fantastic right out of the box...and there is nothing like a balanced amp setup, in addition the hirose is a great connector too!


----------



## drews

Out of the box fed by my Pico DAC it is very detailed, bordering on bright (both with stock and AD797 opamps) on my ATH-W1000x compared to my WA6 and Apogee Duet...  My LCD-2's are en route so I'll be able to comment on that pairing soon - I suspect it will work well since the PB2 oozes power and the LCD-2s are supposedly dark sounding..
   
  Quote: 





racio said:


> I'm eyeing this amp like a hawk, so, I'd appreciate it if anyone here could please give their impression on this headamp (stock and the supplied alternative op-amps) with the Audez'e LCD-2. I used to own the PB1 and I felt that particular amp had a tendency to become a bit overly-sibilant, specially when used with silver cabling. Now, I'm wondering if it's the same case with the newer PB2 with different op-amps. Thanks in advance.


----------



## Jalo

Quote: 





racio said:


> I'm eyeing this amp like a hawk, so, I'd appreciate it if anyone here could please give their impression on this headamp (stock and the supplied alternative op-amps) with the Audez'e LCD-2. I used to own the PB1 and I felt that particular amp had a tendency to become a bit overly-sibilant, specially when used with silver cabling. Now, I'm wondering if it's the same case with the newer PB2 with different op-amps. Thanks in advance.


 

 For all the talk about how the LCD2 has a recess treble, I am surprised to hear that the PB1 paired with the LCD2 will become a bit sibilant.  Are you sure?  
   
  I am also extremely interested in the PB2 and want more impression with the PB2 and LCD2 from anyone.  I have not done any opamp rolling, so I would be specially appreciative for those especially Hiflight to comment on the different characteristic of each opamp that comes with the PB2.


----------



## Racio

Quote: 





jalo said:


> Quote:
> 
> 
> 
> ...


 

 I only notice the sibilance when I'm using Mundorf's 18awg silver-golds with my LCD-2 and only when paired with the PB1 Toucan. But with the stock Canare cables, there's no sibilance at all, in fact I find the LCD-2 with the Canare StarQuad a bit too dark to my liking. In light of the said, I always prefer using the Mundorfs over the stock cables, not only do I hear better bass control and treble extension, sonic nuances are more pronounced as well.
   
  I'm looking forward to HiFlight's impressions on the different op-amps as well, I'm interested in the op-amps that'd not be too treble happy with the PB2. 
	

	
	
		
		

		
		
	


	



   
   
   
  P.S. To non-cable believers here, I'm only trying to express what my ears actually hear between cables, no need to start a cable debate.


----------



## saggett

Quote: 





georgegoodman said:


> I think the difference is worth it. The PB2 sounds better, and is more powerful. Besides, you may decide want to roll opamps later. Hiflight usually makes up a topkit that includes everything you need to make the amps sound better, so it is not hard. Also, if you decide to get another headphone or get a deal that you can't resist, especially on one that is hard to drive, the PB2 can probably drive it.


 
   
  Sounds better with which headphones? I can understand why moving from the PB1 to PB2 will make a big difference with very hard to drive headphones (like the AKG K1000) but any phone that is already sufficiently well powered by the PB1 won't necessarily benefit from the extra voltage swing on offer with the PB2.
   
  Can you or HiFlight point me to some posts on before / after impressions of the topkit vs stock opamps? I'd be interested in whether it delivers a clearly improved sound signature rather than just something different.


----------



## trentino

paulybatz said:


> Ill be doing some A/B comparisons over the weekend.
> This amp sounds fantastic right out of the box...and there is nothing like a balanced amp setup, in addition the hirose is a great connector too!





 


Nice. Please share


----------



## GeorgeGoodman

Quote: 





saggett said:


> Quote:
> 
> 
> 
> ...


 
  He has said bass is more present over the PB1. Wolfen86 said the PB1/DB1 could not match his RSA Predator for bass impact, and so I am assuming the PB2 improves on this. And like I said, you can roll opamps for a better or different sound.


----------



## kargi

Does volume knob make hiss like pb1, thanks?


----------



## wolfen68

Quote: 





georgegoodman said:


> Wolfen86 said the PB1/DB1 could not match his RSA Predator for bass impact, and so I am assuming the PB2 improves on this. And like I said, you can roll opamps for a better or different sound.


 


 Wolfen86 might be my evil twin...but you may have gotten someone else's comment mixed up with me.  I personally would take the PB1/DB1 over the Predator any day.


----------



## GeorgeGoodman

Quote: 





wolfen68 said:


> Quote:
> 
> 
> 
> ...


 

 Sorry about that. Didn't you say that some Ray Samuels' amp/DAC, I think it was the Predator, had more impact in the bass? You said the DB1/PB1 were better in every way except that aspect. Correct me if I am wrong, and thanks for chiming in. These are awesome products.


----------



## jbusuego

Is there a thread sbout a PB1 driving an AKG K1000? Can somebody point me to it please.
   
  HIFLIGHT  if its not much of a trouble can you please write a review on PB2 driving the K1000.  I currently owned the PB1 but I haven't tried with my K1000 I'm still waiting for the hirose connector to arrive.  I would definitely sell the PB1 and get the PB2 if this can really drive the k1000 with authority. thanks much


----------



## wolfen68

Quote:


georgegoodman said:


> Sorry about that. Didn't you say that some Ray Samuels' amp/DAC, I think it was the Predator, had more impact in the bass? You said the DB1/PB1 were better in every way except that aspect. Correct me if I am wrong, and thanks for chiming in. These are awesome products.


 
   
  Thinking of this (vs. SR71)?

http://www.head-fi.org/forum/thread/499184/ibasso-boomslang-and-toucan-balanced-portable-dac-and-amp-silver-and-black-pg-1-19-25-26/495#post_7054149


----------



## Jalo

This is a question for the cable believer.  Do you think a silver cable like the TWag or silver dragon will match better with the PB1/PB2 amps or do you like the UPOCC type copper better.  I am ordering the PB2 and since I have not heard either the PB1/PB2, I do not have a feel of the over all sound signature.  Does the PB2 need help in the treble or in the bass department? Is it cold, or warm, or colored? Is it transparent and clear?
   
  Also, for connection between DB1 and PB2, do you prefer silver or copper?  Please help.Thanks


----------



## GeorgeGoodman

Quote: 





wolfen68 said:


> Quote:
> 
> 
> georgegoodman said:
> ...


 

 This is what I meant. Sorry. Do you still feel this way, and do you plan on getting the PB2?


----------



## HiFlight

Quote: 





jbusuego said:


> Is there a thread sbout a PB1 driving an AKG K1000? Can somebody point me to it please.
> 
> HIFLIGHT if its not much of a trouble can you please write a review on PB2 driving the K1000. I currently owned the PB1 but I haven't tried with my K1000 I'm still waiting for the hirose connector to arrive. I would definitely sell the PB1 and get the PB2 if this can really drive the k1000 with authority. thanks much


 


  I had my K1000s set up with the PB1 at one of our local mini-meets and several people heard them and commented on the fact that a portable could actually drive them to a reasonable level.  That level was suitable only with the PB1 maxxed on volume, and then only with a source that ran a really good line-out voltage. 
   
  After reading your post today, I compared the PB1 and PB2 with the same inputs using my K1000's.  The PB2 clearly outperformed the PB1 both in tonal accuracy and in volume.  I had configured the PB2 with 2X stacked buffers, but not Hi-C.  I also tried it with a number of top-quality L/R opamps.   I should mention that I did all of my evaluations running the K1000 from the balanced output. 
   
  Volume control needed to be at least 2PM and for some recordings with less line-out voltage, I needed nearly full volume for what I consider to be a normal listening level.  I would say that my listening preference is a "moderate" volume level. 
   
  At no time, even at full volume, did I experience any clipping or distortion.  Tonal balance was excellent, with as much bass as I get from my desktop amp, albeit at lower volume level.
   
  I would not suggest that the PB2 be considered as day-to-day source for the K1000 as there are other more appropriate choices for about the same or less cost.  As an example, the Virtue Classic or Virtue 1.2 outperforms the PB2 in all respects when driving the K1000 balanced from the amplifier speaker terminals.  It is not, however, a headphone amp, but then the K1000 should more correctly be called near-field speakers rather than a headphone. 
   
  For occasional use with the K1000 and any other lesser phones, the PB2 is an outstanding performer, both from the SE output as well as the balanced output. 
   
  While the PB2 sounds quite good as delivered, it responds very well to synergistic opamp combinations.  FWIW, I did not detect any change in volume level when using the AC adapter over using battery only.  The charger should provide some additional headroom, but I was not able to hear any audible differences. 
   
  I hope this helps with your decision!


----------



## HiFlight

Quote: 





jalo said:


> This is a question for the cable believer. Do you think a silver cable like the TWag or silver dragon will match better with the PB1/PB2 amps or do you like the UPOCC type copper better. I am ordering the PB2 and since I have not heard either the PB1/PB2, I do not have a feel of the over all sound signature. Does the PB2 need help in the treble or in the bass department? Is it cold, or warm, or colored? Is it transparent and clear?
> 
> Also, for connection between DB1 and PB2, do you prefer silver or copper? Please help.Thanks


 

 I don't consider the PB2 to be colored in any way.  It is well-balanced across the audio frequency and responds accurately to the quality of the input.  I believe the copper Hirose interconnect sold by iBasso works just fine for connecting the DB1 to the PB1/PB2.  Neither to I think that an expensive silver cable is necessary.  I have tried both silver and copper headphone cables (TWag and Black Dragon) plus my own OFC coppoer and can hear little, if any, difference between the two.  The quality of the source and the recording makes far more difference, IMO, than does the choice of cable material. 
   
  I do believe that choices of cable material and construction are personal preferences that cannot be applied across the board to all users.  If this was the case, the marketplace would consist of one cable maker.


----------



## jbusuego

Thanks HIFLIGHT. That was quick.  I guess I'll give PB1 first a try and then decide later on if I should get PB2, which is most likely to happen


----------



## GeorgeGoodman

Jalo, this is what I found from the PB1/DB1 thread:

   

   

  By Jamato: 

   

  I am using a Twag balanced IC by Whiplash Audio with the Boomslang and Toucan. Very nice. In thinking about it, how could 2 inches of IC make any difference unless what you were replacing was really bad but then I realized, that in a good IC, it isn't really adding to the sound but it amounts to what it doesn't take away from it (the signal). I hear more separation and transparency and what I would term as impact or dynamics. This is a nice addition as the copper IC iBasso sells, is a little warmer, which may suit some music. I find the Twag to be very neutral and really not tilted warm or cold in sound. 

   
  By Paulybatz:
   
  I'm too a fan of silver interconnects...silver is in my opinion very neutral ...some say silver lacks bass, I don't agree, I think copper is thick/warm sounding...also copper corrosion hinders the connection...silver corrosion does not hinder conductivity...long term silver is better


----------



## Jalo

HiFlight and Goergegoodman, thank you both for you help.


----------



## GeorgeGoodman

Quote: 





jalo said:


> HiFlight and Goergegoodman, thank you both for you help.


 

 You are welcome.
   
  IMO, is the TWag worth the $120? In most cases, no. However, if you want a sound with slightly more precision and clarity, more like a razor as opposed to a cleaver, over what the amazing combo already offers or you want a slightly brighter or different sound sig, the TWag is not a bad purchase. Also, it will probably be wasted if your headphones and sources are not up to the task, but I think that is obvious.


----------



## wolfen68

Quote:


			
				GeorgeGoodman said:
			
		

> This is what I meant. Sorry. Do you still feel this way, and do you plan on getting the PB2?


 


 I have since sold the PB1 as I have been quite "smitten" with the SR71b and DB1 combination.  I have no plans to get a PB2.


----------



## Jalo

Quote: 





wolfen68 said:


> Quote:
> 
> 
> 
> ...


 

 I am listening to the CCR via DB1-->SR71B-->LCD2 in full balance mode.  You are right, it's got everything a person wants.  The beat is just snapping away.  But the PB2 with 2.5W per channel is still very tempting


----------



## qusp

wheres that picture of that old school headfier using the K1000 potable and how cool it can look when I need it. Jamato8, you know the one I mean? I just searched for it to no avail because I cant remember who it was


----------



## qusp

also guys, please do not continue the cliches of copper = warm bassy and silver interconnects = cool detailed sound in here, I have a hard enough job trying to explain that just isnt true as it is. system synergy is much more important. you simply cannot make generalized statements like that IMO


----------



## jbusuego

this one.







qusp said:


> wheres that picture of that old school headfier using the K1000 potable and how cool it can look when I need it. Jamato8, you know the one I mean? I just searched for it to no avail because I cant remember who it was


----------



## jamato8

Quote: 





qusp said:


> also guys, please do not continue the cliches of copper = warm bassy and silver interconnects = cool detailed sound in here, I have a hard enough job trying to explain that just isnt true as it is. system synergy is much more important. you simply cannot make generalized statements like that IMO


 
   
  I agree, you can't put the sound signature to either one. I find that gauge and combination of the strands and number has more to do with the final sound and as qusp states, synergy is a Huge one.


----------



## GeorgeGoodman

Quote: 





wolfen68 said:


> Quote:
> 
> 
> 
> ...


 

 That is cool. I have heard the SR71B with Ray's Meridian CD player and the HE-6, and it is really something special. Getting the PB2 after that is pretty much superfluous, unless you needed the extra power or wanted to roll opamps.
   
  Quote: 





qusp said:


> also guys, please do not continue the cliches of copper = warm bassy and silver interconnects = cool detailed sound in here, I have a hard enough job trying to explain that just isnt true as it is. system synergy is much more important. you simply cannot make generalized statements like that IMO


 
  I am sure synergy is the most important thing. I just pulled up what a few members noticed about this particular amp/DAC and two particular ICs.
   
  I searched for what Warp08 said, but couldn't find it. He said basically the same thing, that the copper gave a more analog bass reproduction and the silver was a little more exacting. I don;t think he really said one was necessarily better than the other.


----------



## Jalo

Quote:


qusp said:


> also guys, *please do not continue the cliches* of *copper = warm bassy and silver interconnects = cool detailed sound* in here, I have a hard enough job trying to explain that *just isnt true *as it is. *system synergy* is much more important. you simply cannot make *generalized statements* like that IMO
> 
> Quote:


 


jalo said:


> This is a question for the cable believer.  Do you think a silver cable like the TWag or silver dragon will match better with the PB1/PB2 amps or do you like the UPOCC type copper better.  I am ordering the PB2 and since I have not heard either the PB1/PB2, I do not have a feel of the over all sound signature.  Does the PB2 need help in the treble or in the bass department? Is it cold, or warm, or colored? Is it transparent and clear?
> 
> Also, for connection between DB1 and PB2, do you prefer silver or copper?  Please help.Thanks


 
  Quote: 





jamato8 said:


> Quote:
> 
> 
> qusp said:
> ...


 

 Qusp, since I am the one that brought this issue up with regard to cable matching of the PB2, and I understand that you have a difficult time in explaining that it is "just isn't true", but could you at least try to explain why it "just isn't true" for my benefit?  When you say it isn't true, do you mean:
   
  1.   Do you mean that this statement just isn't true period.  If so, what part of this statement is not true, (for instance, you may say cable doesn't make any difference and that is fine with me), or
  2.   Do you mean that this statement isn't true AS IT IS, but it could be true under certain conditions, if so, under what condition could it be true? or
  3.   Do you mean that this statement is too generalized and cannot be applied to all cases, if so, under what specific condition can you make this statement?
   
  You also stated that system synergy is much more important, as System Synergy is also a generalized term for me, could you elaborate what you mean? By system synergy, do you include cable as a factor that could affect system synergy? If so, what about cable that you consider as a factor that may affect system synergy, is it the type (silver vs copper vs sxc), the format (balance vs SE), the construction (like Jamato says above--the gauge and the combination of the strands and number, single vs multi core), or others like the shielding, braiding, numbers of solder joints, type of solders, connector, or others?  If you don't think cable is not a factor in system synergy at all, then could you list the factors that you consider as important starting with A.  For instance, tube vs SS, power considerations like impedance, voltage, current etc, designs (Class A, AB, B, Cmoy, Opamp, push-pull, balance vs SE etc).  I don't mean it as a challenge to your statement, I just want more info, that's all.
   
  Furthermore, I like to state that if you do not believe that cable can make a difference in sound.  That is totally fine with me.  We have enough discussion in these forums on this subject matter and I don't want to start any discussion at all.  We just have to agree to disagree.  I specifically started my post saying "This is a question for the cable believer".  So we don't need to go there.  
   
  Interestingly enough, if what Jamato said above is true and I am not saying it isn't, I think there are less people that believe in that statement than the one about silver vs copper.
   
  But if you say it is the other factors in the system synergy that are more important, than is has nothing to do the the type of cable use.  You can do both, it doesn't invalidate that statement.  I am very curious to hear your thoughts on the above.


----------



## jamato8

The discussion above would be better offline or in the cable section since this is about the PB2. 
   
  I received my PB2. Now for the listening. I also received my HE-6 so let the listening begin, after I terminate the HE-6 to a different balanced connector.


----------



## Jalo

Jam, I am just asking Qusp for information which I believe may interest other readers.  There is no argument here.  I already said we don't need to have a cable argument.  Qusp seems to have information that may be able to benefit a few of us here.  He can believe anyway he likes and that will be fine with me.  Besides, I like to know more about system synergy and its impact on the PB2.


----------



## jamato8

Quote: 





jalo said:


> Jam, I am just asking Qusp for information which I believe may interest other readers.  There is no argument here.  I already said we don't need to have a cable argument.  Qusp seems to have information that may be able to benefit a few of us here.  He can believe anyway he likes and that will be fine with me.  Besides, I like to know more about system synergy and its impact on the PB2.


 
  I am glad you asked him and not me. I got tangled up trying to read it. lol 
   
  The PB2 with extra set of buffers and biased to wide band is great sounding. I need time to compare and digest but the bass is well textured and well done. I am surprised that it does so well with the HE-6. Now to try it with the LCD-2. And then on to op amp rolling. Some nice AD744 in OB and CA.


----------



## Jalo

Quote: 





jamato8 said:


> Quote:
> 
> 
> 
> ...


 

 Jam, don't worry, I am a peaceful person like you and have zero interest in arguing with anyone here.  I just want info.  Thank for your input on the PB2.  I know it is early on, but how do you compare the PB2 to the SR71B?  I have the JH13 and the LCD2 also.  I am particularly impressed with the bass coming out of boomslang and SR71b into the LCD2.  The LCD2 makes some A-Kicking bass. With all the favorable impression on the bass aspect of the PB2, I am just very curious how the PB2 would sound out of the LCD2 with it immense power.  You have mentioned, if I remember correctly, that the PB2 is also very clean or quiet?  This is something very important to me as portable amp is very prone to noise or high noise floor.
   
  PS  What do you mean by biased to wide band?


----------



## jamato8

On the buffer 634 you use a 100 or 200 ohm resistor from pin 1 to pin 4. This puts the buffer into wide bandwidth (WB), which gives potentially a little better sound. I have found this to be the case in listening. The kit comes with 4 buf634 in WB so you can stack them on the buf 634 already in the sockets for 2 buffers per socket or 8 total and they will all be in the WB mode!
   
  I just got the PB2 so have no comment on hiss etc. but I haven't read of anyone experiencing it but that also depends upon the op amp being used. I have to say that right now, with the PB2 an HE-6 new, something has gone raspy. Gah. . . . not pleasant so one of the two is settling in and I don't feel like doing the AB thing of what it is so I will let both just run for a while. I can listen to the fi.Q and LCD-2, and that is an excellent combination.


----------



## Jalo

Thanks, I will have to bother you or Ron later for some coaching on Opamp rolling.


----------



## Jalo

Quote: 





paulybatz said:


> Quote:
> 
> 
> 
> ...


 

 Pauly, any new impressions on the PB2?  Thanks


----------



## paulybatz

Funny you ask...I am loving this amp, since getting it I have not used the PB-1, I am just intrigued by this amp...I feel IMHO that balanced is just the way to fly, especially with the HD650s....and likely any phones, this is my favorite setup, Im waiting to roll, rather than reinvent the wheel HiFlight impressed the hell out of me with his kit for the D4, which turned that little dude into a monster...I will do some A/Bing soon, but I absolutely love the synergy of this amp with the HD650...at this point I cannot tell which I like better, it is similar, I know to the PB1 but there is something about this one but I will wait a bit to do the comparison...in addition, what is nice is to have the option to change the signature as well...(and the cable question, I LOVE my silver ICs...simple 24ga dead soft silver in teflon tube, just fantastically pure sound...and you never have to worry about corrosion with silver as the corrosion with silver is just as conductive, unlike copper's tarnish that hinders transmission....but NO MORE ABOUT CABLES just the PB2 follks)


----------



## Jalo

Well, I'll be waiting for your thoughts.  With regard to balance setup, ever since the Protector and now the SR71B, I am also sold on the balance setup.  I love the additional power, better sound stage, the openess and additional air with the balance.  I know a lot of people hate the additional cost and the inconvenience of recabling, but I thought it is well worth it.  By the way, which silver IC did you get?


----------



## paulybatz

I had a local DIY guy make it for me...the actual wire is inexpensive, its all about finding someone to do the work for you....also with the relative price of these Ibasso amps, recabling is FREE!
  Quote: 





jalo said:


> Well, I'll be waiting for your thoughts.  With regard to balance setup, ever since the Protector and now the SR71B, I am also sold on the balance setup.  I love the additional power, better sound stage, the openess and additional air with the balance.  I know a lot of people hate the additional cost and the inconvenience of recabling, but I thought it is well worth it.  By the way, which silver IC did you get?


----------



## qusp

wow Jalo, haha I should have known, ok guys, this is waaay OT, so its going in a box, read it of you will, but please do not continue it in here, so Jalo, feel free to PM me if you want to discuss it further
  
   


> Spoiler
> 
> 
> 
> ...





   
   
  the search for definitive answers on the above will send you insane and cost mega $$$$. I speak of synergy amongst many different variables, more wide ranging than just a single cable metallurgy, cable topology, cable dielectric, headphone amp, tubes, chips or solid-state, or a single headphone apply. Matters of music choice, personal taste and personal subjective definitions of terms come in and mess all of that neatness up. We can only make educated guesses based on past personal experience, you just cannot make blanket statements one way or the other, because the chances of all the variables being the same for an apples to apples comparison are almost nil and if taste comes into it; impossible.


----------



## GeorgeGoodman

Very informative, Qusp.^ I may make a silver interconnect for my balanced DAC and a PB2 if I get one, as well as a silver headphone cable. But before I do that, I am going to get good at doing those in copper. I will report back here with what I hear. I just found this company White Zombie Audio, and e-mailed them to ask about getting some cable for some headphones or interconnects. He said he couldn't really help me because they are an interconnect company, and I should buy one of their cables and put that on a headphone. He said that at their prices, it is not a bad idea, and I am inclined to agree. He said he spent a lot of time experimenting to get a sound he felt is the closest to hardwiring the components together, and that I should experiment and find what sounds the best.


----------



## qusp

Good George, i'm glad you got something out of it. some might say I made a lot of noise without really saying anything and truth be told that was kinda the point. you may well find you prefer copper in the end depending on how your system turns out.
   
  anyway back to this rather intriguing headamp, I would be all over this if I didnt already have a portable balanced rig.


----------



## Jalo

Qusp, I appreciate your thoughts on the topic.  I understand much better of what you mean now.  Since this is off track, I will not continue the discussion here any more but suffice it to say that I did not regurgitate stuffs that are passed around here on the forum.  I think I have spent enough money to experiment and to know what I am talking about.  For instance, I have the TWag silver cable and the ALO chain Mail UPOCC copper cable for my JH13 in the same system, and I know they sounded differently.  I have the SAA Voice for my HD800 and I know it altered the sibiliance character of the phone.  I have used from generic cable to Black Dragon (GS1000), Silver Dragon, Cardas cable (HD600), Transparent cable, ALO Chain mail (LCD2) and so on.  I just want you to know that I have personal experience on cable when I talk about them.  But I do appreciate your thoughts, and actually I agree with a few aspect of them.


----------



## qusp

not all was directed at you personally; I was not labeling you with every example in my post, I was just saying that such generalizations contribute to noobs picking up what I deem falsehoods as defacto standards and 'fact'; as a result system synergy is often overlooked when I feel it is the most important aspect of the lot.
   
  so enough of the sidebar, I almost feel like buying one of these so I can make a cool 6 wire interconnect for it


----------



## saggett

Does anyone have any more impressions of the PB2 compared to the PB1?


----------



## jamato8

Quote: 





saggett said:


> Does anyone have any more impressions of the PB2 compared to the PB1?


 
  I am still forming my opinion and I want the PB2 to get some time on it both for burning it in and listening impressions. One thing I can say is that it goes deeper in the bass, sustains the note better and still keeps the sound well articulated. The upper bass does not smear into lower midrange area and the amp is well extended. It can also power my HE-6, which is amazing with the volume control anywhere from 1 to 3 o'clock and no clipping or distortion even on bass heavy music. On other headphones on high gain I am around 9 to 10o'clock and with all the power the PB2 has, any other phone is easy to drive (that I own).


----------



## saggett

Quote: 





jamato8 said:


> I am still forming my opinion and I want the PB2 to get some time on it both for burning it in and listening impressions. One thing I can say is that it goes deeper in the bass, sustains the note better and still keeps the sound well articulated. The upper bass does not smear into lower midrange area and the amp is well extended.


 

 Does the extent of the improvement vary depending on what headphones you're using? In other words, is the improvement more noticeable on some of your phones than others? I'm most interested in the difference it makes with the HD650.


----------



## jamato8

Quote: 





saggett said:


> Quote:
> 
> 
> 
> ...


 
  I will try it with them and get back. 
   
  edit:
   
  Yes, in a very good way the HD650's go low and are extremely well controlled. I like the drum on the start of Hotel California, Hell Freezes Over. The bass can just truncate or in the right system, go low and resonate. It sounds excellent with the PB2 and the 650's, lower and a better trailing bass note, it is not truncated at all.


----------



## Jalo

Quote: 





qusp said:


> I was just saying that such *generalizations contribute to noobs picking up what I deem falsehoods as defacto standards *and 'fact'; as a result system synergy is often overlooked when I feel it is the most important aspect of the lot.


 
   
  Hehehe, Qusp, isn't that is how noobs learn?  By spending a lot of money?  Why are we robbing them of that valuable experience of being a noob?  
	

	
	
		
		

		
			





   Besides, I really think cable believers are the ones that really knows the limitation of cable, because they/we tried so hard to spend the money and make cable do what we want them to do.  But we all knows there is only so much cable can do to the sound.  And you are right System Synergy is important and there is no disagreement from me.  Thnaks for pointing that out.


----------



## saggett

I take it then that with the PB1 and the HD650's the bass was truncated at the same passage?
  Quote: 





jamato8 said:


> Yes, in a very good way the HD650's go low and are extremely well controlled. I like the drum on the start of Hotel California, Hell Freezes Over. The bass can just truncate or in the right system, go low and resonate. It sounds excellent with the PB2 and the 650's, lower and a better trailing bass note, it is not truncated at all.


----------



## Jalo

Jam, could you comment on the difference in the bass department between the SR71b, D6 and PB2 using the LCD2 as reference?  Which one has the most bass?  Which of these has the best bass definition, tightness, punchiness, quickness etc. Thanks


----------



## jamato8

Quote: 





saggett said:


> I take it then that with the PB1 and the HD650's the bass was truncated at the same passage?
> Quote:
> 
> 
> ...


 
  To a degree, yes, the PB1 is a little truncated in direct comparison. It doesn't go as deep or sustain the bass note as long or with as much authority, on the same passage. 
  
   


  Quote: 





jalo said:


> Jam, could you comment on the difference in the bass department between the SR71b, D6 and PB2 using the LCD2 as reference?  Which one has the most bass?  Which of these has the best bass definition, tightness, punchiness, quickness etc. Thanks


 

 That will take a while as I am still getting used to everything and take it very serious when I make statements. If someone says, wow, this guy said it does this and then buys something because of that and I didn't evaluate carefully enough or listen long enough, I feel bad. I don't enjoy that feeling and never want to lead Anyone astray. 
   
  ---------------------
   
  On another note, I modified my DB1 because somehow I blew one op amp. I put a socket in the DB1 and changed the caps out for Black Gate (rare now) 47uf HiQ 6.3 volt. I am sure I still have some in storage back in Tucson Arizona (BG's) but have no idea when I will see those. Yes the Black Gates have a positive impact but the DB1 needs more time now to form the caps.


----------



## Jalo

Thanks, Jam, take your time.


----------



## HiFlight

I have spent considerable time evaluating different opamp combinations in the PB2 and below are some of the top contenders so far along with a few comments.  I used both BUF634 singly, 2X and 2X Hi-C (not recommended due to high battery drain) and AD797 as buffers.  The 797's were more "polite" with a warmer SQ but, IMO, did not control the bass as tightly as BUF634.  They also ran a bit warm to the touch.
   
  Most of my evaluations were with 2X stacked BUF634 non-Hi-C.  Phones used were Sony Z1000, driven from the SE output, as these are tonally very accurate and present both instrumental timbres and vocals in a very realistic manner.
  Gain was set to mid position.  A variety of instrumental, vocal and acoustic musical genres were used in the trials.   The opamps below were the best sounding of the many different ones that I tried. 
   
  AD743.  Single-channel: Well-balanced, accurate, but now almost impossible to source.
  LT1678 Class A. Dual-channel: Overall, my favorite for accuracy, imaging and 3-dimensional soundstage. 
  OPA1642  Dual-channel: Just behind the 1678 in my ranking, not quite as analytical. 
  LME49990 Single-channel: Very transparent, accurate, taut bass.  Can be a bit on the dry and bright side.
  OPA606  Single-channel: Favorite of iBasso.  Warm, analog sound.  Lacks that extra bit of 3-dimensional depth.
  TLE2142 Dual-channel:  Similar to OPA606 but with a bit more depth.  If you liked the D10 Topkit, you will like this. 
  AD797 Single-channel: Can be used as either L/R or buffer.  Warmish tube-like SQ.  (included in rolling kit)
  LT1358 Nice all-around SQ.  Well-balanced,  a bit narrower soundstage reminiscent of crossfeed. 
   
  I do have several more combinations to try, and hopefully, I will be able to source the adapters to use the HA5002 buffer.


----------



## Jalo

Wow, Ron, can you really tell the difference between those opamps and their characteristics?  That's amazing.  Looking forward to more impressions.  Great job.


----------



## drews

He can.


----------



## jamato8

Quote: 





jalo said:


> Wow, Ron, can you really tell the difference between those opamps and their characteristics?  That's amazing.  Looking forward to more impressions.  Great job.





   
  Yeah, I trust Ron's more than my own. lol   He really works at it and takes it very serious. Hopefully he is having fun at the same time but it can get tedious.


----------



## wolfen68

Quote: 





jamato8 said:


> Quote:
> 
> 
> 
> ...


 


 Comparing opamps is tedious and not for those who want instant results.  It always takes me a long time to begin to recognize those usually minor differences.  I agree that Ron seems to have the ear and patience for it.


----------



## anm

is there any desktop amp in this price range, balanced or se, that can compete with these new powerful portables?


----------



## BebopMcJiggy

That depends on your qualifications for competing...
   
  If you count the sr71b in your price range then almost certainly, by any qualifications excluding size.


----------



## Jalo

Quote: 





parrots said:


> @ jamato8, Would really like to hear what you think between the 71B and the PB2, I have the PB2 ordered but it won't ship till the 8th when ibasso get back from holiday but just wanted to know if it's really worth also ordering the 71B.


 

 I second that request from anyone.  Hehehe, Parrots, with your cable and IEMs inventory, you could have easily sell one of the Picollino cable and get both PB2 and SR71b and listen for yourself and everyone here.


----------



## Jalo

Where did you get the piccolino from.  I can't believe you have piccolino in, hp cable, adaptor etc.  That is wild.  When you get you PB2, can you tell me if it is a quiet amp?  Thanks.


----------



## anm

actually I meant in the price range of $325 - which is PB2, and PB1 is even lesser. Sorry for not being clear. I meant these [PB1/ PB2], and not sr71b as it is $650.
  I am actually torn between spending $325 on a balanced portable, or look for a balanced desktop amp, that is in this price range. But I sure want to try the balanced stuff.
  
  Quote: 





bebopmcjiggy said:


> That depends on your qualifications for competing...
> 
> If you count the sr71b in your price range then almost certainly, by any qualifications excluding size.


----------



## debitsohn

Quote: 





anm said:


> actually I meant in the price range of $325 - which is PB2, and PB1 is even lesser. Sorry for not being clear. I meant these [PB1/ PB2], and not sr71b as it is $650.
> I am actually torn between spending $325 on a balanced portable, or look for a balanced desktop amp, that is in this price range. But I sure want to try the balanced stuff.
> 
> Quote:
> ...


 


  balanced desktop in the 300$ range?


----------



## BebopMcJiggy

Quote: 





debitsohn said:


> Quote:
> 
> 
> 
> ...


 

 Yeah you can probably get some single ended desktops in the 300$ range that can compete but it would be difficult to buy a 300$ balanced desktop amp.  You could diy a balanced desktop amp in the $300 range though if you don't mind shoddy casing.  I dunno a balanced a20 or something could probably be made for < 325$.


----------



## drews

The PB2 plus DB1 plus Hirose adapters (balanced IC and XLR-4) come out to $625...  The Audio-gd NFB-10WM is $780 and is fully balanced, more powerful, fully discrete, and contains dual DACs (like the more expensive DB2 presumably will).  If I had to get one setup it would be the Audio-gd...
   
  Drew


----------



## jamato8

Quote: 





drews said:


> The PB2 plus DB1 plus Hirose adapters (balanced IC and XLR-4) come out to $625...  The Audio-gd NFB-10WM is $780 and is fully balanced, more powerful, fully discrete, and contains dual DACs (like the more expensive DB2 presumably will).  If I had to get one setup it would be the Audio-gd...
> 
> Drew


 
  Wow, the NFB-10WM is portable? Great. If not then comparison to other non portables seems appropriate of which there are many and many that are very powerful, if that is what is required. If you want to go fully balanced and the NFB-10WM is a home unit then there are choices of tube amps and dacs, solid state and the varieties and price range are huge.


----------



## drews

jamato8 said:


> Wow, the NFB-10WM is portable?


 

 No, it's not.  I was responding to the question "is there any desktop amp in this price range, balanced or se, that can compete with these new powerful portables?".  Since the price is comparable I thought it was worth mentioning (I own the PB2 by the way, waiting for the DB2). 
   
  Drew


----------



## jamato8

Quote: 





drews said:


> jamato8 said:
> 
> 
> > Wow, the NFB-10WM is portable?
> ...


 
  Ah, I see. Well it does look interesting. There seems to be a lot on the market that offers pretty good bang for the buck. I look forward to a review of the unit but maybe I should search over on desk top units. Thanks for bringing it up.


----------



## Jalo

Quote: 





drews said:


> jamato8 said:
> 
> 
> > Wow, the NFB-10WM is portable?
> ...


 

 If you own the PB2, would love to hear your impression on it.


----------



## anm

Thanks. have started a thread here - http://www.head-fi.org/forum/thread/538209/balanced-desktop-amps-vs-balanced-portable-amps#post_7256248
  Lot of views but no comments.
  Quote: 





jamato8 said:


> Quote:
> 
> 
> 
> ...


----------



## jamato8

Yes, the DB2 will offer single ended input and output and dual dacs and I would imagine some other refinements.


----------



## Jalo

I heard that the DB2 has both balance and SE outputs and dual DAC.  But if they use the same WM8740 than it is not much of an upgrade for me.  It will be nice if someone can ask them if the DACs they use in the DB2 are the same.
   
  By the way, Jam, there are no SE vs balance input for DAC.  They are either USB, Optical or Coax inputs


----------



## jamato8

Quote: 





jalo said:


> I heard that the DB2 has both balance and SE outputs and dual DAC.  But if they use the same WM8740 than it is not much of an upgrade for me.  It will be nice if someone can ask them if the DACs they use in the DB2 are the same.
> 
> By the way, Jam, there are no SE vs balance input for DAC.  They are either USB, Optical or Coax inputs


 
  Too many wires, too many wires! lol


----------



## Jalo

Jam, how does the PB2 compare to the SR71B when driving the LCD2 and the HE-6.  Do you notice any difference with the additional power of the PB2?  Thanks.


----------



## Anouk

Hi everyone,
 I am pretty interested in either the sr71b or the pb2 for use with a twag ballanced jh16. I know that some other ibasso amp, i think the d4, could be made to sound alike the mustang p51 I wonder if the seem goes for these two? I wonder about size differences and battery drain for both. Also, I know that with the 71b its still pretty good if run from a single ended source because that signal is then converted to balanced. How does this work with the ibasso amp? I would primarily want to use it with a balanced dac but it would be nice if it could sound close to optimal from an unbalanced source as well (of course with balanced headphones in both cases).
 Greetings, Anouk,


----------



## Anouk

Hello again, A bit ot maybe but what are peoples experiences with running iems se vs balanced (and with or without an amp for that matter)? My be-all end-all rig will consist of the jh16 custom iems and I am thinking what to do with them cable and amp-wise. Greetings, Anouk,


----------



## saggett

Thought this might be of interest:
http://www.headfonia.com/ibasso-pb-2-first-impression/
   
  PB1 vs PB2:
  Quote: 





> Compared to the PB-1, the PB-2 has an almost identical sound signature and tonal balance. Ignoring the power output differences, the PB-2 on the stock op-amp and buffer sounds slightly warmer with less aggressive treble and more low end body, while the PB-1 has a better clarity on the treble area. When you take out the buffer and only run it on the stock OPA604 op-amps, then the PB-2 sounds improves the clarity on the treble to match the PB1 while still being warmer and more neutral.


 
   
  PB2 with balanced IEMs:
  Quote: 





> With custom IEMs like the JH16Pro, the balanced drive gives an instant boost in soundstage size and bass quantity and you get a much bigger sound than you do when driving in single ended. However, I do think that while very impressive in short listening sessions, the balanced drive only increases the phase inaccuracy already inherent in the multi-driver IEM design. The balanced drive also didn’t improve things like articulation, detail extraction, imaging precision, or bass control out of the JH16, and again I will have to go with the Pico Slim or the RSA Shadow for my JH16.


 
   
  Conclusion:
  Quote: 





> Throughout my listening time with the PB-2, I almost never see the need to use the mid or high gain level, other than just testing how loud it can drive the HE-6 headphones. But for actual listening, I actually find the low gain to be enough even for the HD650 and the HE-6. With the HE-6, though the voltage swing is plenty, it didn’t quite have the authority to make a slamming bass impact. However, with the 300 ohm HD650, the experience is very enjoyable as the PB-2 is perhaps the most affordable amp I’ve tried with the HD650.


----------



## Jalo

In my experience with balance amps with my JH13, I like it a lot.  May be it is because  of the already restricted sound stage that is inherent in IEM design, the number one benefit for using balance amp is that of an increase in sound stage.  I also like the additional increase in dynamics, power and slam with my SR71B.  And another benefit of using balance amps like the PB2 and 71B is the ability of using balance DAC for balance input.  The ability to improve your upstream materials is always a welcome additional when we are dealing in hifi realm.


----------



## GeorgeGoodman

Quote: 





anouk said:


> Hello again, A bit ot maybe but what are peoples experiences with running iems se vs balanced (and with or without an amp for that matter)? My be-all end-all rig will consist of the jh16 custom iems and I am thinking what to do with them cable and amp-wise. Greetings, Anouk,


 

 I would try a PB2 with TWag. Get it balanced with the Hirose connector. You really can't lose. If you don't want to go TWag, Just have someone balance the stock cable and see how you like it.
   
  From personal experience, I kn ow the soundstage and control increases with balancing. I think it is a very positive change.


----------



## Anouk

Thanks everyone this was very informative. I am pretty sure that I would get ibassos balanced dac as source for home listening and when I use my laptop. I might also rebuy an iriver h140 or just use the balanced amp with my iphone when I am not able to use a laptop. Greetings, Anouk,


----------



## qusp

Quote: 





jalo said:


> I heard that the DB2 has both balance and SE outputs and dual DAC.  But if they use the same WM8740 than it is not much of an upgrade for me.  It will be nice if someone can ask them if the DACs they use in the DB2 are the same.
> 
> By the way, Jam, there are no SE vs balance input for DAC.  They are either USB, Optical or Coax inputs


 


  ermm, there is AES which is balanced digital input (I use this along with i2s on my dac), USB is actually a balanced signal too  consists of 2 twisted  pairs, one for signal and one for power, the signal pair is balanced/differential. I thought the DB2 was using the WM8741? which is actually a pin compatible upgrade to the WM8740; might be too power hungry


----------



## jamato8

That is the situation with a portable dac. You have to be able to conserve power at the same time try and get the most out of the sound quality. For the DB2, the limitation will be trying to get the best of sound quality and not rob the batteries to too much current for a given time period.


----------



## r2ymond

Sorry to digress a bit..
  Just ordered the DB1, should i wait for the DB2 or should i just stick with the DB1 to feed it into my SR-71B?


----------



## Jalo

Quote: 





qusp said:


> Quote:
> 
> 
> 
> ...


 

 Qusp, you are right, the AES is a balance connector but you don't usually see it in portable configuration, they are usually used in desktop setting.


----------



## Jalo

Quote: 





r2ymond said:


> Sorry to digress a bit..
> Just ordered the DB1, should i wait for the DB2 or should i just stick with the DB1 to feed it into my SR-71B?


 

 From all the feedback, the DB2 won't be out for another two months.  I just don't think you can last that long without trying a balance input into the 71b .


----------



## drews

Quote: 





jalo said:


> If you own the PB2, would love to hear your impression on it.


 
   
  I don't think I can give a fair assessment yet since I sold my other DACs and don't have a balanced cable yet (still waiting for APureSound to ship my LCD-2 cable).  My only DAC now is the uDAC-2 and surprisingly to me I actually prefer using its headphone amp alone to the uDAC-2+PB2 with my LCD-2.  The uDAC-2 has weak RCA outputs which I suspect is to blame.  Once I get a balanced setup with a DB2 (and Ron's Topkit!) I expect it will be a different story (unless the Sabre DAC in the uDAC-2 just beats the WMs in the DB2).
  
  Drew


----------



## Jalo

Thanks.


----------



## Drake22

I don't get it...
   
  For some reason, the default jumper setting (+6 db) is the loudest out of all 3. But anyway, having source at max volume, and pb2 at max volume, it can barely drive dt880 250 ohm to medium listening levels... If I try changing setting to +10 db it gets quieter. (I am not looking at it upside down). All that on single end output and stock opamps.
   
  What am I doing wrong? Or is it just limited by source? (cowon s9)


----------



## jamato8

Quote: 





drake22 said:


> I don't get it...
> 
> For some reason, the default jumper setting (+6 db) is the loudest out of all 3. But anyway, having source at max volume, and pb2 at max volume, it can barely drive dt880 250 ohm to medium listening levels... If I try changing setting to +10 db it gets quieter. (I am not looking at it upside down). All that on single end output and stock opamps.
> 
> What am I doing wrong? Or is it just limited by source? (cowon s9)


 
  Can you take a quick image of the jumper section? On most phones on high gain I can't get past 11 oclock without the volume being way too loud. That is with the LCD-2, HD650 or any of the other phones I own except the HD-6 which have a lot of needs.


----------



## Drake22

Sure, as you can see, thats +10 db and max volume, also max volume on s9, plugged in 2005 beyer dt880 250 ohm, and it's just medium listening level, which is not quite enjoyable  I even had to EQ it higher to have some more volume
   

   
  I think it's because the player's output signal is too weak? 29mW


----------



## HiFlight

In the pix, the jumpers are set on the 6 db setting, not 10.  Unless you are using the balanced output, you are only getting 1/2 the rated voltage swing.  Nonetheless, with adequate input, you should be getting ear-splitting volume with the jumpers on high gain, even out of the SE output. 
  Quote: 





drake22 said:


> Sure, as you can see, thats +10 db and max volume, also max volume on s9, plugged in 2005 beyer dt880 250 ohm, and it's just medium listening level, which is not quite enjoyable  I even had to EQ it higher to have some more volume
> 
> 
> 
> I think it's because the player's output signal is too weak? 29mW


----------



## Drake22

Thanks for the reply, but are you sure you are not reading the documentation wrong? http://ibasso.com/download/2011118233128.pdf according to this they are set to 10db. It's also nothing to do with voltage swing, the reason why it uses double the voltage on balanced is to remove the noise coming from right/left channels to make the signal clearer. So the volume on single end and balanced will be same, it will just be processed differently..
   
  Also I've now tried with both, player and laptop, and the difference between 6 and 10db channels is barely noticeable, with 6db one being just slightly louder.
   
  Another thing, dt880 plugged straight into cowon s9 at max volume gives almost as much volume as maxed s9 with maxed pb2. Shouldn't it be much higher with pb2 in the chain? Or is this because of some input impedance it makes the signal too weak?


----------



## jamato8

You have the jumpers set to the lower gain setting. From the front, they need to be to the right making sure the 2 pins on the right of each of the 4 jumpers are bridged by the jumper. Does the Cowon have a line out? I am not sure if you are using a line out or the output that would be for a headphone. If for a headphone then you have another amp in the signal, which will most likely degrade the sound. But yes, it should be louder with the PB2 in the chain after the Cowon.


----------



## Drake22

look, i flipped the picture and put the scheme side by side, is this the lower gain? It sure seems like high gain to me... 
   
Quote:
   
  And yeah, it's the headphone out, it doesn't have any other output sadly.



jamato8 said:


> You have the jumpers set to the lower gain setting. From the front, they need to be to the right making sure the 2 pins on the right of each of the 4 jumpers are bridged by the jumper. Does the Cowon have a line out? I am not sure if you are using a line out or the output that would be for a headphone. If for a headphone then you have another amp in the signal, which will most likely degrade the sound. But yes, it should be louder with the PB2 in the chain after the Cowon.


----------



## wuwhere

^^^ Have you tried a different headphone to see if you get the same results?


----------



## Drake22

Quote: 





wuwhere said:


> ^^^ Have you tried a different headphone to see if you get the same results?


 


  I haven't, but I will do. However, all my other phones are low impedance, so the difference would be harder to tell on low ohm phones. And to be fair, I don't really see the point of this, as it supposed to be much more audible on 250 ohm beyers, especially at high volumes. Why is it doing vice versa, I have no idea. All I can think of is that there's something wrong with the amp.


----------



## wuwhere

The point is trying to pin down where the problem lies. 250 Ohms is not much. I have a 300 Ohm HD600 that can be deafeningly powered by less powerful portable amps than the PB2.
   
  It may very well be a faulty PB2.


----------



## Drake22

Yeah, just tried it with se530, hd598 and w5000 and it's the same on all phones.
  I can definitely tell that +6db gain is louder than +10db one.
   
  I had an idea that maybe the battery is running low, so I fully charged it, but it stayed the same.


----------



## wuwhere

Can you try a different source than your S9? Like a receiver/preamp? Also, isn't it true in Europe that portable MP3 players have a volume limit?


----------



## HiFlight

The numbers on the drawing are reversed.  The gain setting jumpers should be set as they are on the db chart, as looking down at the jumpers.  High gain on the rightmost 2 jumper pins. 
  
  Quote: 





drake22 said:


> look, i flipped the picture and put the scheme side by side, is this the lower gain? It sure seems like high gain to me...
> 
> Quote:
> 
> ...


----------



## Drake22

*HiFlight*, it would make sense if they are reversed, but that makes the graph kind of misleading. Did your PB-2 came with high gain setting by default also then?
   
*wuwhere*, i ve tried headphone out on the laptop and rsa line out on essence stx and the difference was much more audible between the channels, although it still feels more like 0.5-1db difference rather than 4db. Also the "ear-splitting" volume on highest gain was only at 90+ % of volume.
  S9 is korean player afaik, but it seem to have low output power (29mW) which is probably even more killed on the input impedance on pb2, the only reason i can think of why it is the almost same volume with and without amp..
   
  Eh, and I planned to pick up 600 ohm closed cans and walk around town in them, I guess that won't happen 
   
  Anyway, thanks for the help guys


----------



## wuwhere

It could very well be that your S9 can't adequately drive the PB2 through its HP out. I have a Cowon D2 that I used to drive my portable amps too through its HP out without any problem, BUT I was listening on IEMs not full size headphones.


----------



## qusp

Quote: 





drake22 said:


> Thanks for the reply, but are you sure you are not reading the documentation wrong? http://ibasso.com/download/2011118233128.pdf according to this they are set to 10db. *It's also nothing to do with voltage swing, the reason why it uses double the voltage on balanced is to remove the noise coming from right/left channels to make the signal clearer. So the volume on single end and balanced will be same, it will just be processed differently..*
> 
> Also I've now tried with both, player and laptop, and the difference between 6 and 10db channels is barely noticeable, with 6db one being just slightly louder.
> 
> Another thing, dt880 plugged straight into cowon s9 at max volume gives almost as much volume as maxed s9 with maxed pb2. Shouldn't it be much higher with pb2 in the chain? Or is this because of some input impedance it makes the signal too weak?


 

 that is incorrect, balanced swings the same amount in both phases, thus a balanced input has twice the swing and using balanced output also has twice the swing (sometimes referred to as 4 times gain), CMRR is also a benefit and is why balanced cable runs and gear were invented, but inherently it also has double the voltage swing, so balanced inputs on pro mic preamps, mixers and such will have a pad for when using balanced input that reduces the input gain by 10db.


----------



## Drake22

Why is it incorrect? The point of balanced output is to give the least amount of detail loss and make signal as clear as possible and it does that by separating left and right channels and removing the noise from each separately. It's just different sound processing concept that requires more voltage. In fact at same db setting the balanced output would be quieter than single end, and that's why it has double the gain on the jumpers compared to single end. So the balanced output would be just as loud as single end, it could be slightly louder because of different interpretation of sound processing, but it could also be quieter depending on the input.


----------



## HiFlight

Yes, my PB2 came with the jumpers set to high gain.  That is the default setting when the amps are shipped.  I agree that the graph is misleading.   Likely a printing error during translation. 
  
  Quote: 





drake22 said:


> *HiFlight*, it would make sense if they are reversed, but that makes the graph kind of misleading. Did your PB-2 came with high gain setting by default also then?
> 
> *wuwhere*, i ve tried headphone out on the laptop and rsa line out on essence stx and the difference was much more audible between the channels, although it still feels more like 0.5-1db difference rather than 4db. Also the "ear-splitting" volume on highest gain was only at 90+ % of volume.
> S9 is korean player afaik, but it seem to have low output power (29mW) which is probably even more killed on the input impedance on pb2, the only reason i can think of why it is the almost same volume with and without amp..
> ...


----------



## BebopMcJiggy

Quote: 





drake22 said:


> Why is it incorrect? The point of balanced output is to give the least amount of detail loss and make signal as clear as possible and it does that by separating left and right channels and removing the noise from each separately. It's just different sound processing concept that requires more voltage. In fact at same db setting the balanced output would be quieter than single end, and that's why it has double the gain on the jumpers compared to single end. So the balanced output would be just as loud as single end, it could be slightly louder because of different interpretation of sound processing, but it could also be quieter depending on the input.


 

  
  What the hell have you been reading?  The reason it inherently provides double the voltage (and +6dB) in balanced output is because... there are double the (exact same) amplifiers as are used in single ended operation.  It's not voltage lost for some magical sound processing.


----------



## Drake22

That's exactly what i'm saying, but it won't sound louder because of more voltage. It has stronger signal, but what you hear is not louder compared to single end... that's all i'm trying to say


----------



## BebopMcJiggy

Given the same input, without question it will.  You said it yourself.  Stronger signal delivered through the load is exactly how one increases the volume... hence it is louder.  It's no coincidence that balanced is +6dB over single ended and that doubling of power equates to +6dB.


----------



## Drake22

Dude, but you don't plug it straight into your brain, there is a whole chain there. I ll try to explain you how this amp works,
   
  opamps are working with unbalanced signal.
  When they receive an input balanced signal, it converts into unbalanced. There is a converter between balanced input and opamps. It converts your balanced input into unbalanced signal for opamps. This converter takes out one phase of another, which results in removal of noise, while good signal gets stronger (it's not as simple as that, as there are also lots of other stuff, such as voltage stabilizators, extra impedances, transformators, etc). In the end, the signal can be higher or lower in volume.
   
  After that unbalanced signal travels to your opamps, where it gets stronger (using the same algorithm, as the opamps don't care from which input you received the signal, and then provide balanced signal to your out.
   
  Single end, on the other hand, is unbalanced as it is, and goes straight to opamps, bypassing the converter. And because we don't know if the signal becomes lower or higher in the converter without voltmeter, we can't tell if the output on balanced is higher or lower than on single end.


----------



## BebopMcJiggy

You're crazy.  There are 4 opamps and 4 buffers with traces leading directly to the balanced outputs. By extension it amplifies the signal in balanced operation and then converts to single-ended for that output only and also it converts single ended input into balanced signal before amplification.  There is no difference between an opamp that works on a balanced signal and unbalanced signal except that there are twice as many.  Or that 2 dual opamps are used instead of 4 singles.
   
  Besides which just try it... I am certain on this amp the balanced output is louder using the same input as the single ended output.


----------



## Drake22

So basically what you are saying is that:
   
  It is fully balanced throughout the whole chain, but it can also take single end input, which straight converts into balanced signal, and it can provide single end output if required?
   
  But I don't understand about twice as many part, if it uses 4 opamps on the balanced signal, then it uses 2 opamps on unbalanced? But wouldn't that result in different sound? Can't process balanced signal of each channel with different opamps - different sound structure?
   
   I am much confused now -.-


----------



## debitsohn

i understand nothing typed on the last two pages lol. i hope whatever is going on gets resolved. this stuff is way over my head.


----------



## BebopMcJiggy

No I am saying it converts single ended input signal into balanced signal before amplifying, or leaves the signal alone given a balanced source.  After amplifying it then coverts to single ended for the single ended output.
   
  I just mean the difference between a balanced amp and an unbalanced amp is not a magical opamp that only works on balanced signals.  It is that there are 4 of the same amplifier (2 for each channel) instead of 2 (1 for each channel).


----------



## Drake22

I know there's no magical opamp  All opamps treat the signal the same regardless balanced or unbalanced. Just the numbers confused me and the point of having single end if it's a fully balanced chain. (which i've not seen yet in portable amps). Although, there's gotta be unbalanced link since there's only one volume knob for both outputs.
   
  Also i think people get louder volume on balanced output because they might be using single end input. On the balanced input there's generally reduced gain on the input for signal to work with no overload... well, anyway, thanks for interesting conversation


----------



## BebopMcJiggy

The volume control is a 4 gang pot that operates on the balanced signal.  At least this was certainly the case with the pb1.  The PB1 / DB1 was meant to be a fully balanced chain I don't see why they would compromise now.
   
  The purpose of having the single ended input/output is it makes the device a whole lot more versatile without having to re-terminate every headphone or buy a balanced source to even use the damned thing.
   
  I assure you that with the pb2 if you take a headphone that is terminated in such a way as you can go back and forth from the balanced and single ended outputs of the amp, the balanced output will be louder, using either a balanced or single ended source, it doesn't matter.


----------



## HiFlight

In the case of the PB2, the gain is not reduced with the balanced input, it is doubled.  Check the db figures for each of the gain settings. 
   
  The voltage swing on a SE amplifier is referenced from the common ground (negative) and measured to the peak of the positive input, whereas on  balanced amplifiers, as both the positive and negative signals are actively driven, the voltage swing is the same for both positive and negative inputs, as measured from the zero voltage point resulting is 2x the voltage swing as compared to the SE. 
  
  Quote: 





drake22 said:


> I know there's no magical opamp  All opamps treat the signal the same regardless balanced or unbalanced. Just the numbers confused me and the point of having single end if it's a fully balanced chain. (which i've not seen yet in portable amps). Although, there's gotta be unbalanced link since there's only one volume knob for both outputs.
> 
> Also i think people get louder volume on balanced output because they might be using single end input. On the balanced input there's generally reduced gain on the input for signal to work with no overload... well, anyway, thanks for interesting conversation


----------



## Drake22

Well thanks for explanations guys. Sorry for my misunderstanding, I really didn't think it would be balanced throughout the whole chain which raised my doubts. That actually makes it a very cheap product compared to what it offers.
   
  And the misleading graph as well. I actually got a reply from iBasso and they said they are going to change the manual
   
   Quote: 





> Hi,
> Thank you for your email.
> It is our mistake. We are going to change the user manual.
> When the jumper is on pins 1,2, the gain is +10dB.
> ...


----------



## jamato8

The PB-2 sounds very good with the HA5002 buffer. Dynamic and with a nice soundstage and it will power my HE-6.


----------



## GeorgeGoodman

Nice! How does it sound?


----------



## debitsohn

nice! if i needed a portable/desktop amp, id probably pick one up. but i found for me, its kinda an inbetweener.  i dont really need another desktop amp but i find it bulky to take around with me.  i felt the same way about the sr71b i had.


----------



## HiFlight

Parrots...
   
  The large black opamps in the rolling kit with the resistors are the BUF634 Hi-C.  (Do not use them to replace the 604's!!)  They can be used in place of the BUF634 that are already installed in the buffer sockets or stacked on top for double buffers.  The 4 blue opamps are the AD797 and can be used either in the L/R sockets or as buffers. 
   
  The small adapters with the tiny SMD resistor is a bypass buffer and can be used in place of any of the buffers.  They sound nice when using the blue opamps (AD797) in L/R.   Make sure that the notches in the end of the opamps or the dot on the corner of the black opamps point towards the front of the amp.  If they are inserted backwards, they will be damaged.
   
  The 604's can be used in the buffer sockets without damage, but are not designed as buffers and will not sound as good as the 634's or 797's.  
   
   
   

  
  Quote: 





parrots said:


> Quote:
> 
> 
> 
> ...


----------



## BebopMcJiggy

http://www.headfonia.com/ibasso-pb-2-first-impression/ I am lazy but he kind of goes over different opamp configurations in this article.


----------



## paulybatz

Love this little beast!!!
  I cannot wait to roll this girl around a little bit!!!
   
  THANK YOU IBASSO!


----------



## jamato8

Quote: 





paulybatz said:


> Love this little beast!!!
> I cannot wait to roll this girl around a little bit!!!
> 
> THANK YOU IBASSO!


 
  Whoa, your getting a little strange there. I think you need to get out more. :^)


----------



## HiFlight

Yes, the 604's are the default L/R opamps.  Needlenose are OK, but I prefer a set of slim, curved medical hemostats.  You can buy them at about any flea market that sells scissors, tweezers, etc. 
  Quote: 





parrots said:


> Thank you very much for the reply HiFlight, one last question which the L/R are, is that where the 604 comes connected. I just want to make sure I don't get it all wrong.
> 
> Thanks
> 
> EDIT: Is it ok to use needle nose pliers to remove these chips


----------



## HiFlight

Now that I have some socketed HA5002 buffers for the PB2, I have been able to go through a lot of what I considered to be really good audio opamps in hopes of finding a short list of those that I would want to have on hand for use with the Pelican.  I have favored the HA5002 as a buffer for years, as it is very musical and can output quite a high amount of current. 
   
  For the most demanding testing scenario, I used my HE-6 planar phones as my reference headphones.  I continue to be amazed at how well the Pelican can drive these phones.  Some folks on the HE-6 thread are spending huge amounts of money on headphone amps that still are unable to drive the HE-6 to its potential.  Yet this small portable is capable of delivering very satisfying performance from these phones, albeit not at headbanging volume levels. 
   
  I do still have a couple of opamps yet to try, but for now, here are some of my favorites when paired with the HA5002:
   
  AD8599:  Superb imaging, vocalists are presented in their own space, tonally, instruments are rendered very accurately.
  LT1678:   Most detailed of the group.  Crystalline highs without sibilance.  Sennheisers will love this opamp.
  LT1355:  Great all-arounder.  Nicely balanced tonally, accurate imaging, not as deep as 8599, but still very good. 
  THS3032:  Warmest SQ and "closest to the band".  A good choice for Rock genres.  
   
  OPA27:  For those who might prefer single-channel opamps, this one is quite similar in sound to the LT1355.
   
  As purchasing 4 HA5002 buffers + adapters along with 4 L/R single-channel opamps can be pricey, I have mostly favored the dual-channels.
   
  As I said previously, I still have a few more opamps I would like to evaluate, but I had to re-order and will update this post following their arrival and testing.
   
  I hope these opinions are of help to some of you "high-rollers"!


----------



## paulybatz

You are right Jam!
  I was supposed to last night but let wifey go out instead...all work and no play!
  
  Quote: 





jamato8 said:


> Whoa, your getting a little strange there. I think you need to get out more. :^)


----------



## wuwhere

Quote: 





hiflight said:


> Now that I have some socketed HA5002 buffers for the PB2, I have been able to go through a lot of what I considered to be really good audio opamps in hopes of finding a short list of those that I would want to have on hand for use with the Pelican.  I have favored the HA5002 as a buffer for years, as it is very musical and can output quite a high amount of current.
> 
> For the most demanding testing scenario, I used my HE-6 planar phones as my reference headphones.  I continue to be amazed at how well the Pelican can drive these phones.  Some folks on the HE-6 thread are spending huge amounts of money on headphone amps that still are unable to drive the HE-6 to its potential.  Yet this small portable is capable of delivering very satisfying performance from these phones, albeit not at headbanging volume levels.
> 
> ...


 

 Hi Ron, so 4 HA5002 with 4 OPA627 would have enough current/power to drive the HE-6 in balanced? Does the Hirose connector takes 24awg cable? Thanks.
   
  edit: After I get my Oppo-95 (it has balanced out) this is going to be my next project. I will make an XLR3 to Hirose IC and do the same for my HE-6.


----------



## jamato8

I have 4X627 and 4X5002 and like the sound over the 627 and 8 buf634 and yes, the HiRose will take the 24 guage. It will take up to 22 guage but if stranded wire, it has to be very lightly tinned for it will be too thick.


----------



## wuwhere

Quote: 





jamato8 said:


> I have 4X627 and 4X5002 and like the sound over the 627 and 8 buf634 and yes, the HiRose will take the 24 guage. It will take up to 22 guage but if stranded wire, it has to be very lightly tinned for it will be too thick.


 

  
  Thanks Jam. I'll probably use a 24 gauge. I believe the HE-6 cable is also 24 gauge.


----------



## Anaxilus

@hiflight, jamato, anyone applicable...
   
  I noticed it was mentioned the PB2 might even be able to drive electrostats?  Is this right?!  Would that only be w/ an adapter w/ the full 32 volts or even w/ just the battery?  I would love to be able to reterminate my ESP950 balanced and plug into a PB2 portably if it were possible.  Thanks in advance.


----------



## HiFlight

I don't know where that information came from, but the PB2 is not capable of driving electrostatic headphones.  They require a special amplifier that is cable of providing the very high bias voltage necessary for the operation of ES headphones.   The PB2 can drive planar headphones, which share some similar sound characteristics with ES phones, but the answer to your question is a resounding NO!
  Quote: 





anaxilus said:


> @hiflight, jamato, anyone applicable...
> 
> I noticed it was mentioned the PB2 might even be able to drive electrostats?  Is this right?!  Would that only be w/ an adapter w/ the full 32 volts or even w/ just the battery?  I would love to be able to reterminate my ESP950 balanced and plug into a PB2 portably if it were possible.  Thanks in advance.


----------



## Anaxilus

Quote: 





hiflight said:


> I don't know where that information came from, but the PB2 is not capable of driving electrostatic headphones.  They require a special amplifier that is cable of providing the very high bias voltage necessary for the operation of ES headphones.   The PB2 can drive planar headphones, which share some similar sound characteristics with ES phones, but the answer to your question is a resounding NO!


 

 Thanks.  Somebody said they couldn't imagine it not being able to considering how well they drove their HE6 and such.  Thought it was over exuberant.  Appreciate it.  Might pick one up for my modded T50rp for obvious reasons anyway.


----------



## jamato8

I ran the PB-2 for a few days in low gain. After a while there just seemed like something was missing. The same thing happens with the fi.Q in low or medium gain. Then I figured it was just the PB2 and I guessed it wasn't as good as I thought. So back into high gain and there is the bite and dynamics. It seems that like I have experienced with so many amps, gain setting really does effect the sound quality and it isn't just listening to a higher volume and not realizing it with high gain as I tend to like a certain volume most of the time and the has nothing to do with the gain setting, which it shouldn't.


----------



## novacav

I feel the same way about the PB1 - even though my D5000s don't need it at all, I generally keep it on high gain. Also, I'm scared to play with those fragile gain switches too much!


----------



## jamato8

Quote: 





novacav said:


> I feel the same way about the PB1 - even though my D5000s don't need it at all, I generally keep it on high gain. Also, I'm scared to play with those fragile gain switches too much!


 
  Yes, to me it is better in all areas. The pieces used to change the gain are plenty tough. There isn't much of anything to go wrong with them and it is hard to ruin them.


----------



## iVinyl

I have been following this forum for a while and have taken the plunge. There is some real useful knowledge here that one would never have the time to evaluate individually. It's level headed too, which is a relief and confirms the diminishing return that is the audiophile's quest! On my shortlist were the Pico and the iBasso. I have ordered balanced silver dragon cables for my HD650's and the PB2 from iBasso.   I read somewhere that there is likely to be a dual DAC (DB2) with balanced output sometime soon.
   
  I currently have the Headroom Ultra Micro Amp, which is fantastic but ties me to a power supply. It will be interesting to see how the two compare initially and after a burn in period. I'll also do the single-ended comparison first so that I can judge the cable and amplifiers on their own merits. If the cable change is anything like as significant as that of my full system, I'm in for a treat.
   
  thanks for all the work, keep it up!


----------



## Jalo

I'll be interested to hear your comparison between the Ultra Micro amp and the PB2.


----------



## HiFlight

I look forward to your comparisons, but to do justice to the PB2, the amplifier should be evaluated using the balanced output, as this amplifier was designed first and foremost to perform best using the balanced output.  The SE output is frosting on the cake.   It might not be an apples to apples comparison with the Headroom which was designed from the start as a SE amplifier.  
  
  Quote: 





ivinyl said:


> I have been following this forum for a while and have taken the plunge. There is some real useful knowledge here that one would never have the time to evaluate individually. It's level headed too, which is a relief and confirms the diminishing return that is the audiophile's quest! On my shortlist were the Pico and the iBasso. I have ordered balanced silver dragon cables for my HD650's and the PB2 from iBasso.   I read somewhere that there is likely to be a dual DAC (DB2) with balanced output sometime soon.
> 
> I currently have the Headroom Ultra Micro Amp, which is fantastic but ties me to a power supply. It will be interesting to see how the two compare initially and after a burn in period. I'll also do the single-ended comparison first so that I can judge the cable and amplifiers on their own merits. If the cable change is anything like as significant as that of my full system, I'm in for a treat.
> 
> thanks for all the work, keep it up!


----------



## iVinyl

I will certainly share any observations. My Sugden CD player is away for adjustment right now, but when it is back, I will also be comparing the Sugden's preamp class-A headphone output too. I haven't bothered too much with headphones up to now, but since I bought a decent TV and a HD recorder, I cannot get the children out of the lounge .  
  When it is all burned in, I will also compare, for my own sanity, 128 vs 256 kbps AICC vs lossless AIFF out of the iMac SPDIF and also via a 5th Gen Ipod Classic which I managed to pick up. With the balanced circuit and the dual DACs, an iBasso system 'should' outperform the iMac/iPod output coupled with the Ultra Micro Amp. Both amps are known for their high power outputs, so it will be interesting to see how they compare with HD 650's. If I have guessed right, I will probably sell the Ultra Micro unit.
  At the moment, I'm also using a Roland FA-66 as a DAC which is surprisingly good, via optical, firewire or electrical feed. The headphone monitor circuit doesn't disgrace itself but has less authority than the Ultra Micro via the FA-66 line out. For casual use, it is rather convenient since the whole unit is powered through the Firewire connection.


----------



## Drake22

I have a question. I've incoming balanced dt880 with silver dragon which is terminated with mono 3 pin xlr plugs. So if i buy this ibasso adapter http://ibasso.com/en/products/show.asp?ID=66 to connect them to pb2, will the quality of silver dragon suffer? I mean will it bring it to its full potential or do I need an adapter from the matched cable? And do you think pb2 will have no problem driving 600 ohm dt 880? Thank you


----------



## HiFlight

I don't think you would notice any difference at all if you compared the iBasso connector directly to the same adapter in Silver Dragon.  I also believe that your PB2 will have no difficulty driving the 600 ohm Beyers.  
  I look forward to your impressions.  I think you are in for a real treat!


----------



## Pitts Pilot

Firstly, I'd like to thank all those who spend so much time answering peoples questions and sharing valuable knowledge.  I've learned a ton in the last few weeks, as I'm new to the headphone thing.  I recently purchased HD650s and have read a bunch of threads for amp recommendations.  Dark Voice, Woo 3, Gilmore Lite, and Graham Slee are often recommended.  But if I can get quite close to the same power in a portable package, I'd be very happy.  With the PB2 - how close are we talking?  A guestimated percentage would be greatly appreciated, as I'm new to all this.  Currently, I have an E9 running the 650s, but I'd like a little more kick.    Will the PB2 offer me anything the E9 isn't.  I'm looking at the specs, but they don't really help me much.  Thanks in advance.


----------



## HiFlight

The PB2 does have a lot of grunt, but as both + and - are actively driven in the balanced circuitry, you will get twice the voltage swing from the balanced output compared to the SE output.  iBasso has a balanced cable available for your HD650 that would really make them sing!  Cost of this cable is very reasonable.  Besides the benefit of the extra output power, you will also notice an improvement in imaging and stability of the soundstage when running balanced.  
  Quote: 





pitts pilot said:


> Firstly, I'd like to thank all those who spend so much time answering peoples questions and sharing valuable knowledge.  I've learned a ton in the last few weeks, as I'm new to the headphone thing.  I recently purchased HD650s and have read a bunch of threads for amp recommendations.  Dark Voice, Woo 3, Gilmore Lite, and Graham Slee are often recommended.  But if I can get quite close to the same power in a portable package, I'd be very happy.  With the PB2 - how close are we talking?  A guestimated percentage would be greatly appreciated, as I'm new to all this.  Currently, I have an E9 running the 650s, but I'd like a little more kick.    Will the PB2 offer me anything the E9 isn't.  I'm looking at the specs, but they don't really help me much.  Thanks in advance.


----------



## jamato8

I totally agree with Ron. The one thing that really brought my HD650's to life was balancing them and what I use is the stock cable balanced. iBasso has this with the Hirose in place and ready to go. The sound, to me, is better in all areas with more control and better imaging, as Ron has mentioned. Bass is also improved and clarity is enhanced.


----------



## iVinyl

iBasso just confirmed with my PB2 order that the DB2 should be available in April.   Just time enough to run in the amplifier....


----------



## Pitts Pilot

"Make my 650s sing!"  That really leaves me no choice and iBasso is making it easy with the $40 Hirose/Senn cable.  It's tempting to wait a couple weeks for the DB2 and save on shipping.  I wonder which will piss my wife off more - two separate $350 orders - or one $700 order?  Those with experience in both of these situations feel free to answer.


----------



## Anaxilus

Quote: 





pitts pilot said:


> "Make my 650s sing!"  That really leaves me no choice and iBasso is making it easy with the $40 Hirose/Senn cable.  It's tempting to wait a couple weeks for the DB2 and save on shipping.  I wonder which will piss my wife off more - two separate $350 orders - or one $700 order?  Those with experience in both of these situations feel free to answer.


 

 2x350=better.  Just say maybe it was a double billing if it catches her attention.  Hopefully to be forgotten by the following month.  There is no good answer to a single $700 charge.  Other than I don't love you anymore?


----------



## debitsohn

Quote: 





anaxilus said:


> 2x350=better.  Just say maybe it was a double billing if it catches her attention.  Hopefully to be forgotten by the following month.  There is no good answer to a single $700 charge.  Other than I don't love you anymore?


 
  +1 or if theres a 1400$ charge for a bag or spa treatment.


----------



## Pitts Pilot

If I want to run iPad>???>DB2(1)>PB2, what are a couple of options to stick in there?  I assume I would want to bypass the iPad's DAC with something that isn't a DAC ( like the iStreamer.)


----------



## Drake22

I wonder if I get DB-2 when it comes out, and use optical out on my laptop into db2+pb2, but use the single end output on pb2 because all my phones are singled ended. Would I be missing too much? Should i get my headphones reterminated..
   
  And overall would that be a nice semi portable/desktop setup? Im just thinking that for the same price a decent unbalanced amp can be bought, such as Concerto or WA6, would that perhaps be a better solution for me?


----------



## qusp

yes of course you should get the reterminated, may as well get one of their single ended dac/amps if you are just going to use single ended. its not the whole point, but may as well be. also neither of those amps have dac, so you would still need a dac to go with wa6 etc. i havent heard this combo yet, but going by spec and my experience with their other gear and the dac chip they use, it should be a nice solution, especially with some nice opamps


----------



## HiFlight

Probably the D6 or D12 would be a better choice, as they are less expensive by far than the DB2/PB2 just for SE portable use.  Both have an excellent DAC that can be used as a stand-alone with other amps if you choose to do so. 
   
  The PB2 was designed for balanced use, and that is where you will find its best performance and power.  The SE headphone output is an added bonus.


----------



## debitsohn

yea go balanced.  wish i had money right now to purchase the pb2 with the upcoming db2 (slated to be about the same price as the pb2).


----------



## Jalo

Drake, if you go all the way to get the DB2 and PB2, you just owe it to yourself to reterminate your phone so you can get the best value for what you've spent.  That set up should be awesome.  I am using the DB1 now and think it is a very good DAC.  The DB2 should be even better.


----------



## Drake22

Problem is that I don't know any decent company in UK that can do it and myself I've never reterminated before and don't have the tools either.
  And honestly I am not sure if I am going DB-2 yet. I have an opportunity to trade my w5000 for woo audio 6, and maybe that would be the best choice for me, what do you think guys?


----------



## Jalo

If DB2/PB2 set up doesn't fit your situation, then HiFlight's suggestion of D12 is your next best bet.


----------



## jamato8

The DB2 is going to have some nice additions and improvements. There is a particular isolation that will add to the sound quality.


----------



## Jalo

Jam, do you know if the DAC chip is the same as the DB1?


----------



## Drake22

Parrots - that is a very kind offer, thank you. However, I've decided to trade my w5000 for wa6 with pdps and sophia, so I will probably stick to unbalanced for now


----------



## iVinyl

Well, the first part of my experimentation, whilst waiting for the PB2 to arrive was comparing an ipod 5.5 through a dock connector (Kimber cable) and the headphone outlet into the amp. I have to say, not a huge difference. Phones were HD650's and SR225i's. The Headroom amp has two inputs, so I can connect both, get the levels identical and then switch between them. There was a very subtle loss in dynamics and a tad less bass on the headphone output, but that was all. I guess, since the headphone output of the iPod is going into a high impedance, the series capacitor has less of an effect.  I also had a brief flirtation with Rockbox / Songbird but the randomness of the Rockbox interface started to annoy after several freezes and stutters. I couldn't tell of any fundamental improvement with flat EQ.
   
  I hope all these nuances from my $700 add up to something significant in the end! It's rather fun playing though. The permutations are endless.


----------



## iVinyl

Apologies for my ramblings but I just tried the iPod through my normal Sugden system, with Totem Model 1 speakers. The difference between the 256 kbps AAC and ALE was obvious. ALE was far more spacious and you could hear the ringing on cymbals. That surprises me. I expected the headphones to be more revealing than a loudspeaker system. Mind you, the Totem/Sugden combination is very transparent. It appears the phones are masking the differences and I might need to think of more revealing ones before I try and compare iBasso and Headroom amps. It also suggests that if I get to an equivalent transparency, I need to re-evaluate Rockbox too. I think the $700 just crept up.


----------



## dcph

Does anyone know if the DB2 will have the capability to tap digital output from the iPod just like the AlgoRhythm Solo?  If so, it will be perfect.


----------



## jamato8

Quote: 





dcph said:


> Does anyone know if the DB2 will have the capability to tap digital output from the iPod just like the AlgoRhythm Solo?  If so, it will be perfect.


 
  That requires a licensing, from what I understand, for the chip and is expensive. Unless things have changed. From what I understand, it won't.


----------



## Pitts Pilot

Quote: 





dcph said:


> Does anyone know if the DB2 will have the capability to tap digital output from the iPod just like the AlgoRhythm Solo?  If so, it will be perfect.


 
   
  That would certainly answer my question of what to put between my iPad and DB2!  Nothing.
   
  Wishful Thinking.


----------



## DanBa

If the DB2 has the same coaxial input than the DB1, you could use the Solo:
http://www.head-fi.org/forum/thread/542480/my-new-solo-thanks-ken


----------



## dcph

I had thought of this but why carry two DACs if one gets the job done.  Imagine if the AlgoRhythm Solo had balanced input and output, you wouldn't need the DB1 and likewise, if the DB1 can decode digital input from the iPod, you wouldn't need the AlgoRhythm Solo.  If such a DAC exists, I wouldn't mind paying extra for it as the whole package will become a little more portable/compact and there is also one less digital cable to purchase.  I am holding back on the purchase of the AlgoRhythm Solo and DB1 hoping such a DAC will be available in the near future.


----------



## wolfen68

DanBa...on your balanced interconnect, is that Silver Dragon IEM cable?  If so, how long is it?


----------



## DanBa

It's not mine.
  You should ask Kyan for that.
http://www.head-fi.org/forum/thread/542480/my-new-solo-thanks-ken


----------



## Pitts Pilot

A PB2 is probably in my near future.  I'm holding off, as iBasso is currently out of the Senn./Hirose balanced cables.  Waiting (a week) for that gets me  closer to the supposed (March?) release of the DB2 so I'll probably hang tight for a couple weeks.  This leaves me to sit and imagine how wonderful/complete/perfect my life will soon be, but a nagging form-factor question plagues my euphoric vision.
   
  I'm assuming that the DB2 will have it's output on the front like the DB1.  The PB2 inputs are on the back.  So if you're going to put the two on your desk next to your computer, you'd have the IC cable away from you and be looking at the front of the PB2, but the back of the DB2(1) with a USB or other cord coming out it's backside - toward you - to the computer.  Thus there is no way to have all your cables, except the HPs, of course, back and out of your way.
   
  This just makes no sense to me.  The PB1 and DB1 were made to go together but have this ridiculous form factor incongruence.  It would make so much more sense (to me) to put both the inputs and outputs at the back of the DAC - not enough room I suppose.  In my perfect future imaginary world, the DB2 has solved this ATROCITY.  (Oh, and also a SE line out.)


----------



## jamato8

Not enough room to have everything at one end, unless you made it with a double large rear. It will have SE out and some other nice surprises I would imagine.


----------



## HiFlight

I can confirm that the DB2 will, indeed, have SE output.


----------



## Jalo

Quote: 





hiflight said:


> I can confirm that the DB2 will, indeed, have SE output.


 

 But can you confirm the type of Dac used?


----------



## HiFlight

No, and I didn't ask as I think iBasso would prefer to reveal that themselves when they launch the DB2.  Should be next month. 
  
  Quote: 





jalo said:


> But can you confirm the type of Dac used?


----------



## iVinyl

My PB2 arrived yesterday and is currently burning in with some pink noise. I took a look at the rolling kit and compared it with the various posts and recommendations from this thread and its links.
   
  Clearly iBasso have gone to some trouble to offer alternatives. I understand the reason for the buffers and the bypass but I'm puzzled by the fact that their alternative op-amps do not feature on the favourites list?  Why go to all the trouble - they clearly have their ear to the ground.  Am I missing something?


----------



## anm

I tried searching the forum, but seems no one has yet done a detailed comparison of pb2 and sr71b. Eagerly looking forward for the same.


----------



## HiFlight

You might try sending Jamato8 a PM as he has had both for quite some time and can probably give you a very unbiased comparison.  Although I have owned the Predator, PB1 and PB2, I have never heard the SR71b so can't provide any help there. 
  
  Quote: 





anm said:


> I tried searching the forum, but seems no one has yet done a detailed comparison of pb2 and sr71b. Eagerly looking forward for the same.


----------



## Jalo

Quote: 





anm said:


> I tried searching the forum, but seems no one has yet done a detailed comparison of pb2 and sr71b. Eagerly looking forward for the same.


 

 There you go:  Enjoy!
   
  http://www.headfonia.com/rsa-sr71b-first-impression/
   
  "Now, what about the sound? The primary difference between the two amps is the sound signature, where the SR-71B maintains a warmer, darker, and heavier bottom end sound, the PB-2 less heavy on the bottom though not light and more low treble presence. Of course, while rolling opamps, you can “EQ” the PB-2 to be more trebly or more bassy, depending on what you’re using on the opamps and buffers. But even at the “darkest” and fullest bottom end setting with the stock opamp kits, the SR-71B still has a more solid bottom end body that I couldn’t find on the PB-2. On the other hand, if you are more into trebles, then the PB-2 will probably be a better suit for you."


----------



## Saintkeat

hey guys need help.. trying to diy a balanced cable, but not quite sure how to open up the hirose connector?
   
  anyone help out a noob?


----------



## Saintkeat

thank you!! i just did it and it worked! i think soldering it would be very challenging!


----------



## Saintkeat

roger.. got that.. but what kind of cable did you use? i'm thinking of going with 28 awg solid core silver. the opening seems really small thats why i don't think i can use a 24..


----------



## jamato8

When you solder use female with the male because when you heat the pins you solder to they can move in the plastic when it is hot and they will no longer be aligned. If the plug is inserted then the pins will be held in place.


----------



## Saintkeat

oh so what you're saying is i should plug it into the amp and solder when its plugged in? sounds good.. i guess the only risk would be pulling it out before its cooled off..


----------



## Saintkeat

HAHAHAA gosh i feel stupid. ok. i'll try doing without then.. the size of those contact points require a surgeons hand! i'll do my best and post back here...


----------



## jamato8

Before I used an extra female plug I did have a couple of pins float some and I use a hot tip temp controlled iron and I know that iBasso also does this. I have soldered many of these and I just find it safer and easier plus it is easy to to a continuity check to double check for correct wire placement and a good solder.


----------



## HiFlight

The PB2 Topkit has at last been finalized and "Rocks".


----------



## jamato8

Quote: 





hiflight said:


> The PB2 Topkit has at last been finalized and "Rocks".


 
  So when it be available?


----------



## HiFlight

Now.  

  
  Quote: 





jamato8 said:


> So when it be available?


----------



## Pitts Pilot

Quick question that I'm not smart enough to figure out:
   
  Will the PB2 running balanced push my HD650s as loud as my Fii0 E9?
   
  The only numbers I can find for the E9 say: 1W at 16 ohms; 80mW at 600 ohms.  The Pelican says: 2500mW Max. (at ?); 32 Voltage swing.  (None of this means anything to me.)
   
  If this has as much (or more?!) "grunt" as my E9 I think I shouldn't deprive myself any longer.  If it's going to feel weaker/quieter, I may still go for a more powerful, SE desktop.


----------



## jamato8

The rating is at 32 ohms and it would be much more powerful. I also find the HD650's to sound better balanced and out of the PB-2, it will go louder than you could ever listen but more importantly, it will sound good. It is more powerful than many desktop amps.


----------



## Pitts Pilot

Ordered!
  I'm close by, in Taiwan, but I bet it still won't get here as quickly as I'd like.  (say, tomorrow, for instance)
  Now how does one go about acquiring a "PB2 Topkit?"


----------



## jamato8

Quote: 





pitts pilot said:


> Ordered!
> I'm close by, in Taiwan, but I bet it still won't get here as quickly as I'd like.  (say, tomorrow, for instance)
> Now how does one go about acquiring a "PB2 Topkit?"


 
  You contact HiFlight. He is on the page before this one.


----------



## qawsedrf

Quote: 





jamato8 said:


> The rating is at 32 ohms and it would be much more powerful. I also find the HD650's to sound better balanced and out of the PB-2, it will go louder than you could ever listen but more importantly, it will sound good. It is more powerful than many desktop amps.


 


  Hey jamato8! Remember me?  I'm thinking of getting an amp for my Sennheiser HD650, and I am pretty much attracted to the PB-2 as it's, well, balanced. Haha. Oh and cheaper than most desktop amps I have in mind (I was contemplating the Burson HA-160, but that'd be a long stretch). I'll be hooking a Yuin PK3 as well on the amp just for convenience sake (I find it to scale exceptionally well with proper amplification, plus I tend to use my earbuds quite alot), so it'd be best if the amp doesn't goes over the top with gain.
   
  As you've mentioned, the PB-2 is more powerful than many desktop amps. Do you mind letting us know which desktop amps are you referring to? Does the iBasso PB-2 allow simultaneous usage of both the balance-out and stereo out? Also, is it as refined in other areas compared to the aforementioned desktop amps (should you be willing to give us examples)?
   
   
   
  Thanks!


----------



## jamato8

There are many tube amps that the PB-2 has more power than. Power isn't the whole story though and not the most important. Having enough power is important but obviously and sound quality to match. I can't say what you would like or not but you can compare the power out of the PB-2 to the specs of other amps and most amps list their output. I believe you can use the SE and balanced but I wouldn't. I don't think it is the best way to use the amp or to get the best sound quality out of it.


----------



## Pitts Pilot

I lost you at the end there, jamato.  Do you mean to say that you wouldn't use this amp SE?  Or perhaps that it's full potential can only be reached by using it balanced?


----------



## Jalo

Quote: 





qawsedrf said:


> Does the iBasso PB-2 allow simultaneous usage of both the balance-out and stereo out?
> 
> Thanks!


 

  
  Last time I check I only have one pair of ears, may be things have changed latelt


----------



## HiFlight

There will likely be a volume difference between the balanced earpiece and the SE earpiece as the voltage swing is twice as great from the balanced output.  Tonally, I find the SE to be quite similar to the balanced output, but IMO, the balanced output offers more precise imaging and a more stable soundstage. 
  
  Quote: 





parrots said:


> I just checked and yes you can use both outputs at the same time, wonder how it will sound if I connect one earpiece to balanced out and the other to SE lol I have previously tried my 16's in one ear and the 13's in the other on same output and cable lol I get really bored sometimes.


----------



## jamato8

Quote: 





pitts pilot said:


> I lost you at the end there, jamato.  Do you mean to say that you wouldn't use this amp SE?  Or perhaps that it's full potential can only be reached by using it balanced?


 
  I meant I would use one or the other but not both at the same time. As Ron mentioned, the balanced section offers a little more solid imaging and for me, 3D but they are both good.


----------



## TheWuss

ordered one of these bad boys last night.
  as well as accessories - 4-pin xlr to Hirosa adapter, and a Hirosa-terminated cable for Sennheisers...
   
  i'm excited to give it a whirl.  
	

	
	
		
		

		
			




  funny thing is, i bought the Sennheiser cable for my lowly HD25-1 II.  That's sort of my all-purpose / travel headphone.  one that i'm not afraid to drop or to sweat on...
  i've been using the crappy stock cable, which i believe is basically coathanger wire. 
   
  i also plan to try the Pelican with my LCD-2, HE-6, T1, and eventually a reterminated D7000...
   
  and, even though they aren't balanced, i'll probably use the SRH840 with it a good bit...
   
  going to PM Ron about the topkit now...


----------



## HiFlight

The HD650 cable that iBasso sells is genuine, not a copy of Sennheisers cable.  I have re-terminated one of these and find the HD650 cable to be of very decent quality internally.   I don't know whether coathanger wire represents an upgrade or not as I have never tried it, but I would not look down my nose at the HiRose/Sennheiser HD650 cable.   IMO, it is a bargain considering the level of difficulty in re-terminating a cable with the HiRose connector.   It is a challenging job that I do not enjoy. 
  
  Quote: 





thewuss said:


> ordered one of these bad boys last night.
> as well as accessories - 4-pin xlr to Hirosa adapter, and a Hirosa-terminated cable for Sennheisers...
> 
> i'm excited to give it a whirl.
> ...


----------



## jamato8

I do not find that the stock HD650 cable is poor wire. I have compared it to some high end silver and a copper and frankly, it did very well. Balanced I enjoy it quite a bit and like the fact that it is light and flexible.


----------



## GeorgeGoodman

Hiflight and Jamato, how do you find the bass with the Sennheisers running out of the PB2? Mike at headfonia.com says that running the HD600 and 650 balanced gives great tonality, soundstage, etc, but the bass is not as impactful or as good as a powerful single ended home amp. He has a review on the S:Flo2 where he states that the bass is lacking, and having had that player, I know this is not the case. Could you provide your inputs, giving your opinions on the bass compared to your home amps? Thanks.


----------



## HiFlight

While I no longer own any Sennheisers, I would hesitate to call the PB2 bass-shy or that it lacks impact.   Such impressions are more likely the result of source recording limitations or shortcomings of the components further upstream from the PB2.   I think it is categorically impossible to make such sweeping generalizations. 
   
  That said, the PB2 does perform better in the lower octaves than does the PB1 with the same recording and source equipment.   The PB2 SQ and bass impact is also noticeably affected by the choice of opamps used. 
   
  I do think that  the PB2 can hold its own against many desktop amplifiers that are priced considerably higher.
  
  Quote: 





georgegoodman said:


> Hiflight and Jamato, how do you find the bass with the Sennheisers running out of the PB2? Mike at headfonia.com says that running the HD600 and 650 balanced gives great tonality, soundstage, etc, but the bass is not as impactful or as good as a powerful single ended home amp. He has a review on the S:Flo2 where he states that the bass is lacking, and having had that player, I know this is not the case. Could you provide your inputs, giving your opinions on the bass compared to your home amps? Thanks.


----------



## TheWuss

Quote: 





hiflight said:


> I don't know whether coathanger wire represents an upgrade or not as I have never tried it, but I would not look down my nose at the HiRose/Sennheiser HD650 cable.


 

 the coathanger wire cable i spoke of was the stock hd25 cable.  which is steel, i believe.
  i'm certain the hirosa balanced hd650 cable will be a nice upgrade from the stock hd25 cable.


----------



## GeorgeGoodman

Quote: 





hiflight said:


> While I no longer own any Sennheisers, I would hesitate to call the PB2 bass-shy or that it lacks impact.   Such impressions are more likely the result of source recording limitations or shortcomings of the components further upstream from the PB2.   I think it is categorically impossible to make such sweeping generalizations.
> 
> That said, the PB2 does perform better in the lower octaves than does the PB1 with the same recording and source equipment.   The PB2 SQ and bass impact is also noticeably affected by the choice of opamps used.
> 
> I do think that  the PB2 can hold its own against many desktop amplifiers that are priced considerably higher.


 
  Thanks. I am inclined to trust your opinion more than others, so this comes as an assurance. I will have to hear it myself, which hopefully I will get to do this weekend in NYC.


----------



## jamato8

Running the HD650's balanced with the HD650 cable terminated to the Hirose is fine. The bass impact is there and well controlled. I am not sure what a reviewer was listening to but it was different from all the sources and music I have.


----------



## GeorgeGoodman

Quote: 





jamato8 said:


> Running the HD650's balanced with the HD650 cable terminated to the Hirose is fine. The bass impact is there and well controlled. I am not sure what a reviewer was listening to but it was different from all the sources and music I have.


 
  Thanks. I am looking forward to hearing it on Saturday if I get to the NYC meet.
   
  You confirmed my impression of Headfonia.com. Mike does the best he can, but occasionally he just doesn't hear things like me, or other people for that matter. I am sure he is honest and sincere, however. He also take amazing pictures.


----------



## Pitts Pilot

Wow!
  I ordered Monday afternoon.  It shipped Tuesday.  48 hours after payment, I received a tracking number.  49 hours after payment, I received the PB2 and balanced Senn. cord.  Now, I did cheat by living in Taiwan, but that's still pretty fast!  I'm bummed that it's black and not the silver I ordered, but I'll get over it.  I'm even more bummed that I just realized that the line out on my E7/E9 (only DAC option I have at the moment) is RCA.  So I need an adaptor and can't really give it a proper listen.  (Hmmmmm - in 49 hours I could get a DB1?!)


----------



## Gorthon

Quote: 





jamato8 said:


> Running the HD650's balanced with the HD650 cable terminated to the Hirose is fine. The bass impact is there and well controlled. I am not sure what a reviewer was listening to but it was different from all the sources and music I have.


 

 I can't comment on how the PB2 sounds, as I have never heard it, but I find that the HD600 in my balanced setup (DB1 --> SR71b) has great bass impact and control.  I would have to go along with what Jamato has said.


----------



## GeorgeGoodman

Quote: 





gorthon said:


> I can't comment on how the PB2 sounds, as I have never heard it, but I find that the HD600 in my balanced setup (DB1 --> SR71b) has great bass impact and control.  I would have to go along with what Jamato has said.


 
  Thanks. The review at headfonia.com said that the SR71B had more bass impact, but how much more if any is the question that is pretty much answered for me by jamato and Hiflight. Sometime people just hear things differently. I am going to have a chance to hear both of the amps this Saturday if I can make it to the NYC meet which I am really trying to do. I will report back and everyone what I think.
  
  Jamato: Does the SR71B have significantly more bass impact than the PB2? Your response would help me, because I am slightly confused right now. In any case, it is all good, because I will hopefully listen to both amps for myself this weekend.


----------



## wolfen68

Quote: 





georgegoodman said:


> Jamato: Does the SR71B have significantly more bass impact than the PB2? Your response would help me, because I am slightly confused right now. In any case, it is all good, because I will hopefully listen to both amps for myself this weekend.


 


 The SR71b does have a lot more bass impact than the PB1 if that helps.


----------



## Pitts Pilot

What effect does "stacking" or doubling up on the buffers have?
  (I don't know what buffer or an opamp are, but since I'm about to start fiddling with them...)
  I did order a TopKit, so I suppose I'll end up just sticking that stuff in and leaving it be?


----------



## HiFlight

Quote: 





pitts pilot said:


> What effect does "stacking" or doubling up on the buffers have?
> (I don't know what buffer or an opamp are, but since I'm about to start fiddling with them...)
> I did order a TopKit, so I suppose I'll end up just sticking that stuff in and leaving it be?


 


  It effectively doubles the output current but also decreases the input impedance as the buffers now are acting in parallel.  A high input impedance is desirable for an effective buffer stage.  Stacking will improve the headroom but will not greatly increase the volume as to double the perceived loudness requires that you increase the power by a factor of 10.  Stacking also doubles the quiescent current draw of the buffer stage and will significantly shorten battery run time. 
   
  Personally, I am not a big fan of stacking, although there are others who feel to the contrary.  I just feel that the negatives outweigh the positive benefits of stacking.


----------



## paulybatz

Quote: 





jamato8 said:


> Running the HD650's balanced with the HD650 cable terminated to the Hirose is fine. The bass impact is there and well controlled. I am not sure what a reviewer was listening to but it was different from all the sources and music I have.


 

 I have to agree with Jam here...I am a stock cable guy...I think more important are the interconnect cables from source to amp (which I prefer silver)...the HD650 cable produces a perfect sound.


----------



## Pitts Pilot

Will running the PB2 balanced in and balanced out yield more headroom and/or volume than running it single in and balanced out?  (I don't currently have a balanced source option, but am contemplating one.)


----------



## HiFlight

No, the same amount of output will be provided from the balanced output regardless of whether the input is SE or balanced assuming equal input voltage from each source. 
  Quote: 





pitts pilot said:


> Will running the PB2 balanced in and balanced out yield more headroom and/or volume than running it single in and balanced out?  (I don't currently have a balanced source option, but am contemplating one.)


----------



## TheWuss

the stork dropped off my pelican today.  
	

	
	
		
		

		
		
	


	



   
  so far, i'm pretty impressed.
  the build quality is excellent.  the matte finish is pretty neat-o.  
	

	
	
		
		

		
		
	


	



   
  so i just had to give it a whirl with the HE-6... and, as reported, it drives this headphone respectably.
   
  to my surprise, the sound (using moon audio blue dragon LOD) is warmer and more tame in the highs than from my Virtue TWO.2.
  i was playing it at 3 o'clock on the volume knob, and getting a nice full sound.
   
  crazy!


----------



## jamato8

The Boomslang 2 is coming out:
   
  Here are some of the features:
   

  1, Dual WM8740 +CS8416 +TAS1020B

  2, 110dB SN and 101dB Crosstalk
  3, Separated battery power supplies for the Analog section and Digital section.
  4, Balanced line out and 3.5mm line out
  5, It will take USB input (up to 24/96) and optical and coaxial inputs (up to 24/192)
  6, Low pass filter rollable.
  7, 20 hours play time.
  8, And it is the same size and same case finish as the PB2.
   
  The selling price is $299. 
   
*The total sales price of the first 10 will be contributed to the Japan Earthquake and Tsunami Relief . That is the total sales price not a percentage or $2990.00*. 
   
  They will be taking preorders with shipping around the 6 to 10th of April.


----------



## GeorgeGoodman

Quote: 





jamato8 said:


> The Boomslang 2 is coming out:
> 
> Here are some of the features:
> 
> ...


 

 Nice! Sounds really good. I am looking forward to impressions. I wonder how close the DB2 and the PB2 are to most desktop amps and DACs. Like 90%?


----------



## jamato8

I think the division of the power supply between the digital and analog section is a big step. I also like the idea of the rollable low pass filter.


----------



## Jalo

So the DB2 is 19 mm longer than the DB1.  I was hoping it will be the same size as the first version.  Rollable low pass filter meaning you have to open the case to made adjustment and not a switch operation. Battery life is 20 hours as compare to 24 hours.  Hopefully there is real improvement with the sound comparing to DB1.  But the DB2 and PB2 combo is no doubt a formidable package, just wish the whole package is a little smaller.


----------



## jamato8

Quote: 





jalo said:


> So the DB2 is 19 mm longer than the DB1.  I was hoping it will be the same size as the first version.  Rollable low pass filter meaning you have to open the case to made adjustment and not a switch operation. Battery life is 20 hours as compare to 24 hours.  Hopefully there is real improvement with the sound comparing to DB1.  But the DB2 and PB2 combo is no doubt a formidable package, just wish the whole package is a little smaller.


 
  Sure but just think about what you are getting in what really is a small package. A dual power supply, 24/192, multiple input balanced dac. There is a lot in there. And 20 hours of portable use is more than enough for me. I mean I can take this anywhere and pack along my LCD-2 or the JH13 or whatever other big or small phones I want and get some formidable sound.


----------



## wuwhere

Quote: 





georgegoodman said:


> Nice! Sounds really good. I am looking forward to impressions. I wonder how close the DB2 and the PB2 are to most desktop amps and DACs. Like 90%?


 

  
  If they are 90% of an Anedio D1 DAC and a WA 6 SE, I'll buy two.


----------



## GeorgeGoodman

Quote: 





wuwhere said:


> If they are 90% of an Anedio D1 DAC and a WA 6 SE, I'll buy two.


 

 My point exactly. I am sure they are close. Headphone audio has some pretty bad ROI. I really love my $26 recabled and modded Koss KSC75s. I have no problem getting "there" with them. Anything more is delicious sounding icing on the cake.
   
  The Anedio and the Woo might really get you "there," but I am sure the Ibassos will do almost the same thing. I did not make it to the NYC meet unfortunately, so I can not tell you exactly how they sound. However, Warp08 uses the Ibassos to drive his Sony Qualias and I am pretty sure he says that combo is not far behind his multi $$$ home (not even desktop) setup. You might want to check out his reviews and ask him a question.


----------



## wuwhere

Quote: 





georgegoodman said:


> My point exactly. I am sure they are close. Headphone audio has some pretty bad ROI. I really love my $26 recabled and modded Koss KSC75s. I have no problem getting "there" with them. Anything more is delicious sounding icing on the cake.
> 
> The Anedio and the Woo might really get you "there," but I am sure the Ibassos will do almost the same thing. I did not make it to the NYC meet unfortunately, so I can not tell you exactly how they sound. However, Warp08 uses the Ibassos to drive his Sony Qualias and I am pretty sure he says that combo is not far behind his multi $$$ home (not even desktop) setup. You might want to check out his reviews and ask him a question.


 

 I still have my D10 which I heavily modified (top kit & Blackgate caps). I mainly use it now as a DAC. I like the sound of the WM8740. Its amazing what these little portable audio equipment from iBasso can provide for aural enjoyment and at the price that they sell for. I prefer these tiny things than home/desktop equipment. They occupy so little space yet sound really good for the money.
   
  Ibasso has been using the WM8740 for a few years now so they have a long experience with this DAC chip. With a dual WM8740, I'm sure they can make the DB2 sound like another winner.


----------



## GeorgeGoodman

Quote: 





jamato8 said:


> I think the division of the power supply between the digital and analog section is a big step. I also like the idea of the rollable low pass filter.


 

 What exactly is a rollable low pass filter? I know what it means, it cuts off the high frequencies by a certain amount. Is this just a matter of a few dbs, because all headphones are rolled off a little bit otherwise they would be unlistenable. It sounds really cool. From what I understand, many tube amps do not have the most pronounced high frequencies, and their sound is admired. I like a sound with everything in it, but not sharpness or sibilance in the treble. It can sound really good, especially on certain types of music, to cut off the highs a tiny bit.


----------



## Pitts Pilot

I'd like to be one of those first 10.  Are they taking orders NOW?  No mention of it on their site.


----------



## wuwhere

Quote: 





georgegoodman said:


> What exactly is a rollable low pass filter? I know what it means, it cuts off the high frequencies by a certain amount. Is this just a matter of a few dbs, because all headphones are rolled off a little bit otherwise they would be unlistenable. It sounds really cool. From what I understand, many tube amps do not have the most pronounced high frequencies, and their sound is admired. I like a sound with everything in it, but not sharpness or sibilance in the treble. It can sound really good, especially on certain types of music, to cut off the highs a tiny bit.


 


  It depends on what frequency, what kind of filter and the components of the filter.


----------



## wuwhere

Quote: 





pitts pilot said:


> I'd like to be one of those first 10.  Are they taking orders NOW?  No mention of it on their site.


 


  I just pre-ordered a DB2, its on their site now.


----------



## Pitts Pilot

Thanks wuwhere - saw that.  Now I can tell my wife that I "Donated $300 for Japan Tsunami Relief." - and mumble something about a free amplifier.
   
  I installed a PB2 "TopKit" and am very pleased with the results.  I didn't think I'd hear much of a difference and I don't know that I could describe that difference, as rolling the opamps takes too long for comparisons.  But I do hear a difference and I LIKE IT!


----------



## Nachkebia

Very stupid question but I have to ask you never the less. Even when you feed ipod to balanced amp, are you getting balanced signal out?


----------



## wolfen68

In the case of the PB-1, PB-2, SR71b, and Protector...a single ended input can result in a satisfactory balanced output.


----------



## GeorgeGoodman

Quote: 





wolfen68 said:


> In the case of the PB-1, PB-2, SR71b, and Protector...a single ended input can result in a satisfactory balanced output.


 


 It is not "Fully Balanced" in the sense of a complete balanced signal that results when the input is balanced.
   
  However, the amps split the single ended input into the positive and negative signals, resulting in the ouput being balanced. This sounds very good, from what I have heard and read. You are not getting the inherent noise rejecting characteristics that a fully balanced input would give you, but the pseudo balanced signal is still very good.


----------



## trentino

Hi guys. Is my pic showing the PB2 in high gain? From what I understand this is the case.


----------



## Saintkeat

since receiving my repaired customs.. i can now determine that the difference single ended between PB1 and ipod classic is not grand. bass tightens up a bit, mids more forward, but the most noticeable difference is sound stage.. I'll make a balanced cable and see what happens.. i think headphones benefit more.


----------



## wuwhere

Quote: 





pitts pilot said:


> Thanks wuwhere - saw that.  Now I can tell my wife that I "Donated $300 for Japan Tsunami Relief." - and mumble something about a free amplifier.
> 
> I installed a PB2 "TopKit" and am very pleased with the results.  I didn't think I'd hear much of a difference and I don't know that I could describe that difference, as rolling the opamps takes too long for comparisons.  But I do hear a difference and I LIKE IT!


 

 You meant a free portable DAC. 
	

	
	
		
		

		
			




   
  This is the DAC that I've been waiting for from iBasso. I didn't really like the DB1, it didn't have an SE out.
   
  They listed the pre-orders. I'm #3, 1st from USA.
   
  [size=medium]Six orders received. [/size]Mar 24th 22:00
 [size=medium]1, K***** O***** Japan
 2, C********* W******** United Kingdom
 3, Y****** R**** United States
 4, N******* S******* Japan
 5, P*** J**** TaiWan
 6, H***** C**** HongKong[/size]


----------



## wolfen68

Quote: 





georgegoodman said:


> It is not "Fully Balanced" in the sense of a complete balanced signal that results when the input is balanced.


 

 I'm sure you're just clarifying...but I'll add that I never suggested those amps would provide a "Fully Balanced" output from a single ended input.  They will however provide a balanced output from a single ended source that many folks with balanced headphones seem to be happy with.


----------



## GeorgeGoodman

Quote: 





wolfen68 said:


> I'm sure you're just clarifying...but I'll add that I never suggested those amps would provide a "Fully Balanced" output from a single ended input.  They will however provide a balanced output from a single ended source that many folks with balanced headphones seem to be happy with.


 
  That is what I meant. Thanks.


----------



## Pitts Pilot

Yep - that is what I meant.
   
  And . . . I must be that #5 shipping to Taiwan.  Cool - I was hoping to make top 10 - that way I can pretend the free DAC bit is true.
   
  I'd say I have a shot at receiving the first one.  My PB2 was in my hands 49 hours after I PayPal'd iBasso.
   
  WRT the single in - balanced out vs. balanced in - balanced out:  SkyLab claims that the the SR-71B will go louder running balanced-in due to the higher voltage, but I guess that would depend on you SE source (which in his case was an iPad that he suspects is relatively low voltage.
  
  Quote: 





wuwhere said:


> You meant a free portable DAC.
> 
> 
> 
> ...


----------



## Pitts Pilot

trentino -  nobody answered your question.  Yes - that PB2 is set for high gain.
   
  The diagram in the initial manual was backwards but is now correct on the iBasso website.


----------



## jamato8

Wow, iBasso has already donated the nearly $3000.00. That was fast. Such a great thing to do.


----------



## Saintkeat

can someone who has tried balanced cables with their IEMs please tell me if they've heard a significant difference? I just made a balanced cable for my customs and I don't hear a WHOLE lot of difference.. just more head room and overall tightness and some instrument seperation but nothing drastic? can't help but feel a tad disappointed after hearing all this hype about the balanced output.


----------



## HiFlight

With my balanced phones, most of the improvements are improved imaging, more stable soundstage and a more 3-dimensional musical presentation.   The difference is not night and day in most cases, but rather a more subtle sense of realism.


----------



## Pitts Pilot

For me, the difference is like dusk and twilight.  It's really that noticeable.


----------



## jamato8

Some opinions were offered right above your post.


----------



## Saintkeat

Thanks Hiflight. Yes its bloody not night and day like some others have suggested. I'll give the cable some time before deciding, but not entirely convinced it was worth all that trouble.


----------



## jamato8

Quote: 





parrots said:


> I've never listened to a fully balanced setup and was wondering what kindof improvement I will hear them I get my DB2 and pair it with the PB2, will there be a good noticeable improvement?


 
  For me, the HD650 open up and sound very good balanced and like a different headphone single ended. On some other there is a less noticeable change. I like the increased impact and imaging of balanced but it depends upon the headphones as to how much of a difference there will be, IMO.


----------



## Pudu

Quote: 





pitts pilot said:


> For me, the difference is like dusk and twilight.  It's really that noticeable.


 







 - That one made me laugh (out loud).


----------



## GeorgeGoodman

Quote: 





parrots said:


> Quote:
> 
> 
> 
> ...


 
  Parrots wants to know what the difference is between a single ended and balanced source. I think Jamato and Hiflight have said the sound is a little more 3-D and imaging is a little better. Overall, it doesn't sound like the sound is completely changed, just made a little more realistic. Pretty much the same with the single ended and balanced output.


----------



## wolfen68

Quote:


saintkeat said:


> can someone who has tried balanced cables with their IEMs please tell me if they've heard a significant difference? I just made a balanced cable for my customs and I don't hear a WHOLE lot of difference.. just more head room and overall tightness and some instrument seperation but nothing drastic? can't help but feel a tad disappointed after hearing all this hype about the balanced output.


 


 Several have answered and I agree headphones are different (improved) going balanced.  However, you were asking about IEM's specifically...and so far all evidence I have been able to gather seems to suggest that the improvement is not as pronounced as it may be with 'phones such as the 650's or RS-1's.  For this reason I have not yet invested in a balanced cable for my JH13's.


----------



## Jalo

Saintkeat and Parrots:  I have the Protector and the sr71b.  They are the classic example to your questions, SE vs balance input with balance output.  I also have the DB1 and have been using full balance input to balance output.  To me the difference is noticeable.  Actually Jamato said it pretty good, fast impact and better sound stage.  The increase in power output also help.  It does increase the sense of in vivo and makes the music sounds more personal.  At least to me, after I got used to balance, I feel like I want something more whenever I listen to se.  The SR71b is a very good amp to play with the difference because it offers both balance and SE input and output.  IF you read the Protector thread and Skylab review you will see more description of the difference between balance and SE.  Saintkeat, if you are making the balance cable DIY, make sure the wires are connected accurately.  I have not tried th PB1/2 so I cannot comment on it.  But on SR71b  the difference is clearly there.


----------



## Saintkeat

if they weren't connected carefully the cable would short or there will be an obvious tonal imbalance. perhaps my ears don't fancy silver plated copper, i'll be receiving a shipment of 4N silver, will be using that to reassemble the cable and see if the sound quality becomes favourable. to be honest, the only person who can give an unbiased fair opinion on whether theres a significant improvement from SE vs Balanced for IEMs is someone who has 2 almost completely identical cables using the same rig. so it'll be 2 cables later before i post some proper fair impressions. in fact, i think parrots has all the materials to pull it off faster than i can lol


----------



## dinkoy

Anybody tried pairing the PB2 with the HE-5LE?


----------



## Gorthon

Quote: 





saintkeat said:


> if they weren't connected carefully the cable would short or there will be an obvious tonal imbalance. perhaps my ears don't fancy silver plated copper, i'll be receiving a shipment of 4N silver, will be using that to reassemble the cable and see if the sound quality becomes favourable. to be honest, the only person who can give an unbiased fair opinion on whether theres a significant improvement from SE vs Balanced for IEMs is someone who has 2 almost completely identical cables using the same rig. so it'll be 2 cables later before i post some proper fair impressions. in fact, i think parrots has all the materials to pull it off faster than i can lol


 

 You could also end up with the Right and Left channels "Out Of Phase" with each other by swapping the Hot and Cold wire of one of the channels.  The headphones will work, but the sound will be off.


----------



## Saintkeat

I didn't say they sounded worst than single end. Is it so hard to accept that it isn't night and day difference with custom iems? I think full size headphones would show a clearer difference.

This is the part I don't like about hype, when someone offers honest critical feedback it gets shot down simply because it doesn't agree with the hype. It's time we get real and acknowledge the law of diminishing returns. Believe the hype all you want, I'm going into things with an open mind, and this thread WILL hear from me again when I explore the realistic improvements of going balanced from an UNbalanced source.


----------



## Jalo

Quote: 





saintkeat said:


> if they weren't connected carefully the cable would short or there will be an obvious tonal imbalance. perhaps my ears don't fancy silver plated copper, i'll be receiving a shipment of 4N silver, will be using that to reassemble the cable and see if the sound quality becomes favourable. to be honest, *the only person who can give an unbiased fair opinion on whether theres a significant improvement from SE vs Balanced for IEMs is someone who has 2 almost completely identical cables using the same rig. *so it'll be 2 cables later before i post some proper fair impressions. in fact, i think parrots has all the materials to pull it off faster than i can lol


 

 Saintkeat, you really don't need two cables, all you need is one cable terminated in balance and get an adaptor from balance to SE then you pretty much can try out the two connection with very little change to the sound signature.  This is specially true if you use the same wire to built the adaptor.


----------



## Saintkeat

creating an adapter adds resistance that could affect the sound quality. and if i'm going to do this right i can't let that affect it.
   
  from a design point of view, having 2 heavy hirose plugs (male+female) would cause unnecessary stress on the 3.5mm plug, heck even the hirose plug joints would be stressed. unless the cable isn't portable then there isn't a problem.
   
  i'm waiting on Parrots to post his opinions, like i said, he has the materials to get it done way faster than me.


----------



## AVU

Of course, the reviewer at Headphonia found the JH13s worse when balanced with either the Ibasso or the RSA balanced then single ended, all things considered, finding that balanced gave greater separation and bass emphasis, but  at the cost of "inaccurate imaging and the lack of a proper center image," less articulate, and a worse better overall texture. He states that proper balanced amps require a large amount of space, and the idea of making a portable balanced amp is necessarily a great compromise.


----------



## jamato8

I doubt you could even measure the resistance of an adapter. I use one all the time if I want to go single ended. There is no real strain problem and this is with many different headphones and setups.


----------



## Saintkeat

Hmmmm ok I wouldnt mind giving it a shot. Did you use the female plug or just the socket? Could you post a pic of your adapter?

This actually benefits me since I'll cause less wear on the custom sockets. 

And I just read headfonia's multi amp review where he gave his impressions on going balanced. Anyone else with similar observations?


----------



## Saintkeat

Cheers Parrots. thats excellent.
   
  and even better thanks for including what you heard from the adapter, as such I'm going to make 2 seperate cables instead.
   
  which 3.5mm plug did you use for your adapter though?


----------



## Saintkeat

hmmmmm thanks again.. I'll put some thought into it..
   
  any tonal inaccuracy like headfonia mentioned?


----------



## Saintkeat

ah sorry mate didn't mean to put you in a spot. important thing is you felt that balanced sounded better than single ended. that confirmation is great! and heres the link: http://www.headfonia.com/the-usual-suspects-12-portable-amps-compared/


----------



## Boringz

thinking of getting the pb2 for my ipod classic, would there be a need to custom a set of LOD - Hirosa plug balanced cable (if yes, what's the pin out like?) or the regular mini - LOD will work? I intend to balanced my HD600 cables too.


----------



## Nachkebia

How does this compare to PB-1? I want small and light balanced amp, I should go for PB-1 right?


----------



## HiFlight

Quote: 





avu said:


> Of course, the reviewer at Headphonia found the JH13s worse when balanced with either the Ibasso or the RSA balanced then single ended, all things considered, finding that balanced gave greater separation and bass emphasis, but  at the cost of "inaccurate imaging and the lack of a proper center image," less articulate, and a worse better overall texture. He states that proper balanced amps require a large amount of space, and the idea of making a portable balanced amp is necessarily a great compromise.


 


  I think that is B.S.!


----------



## HiFlight

The easy and probably least expensive way to do your Senns. is to order the balanced Sennheiser cable from iBasso.  It already has the Hirose connector termination.   I see no point in an ipod LOD to hirose adapter as the output of the ipod is not balanced.  A standard LOD plugged directly into the PB2 would accomplish the same result.
  Quote: 





boringz said:


> thinking of getting the pb2 for my ipod classic, would there be a need to custom a set of LOD - Hirosa plug balanced cable (if yes, what's the pin out like?) or the regular mini - LOD will work? I intend to balanced my HD600 cables too.


----------



## Boringz

Thanks for the reply!


----------



## Jalo

Quote: 





hiflight said:


> I think that is B.S.!


 

 I agree with that.


----------



## Saintkeat

hope it'll sound great. if it doesn't i'll just put my pb1 for sale and spring for a sr71b


----------



## jamato8

Quote:


avu said:


> Of course, the reviewer at Headphonia found the JH13s worse when balanced with either the Ibasso or the RSA balanced then single ended, all things considered, finding that balanced gave greater separation and bass emphasis, but  at the cost of "inaccurate imaging and the lack of a proper center image," less articulate, and a worse better overall texture. He states that proper balanced amps require a large amount of space, and the idea of making a portable balanced amp is necessarily a great compromise.




  The reviewer must have been using one monitor instead of two. Maybe it was the left, maybe right, hard to say. There are several ways to design and build a balanced amp but to say that it can't be done portable is naive at best.


----------



## AVU

I don't think he ever said it can't be done.  He said that it entails compromises, like anything, and that sometimes the hype surrounding a new product is unjustified. It's just one review, to be taken with a grain of salt.  But I don't know many other reviewers who have compared all 12 of those portable amps in a short amount of time with the same source and headphones to be able to evaluate one against the other.  Most of us at best try two at a time. 
   
  FYI - I couldn't stand not knowing, so I've purchased the Pico Slim, the RSA Shadow and the iBasso Toucan to test against one another with my JH13s.  Will use my iphone4 and my sparrow 8741 as sources to see, and post results.  So far, I only have the Pico Slim and it's amazing.  A huge improvement over the T3D in every way imaginable, while being roughly the same (tiny) size.  
   
  If anyone wants to loan be a protector or a 71B and a balanced JH cable, I'll include them in the test!


----------



## Jalo

AVU, Wow, you bought three amps at once, awesome.  They are all good amps.  I just wish you would get the Protector also.  I am happy to loan you the Protector if I didn't sell it a last month.  I like the Pico Slim a lot.  Right now I am switching between the Slim and 71B and loving both.


----------



## Saintkeat

to be honest i'd really like to hear your opinion on the pico slim vs the toucan balanced. I've only heard the pico briefly and from grado sr60i it sounded a little better than the toucan single ended, but probably less bass.


----------



## Jalo

Quote: 





saintkeat said:


> to be honest i'd really like to hear your opinion on the pico slim vs the toucan balanced. I've only heard the pico briefly and from grado sr60i it sounded a little better than the toucan single ended, but probably less bass.


 

 Well I am not going to have the PB1, so I can't compare the two.  But you can do it for me when you have them


----------



## Pitts Pilot

[size=medium]Thank you to HiFlight for all the descriptions of the signature using different opamps and buffers.  Would you be willing to offer a brief description of the sound with the ISL 50002 L/R opamps and HA 5002 buffers? It would be more meaningful when compared with the descriptions on page 16 if it came from HiFlight.  Maybe something more detailed than "It Rocks," although I agree.​[/size]


----------



## AVU

I can't wait myself-- 
	

	
	
		
		

		
		
	


	



   
  So far, only the Pico Slim and I'm loving it. Really nice full sound, highs aren't exactly rounded, but they are less abrasive than either my Sparrow or my iBasso T3D - less fatigue when listening at higher levels   Good definition and power on the bass as well - I think I actually prefer it to the Audio-Gd sparrow desktop amp - all this just for the JH13s, of course.  Also, LOVE the digital volume pot - my sparrow was specifically made low gain for iems, and it still doesn't go completely silent when turned "off."  The attenuation and detail at low volumes of the slim is like nothing I've ever experienced - in a silent room, or with a good fit, you can hear the music at incredibly soft levels and it's still perfectly balanced L/R.  
   
  It's also tiny and gorgeously built. I thought the volume knob might get in the way and change in my pocket, but it's too small behind my phone for that.  I've had the shadow before, so I know the form factor isn't quite as good, but I'm very curious to see how the sound and the volume pot compare, not to mention the balanced Toucan!


----------



## HiFlight

The ISL55002/HA5002 combination is very smooth with excellent low-end weight.  It has a warm, full sound with excellent imaging and is quite 3-dimensional.  It is a combination that one can listen to for long periods of time without fatigue.   The tonal balance and instrumental timbre is also one of the best I have found.  The ISL55002 and HA5002 really play well together. 
  Quote: 





pitts pilot said:


> Thank you to HiFlight for all the descriptions of the signature using different opamps and buffers.  Would you be willing to offer a brief description of the sound with the ISL 50002 L/R opamps and HA 5002 buffers? It would be more meaningful when compared with the descriptions on page 16 if it came from HiFlight.  Maybe something more detailed than "It Rocks," although I agree.​


----------



## jamato8

I really like my OPA627 and even more my 637 and I had to go and buy some ISL55002 from Ron. Now the 627 rest back in the op amp box. These new, to me, op amps, have dynamics, bass and a very interesting presentation as in 3D and layer the vocalist and instruments extremely well. I would highly suggest anyone wanting roll some op amps, try these. I am using the HA5002 as buffers. Good stuff. 
   
  Listening to Peter Green on Soho Sessions "Supernatural", is just too good. The phones I am using are the balanced LCD-2.


----------



## AVU

Quote:


saintkeat said:


> to be honest i'd really like to hear your opinion on the pico slim vs the toucan balanced. I've only heard the pico briefly and from grado sr60i it sounded a little better than the toucan single ended, but probably less bass.


 
   
  Well, have all three, but still waiting on the balanced cable from Craig at Whiplash. Should arrive monday.  I'm not going to bother testing the PB1 unbalanced, since that's not what it's made for, but I will say it sounds very good even unbalanced.  All three are quite different, all good, but different.


----------



## zeroryu

Where can i get those opamps and buffers ?
   
  and, if i may ask, is there any benefit getting opa627bp over opa627ap if you were to compare them. I'm looking for where to buy opa637 and ha5002 btw. it seems newark.com have it and probably digikey.com however, i've never bought anything from them. if you have a source you can share with me, that would be very helpful.
   
  Thanks!
   
  PS:
  my DB-2 shall arrive in 2 days. They just confirmed with me the UPS shipped from china along with the hirose balanced interconnect to PB-2.
  
  Quote: 





jamato8 said:


> I really like my OPA627 and even more my 637 and I had to go and buy some ISL55002 from Ron. Now the 627 rest back in the op amp box. These new, to me, op amps, have dynamics, bass and a very interesting presentation as in 3D and layer the vocalist and instruments extremely well. I would highly suggest anyone wanting roll some op amps, try these. I am using the HA5002 as buffers. Good stuff.
> 
> Listening to Peter Green on Soho Sessions "Supernatural", is just too good. The phones I am using are the balanced LCD-2.


----------



## jamato8

Quote: 





zeroryu said:


> Where can i get those opamps and buffers ?
> 
> and, if i may ask, is there any benefit getting opa627bp over opa627ap if you were to compare them. I'm looking for where to buy opa637 and ha5002 btw. it seems newark.com have it and probably digikey.com however, i've never bought anything from them. if you have a source you can share with me, that would be very helpful.
> 
> ...


 

 You can get the op amps from HiFlight. The 5002 buffers require a special board that he has as they are not standard pinout. The 627 is better in bp IMO but the 637 is thought to be better in AP. 
   
  I look forward to the impressions of the DB-2. I think it should be something special. It won't have a long run time on batteries if working at 24/96 or 24/192 but that is a lot of work going on there. There isn't any portable that does true 24/192. There are some that say they do but they upsample, the DB-2 doesn't it works with true 24/192 recorded music.


----------



## Pitts Pilot

> PS:
> my DB-2 shall arrive in 2 days. They just confirmed with me the UPS shipped from china along with the hirose balanced interconnect to PB-2.


 

 Just got word as well (on the same two items.)  I expect mine in about 24 hours.
   
  some wording from the email:
   
  "We must correct the play time of the DB2 to "up to 13.5hours". It is shorter than our description on the preorder page. If you are not satisfied with this play time, please feel free to contact us. You can send the DB2 back for full refund, and we will be respsonsible for all shipping cost. 
 Please accept our apology, and hope you like the DB2"
   
  That doesn't bother me any, but may be relevant for some.


----------



## Pitts Pilot

I don't want to start some big debate so if this is one of those questions just say so and I'll stick with what's on hand but:
   
  The DB2 gives me the opportunity to use optical from my MacBook, which is where it will spend most of it's time.  Is that cable expensive/cheap/irrelevant/audiobliss.
   
  My guess is that it's rather insignificant vs USB?


----------



## Saintkeat

@ AVU -  Thanks, I made a 4N Pure silver balanced cable for my customs and I think I won't be upgrading my amp anytime soon. Its certainly good enough for me at this point. and I'd rather upgrade my customs than upgrade the amp.


----------



## zeroryu

Thanks for the info. My first impression on the DB-2 is an OK DAC. However, i think it might be limited by the headphone i'm using at work(HD280pro). I have ATH-AD700 at home that can at least benefit from the combo.
   
  First Impressions:
  Clarity definitely improved compared to using just PB2. Bass is a little bit punchier.
  I think it's cool that you can also roll opamps(minus the buffer) but i'm not expert enough to know if rolling opamp on DAC will help or not.
   
  I'll report back in the correct thread about DB-2 once someone set that up and also when i got my paycheck so i can support a HD600.
   
   
  Quote: 





jamato8 said:


> You can get the op amps from HiFlight. The 5002 buffers require a special board that he has as they are not standard pinout. The 627 is better in bp IMO but the 637 is thought to be better in AP.
> 
> I look forward to the impressions of the DB-2. I think it should be something special. It won't have a long run time on batteries if working at 24/96 or 24/192 but that is a lot of work going on there. There isn't any portable that does true 24/192. There are some that say they do but they upsample, the DB-2 doesn't it works with true 24/192 recorded music.


----------



## jamato8

Quote: 





pitts pilot said:


> I don't want to start some big debate so if this is one of those questions just say so and I'll stick with what's on hand but:
> 
> The DB2 gives me the opportunity to use optical from my MacBook, which is where it will spend most of it's time.  Is that cable expensive/cheap/irrelevant/audiobliss.
> 
> My guess is that it's rather insignificant vs USB?


 
  The USB can now be used up to 24/96 and is very good vs 16/44. I use optical out of habit but also I like the results. With optical, if your source outputs it, you can go up to 24/192 with the DB-2, which is the first portable to truly do 24/192 without upsampling, as far as I know. I also like optical for the isolation.


----------



## Pitts Pilot

Thanks HiFlight -
   
  Another advantage is that one can then keep the unit plugged in and charging on the USB cable.


----------



## Anaxilus

By chance has anyone heard the PB2 and also the uHA-120 or AHA-120 that could offer a comparison??


----------



## trentino

I'm considering buying a used Denon ah-d5000, I've always wanted to own them, although I've never listened to them  Has anyone tried the Denons single ended from the PB2? I'm very pleased with the PB2 when it comes to driving the HD600 and HD650 balanced and though the Denons seems to be easier to drive maybe the Denons won't be happy with the power from the single ended PB2?


----------



## paulybatz

I am sold on headphones, at least open phones...the HD650 balanced are my fit...comfort and sound!
  Along with the PB2 (or PB1)


----------



## Pitts Pilot

My PB2 and balanced HD650s are impressing me as well.  That combination is also an excellent value for a balanced set up.  I'm using the very reasonably priced, iBasso modified, Sennheiser cord.


----------



## jamato8

I have been letting the DB-2 run since I got it with a few times shutting it down for a few hours. I have to say that after 150 hours or so, it has opened up and the articulation and quality of the sound is nothing short of excellent in all areas. A dac this tiny that produces a layered and dynamics sound with a black back ground is a joy to use.


----------



## Jalo

Jam, do you have the DB1?  Can you compare the DB1 and DB2?  What are the clear differences between the two?  Thanks.


----------



## jamato8

Quote: 





jalo said:


> Jam, do you have the DB1?  Can you compare the DB1 and DB2?  What are the clear differences between the two?  Thanks.


 
  The DB-2 has a better bass, separation and depth. To me, with well recorded music, it is a startling good portable dac. With the dual power supplies, so the digital and analog supplies are separating, I think you are really getting the best of what the two dac chips can offer. Because it does use electrolytic caps, they take a while to form. I noticed the sound started off sounding very good and then went flat for quite a few hours. At around 100 hours or so it opened up again and became very transparent and dynamic, with great bass articulation, meaning that it is well defined and tuneful.


----------



## Jalo

Thanks so much, I just noticed your other comment in the other DB2 thread.  I just bought the PB2 and liked it a lot.  I will pick up the DB2. What kind of cable do you use between the PB2 and Db2?


----------



## Anaxilus

What is the output impedance of the PB2?


----------



## jamato8

Quote: 





jalo said:


> Thanks so much, I just noticed your other comment in the other DB2 thread.  I just bought the PB2 and liked it a lot.  I will pick up the DB2. What kind of cable do you use between the PB2 and Db2?


 
  iBasso makes one for a very reasonable cost out of good copper. I am used a Whiplash Twag V2 IC between them.


----------



## Jalo

Quote: 





anaxilus said:


> By chance has anyone heard the PB2 and also the uHA-120 or AHA-120 that could offer a comparison??


 

 from Ibasso site:
  "32V voltage swing, the highest voltage swing among portable Amplifiers
 - Up to 2500mW output power"


----------



## Anaxilus

Quote: 





jalo said:


> from Ibasso site:
> "32V voltage swing, the highest voltage swing among portable Amplifiers
> - Up to 2500mW output power"


 

 Don't think that answered my question but thx for the specs.  I've seen it.


----------



## jamato8

I don't remember what the output impedance is. I can check. 
   
  It is 10 ohms.


----------



## DanBa

Quote: 





jalo said:


> Thanks so much, I just noticed your other comment in the other DB2 thread.  I just bought the PB2 and liked it a lot.  I will pick up the DB2. What kind of cable do you use between the PB2 and Db2?


 
   
  Quote: 





jamato8 said:


> iBasso makes one for a very reasonable cost out of good copper. I am used a Whiplash Twag V2 IC between them.


 
   
   
  I’m planning on getting PB2 or SR71B.
   
  iPhone > AlgoRhythm Solo (> DB2) > PB2 > LCD2
  or
  iPhone > AlgoRhythm Solo (> DB2) > SR71B > LCD2
   
  What would you recommend?
  Thanks


----------



## Jalo

Quote: 





danba said:


> I’m planning on getting PB2 or SR71B.
> 
> iPhone > AlgoRhythm Solo (> DB2) > PB2 > LCD2
> or
> ...


 

 Dan, the biggest differences between the two are price and size more so than SQ.  71b cost more but comes in a smaller case whereas PB2 is 60% of the cost and is bigger even though it will match nicely with the DB2 (exactly the same size).  To me the mid and upper mid sound a little nicer on the PB2 but the 71b has a little nicer bass.  The 71b has separate left and right channel gain switches that makes it very nice to make adjustment on the fly.  With PB2, you will have to open the case and add/remove jumpers for different gains.  I suspect the PB2 with it 2.5 wpc has a little more power than the 71b but both can drive LCD, 800 and HE6 rather nicely.
   
  I have both setup above and you should be happy with either killer setup.  Well, I have the DB1 and getting the DB2 soon.


----------



## DanBa

Thanks!


----------



## Anaxilus

Quote: 





jamato8 said:


> It is 10 ohms.


 

 Thank you.


----------



## Uchiya

I haven't heard the SR-71b but with how good this PB-2 is sounding with Hiflight's topkit, I'm willing to bet it sails over the SR-71b.


----------



## estreeter

Quote: 





uchiya said:


> I haven't heard the SR-71b but with how good this PB-2 is sounding with Hiflight's topkit, I'm willing to bet it sails over the SR-71b.


 

 Thats a wild statement, friend. All 3 of my portables came from iBasso - they are the only portables I have ever owned - but I would never make a statement like that without actually hearing the competition, preferably over a period of weeks. I dont like Headfonia's reviewing style, but Mike is one of few online reviewers to directly compare the PB2 to the SR71-B and he preferred the latter : he readily admits that it was his personal preference for warmth and the RSA 'house sound' that made the difference, but there you have it. If anything, he seems to prefer the PB1 to the PB2 for outright sound quality - he reviewed both on the site.
   
  Sonically, I would love to DBT the PB2 against the P4, single ended with modestly easy to drive cans. I realise that isnt playing the PB2s game, but it would still be an interesting excursion.


----------



## Uchiya

Yea, it's a crazy statement.  Can't be afraid to be wrong to stir the pot!  I say anyway.


----------



## jamato8

They are two different flavors, both excellent (the 71B and the PB-2). With the ability to change the op amps in the PB-2 unless a reviewer has tried a few of the op amps and some that have proved out to be very good, I don't think a reviewer or anyone has heard an amp or dac or whatever, until they have heard the different configurations. Just like tube equipment, op amps make a difference. One thing I liked about Stereophile is that they would often change out the stock tubes to get a better feel of what the piece of equipment was really capable of. Having heard the 71B and PB-2 extensively and on a continuing basis, neither to my ear is really better, just a little different.


----------



## Vault101

Jamato, Do you think 71b worth the extra dollars than pb2 for the little difference. Thanks.


----------



## BlackbeardBen

Quote: 





jamato8 said:


> I don't remember what the output impedance is. I can check.
> 
> It is 10 ohms.


 

  
  Where did you get the number from?  That seems awfully high for a modern SS amp that's intended to drive very low impedance (albeit inefficient) headphones.  I don't know much about their designs, but are the PB1 and PB2 transformer coupled to get the balanced output (that would make sense with the unbalanced output)?  That would explain the relatively high output impedance, right?
   
  Did you measure it yourself or get it from iBasso?  I can't find a claim from them anywhere as to the output impedance of either the PB1 or PB2, and I'm interested in finding out about this.


----------



## jamato8

Quote: 





blackbeardben said:


> Where did you get the number from?  That seems awfully high for a modern SS amp that's intended to drive very low impedance (albeit inefficient) headphones.  I don't know much about their designs, but are the PB1 and PB2 transformer coupled to get the balanced output (that would make sense with the unbalanced output)?  That would explain the relatively high output impedance, right?
> 
> Did you measure it yourself or get it from iBasso?  I can't find a claim from them anywhere as to the output impedance of either the PB1 or PB2, and I'm interested in finding out about this.


 
  At the size of these portable, it would be hard to use transformers. The output impedance I got from iBasso. I should have phrased it differently. They said it is less than 10 ohms, which does not give you an exact number but less than.


----------



## jamato8

Quote: 





vault101 said:


> Jamato, Do you think 71b worth the extra dollars than pb2 for the little difference. Thanks.


 

 I like the design of both amps and yes, the sound is different. Do I think the extra money for the 71B is worth it, yes. I love the size and the sound. I haven't been able to duplicate the sound with the PB-2 and enjoy the open and dynamic sound of the 71B and the extremely low noise floor. The sound if different in such a way that having both is worth it to me.


----------



## oosek

For those who have the Solo, by adding a DB2 in the equation with your SR71-B, what improvements in sound did you notice, balanced or SE.


----------



## Sharklordy

Just wondering, can the solo connect to Fiio X3 coaxial digital out?


----------



## GeorgeGoodman

Quote: 





oosek said:


> For those who have the Solo, by adding a DB2 in the equation with your SR71-B, what improvements in sound did you notice, balanced or SE.


 

 You know that is four boxes, right? Pretty big but sick nonetheless.
	

	
	
		
		

		
			





 From what I have heard, the Solo has a great internal DAC, so I can't imagine huge differences in sound. It would almost fully balance the signal, but whether that change is very audible or just icing on the cake is a good question. My guess is that the DB2 would give a wider soundstage with better imaging and realism, from what I have read on this thread about its improvements. Again, I don't have any direct experience with either.

  
  Quote: 





sharklordy said:


> Just wondering, can the solo connect to Fiio X3 coaxial digital out?


 
  The Solo only works with Idevices. From the X3's coax out, you can connect that directly to the DB2, saving yourself $600. The whole PB2/DB2 is about $720, including ICs. Pretty good when you compare with the Solo.

 I have a ZX Audio Hirose six pin balanced to four pin XLR for sale. It allows you hook any headphone with a four pin XLR right up to the Ibasso balanced amps without having to reterminate into the Hirose. I was going to get an Ibasso, but can not justify it right now. Maybe another time. I know this is advertising in a thread but I woud like to help someone out who needs it.


----------



## Sharklordy

Do you think Fiio X3 > DB2 > PB2 or SR-71b fully balanced are far better than a HM-801 in terms of sound quality?


----------



## GeorgeGoodman

Quote: 





sharklordy said:


> Do you think Fiio X3 > DB2 > PB2 or SR-71b fully balanced are far better than a HM-801 in terms of sound quality?


 


  That is a good question. I have only heard the SR71B, but because that and the PB2 are certainly technically better and more powerful than the HM801's internal amp, I would say absolutely. That rig is also almost completely balanced. The HM801 is single ended through and through, although a balanced amp card is coming out for it.
   
  If you are considering that rig, it sounds really good. I would go for it if I had the money. It will drive pretty much any headphone out there almost to its potential, and have amazing sound quality.


----------



## Jalo

Quote: 





parrots said:


> Anyone know if the PB2/71B run the HD800's ok and if it sounds any good.
> I'm thinking of getting the 800's but not if it means I will need a desktop amp for it.


 
  Parrots, it will run very nicely.  I now have both the PB2 and 71B.  I tried the PB2 with Crystal cable at Jaben and it sound pristine.  And I bought the PB2 as a result.


----------



## Sharklordy

Hey Jalo, is your PB2/SR71B better than a HM-801?


----------



## Anaxilus

Quote: 





parrots said:


> I've heard the 801 and both my PB2 and 71B sound much better.


 

 How can an amp sound better than a DAC?  I think your source into the PB2 and 71B would help to explain things.


----------



## Sharklordy

Sorry I mean DB2


----------



## hyururi

Quote: 





parrots said:


> When I heard the 801 I compared them using an RWA imod + PB2/71B.
> I also used it with my own iPod + 71B and even that sounded better to me then the 801 and I actually went to audition it that day to buy of the guy but did not feel the price is justified for me because I found the rig I had on me to already sound better.


 


  Is this really true? Anyone else prefer a DAP+71B?


----------



## pooslice

I just got my PB-2. Will I damage it by using both the SE and balanced ports at the same time?


----------



## Jalo

Quote: 





sharklordy said:


> Hey Jalo, is your PB2/SR71B better than a HM-801?


 

 Sorry, I cannot comment on the HM801 as I do not have it.  But I have heard and own the PB2/SR71b and I used it with Ipod--Solo--DB1---PB2/SR71b fully balanced setup and it sounded very very good with JH13/ED8le/LCD2/HD800/SA5000.  Those are the phones I have tried.  I was particularly impressed with the Piccolino cable connected to the HD800.


----------



## AVU

wondering about hiss and background static using either the PB-1 or PB-2 with JH13s. Anyone?


----------



## charpi

Quote: 





jalo said:


> Sorry, I cannot comment on the HM801 as I do not have it.  But I have heard and own the PB2/SR71b and I used it with Ipod--Solo--DB1---PB2/SR71b fully balanced setup and it sounded very very good with JH13/ED8le/LCD2/HD800/SA5000.  Those are the phones I have tried.  I was particularly impressed with the Piccolino cable connected to the HD800.


 

 How would you compare the sound of DB + PB with a stock JH13 cable + iPhone? Do you think that it is much better/ worth the upgrade?
   
  Also, which cable did you use? Although I would love the piccolinos, I doubt I would have the budget... 
   
  Lastly, similarly to AVU, I would love the hear about the hiss with this combo.
   
  Thanks a lot for answering  This might make me come back to this hobby!


----------



## wolfen68

Quote: 





avu said:


> wondering about hiss and background static using either the PB-1 or PB-2 with JH13s. Anyone?


 


 I experienced no hiss/static with JH13's and PB-1.


----------



## Jalo

Quote: 





charpi said:


> How would you compare the sound of DB + PB with a stock JH13 cable + iPhone? Do you think that it is much better/ worth the upgrade?
> 
> Also, which cable did you use? Although I would love the piccolinos, I doubt I would have the budget...
> 
> ...


 

 The sound of the DB+PB combo out perform the iphone+JH13 by a big margin.  The piccoline is the best, but I think the TWag also gives you very good sound.  Like Wolfen said above, there is no hiss with the above combo.  But if you are using the DB1/2, you have to use a source that output digital (i.e. Coax/optical/usb), so if you want to use an iphone, you will have to get the Solo to get to the digital signal.  But if you do that, you are basically bringing the SQ level equivalent to that of a desktop system with you.


----------



## AVU

Ok, when you people are saying there's no hiss - I just want to clarify what you mean, so we're on the same page.  On mine, there is a very, very minor hiss between the bottom of the range and about 10pm.  It might not be noticable to people who've never had a black amp, but compared to the Pico Slim, which is black at least on the bottom half of its range, there's a very faint sound you can tell because when you unplug the headphones it goes away.  Then there's a noticable jump in hiss, along with a thrashing initial hiss that goes away after 1-2 sec when you push the pot past 10pm to 11pm. This hiss pretty much stays the same, maybe building a tiny bit, up to the top of the pot.  
   
  This is on LOW (+6db balaned) - on high, the problems above are MUCH worse. 
   
  Could you please double check that you don't have this, because if I have an anomaly, I need to know - it's either the Whiplash TWcu cable (brand new) or the amp itself, which is still under warranty.  Thanks!


----------



## Jalo

Hi AVU, I do have the Pico Slim also.  Give me a few days and let me verify your observation above.  I didn't want to share something from memory that may be off.  Thanks.


----------



## jamato8

Quote: 





avu said:


> Ok, when you people are saying there's no hiss - I just want to clarify what you mean, so we're on the same page.  On mine, there is a very, very minor hiss between the bottom of the range and about 10pm.  It might not be noticable to people who've never had a black amp, but compared to the Pico Slim, which is black at least on the bottom half of its range, there's a very faint sound you can tell because when you unplug the headphones it goes away.  Then there's a noticable jump in hiss, along with a thrashing initial hiss that goes away after 1-2 sec when you push the pot past 10pm to 11pm. This hiss pretty much stays the same, maybe building a tiny bit, up to the top of the pot.
> 
> This is on LOW (+6db balaned) - on high, the problems above are MUCH worse.
> 
> Could you please double check that you don't have this, because if I have an anomaly, I need to know - it's either the Whiplash TWcu cable (brand new) or the amp itself, which is still under warranty.  Thanks!


 
  Do you have any hiss with nothing plugged into the amp?


----------



## charpi

Sorry, but another question to the people who have these. I just want to double confirm is this right...
   
  Macbook USB out ---> iBasso DB2 ----> ???? interconnect ----> iBasso PB2 -----> Silver dragon Cable + Hirose terminator ------> JH13
   
  Is this right? Am I missing anything?
   
  Where can I get the interconnect for the DB2 to PB2? Does iBasso sell them?
   
  Another thing, I'm probably going to buy the Silver Dragon Cable from this site
   
  http://stage93.com/cables/
   
  Do I just purchase a normal cable and add the iBasso Hirose?
   
  Is this rig fully balanced? I would love to try a fully balanced sound.
   
  I apologise for the many questions, I just want to be sure before I put down my money. I really appreciate the answers 
   
  Edit: Argh....some contrains with money came up, I may have to delay this....but I would still like to know the answer to my question


----------



## Jalo

Charpi, you can go to the ibasso site and buy one of their DB2 to PB2 (Hirose to Hirose) interconnect.  Very reasonable pricing.  If money is an issue, you can order a hirose connector from ibasso also for very very low cost and just reterminate your JH13 cable into hirose connector.  This way you will still get a kick ass system like you describe above.  One thing I will do differently is to use an optical connection between your macbook and the DB2 instead of a usb connection.  IMO, this system as described above has the best SQ to value ratio on the market now.  Good choice.


----------



## Hiyono

What is included in HiFlight's topkit?  Which op amps and buffers? and how much?


----------



## AVU

Quote: 





jamato8 said:


> Do you have any hiss with nothing plugged into the amp?


 
   
  I realized I actually have no hiss single ended, so I'm 99% certain it's a problem with the cable.  Sent back to Whiplash for testing.


----------



## Yitaro

Very interested to hear your opinion with regards to the sound of PB2 with OPA627AP opamp.  I have HD650 for headphone.  Been rolling the supplied opamps and prefer the sound of the stock setup which includes the OPA604 with the 634 buffers.  I would like to have a wider sound stage and more detail sound.  Will replacing the 604 opamps with OPA627 improve the sound.
  I want to make sure that the sound will be an improvement over the 604 before I place an order for the 627.  Your opinions is greatly appreciated.


----------



## jamato8

I would shoot HiFlight an PM as he has heard many combination as has refined many combinations. It would save you a lot of time.


----------



## HiFlight

Quote: 





yitaro said:


> Very interested to hear your opinion with regards to the sound of PB2 with OPA627AP opamp.  I have HD650 for headphone.  Been rolling the supplied opamps and prefer the sound of the stock setup which includes the OPA604 with the 634 buffers.  I would like to have a wider sound stage and more detail sound.  Will replacing the 604 opamps with OPA627 improve the sound.
> I want to make sure that the sound will be an improvement over the 604 before I place an order for the 627.  Your opinions is greatly appreciated.


 
  IMO, the OPA627 is not a significant improvement over the 604.  As I have stated previously, it is my opinion that the 627 is over-priced and over-rated.   I might suggest that you try the OPA1611's biased Class A, the OPA1612 If you only want to use 2 opamps instead of 4 or the ISL55002.  If you want to favor detail and a very open sound, the LT1678 biased Class A is a good option.   The use of HA5002 buffers instead of the BUF634 offers a smoother, slightly warmer SQ.  IMO, much less fatiguing than the 634.


----------



## Yitaro

Thank you very much Ron.  I value your opinion.  Just pm'ed you.


----------



## kaushama

For DB2 > SR71B > HD650 balanced set up, how would I connect DB2 > SR71B? These two devices have different input connectors. Is there a way to terminate HD650 stock cable with RS connector like iBasso does?
  Or what is a reasonable HD650 cable which has SR71b connector?


----------



## pooslice

You could DIY an ibasso to a protector connector. But if you're not into that thing i'm sure cable manufacturer's like moon audio can make you one and they can also sell you a 650 cable with the SR71 connector.


----------



## Uchiya

Just got the LCD-2 v2.  With the stock setup but stacked buf634's, the headphones border near bright without being sibilant.  Separation remains very good, not as good as with the ha5002 buffers but the qualities of the LCD-2 make up for the small loss.  Are they worth the money over my old hd650s?  Hell yes.  What a perfect match; if you can hear the difference.  I've now closed my listing to sell this setup, I can't imagine sound getting any better.


----------



## jamato8

I look forward to getting the v2 sometime in the future. Great sounds. We are in good times for audio.


----------



## Vainkid

Hi anyone tries to pair the pb2 with senn hd25-1ii? It's seems that most people using it with hd650 or 600. 

Thanks


----------



## swbf2cheater

Would love a recommendation for a balanced interconnect


----------



## jamato8

I have used the iBasso balanced and it works very well. The Twag v2 has a little more resolution but at a price. The iBasso is very well made, sounds good and for the price, you are just paying for parts.


----------



## ahmadmfz

Hello everyone. I'm thinking of getting the PB2 for my JH5. Yes, this might be overkill, but i am too saving up for an LCD-2 thus that is why i'm getting the PB2  Anyway...
   
  1) If i put in an unbalanced input, the output can still be manipulated by the amp into balanced right?
  2) Also.. does anyone make balanced mini 3 pin xlr JH cables? Other than TWag cause i'm not willing to spend so much for a cable..
 3) Has anyone played with a AD743JN opamp with the PB2? It's a very nice opamp that i use with my p3 heron.

 Thank you everyone!


----------



## Yitaro

Has anyone tried changing the Caps on the PB2?  The one behind the battery.  Would changing this cap improve the sound?


----------



## jamato8

Quote: 





yitaro said:


> Has anyone tried changing the Caps on the PB2?  The one behind the battery.  Would changing this cap improve the sound?


 

 I thought about it but I like the sound of the PB-2 the way it is. Never hurts to try though.


----------



## Jalo

Jam:  Do you know why the power seems somewhat lame when I set the gain setting to the max for my PB2.  With LCD2, I can turn the volume almost to the max. But for my SR71b I can only turn to 2:00 o'clock on high gain?  The PB2 suppose to have a lot of power output.


----------



## Pudu

If I recall correctly, some of the original diagrams had the jumper settings backwards.


----------



## SpudHarris

I have some connectors on the way but I'm not clear as to the diagram relating to them. Is this the inside or outside of the plug? Unfortunately I dont have anything wired already that I can copy. Any help would be greatly appreciated....


----------



## Jalo

Quote: 





pudu said:


> If I recall correctly, some of the original diagrams had the jumper settings backwards.


 
  Thanks, I'll look into that to make sure.  I think I remember something like that also.
  
  Edit:  Yes I found the page, it is on page 13 post 189 of the thread.  And yes I did have the wrong setting.  Thanks for reminding.


----------



## Yitaro

Quote: 





spudharris said:


> I have some connectors on the way but I'm not clear as to the diagram relating to them. Is this the inside or outside of the plug? Unfortunately I dont have anything wired already that I can copy. Any help would be greatly appreciated....


 

 Just finished making a balanced xlr's to hirose connector.  The diagram shows the inside of the plug.  You'll also be able to see the numbers (very small) once you remove the jacket.


----------



## Pudu

jalo said:


> Thanks, I'll look into that to make sure.  I think I remember something like that also.
> 
> Edit:  Yes I found the page, it is on page 13 post 189 of the thread.  And yes I did have the wrong setting.  Thanks for reminding.




My pleasure. Hope that gives you enough juice for the LCD-2's - and I'm not being altruistic here, I love my PB-2 and I ordered a pair of Audeze cans this week.


----------



## SpudHarris

Quote: 





yitaro said:


> Just finished making a balanced xlr's to hirose connector.  The diagram shows the inside of the plug.  You'll also be able to see the numbers (very small) once you remove the jacket.


 

 Many thanks Yitaro, appreciated!


----------



## SpudHarris

OK, now I'm really getting a complex.....
   
Got the connectors but can't get in to it to solder any wires. I can see the tabs looking through the rear of the barrel but that's it. Can anyone tell me? Pleeeeeeaaaaasssee!
   
  Sorted!!


----------



## Uchiya

Man, this amp/dac combo is really amazing.  The ability to switch out buffers and op-amps to your own liking is just too sweet.  Hi-Flight kit makes it all the more flexible.  Amazing synergy with all sorts of cans.


----------



## Yitaro

Wow...balanced hook up to my Oppo bdp-95 and the sound rivals my desktop.  The better the source, the better PB2 perform.  Got me thinking of the source for my portable setup.    Right now its iPod Classic. 
  What would the recommendations be for iPod replacement?


----------



## Jalo

No need to replace the Ipod, just add the CLAS Solo to it.


----------



## Yitaro

New silver wire convert!!!!
  Just finished with my diy Neotech 24g silver LOD.  What a huge improvement over the iBasso LOD.  We're talking about night and day improvement.  A layer has been lifted and your left with smooth high and nice midrange bloom.  The bottom is deeper and more define.
  Looking forward to making some silver interconnects and headphone wire.  Hope the improvement is as dramatic as the silver LOD.


----------



## jamato8

Yes, the iBasso balanced IC is good for the price but a fine silver or other high quality conductor will do better. The copper that iBasso uses in the IC is good quality though.  I use a Twag v2 IC in balanced and the sound is excellent. Very layered and well controlled bass. I run my iRivers with either coax (modified) or optical into the PB2.


----------



## Yitaro

Hi Jamato8,
  Listening to my HD650 with the PB2 right now.  Really enjoying the sound of this Neotech silver.  The music is more transparent and vocal is more prominent.  A well balanced sound.  Planning to order some more Neotech silver wire for interconnects for my WA6.  Will also be making a balanced headphone cable for my HD650.  What kind of improvements will I see with the silver headphone cable?


----------



## jamato8

Quote: 





yitaro said:


> Hi Jamato8,
> Listening to my HD650 with the PB2 right now.  Really enjoying the sound of this Neotech silver.  The music is more transparent and vocal is more prominent.  A well balanced sound.  Planning to order some more Neotech silver wire for interconnects for my WA6.  Will also be making a balanced headphone cable for my HD650.  What kind of improvements will I see with the silver headphone cable?


 
  It depends upon the silver. I can't say what you will hear. Some like the changes some don't. A lot of it has to do with the total synergy of the system. I do like the HD650 much more balanced than single ended. For me, it brings them to life.


----------



## Yitaro

Totally agree with balanced out from the PB2, more lively.  I have a balanced out to my HD650 with Mogami cable right now.  I am hoping to bring more transparency and airiness to my HD650 with the Neotech 7n silver cord.  One surprise was that I didn't lose any bass with the silver LOD.  It added more definition to the bass.  I was expecting the sound to be thin.  Good surprise.
	

	
	
		
		

		
			




  
  Quote: 





jamato8 said:


> It depends upon the silver. I can't say what you will hear. Some like the changes some don't. A lot of it has to do with the total synergy of the system. I do like the HD650 much more balanced than single ended. For me, it brings them to life.


----------



## SpudHarris

Is there anywhere to get stranded silver? I'd like to get all matching cables (except coax) but can't seem to find a decent source. I have a little single core and some really soft teflon (thanks for the teflon John) but can't vouch for the silver because I bought it a few years back probably not knowing what to look for (and it was probably cheap). I know the value of decent wire now but can't find any...
   
  Any help would be appreciated as the DB2 will be here this week along with the extra balanced connectors.


----------



## Yitaro

Quote: 





spudharris said:


> Is there anywhere to get stranded silver? I'd like to get all matching cables (except coax) but can't seem to find a decent source. I have a little single core and some really soft teflon (thanks for the teflon John) but can't vouch for the silver because I bought it a few years back probably not knowing what to look for (and it was probably cheap). I know the value of decent wire now but can't find any...
> 
> Any help would be appreciated as the DB2 will be here this week along with the extra balanced connectors.


 

 Here's a link to ebay store.
   
  http://stores.ebay.com/music-in-life?_rdc=1
  Let me know how it goes.  Decent price and its 6n silver wire.
  Looking to order some silver wires from this seller.


----------



## SpudHarris

Thanks for the link Yitaro but all that stuff is solid not stranded.... Really want stranded stuff if possible.


----------



## markkr

Can those that own this combo post some pictures of their rigs? I'm interested in using this at home and work 50/50...
   
  TIA


----------



## Yitaro

Quote: 





spudharris said:


> Thanks for the link Yitaro but all that stuff is solid not stranded.... Really want stranded stuff if possible.


 

 I ran across one seller on ebay for the silver stranded wires.  I think the seller is from Eastern Europe and it was $5/ft.  I'll post the link when I find it.


----------



## SpudHarris

That would be cool if you don't mind...
   
  Thankyou!


----------



## Yitaro

Here you go SpudHarris.
  http://www.ebay.com/itm/Pure-Silver-9999-Stranded-Wire-26AWG-Teflon-Audio-Cable-/120573749556?pt=LH_DefaultDomain_0&hash=item1c12c16934


----------



## SpudHarris

You are a star, thankyou again


----------



## Yitaro

Hey I was wondering if someone can help me here.
  My PB2 was working great but now its not charging.  When I plug the power cord in, the charging light doesn't light up.  I leave it overnight still no charge.  I can not turn on the amp without plugging the power cord in. 
  It's still under warranty and I just email iBasso.
  I am hoping its a simple fix cause I won't have time to send it in for warranty work.  I am leaving the country in a couple of weeks and won't be back till April.  I was planning to take my PB2 and headphone with me.


----------



## SpudHarris

Have you got a multi-meter to test the power adapter? Just a thought...
   
  I had that problem with my CLAS and I got a bit bent out of shape worrying about sending it back but it was the power adapter that had died and I got another next day of e-bay for anout £5.


----------



## Uchiya

Hiflight, thanks again for that great kit!  The HE-500's impressed me so much at first but were a tad dry and fatiguing with the stock opamps and buffers.  His selection really gave these phones the much needed warmth and smoothing over of the top end.  Fabulous!  Loving my portable Hi-fi!


----------



## LeeSC

There is a switch on PB2 beside the place where you plug your charger to.  Did you accidentally flip the switch to not charge the PB2?
  
  Quote: 





yitaro said:


> Hey I was wondering if someone can help me here.
> My PB2 was working great but now its not charging.  When I plug the power cord in, the charging light doesn't light up.  I leave it overnight still no charge.  I can not turn on the amp without plugging the power cord in.
> It's still under warranty and I just email iBasso.
> I am hoping its a simple fix cause I won't have time to send it in for warranty work.  I am leaving the country in a couple of weeks and won't be back till April.  I was planning to take my PB2 and headphone with me.


----------



## Yitaro

Quote: 





spudharris said:


> Have you got a multi-meter to test the power adapter? Just a thought...
> 
> I had that problem with my CLAS and I got a bit bent out of shape worrying about sending it back but it was the power adapter that had died and I got another next day of e-bay for anout £5.


 

 Tested the power adapter and it shows 16.25V. 
   


  Quote: 





leesc said:


> There is a switch on PB2 beside the place where you plug your charger to.  Did you accidentally flip the switch to not charge the PB2?


 
  No the switch is turn to charge.  When I turn the charge switch off than on, the red charging light lit up very briefly.


----------



## Pudu

I always wonder what the point of that switch is on Ibasso rigs. 

Should it be in the _off _position when plugged in but fully charged? How about when it's not plugged in?


----------



## Yitaro

Quote: 





uchiya said:


> Hiflight, thanks again for that great kit!  The HE-500's impressed me so much at first but were a tad dry and fatiguing with the stock opamps and buffers.  His selection really gave these phones the much needed warmth and smoothing over of the top end.  Fabulous!  Loving my portable Hi-fi!


 


  I just received the latest Kit from Hiflight (the one with class A bias adapter).  I very impressed with the sound.  Instrument separation, smooth tops, and tight bass are all there.  What impress me the most is the instrument separation and placement.  With my HD650, the music comes alive.
  Did you received the latest kit?


----------



## SpudHarris

Quote: 





yitaro said:


> When I turn the charge switch off than on, the red charging light lit up very briefly.


 

 Mine does that when it is fully charged. Strange? ibasso are normally fairly quick to answer, so heres hoping they sort it for you soon.


----------



## Yitaro

Quote: 





spudharris said:


> Mine does that when it is fully charged. Strange? ibasso are normally fairly quick to answer, so heres hoping they sort it for you soon.


 
  Received the reply email and looks like I have to send the unit back in.  Disappointed that I won't be able to take my amp with me on vacation.
  Has anyone dealt with iBasso regarding warranty work?  How was the turn around time?


----------



## HiFlight

Quote: 





yitaro said:


> Received the reply email and looks like I have to send the unit back in.  Disappointed that I won't be able to take my amp with me on vacation.
> Has anyone dealt with iBasso regarding warranty work?  How was the turn around time?


 

 iBasso is absolutely tops in warranty support, with fast turn-arounds.   Before sending it back, take off the top and check the battery connector to make sure it is securely connected.  It does sound like a defective battery pack.


----------



## Uchiya

Ooh, didn't know if there was more than one kit for the pb-2.  Have the ISL55002 and HA5002's.
  Quote: 





yitaro said:


> I just received the latest Kit from Hiflight (the one with class A bias adapter).  I very impressed with the sound.  Instrument separation, smooth tops, and tight bass are all there.  What impress me the most is the instrument separation and placement.  With my HD650, the music comes alive.
> Did you received the latest kit?


----------



## Yitaro

Quote: 





uchiya said:


> Ooh, didn't know if there was more than one kit for the pb-2.  Have the ISL55002 and HA5002's.


 


  His latest kit includes OPA1612, adapter for class A bias, and HA5002's.
  When I first received the kit, I was thinking to myself, Ron must be very confident to only include one set (OPA1612) of opamp in the kit.  No chance of rolling.
  Well, Ron is truly a master of opamps.  This combo with the HA5002 buffers is simply amazing.  Without Ron's kit, I would have never experienced the full potential of the PB2.
  Thank you Ron.


----------



## Jalo

How is Ron's kit different from the stock kit?  Can you share your impressions?  When Ron first tested the PB2, I thought he gave up on coming up with a kit.  I thought he said the stock was pretty good.  May be I should look into getting a opamp kit from Ron.  How many are there?
   
  My DB1 has a loose connection with the LED light, so even thought the light is not on, but it is still charging or working.  I would open the case and check the battery connection to see if it is loose.


----------



## Yitaro

Quote: 





jalo said:


> How is Ron's kit different from the stock kit?  Can you share your impressions?  When Ron first tested the PB2, I thought he gave up on coming up with a kit.  I thought he said the stock was pretty good.  May be I should look into getting a opamp kit from Ron.  How many are there?
> 
> My DB1 has a loose connection with the LED light, so even thought the light is not on, but it is still charging or working.  I would open the case and check the battery connection to see if it is loose.


 
  Checked the battery connection and everything is fine.  Still not charged after plugged in overnight.  Shipped out the unit today. Hopefully, I'll receive it before the 24th of October.
  As for Ron's kit, for me, the money is well spent.  Like I mention earlier, what impresses me the most is the instrument separation and 3-D soundstage.  You can clearly placed each instruments within the soundstage.  With a good recording, the headphone just disappear.  The top is very smooth and bass is well define.
  My system consist of HD650, PB2, and iPod Classic.  I have a diy 4 strand Neotech 7N silver headphone cable and LOD.
  The sound describe here in context with this set up.  I think the silver connections reveal more of what Ron's kit is capable of.
  You PM Ron for more info on the kit.  He's a great guy to deal with.


----------



## Jalo

Thanks for the update.  I'll send Ron a pm.  Ibasso will take care of your problem.  Good luck.


----------



## jamato8

The OPA1612 sounds like something I have to look into.


----------



## qusp

i recommend opa1642 instead if you have enough supply voltage. very similar jfet input opamps, but in my testing the 42 is preferred, while the 1612 is better optimized for lower supply conditions


----------



## qusp

i cant seem edit above for some reason. the 1612 is bipolar, not jfet like the 1642, which explains why i prefer it. both are similarly clean sounding, but i found the 1641 x 2 to have a bit more dynamic sound


----------



## Yitaro

Update on my PB2. 
  I sent my faulty PB2 in and iBasso will send me a new unit, immediately,  via UPS free of charge.  This way, the new unit will be here before the 24th.
  There's a charge of $35 usd for "restore" fee.  This to me is very fair.  iBasso deserves to be complimented on their customer service.  And they allowed me to change the color and added more items to my shipment without charging shipping fees.
  Thank you iBasso for accommodating my request.


----------



## SpudHarris

ibasso are a brilliant company to do business with, I have had nothing but great experiences since my first purchase years back.
   
  I also have an update on my PB2. I got a few HA5002 buffers from Ron for my 3 portables (P4 / Fi-Quest and PB2) and I have to agree with him, these are nicer than BUF634's. They are especially good in my Fi-Quest


----------



## Yitaro

Does anyone here have a four stack portable?  ipod/CLAS/DB2/PB2.
  Could you post some pictures.  Would like to see what the stack looks like.
  What's your impressions of the setup in terms of sound and portability.  Comparing the sound of iPod/PB2 and the 4 stacks.


----------



## HiFlight

post deleted


----------



## Jalo

Ron:
   
  How many opamp kit do you have for the PB2? and can you describe their characteristics?  I am interested in getting getting one of your upgrade kit for my  PB2.  Just for your info.  I have HD800, LCD2, ED8, and JH13.  Do your upgrade kit prefers anyone in particular? If so, could you specify?  Thanks so much.  I am not very knowledgeable with opamps.


----------



## Yitaro

Quote: 





jalo said:


> Ron:
> 
> How many opamp kit do you have for the PB2? and can you describe their characteristics?  I am interested in getting getting one of your upgrade kit for my  PB2.  Just for your info.  I have HD800, LCD2, ED8, and JH13.  Do your upgrade kit prefers anyone in particular? If so, could you specify?  Thanks so much.  I am not very knowledgeable with opamps.


 


  Hey Jalo.  How do you like the LCD-2 with the PB2?  I am thinking of getting the LCD-2 ver2.


----------



## Jalo

Quote: 





yitaro said:


> Hey Jalo.  How do you like the LCD-2 with the PB2?  I am thinking of getting the LCD-2 ver2.


 

 Sorry I have not the opportunity to do so because I don't have the adaptor yet.  But this week I will have the adaptor from Peter (DHC).  But the LCD2 is a fine phone and you will not have problem liking it.  And of course the PB2 is powerful enough to drive it.  I am just taking lesson to fine tune the PB2 for my various phones.  I should also have the thunderpants soon.  Do appreciate Ron for his expertise in this area.


----------



## Anthony1

n00b question here but have trawled everywhere looking for an answer.. is there such thing as a right angle HR10A-7R-6S connector?


----------



## qusp

Quote: 





> n00b question here but have trawled everywhere looking for an answer.. is there such thing as a right angle HR10A-7R-6S connector?


 
   
   
  no


----------



## qusp

DP


----------



## qusp

Quote: 





qusp said:


> i cant seem edit above for some reason. the 1612 is bipolar, not jfet like the 1642, which explains why i prefer it. both are similarly clean sounding, but i found the 1641 x 2 to have a bit more dynamic sound


 


  take this with a grain of salt of course, I dont have the db2 and i did use the 1611 for a long time in unity gain situations and used it very successfully to build an instrumentation amp to measure mosfet transconductance with high accuracy. its a great chip, but i prefer 1642 in my testing in other gear. its just an opinion though, and the fact that Ti had to invent a new noise testing method in order to characterize its noise seems to back that up  I always prefer fet input opamps, i like jfets, i got N and P type jfet symbols on the artwork on my jh13, so i could just be biased =)
   
  the 1641 family, because f this groundbreaking noise, has a very details datasheet including extensive schematics and application notes describing the low noise techniques they used, this makes for fabulous info for a designer starting out. this is what i love about the linear tech and national datasheets too. this makes it easy to get the best out of them, love that.
   
  actually this seems appropriate. looks like 1611 is marginally better down low but looses ground with higher source impedance. current noise is far better on the 1641 and i prefer the sound. but yeah both are excellent and i will continue to use 1611 as well.
   
  I hope someone has a dba2 at the next sydney meet


----------



## SpudHarris

Cheers Jeremy 
   
  I'll have to try these in my PB2. I only have four off them but 2 off have pride of place in my Fi-quest so I'll have to pinch them out of that temperarily, I'll order some more if I like them in the PB2. At the moment the PB2 sounds great with 1611's.
   
  I'll report back when I've had chance to listen for a while.


----------



## qusp

cool, no problem Nigel, i just wanted to make sure Ron didnt think i was criticizing his choice, just being opinionated as always; its a chip definitely worth trying as you well know. have you tried the lme49990 yet mate? its my favorite single at the moment, still that is, in fact i mentioned it in here quite a while ago now when i had only just got them. i remember you liked the ad797 quite a lot, think of the lme49990 as AD797 with a bit more depth, about the same amount of detail retrieval and speed and if you can believe it, more slam. its not quite as picky with its environment either, so should be good for rolling. i'm pretty keen to try this thing out at a meet for kicks and so i can get a comedy portable rig photo for the gallery stacked with my iriver->portable sabre dac/amp hehe maybe stuffed in a massive pair of cargo pants driving lcd-2 thnk ron didnt like it for some reason, oh well his loss =)
   
  happy rolling chaps!!!


----------



## SpudHarris

Haha, that comedy rig you mention sounds a little like mine at the moment even down to the newly aquired LCD-2.
   
  Got another 6 OPA1641's on route from Farnell (TI are asking too many questions about my sample requirements hehe). I am listening to my ES5's balanced via CLAS into DB2 balanced out to PB2 and have to say I think the 1641 sounds a lot like the 1611 to my ears. I'll listen with the LCD's or HE-500's later. I'm waiting on some more Hirose connectors so the LCD's are single ended at the mo but still sound great, just better through the EF-5. Any way, you have me ramblin' as usual...... Off to order 4 x LME49990's now haha!!


----------



## Yitaro

Quote: 





spudharris said:


> Haha, that comedy rig you mention sounds a little like mine at the moment even down to the newly aquired LCD-2.
> 
> Got another 6 OPA1641's on route from Farnell (TI are asking too many questions about my sample requirements hehe). I am listening to my ES5's balanced via CLAS into DB2 balanced out to PB2 and have to say I think the 1641 sounds a lot like the 1611 to my ears. I'll listen with the LCD's or HE-500's later. I'm waiting on some more Hirose connectors so the LCD's are single ended at the mo but still sound great, just better through the EF-5. Any way, you have me ramblin' as usual...... Off to order 4 x LME49990's now haha!!


 
  Hey SpudHarris,
   
  Would you mind posting some pictures of your portable stack.  I am looking at the same set up (ipod, CLAS,DB2, and PB2) but driving HD650.  How's the set up with LCD-2?  Is there sound difference with single 1611 and dual 1612?


----------



## HiFlight

Quote: 





yitaro said:


> Hey SpudHarris,
> 
> Would you mind posting some pictures of your portable stack.  I am looking at the same set up (ipod, CLAS,DB2, and PB2) but driving HD650.  How's the set up with LCD-2?  Is there sound difference with single 1611 and dual 1612?


 

 Both the 1612 and 1642 have completely independent circuitry between the 2 channels so they should sound exactly the same as the 1611 and 1641 respectively.  Very much like a dual-mono amp.  I have listened to each probably hundreds of times with many different phones and have never detected the slightest difference between the single and dual versions.  
   
  Perhaps someone with golden ears might disagree, but I would wager that in DBT, the results would be 50-50.


----------



## qusp

they ARE quite similar, thats why i mentioned them silly =) because they are a good drop in replacement and i find they are a bit more dynamic. 
   
  yeah i dont get many opamp samples from Ti these days, i get the odd other thing, like i got a battery charge manager, an adsl driver (for differential line driver roles) and a low noise reference a little while ago, but yeah they started asking a few questions of me too 
   
  i reckon you'll love the lme49990, its really fantastic imo
   
  I would actually think duals might even be preferred in the dba2, because the idea is in balanced amps for each polarity to track each other well for best noise, this will happen more effectively if they are on the same die because they will have come from the same wafer and will track over temperature more effectively as they are bonded, unless you go to the trouble of hand matching your opamps like single fets in a discrete amp to be better matched than the tolerances in a dual device and then thermally bonding them; but thats crazy talk
   
  yeah i thought you might get a kick out of my comments on the comedy rig, mine would be even larger than yours though, not by much i must admit and only triple stack unless i also borrow a CLAS, because my rig is just iriver with coax mod ->portable sabre es9018 dac/amp->headphones.
   
  the sabre is pretty chunky, but not as large as the ibasso PBA2->DBA2 stack but then i only designed it with ~6.5vrms swing, plenty for jh13 and hd600


----------



## SpudHarris

Quote: 





yitaro said:


> Hey SpudHarris,
> 
> Would you mind posting some pictures of your portable stack.  I am looking at the same set up (ipod, CLAS,DB2, and PB2) but driving HD650.  How's the set up with LCD-2?  Is there sound difference with single 1611 and dual 1612?


 

 I will do that for you but I must mention that I never have it all in a complete stack I have CLAS on the bottom then the PB2 and then the DB2 on top. My ipod is allways on an umbilical usb to the CLAS which allows me to keep the stack in my messenger bag and still be able to choose/change tracks/albums on my ipod which goes in my pocket.
   
  Here's the 3 stack....


----------



## HiFlight

Quote: 





spudharris said:


> I will do that for you but I must mention that I never have it all in a complete stack I have CLAS on the bottom then the PB2 and then the DB2 on top. My ipod is allways on an umbilical usb to the CLAS which allows me to keep the stack in my messenger bag and still be able to choose/change tracks/albums on my ipod which goes in my pocket.
> 
> Here's the 3 stack....


 

 Looking back on the portable choices of just a few years ago, who wudda thunk??????


----------



## SpudHarris

I still can't believe that I can have desktop quality on the go.
   
  It's true that walking around you probably could take something less bulky and I often just throw the imod/P4 combo in my bag for such times. When I know I'm gonna get a bit of ''Me Time'' when out and about then I'll take the ''Stack''. Nothing compares to a day at the beach where my kids are off doing their thing and I can hook up with my tunes in awsome quality. In the UK we've had fantastic weather recently considering the time of year and I like to be outside as much as possible.


----------



## estreeter

Quote: 





spudharris said:


> I still can't believe that I can have desktop quality on the go.
> 
> It's true that walking around you probably could take something less bulky and I often just throw the imod/P4 combo in my bag for such times. When I know I'm gonna get a bit of ''Me Time'' when out and about then I'll take the ''Stack''. Nothing compares to a day at the beach where my kids are off doing their thing and I can hook up with my tunes in awsome quality. In the UK we've had fantastic weather recently considering the time of year and I like to be outside as much as possible.


 

 @spudharris - as much as I try to champion the 'transportable audio' cause, for the money you have laid out I would suggest that you *should* have desktop quality with that stack ! As you know, I'm a massive fan of the P4 as a single-ended solution for mid-fi cans, but your 'big rig' is at the sharp end of 'portable' in both cost and size.
   
  Its a shame, IMO, that Mike didnt include the P4 in Headfonia's 'Usual Suspects' amp roundup, but given his less-than-stellar opinion of most iBasso gear, its probably just as well. I'll get another P4 as soon as I get Xmas sorted and a couple of the other toys on my list crossed off. It never ends


----------



## jamato8

Quote: 





spudharris said:


> I still can't believe that I can have desktop quality on the go.
> 
> It's true that walking around you probably could take something less bulky and I often just throw the imod/P4 combo in my bag for such times. When I know I'm gonna get a bit of ''Me Time'' when out and about then I'll take the ''Stack''. Nothing compares to a day at the beach where my kids are off doing their thing and I can hook up with my tunes in awsome quality. In the UK we've had fantastic weather recently considering the time of year and I like to be outside as much as possible.


 
  I have biked and hiked with a stack and I see it as a encumbrance not, and feel it as an encumbrance not. I do get great enjoyment from a well implemented stack.


----------



## qusp

Quote: 





estreeter said:


> @spudharris - as much as I try to champion the 'transportable audio' cause, for the money you have laid out I would suggest that you *should* have desktop quality with that stack ! As you know, I'm a massive fan of the P4 as a single-ended solution for mid-fi cans, but your 'big rig' is at the sharp end of 'portable' in both cost and size.
> 
> Its a shame, IMO, that Mike didnt include the P4 in Headfonia's 'Usual Suspects' amp roundup, but given his less-than-stellar opinion of most iBasso gear, its probably just as well. I'll get another P4 as soon as I get Xmas sorted and a couple of the other toys on my list crossed off. It never ends


 


  to be fair mate, Nigel has been around long enough, owned similar smaller rigs to what you mention, owned desktop amps, but having a single transportable rig suits his budget and lifestyle better, as ive seen you say before, you just cant argue with informed decisions like that.


----------



## Uchiya

Mmmm, just sublime with the HE-500.  My go to setup every time.  Am curious about the HD-800 though, simply for that extreme soundstage.  Anyone have experience with that and Ron's kit?  Calm down the treble and add some body to it?


----------



## SpudHarris

Quote: 





qusp said:


> to be fair mate, Nigel has been around long enough, owned similar smaller rigs to what you mention, owned desktop amps, but having a single transportable rig suits his budget and lifestyle better, as ive seen you say before, you just cant argue with informed decisions like that.


 

 Cheers Pal, appreciate that.
   
  Yeah, I'm also a big fan of the P4, hell I sold my 2Stepdance and kept it in favour. But there are improvements to be had going balanced. I wouldn't expect peeps to go for a stack like that if they couldn't justify the cost. We all know that improvements get more expensive as you get further along and I guess we all get to a point where we can't justify the spend. Me? I'll find the money somehow haha!


----------



## ckryan3

Hi, got myself a PB2 a couple of months back, and am now using it with an S:Flo2, and the Stage93 Stage6 customs (they're really really new, I think there's only 3 units so far).
  Unfortunately, I found the mids, especially female vocals (along the lines of Utada Hikaru) somewhat reccessed and.. lacking
  I'm using the AD797, and doubling up the BUF634. So... what opamp/buffer set-up would push the mids forward? (I have already ordered the HA5002 though, so that's pretty set-in-stone for buffer options...)
  Alternatively, if it isn't something which can be changed by opamp rolling, I might beg the owner of Stage93 to retune the customs...
  Thanks in advance!


----------



## Uchiya

Oh yea, the mids with the BUF634 will sound veiled after listening to the HA5002's.  They are a must for a delicious midrange.


----------



## SpudHarris

The best I've heard for the PB2 (and I've rolled just about every well know) is the OPA1611 (1612 - Dual) biased to class A. I have never been steared wrongly by Ron (HiFlight) and this is what he recommends in his ''Topkit''.
   
  Just to acknowledge Qusp here also, he prefers the OPA1641 (1642 - Dual) but I'd be lying if I said I could tell a difference between 1611's and 1641's in the PB2. In my Fi-quest I don't know why I just prefer the OPA1641's, no biasing, just as they are. Dunno, is that to do with supply voltage?


----------



## ckryan3

Wow, thanks for the speedy response ^^
  I'm not using the HA5002 yet (unfortunately) as it will only be arriving in about 2 weeks.
  I've heard some pretty yummy things about the LT1677, how would that compare with the OPA1611?
  (Asking because I've ordered the LT1677 at the local electronics store already, and I'd feel kinda' bad cancelling...)


----------



## qusp

with some passive crossovers as put in multidriver iems, going balanced can alter the tonal balance somewhat, because the load impedance (headphones) is driven by 2 parallel amplifiers with the load seen in series. for jh13 i dont find it detrimental, just the usual deepening of bass response and increase in slam and transparency, but conceivably on yours the mids may be slightly effected, either that or you just arent yet used to the increased bass response and the mids therefor seem recessed by comparison. just a couple of other possibilities other than opamp preference. 
   
  @ Nigel: no problem man, all true, I know estreeter is partial to the transportable in the right situation, so thought he should know it wasnt a blind or uninformed choice on your part.
   
  re 1611/41 yeah thats where my preference for 1641 came from too, fiQ, possibly i would prefer 1611 in the dba2 as well, who knows, but i doubt it would displace the lme49990 its my new single opamp poster child. doesnt see much airtime except in 'the wire' home amp these days though, i'm fully differential chips all the way portable these days, rocking opa1632dgn at the moment, love it, yet another jhet input, gonna graft in some lme49610 buffers one of these days and see how badly battery life is effected.


----------



## estreeter

Quote: 





qusp said:


> to be fair mate, Nigel has been around long enough, owned similar smaller rigs to what you mention, owned desktop amps, but having a single transportable rig suits his budget and lifestyle better, as ive seen you say before, you just cant argue with informed decisions like that.


 


  Fair enough - I just have a pathological need to keep banging on about cost - if it gets the job done, the cost is irrelevant.


----------



## Uchiya

Anyone replace the battery for the PB-2 yet?  Seems mine is already dying, can't hold a charge for more than 2 hours without the walwart.


----------



## Yitaro

My battery crapped out on me.  It won't operate without plugging it in.  Sent my in to iBasso for warranty work and end up paying extra $30 for them to send a replacement.  Ibasso was suppose to send a unit out to me on Monday the 10th and provide a tracking number but so far no email from them.  Tried emailing them to confirm the shipment, but they haven't replied yet.
  Is there a holiday in China or something?


----------



## Uchiya

I dunno, Audio-GD is supposed to ship me an NFB-10SE also but they said DHL would take a few days to give them a tracking number, so maybe there is a holiday?


----------



## Uchiya

Guh, 15 for shipping, and if it's the battery it might cost 30 dollars for replacement + shipping cost back from Ibasso and this item is barely 6 months old.  Seriously?  The sound quality is amazing but damn, rofl.  Gotta love that "lack of warranty".


----------



## Yitaro

Quote: 





uchiya said:


> Guh, 15 for shipping, and if it's the battery it might cost 30 dollars for replacement + shipping cost back from Ibasso and this item is barely 6 months old.  Seriously?  The sound quality is amazing but damn, rofl.  Gotta love that "lack of warranty".


 


  I find that iBasso's customer service is excellent.  They made every effort to make sure that my PB2 gets to me before my vacation.  Got my new PB2 today and they shipped it UPS, free of charge.  I had to pay $30 for restore fee.  They had to restore my PB2 to new condition (case, etc.).
  You might try contacting iBasso and I'm pretty sure they will work something out for you.


----------



## Uchiya

Yea, I know they're good.  Just happens that it breaks down right when I'm getting my HD800's and a new setup.  Oivey!


----------



## jamato8

I received the OPA1642 from Ron recently and the sound with the PB2 and the 5002 buffers is outstanding. Great spacial information and a quality of micro dynamics that puts the extra live touch to the music. The 1642 in this situation, sounds very tube like in the 3D and ambience feel to it. Very much worth it! Oh, they are in class A (the socket that Ron has that allows you to use other dual op amps in class A with just switching them as the class A resistors are in a separate socket that the 1642 plugs into).


----------



## Uchiya

Can't help but think that the way it sounds with Ron's kit, that the PB-2 would be a good mate with the HE-4's also; taming that treble and giving that boosted bass some softening and texture.  Time to make a purchase.


----------



## Uchiya

Has anyone tried the  PB-2 with the Beyer T1?


----------



## HiFlight

Quote: 





uchiya said:


> Has anyone tried the  PB-2 with the Beyer T1?


 


  I haven't tried the T1, but I have a set of DT-880 Dragon V1's (600 ohm) with  Black Dragon cables, balanced.  It sounds outstanding with the PB2/DB2 combo.  I can only imagine that the T1 would sound even better!


----------



## SpudHarris

I am listening now with T1 and PB2-DB2 CLAS combo (single ended) and I don't feel the synergy is great compared to ther phones I have here. Modest they may be but I find the HD600's (balanced) sound absolutely fantastic with this combo. The HE-500's probably beat them slightly in terms of SQ but the SS on the HD600's is lovely. I suspect OpAmps will have a part to play in this so for information the DB-2 has stock LP Filters. The PB-2 has LT1678's L/R and HA5002 buffers.


----------



## Uchiya

Thanks for the info.  I find that single-ended is really missing the dynamics and sound-stage, plus it's definitely not enough juice for that 600ohm load.  Was considering T1 or LCD-3 to compliment my HE-6.  Turns out the HE-6 has a different sound on it's own with the PB2/DB2 (Ron's Kit ofcourse), different from the NFB-10SE that I also like.  May just keep the HE-6's or buy another pair.


----------



## Uchiya

Interesting.  Received a new PB-2 while the 1st is being sent out for repair.  This one is very quiet, and no hiss where-as the 1st had a lot of volume-knob noise and hiss around 2-3pm on the dial - high gain and low gain.  Better production than initial batch?


----------



## Girls Generation

So what exactly is the difference between the 1612 and the 1642, and which one is preferred with the DB2?


----------



## HiFlight

girls generation said:


> So what exactly is the difference between the 1612 and the 1642, and which one is preferred with the DB2?




I personally prefer the OPA1612 as it has lower THD, higher slew rate, lower noise and, IMO, is better balanced throughout the audio frequency band. 

There are others who prefer the sound of the OPA1642, so YMMV!


----------



## scootermafia

Hiflight's topkit turned my DB2 into a mini-Beta22.  Highly recommended!


----------



## SpudHarris

PB2 or DB2?
   
  If it is the DB2? can you tell me what the opamps are for the LP Filter.


----------



## Kepic

Quote: 





scootermafia said:


> Hiflight's topkit turned my DB2 into a mini-Beta22.  Highly recommended!


 


  same here but mine's D12~ Hiflight rules!


----------



## trentino

I received my DB2 today. Pairing it with PB2. I used to own the DB1 and I have omly used usb from my pc. Switching from DB1 to DB2 I thought I should also buy a MF V-link (usb>spdif) and try that as a small upgrade. How many of you guys use only usb and not spdif into DB2? Does anyone have experience with coax versus optical on the DB2? Which one should I go for?
  Thanks.


----------



## Girls Generation

I don't personally have experience comparing the two but from what I've read from many people's posts, it seems to be the general consensus that coax > optical. Make sure you have a good 75ohm cable for it though 
  
  Quote: 





trentino said:


> I received my DB2 today. Pairing it with PB2. I used to own the DB1 and I have omly used usb from my pc. Switching from DB1 to DB2 I thought I should also buy a MF V-link (usb>spdif) and try that as a small upgrade. How many of you guys use only usb and not spdif into DB2? Does anyone have experience with coax versus optical on the DB2? Which one should I go for?
> Thanks.


----------



## SpudHarris

I've tried and coax wins every time. Here's my DIY coax from CLAS to DB-2


----------



## trentino

Oh that is really nice. Where can one find short cables like that? I'd hate buying 1 meter coax when i only need 10 cm. Are all these short cables diy'd from knowledgeable users or are there online stores that sell these?


----------



## SpudHarris

I make my own. Did a silver balanced interconnect also...


----------



## Uchiya

T1's are gelling pretty well in balanced mode with the PB-2.  Only using Ipod LOD via SE in, Balanced out but the strengths of the T1 and balanced operation is doing great to compensate for the small soundstage and less than stellar imaging of the Ipod.


----------



## trentino

Has anyone been using the DB2 to feed other amps than iBassos? Since it is balanced I guess one should always try and use the balanced out. I'm considering getting another amp (like the Matrix M-stage) and I guess a cable like this one is needed:
   
  http://www.qalixa.com/static/images/104/supra-2rca-35mmbilinekabel4m%28149170%29-Large.jpg
   
  Any impressions from users feeding other amps than iBassos, and using the SE output from DB2?


----------



## paulybatz

I use my DB to feed, had a hirose to mini made...works great...
   
post #358
   
  feeding my P4


----------



## Girls Generation

AFAIK there's no point in having a Hirose to 1/8 (Balanced to SE) if there's already an SE out on the DB2.
  Use a balanced amp with a fully balanced IC so it actually is a true balanced in/out setup.


----------



## trentino

I am doing that, with the pb2. But I want to try other amps for phones like for example ahd5000, thats why I was looking for impressions on the se out of db2, to feed amps with rca input.


----------



## Girls Generation

I see what you mean. I haven't used the DB2 via SE yet so I can't tell you anything about it. I've seen some people around who have done extensive listening with DB2 SE though, so I'm sure you'll find some information lying around.
  Quote: 





trentino said:


> to feed amps with rca input.


----------



## Jalo

Trentino and GG, just for your information, even though there is a SE out on the DB2, but if you have a cable like what Paulybatz has, an Hirose to mini, it will sound better than the SE out from DB2.  I compared both and I have a Hirose to mini cable.  I was told that the reason is that the balance operation is different and better than the SE operation inside the Db2.  So even if the signal is combined at the hirose to mini adaptor, it will still sound better than the SE circuits inside the DB2.
   
  I also use my DB1 to drive my SR71b, Pico Slim etc and the DB1 sounds very good.  There is literally very very slight difference between DB1 and DB2.  That is why I kept the DB1 for the size and longer battery life.


----------



## trentino

Thanks for the info Jalo. I need to find a hirose>2rca-cable. Any suggestions on where to find one? I guess it's diy stuff, maybe someone can make me one.


----------



## paulybatz

Quote: 





trentino said:


> Thanks for the info Jalo. I need to find a hirose>2rca-cable. Any suggestions on where to find one? I guess it's diy stuff, maybe someone can make me one.


 

 Lots of DIY'rs here in the forum


----------



## Jalo

Quote: 





trentino said:


> Thanks for the info Jalo. I need to find a hirose>2rca-cable. Any suggestions on where to find one? I guess it's diy stuff, maybe someone can make me one.


 

 You are welcome.  You can find the parts at mouse.com at about $13.00 per hirose connector.    
   
  Part number:
   
  798-HR10A-7P-6P73
  Hirose Circular Push Pull Connectors
 6P PLUG SHELL SZ 7
 US HTS: 8536694020 ECCN:EAR99


----------



## trentino

Thanks again. Hm if I buy the parts myself I still need to find someone that can make me the cable. Maybe I should just ask around, make a thread in the diy forum.


----------



## paulybatz

sometimes the DIY'rs will have connectors on hand, unless you are very specific about what you want, get the wire and connectors then contract it out


----------



## trentino

Just to follow up on the hirose>2rca-cable - I was told by DoubleHelixcables to get a mini>2rca and not a balanced>2rca-cable,  those can harm the unbalanced amp, according to DHC.


----------



## Jalo

Any reasons?


----------



## Saintkeat

because balanced output is double the voltage swing.


----------



## LaurentD

Quote: 





spudharris said:


> I've tried and coax wins every time. Here's my DIY coax from CLAS to DB-2


 


 hi,
 sorry for the question ...... but what is the "box" at the bottom (on the left pic)

 thx
  Laurent


----------



## SpudHarris

It'a a CLAS (Cypher Labs Algorithym Solo). Takes the bit perfect digital from the ipod, feeds into the DB-2 gets balanced and feeds into the PB-2.


----------



## trentino

That is an awesome looking short coax cable. Hmm, would be nice to use with the upcoming iBasso dap and the db2 
  Now Spudharris, how about you hooking me up?


----------



## SpudHarris

Cheers. Cut down Switchcraft Right Angle RCA's and the rubber boots of the Hirose male connectors. Not the cheapest way but better to look at than some. I only make cables for myself and for fun. PM me if you want me to knock something up for you. If it's for the DX100 then we have time on our side


----------



## LaurentD

Quote: 





spudharris said:


> It'a a CLAS (Cypher Labs Algorithym Solo). Takes the bit perfect digital from the ipod, feeds into the DB-2 gets balanced and feeds into the PB-2.


 


 thanks a lot. I was away from portable gear (and head-fi) for a long time....... and it seems there is some good news here 

 Laurent


----------



## paulybatz

Quote: 





laurentd said:


> thanks a lot. I was away from portable gear (and head-fi) for a long time....... and it seems there is some good news here
> 
> Laurent


 

 Laurent, it is a fantastic time for the hobby!


----------



## Kremer930

Just bought the PB2.  I have been interested in it for some time now and one was for sale that was too tempting to resist.  
   
  I am really impressed with it so far.  It is very different in character to my RX2 and the power is very evident when using my DT1350.  It helps the dynamics and bass noticeably improve.  I havent done a thorough comparison as yet but it is definitely a keeper.
   
  And the most amazing part so far is that I havent even used it balanced yet.....
   
  I am probably going to ask Qusp to make me an adapter so that I can plug my RSA terminated Twag JH16's into it.  Later on down the track I will also need to get my DT1350's wired up with a balanced setup.
   
  I would have both cables re-terminated to Hirose but I am waiting for the Alo Rx3 to come out and it uses the RSA connector.


----------



## Jalo

Quote: 





kremer930 said:


> Just bought the PB2.  I have been interested in it for some time now and one was for sale that was too tempting to resist.
> 
> I am really impressed with it so far.  It is very different in character to my RX2 and the power is very evident when using my DT1350.  It helps the dynamics and bass noticeably improve.  I havent done a thorough comparison as yet but it is definitely a keeper.
> 
> ...


 

 The most amazing part is to try it balance with the HiFlight Topkit.  
   
  With your JH/16, I'll recommend the opamp 1678 and 55002 with class A buffers.


----------



## Girls Generation

Apparenlty there's a new opamp Ron's found, THS4032, Jalo. Wonder how it measures agaisnt the 1678 with the LCD2.


----------



## Jalo

girls generation said:


> Apparenlty there's a new opamp Ron's found, THS4032, Jalo. Wonder how it measures agaisnt the 1678 with the LCD2.




Won't know until I have the chance to hear it. However, I noticed Ron has very good ears and his description of the various opamps matches very close to my impressions. Last times he sent me 4 sets of opamps and his description of their character matches very close to my impression. So I can almost trust what he describes.


----------



## Pudu

kremer930 said:


> Just bought the PB2.  I have been interested in it for some time now and one was for sale that was too tempting to resist.
> 
> I am really impressed with it so far.  It is very different in character to my RX2 and the power is very evident when using my DT1350.  It helps the dynamics and bass noticeably improve.  I havent done a thorough comparison as yet but it is definitely a keeper.
> 
> ...




I've been toying with the idea of re-wiring my 1350's for balanced use with the PB-2 too.

 What's been holding me back is that I don't know if there's any obvious advantage in doing so.


----------



## Kremer930

Thanks Jalo for the recommendations.  I had a Hiflight kit for my D12 and thought that it lifted the D12 to another level.  I definitely plan to buy the kit for the PB2.  In fact I have already contacted Ron to see how much it will cost.  My only delay is holding back enough toy money to allow for the Alo Rx3.  
   
  I am currently listening to my HE6 with the PB2 balanced on high gain and it is certainly not bad.  I expected it to lack bass but at 3pm on the dial it sounds pretty punchy.
   
  A question though.  With all of the opamps can you just buy them in sets of 4 from shops or do you have to solder them onto the adapters first?  Rons kit will be a great start but, as with your suggested combination for my JH16, I may also want to keep expanding my choices.
   
  Thanks
   
  Quote: 





jalo said:


> The most amazing part is to try it balance with the HiFlight Topkit.
> 
> With your JH/16, I'll recommend the opamp 1678 and 55002 with class A buffers.


----------



## SpudHarris

A lot of the newer (better) opamps come in a soic package, they are small and need soldering onto a single or dual DIP adapter like a 'Brown Dog'...... Even high quality TO99 (metal can) opamps will require soldering onto an adapter. It's worth it though as most of my go to opamps are soic or TO99.


----------



## Jalo

Quote: 





kremer930 said:


> Thanks Jalo for the recommendations.  I had a Hiflight kit for my D12 and thought that it lifted the D12 to another level.  I definitely plan to buy the kit for the PB2.  In fact I have already contacted Ron to see how much it will cost.  My only delay is holding back enough toy money to allow for the Alo Rx3.
> 
> I am currently listening to my HE6 with the PB2 balanced on high gain and it is certainly not bad.  I expected it to lack bass but at 3pm on the dial it sounds pretty punchy.
> 
> ...


 

 Well, I am not very good at soldering, so I think working with Ron is great and has a lot of advantages.  He is very experience with opamps and he keep a tap of what is coming up new . He is a very nice guy to work with.  He sent me four sets and allow me to audition them and sent whatever I don't want to keep back.  I really like the Class A socket where you can put the opamp into.  The difference between the 1678 and the 55002 is that the 1678 gives a cleaner, more natural sound and the 55002 gives more bass and a little more body.  So it depends on what your flavor is.  if you have a bright phone, the 55002 will taper it a little bit, but if you have a phone like the LCD2 that already has a lot of base and body and the mid is a little recess, the 1678 will do great by giving it a little brightness (most of the time, clean, natural sound gives the impression of brightness) but will not compromise the bass and the body of the LCD2.


----------



## Kremer930

Thanks guys for your help.  The idea of being a cheap skate is pretty appealing until I remember that I cant really solder and that Ron is a great guy to deal with....  Interesting to keep in the back of the mind though.  
  
  Quote: 





spudharris said:


> A lot of the newer (better) opamps come in a soic package, they are small and need soldering onto a single or dual DIP adapter like a 'Brown Dog'...... Even high quality TO99 (metal can) opamps will require soldering onto an adapter. It's worth it though as most of my go to opamps are soic or TO99.


 


   


  Quote: 





jalo said:


> Well, I am not very good at soldering, so I think working with Ron is great and has a lot of advantages.  He is very experience with opamps and he keep a tap of what is coming up new . He is a very nice guy to work with.  He sent me four sets and allow me to audition them and sent whatever I don't want to keep back.  I really like the Class A socket where you can put the opamp into.  The difference between the 1678 and the 55002 is that the 1678 gives a cleaner, more natural sound and the 55002 gives more bass and a little more body.  So it depends on what your flavor is.  if you have a bright phone, the 55002 will taper it a little bit, but if you have a phone like the LCD2 that already has a lot of base and body and the mid is a little recess, the 1678 will do great by giving it a little brightness (most of the time, clean, natural sound gives the impression of brightness) but will not compromise the bass and the body of the LCD2.


----------



## Girls Generation

I have an aftermarket pb2 LCD2 cable up for sale if anyone is looking.


----------



## Kremer930

Pulled the pin on a HiFlight kit.  Excited to hear what it does since it made such a huge improvement with my old D12.  Ron is an absolute gentleman.  He gives so much to the iBasso community.  Thanks Ron.
   
  I think that Pudu raised the question a week back but can anyone suggest how much and what the difference would be to get the DT1350 recabled to balanced?
   
  Really liking the PB2 compared to my RX2 with my JH16 in SE mode.  It adds a bit more top end detail and sense of space.  They are both great but quite different.
   
  I ordered a RSA balanced adapter to Hirose adapter so that I could use my existing JH twag cable with the PB2.  I am beginning to think that I may need to get the adapters around the other way such that I have all of my cables terminated Hirose and then clip in the RSA adapter when needed.  (The new Rx3 amp will have RSA plugs and hence why I need the RSA plug option).  What do people suggest?


----------



## Canadian411

Quote: 





spudharris said:


> It'a a CLAS (Cypher Labs Algorithym Solo). Takes the bit perfect digital from the ipod, feeds into the DB-2 gets balanced and feeds into the PB-2.


 


  I don't understand why you will have CLAS (DAC) and another DAC DB2 ?
  Can you educate me what am I missing or any benefit having 2 DACs ?
   
  Cheers,...


----------



## SpudHarris

The CLAS takes the bit perfect digital from the ipod and feeds digital into the DB-2 where the DAC does it's job and sends balanced signal to the PB-2. I could use the DAC in the CLAS and bypass the DB-2 but then I'd only be able to feed single ended signal to the PB-2. I do use the DAC of the CLAS to feed unbalanced amps and it does a great job indeed. 
   
  Hope this makes sense.


----------



## Girls Generation

In short, he's using a DB2 for *balanced* input into his amp, and the CLAS as a transport.


----------



## Kremer930

Got the HiFlight opamp kit for my PB2.  Havent even used in balanced mode yet but already I am in love.  Awesome kit Ron.  Thanks.


----------



## slwiser

Quote: 





kremer930 said:


> I think that Pudu raised the question a week back but can anyone suggest how much and what the difference would be to get the DT1350 recabled to balanced?


 

  For myself what I hear with the DT1350 balanced compared to singled ended is that what I enjoy with the DT1350 is enhanced, better detail, precision of imaging and sound-stage.  This goes the same for the Senn HD-25-I balanced compared with single ended; better bass punch, wider sound-stage and more control over when I thought the Senn got a little loose.  Your mileage may vary compared with mine but that is what I am hearing.  So default listening now is either one balanced for me at this time.  When I got the DB2 and put it into the mix at first I though nothing added but later everything opened up with both of these headphones.  From this I take it that the DB2 has to settle in a bit before revealing itself to me.  I am not sure that I really need the DB2 in the mix though with the SR-71B splitter being able to do very well with the signal.   FYI, I have the DT1350 and HD25s with Moon Audio IEM SIlver Dragon terminated with Switchcraft mini-XLR connectors.


----------



## ahmadmfz

Pretty much getting this as my main amp, for my JH5, DBA-02, TF10 & Grado SR325is. 

 Just a noob question.. if i feed it single ended through the headphone out of my cowon J3, would it still be able to output balanced to my headphones? I will need to recable them though, except for the DBA. 

 Currently i'm using the old iBasso P3 Heron. Anyone remember this amp? xD Currently using AD743JN op-amps. Love the sound. How would the PB2 compare?


----------



## SpudHarris

Yes it will output balanced no problem, I used mine like this for ages befor dropping the cash on the DB2 to feed it balanced also.
   
  I remember the P3, it was a great amp. I had the P3+ and still have a P4, all great amps in my opinion. The PB2 has power to spare but versatile enough to use IEM's and HE-6's on same gain setting (I do adjust the volume very slightly on my MDac though when using HE-6).


----------



## Kremer930

I have read that some people have problems with the battery failing to hold charge eventually on their Pb2's. I bought mine off the for-sale area here at headfi so I don't know the history of the unit. Does anyone know how long the battery should last?

I bought a new battery from iBasso a couple of days ago. It cost $25 for the battery and $5 for normal post. 

Gee I miss not being able to use the pb2. It is my preferred portable amp right now.


----------



## wolfen68

Quote: 





kremer930 said:


> I have read that some people have problems with the battery failing to hold charge eventually on their Pb2's. I bought mine off the for-sale area here at headfi so I don't know the history of the unit. Does anyone know how long the battery should last?
> I bought a new battery from iBasso a couple of days ago. It cost $25 for the battery and $5 for normal post.
> Gee I miss not being able to use the pb2. It is my preferred portable amp right now.


 


 PB2's are still relatively new.  I'm surprised any batteries would be dying yet.  For that matter, most of the PB2's are probably still within their one year warranty.


----------



## Kremer930

I can remember seeing a pb2 in the for sale columns a month or so ago which didn't hold charge. My guess is because they have been connected to mains power for most of their lives and not cycled.


----------



## SpudHarris

That may be true, but there is a switch option to bypass the charging and operate via wall wart only. Mine leaves the house and gets used on occasions and I do charge it when I get back but the majority of the time when used at home the charging facility is bypassed.
   
  By the way the PB-2 punches above it's weight and makes a decent home amp when a) Fed with high quality recordings and B) With the right chipset....


----------



## tom2517

I got a problem with the noise floor (background noise?) of 128SM, anyway to reduce it besides not using it? Thanks.


----------



## Kremer930

I got my new battery for the PB2 and installed it.  Happy days again!!!  Love it.  It has ruined me for quality, dynamics, bass impact and treble detail that I am almost questioning whether I really need to buy the new Alo RX3.


----------



## Saintkeat

Hey guys I need a realistic answer to something I've been thinking of.
   
  Whats the significant difference between PB1/PB2 in balanced out vs PB1/PB2 + DB1/DB2 balanced out?
   
  I'm wondering if its a significant night and day difference or rather negligible.
   
  Of course not everyone can answer this question, so I'll wait patiently for a reply.


----------



## Pudu

saintkeat said:


> Hey guys I need a realistic answer to something I've been thinking of.
> 
> Whats the significant difference between PB1/PB2 in balanced out vs PB1/PB2 + DB1/DB2 balanced out?
> 
> ...




I'm not sure anyone can answer it. It would depend on what your source is. The boomslangs are just DACs and will replace whatever it is you are currently using as a DAC. The Pelican is just an amp. 

It's a bit involved to run balanced in to the PB2 if you aren't using the DB2 since you have to have a balanced source and a cable that adapts from whatever your source connection uses to hirose on the PB2. 

Or are you asking the difference between using the PB2's balanced output with a normal input vs a balanced input?


----------



## Saintkeat

The latter is exactly what I'm asking.


----------



## Pudu

Sorry, I don't really remember using it in that configuration and right now my hirose cable is out of action. 


My advise, for what it's worth, is if you already have the PB2 (or PB1) and you like your current source I shouldn't worry about it. However if you need a DAC anyway, get the Boomslang because it is a good DAC (I'm actually using it as a desktop DAC at the moment) and gives you the most flexibility with your PBx amp. But I wouldn't go chasing the balanced sound thing. It gets too complicated/expensive for any possible returns.


----------



## wolfen68

Quote: 





saintkeat said:


> Hey guys I need a realistic answer to something I've been thinking of.
> 
> Whats the significant difference between PB1/PB2 in balanced out vs PB1/PB2 + DB1/DB2 balanced out?
> 
> ...


 

 I effectively spent a lot of time on this comparison when I first got the DB1 and PB1 using the H1xx as an optical transport. 
   
  At this level, many of the benefits are relatively incremental...however, I felt the introduction of the DB1 and effectively "keeping it balanced all the way through" did yield some benefits to sound stage, bass impact, and especially imaging.  I am sold on that configuration and continue to use it, with the exception that the PB1 was replaced by an SR71b.


----------



## slwiser

For myself I did see a significant change with the introduction of the DB2 into the mix with the HP-P1 and SR-71B by themselves.  The imaging got much better.  One thing though that I found was that for the first few hours of using the DB2 did nothing at all.  It was only after letting it have some hours on it that the imaging got much better.  So out of the box I would agree with the premise but if you don't give it time you will be missing quite a bit I think.


----------



## Saintkeat

Thank you Wolfen68 and Slwiser! These are the kind of answers I've been waiting to hear. Clear, concise, with careful experimentation.
   
  Why did both of you go with the SR-71B though?
   
  I find nothing wrong with the PB1 balanced out, in fact its pretty phenomenal as it is "pseudo-balanced". However, the sound staging feels shallow and stretched.
   
  Could both of you comment on whether there was an increase in depth going with the full balanced set up? As well as whether there was an increase in Bass or was it just the reduction of the noise floor to give the impression of better impact?


----------



## slwiser

Quote: 





> Originally Posted by *Saintkeat* /img/forum/go_quote.gif
> Why did both of you go with the SR-71B though?
> 
> Could both of you comment on whether there was an increase in depth going with the full balanced set up? As well as whether there was an increase in Bass or was it just the reduction of the noise floor to give the impression of better impact?


 
  The reason I choose the RSA was for its "reputation" for having a darker heavier bass presence. Whether or not that is a true comparison against the PB2 is not for me to say since I have not heard it.  Having the somewhat brighter DT1350 balanced, I thought the RSA would be a better match for what I was attempting to hear.  I find having the DT1350 and HD25 both balanced is interesting.  Imaging for both got much better with the DB2 than without.   While the DT1350 starts out imaging better than the HD25 both are better in a fully balanced setup.  I can make the DT1350 sound much closer to the DT1350 when I place on the DT1350 velour pads for the HD25.  This is an easy mod for the DT1350 which makes the mids a little smoother and sometimes I like the DT1350 without the pads as I am doing right now with Cat Stevens; much more like the HD25 balanced itself. Having the pads keeps me from having to carry both to work.  Right now I am only using the DT1350s.  Not sure if what I am hearing is based on noise floor or actually real bass impact but the DT1350 has very good bass response for such a small headphone.


----------



## wolfen68

Quote: 





saintkeat said:


> Thank you Wolfen68 and Slwiser! These are the kind of answers I've been waiting to hear. Clear, concise, with careful experimentation.
> 
> Why did both of you go with the SR-71B though?
> 
> ...


 


  I found the SR71b to be superior.  The sound character is warmer/fuller than the pb1 and imo more realistic.  
   
  Full balanced provides improved depth....it goes along with the improved imaging.


----------



## Saintkeat

I appreciate the input Gents.
   
  Looks like I need to pick up a DB2. When I am not so strapped for cash I'll consider the SR-71B. Always wanted an RSA ever since I heard the SR-71A.


----------



## Pudu

wolfen68 said:


> I found the SR71b to be superior.  The sound character is warmer/fuller than the pb1 and imo more realistic.
> 
> Full balanced provides improved depth....it goes along with the improved imaging.




 I went for the PB2 for the same reason.I found the RSA too warm and the fuller sound a bit artificial, a bit like Dobly headphone on a tiny scale. 

Different strokes...


----------



## Jalo

Well, for me I have both the PB2 w/ topkit and SR71b and I have been going back and forth between the two amps.  Generally speaking, I think the PB2 is a cleaner, natural and leaner amp and the SR71b is a warmer amp with bigger sound stage and body.  So when I am in the mood of wanting more bass, musical and bass I'll choose the SR71b and when I am in the mood for cleaner music, I'll go for the PB2.


----------



## SpudHarris

Quote: 





saintkeat said:


> Hey guys I need a realistic answer to something I've been thinking of.
> 
> Whats the significant difference between PB1/PB2 in balanced out vs PB1/PB2 + DB1/DB2 balanced out?
> 
> ...


 

 I ran the PB-2 from my CLAS for a while, single ended input and balanced output and I enjoyed it a lot. I now feed the DB-2 digital from the CLAS then balanced input into the PB-2. There are subtle differences/gains but they are definately not night and day. Better? yes but not much.....


----------



## Saintkeat

Wow Spud that is starting to put things in perspective.
   
  Where abouts in the UK are you from? Perhaps I could have a listen when I visit June this year.


----------



## SpudHarris

Hey Saintkeat, I'm in the Midlands. A little place just outside Kidderminster. Drop me a line when you are gonna be about and we can meet up for a coffee and you can have a listen by all means my friend. Just let me know.


----------



## Uchiya

Has anyone tried the PB-2 w/Topkit on the HD800?  I found that on other headphones, it's provided the smoothest treble I've ever experienced, more-so than the  NFB-10SE and and especially the Lyr w/S&H E88cc's.  I think the HD800's could mesh with the PB-2's smaller soundstage and ability to cure that high energy treble.  Hell, it even did wonders for the T-1, making it listenable.


----------



## Saintkeat

Thanks SpudHarris! Coffee will be on me! I haven't finalised the date I'm flying up, it should be between June to August. I'll be mostly in London though, but I could drive up somewhere to meet you.


----------



## mlmark

Hi,
   
   I currently use opa627 and buf634, but I just get ha3-5002-5z. Could somebody tell me please that I can replace this buffer with buf634 or not. Someone told me that I cannot replace this chip with buf634 without modification.


----------



## SpudHarris

Ron (HiFlight) will be best to comment on this in detail but I can tell you that they need a special adapter with 2 x smd resisters (I think) on the underside. The are certainly not drop in replacements soldered on normal soic adapters....


----------



## zilch0md

Hey!
   
  I am awaiting delivery of a PB2. Joy!
   
  I was wondering... *Has anybody here tried extending their portable use of the PB2 by using an external battery pack like the Energizer XP8000?*
   
  I wrote iBasso and they said that 15-Volts DC would work fine, plugged into the PB2's power jack, so I intend to try this setup when I get the PB2:
   

   
  The XP8000 is an 8000 mAh Lithium-ion battery pack that can be simultaneously tapped from its 5-Volt port for charging USB devices, from its 12-Volt port (for whatever), and from its 19-Volt port (designed for powering laptops or notebooks).
   
  The XPAL Willy Cable WI15 is an inline voltage regulator that, when plugged into the 19-Volt port of either the XP8000 or the larger XP18000, limits output to 15 Volts (mine measures 15.11 Volts, as shown in the photo.)
   
  The iBasso support rep stressed that I not exceed an input of 16 Volts DC, but I'm confident that a regulated 15 Volts will surely be enough to operate the PB2 and might even be a high enough voltage to charge the PB2's internal battery pack while on the go.
   
*Does anyone know the mAh (milliamp-hour) rating of the PB2's internal battery pack? *
   
  I suspect it's something less than 8000 mAh, but in any case, the XP8000 would probably extend play time by at least a factor of two, likely much more.
   
  Each cell of a lithium-ion battery has a nominal voltage of 3.7 Volts, but when fully charged, each cell reaches 4.2 Volts. The PB2 internal battery has three cells, for a combined voltage of 12.6 Volts when fully charged. Sadly (but true), as you start consuming the power of the fully charged internal battery, the voltage immediately begins dropping from the maximum 12.6 volts all the way down to something no less than 3.0 Volts per cell (a minimum of 9.0 Volts for the three-cell internal battery), by the time the PB2 demands to a recharge.
   
  If the PB2 is designed like the SR-71B in this regard, the maximum p-p voltage swing enjoyed at the amp's output actually decays as the battery is consumed. Surprise! (Somebody please correct me if you think I'm wrong about this.) So, I'm thinking you really only get the PB2's best performance when you are hooked up to an external 16-Volt power supply, where you can enjoy the spectacular 32-Volt p-p swing for which the PB2 is famous (or a swing of 16 Volts with single-ended output). On a fully charged PB2 internal battery, you'll get no better than a 25.2-Volt p-p swing - again, that's only when fully charged. As you run the battery down to somewhere near 9.0-Volts (3.0 volts per cell is where the unit should shut down to avoid damaging the battery pack), you'll only be getting an 18-Volt p-p swing with balanced output - nowhere near the 32-Volt swing had when the PB2 is attached to a 16-Volt external power supply.
   
  Again, I think the SR-71B operates under this same reality check when operated portably, but get this: Its internal lithium-ion battery has four cells, instead of only three. Again, at 4.2 Volts per cell when fully charged, the SR-71B battery pack has a combined voltage of 16.8 Volts (vs. the PB2's internal battery maximum voltage of 12.6 Volts). Ray Samuels' specifications claim a swing of only 13 Volts for single-ended output and 26 Volts with balanced output, using the 16.8 Volt internal, four-cell lithium-ion pack, but I think he's calculating his swing voltages against the nominal voltage of his four-cell battery pack (3.7 x 4 = 14.8 Volts), rather than against the fully charged voltage (4.2 x 4 = 16.8 Volts).
   
  I haven't discussed any of this with Ray Samuels or with iBasso, so please take all of this with a grain of salt until further notice. I don't actually know if the supply voltages can be so directly associated with the output p-p swing voltages - with either the PB2 or the SR-71B. And don't miss the fact that I've purchased a PB2 that will be arriving shortly - I am not trying to claim that the SR-71B is superior to the PB2 just because it has a four-cell battery instead of a three-cell battery!
   
  I genuinely believe the PB2 is everything it's advertised to be and more - in addition to being a great value.
   
  Back on topic - by using the five-cell, external XP8000 lithium-ion battery in combination with the inline 15-Volt regulator cable (the WI15), the voltage seen by the PB2 will always be a constant 15 Volts, even while the XP8000's output port is feeding the WI15 voltage regulator with a voltage that's decaying during use from a fully-charged 21.0 volts (4.8V x 5 cells) down to the minimum 15 volts (3.0V x 5 cells), at which point the XP8000 will shut down. So, if my theories about the relationship between supply voltage and p-p swing voltage are correct, the XP8000 with WI15 cable could allow PB2 owners to operate portably with a constant p-p swing of 30 Volts with balanced output, instead of a constantly decaying p-p swing that begins at only 25.2 Volts with the fully-charged internal battery, then falls to 18.0 Volts when the internal battery is depleted.
   
  I would love nothing better than to get all of this verified or debunked - one or the other. I'm after the truth more than I'm after being "right." I'll continue to investigate this and post my findings.
   
  Here's a question that would shed some light on this: *Has anyone here ever been told by a reputable source that the PB2's output is superior when connected to a an external 16V power supply (vs. using the internal battery)?*
   
http://www.energizerpowerpacks.com/us/products/xp8000/
   
  Thanks!
   
  Mike


----------



## zilch0md

Look what I just found:
   
Quoting jamato8:
   


> The balanced voltage swing of the PB2 with the adapter is 32  volts or 16 pos and 16 negative. With the battery, it is 25.2  as the battery is 12.6 not 16 volts. With  a 16 volt charger, unless you stepped it up, you couldn't have a 16 volt battery, the adapter would have to be of higher voltage. iBasso confirms that the battery is 12.6 and the same battery as the other 12.6 amps they have. So to maximize everything on the desk top, it would be run from the adapter, giving it 32 volts of swing.


 
   
  So....  If it's true that a steady 16V from the external power supply is needed to get the 32-Volt swing with balanced output, then a steady 15V from the XP8000 + the WI15 voltage regulator cable would deliver a 30-Volt swing - instead of an initial 25.2-Volt swing with the internal battery, decaying to an 18.0-Volt swing as it goes from fully charged to fully discharged.
   
  And...
   
  By examining photos of the battery pack in the PB2, I managed to discern the model number "502945" from one of them. Thanks to Google, I soon figured out that this is the model number of a Chinese-made 3.7V Lithium-ion battery (from a company called GEB - General Electronics Battery Co., Ltd.)
   
  For its specifications, search for the string "502945" on this page:
   http://www.gebattery.com.cn/geb/EN/ProductList.asp?SortID=136&SortPath=0,133,136,&Page=6
   
  Here's a picture of a single cell, wrapped differently than we see in the PB2:
http://i00.i.aliimg.com/photo/v0/252795906/polymer_lithium_battery_502945_3_7V_650mAh.jpg
   
  3.7V is the nominal voltage of any Lithium-ion cell.  Fully charged each cell will deliver 4.2V.
   
  So, what's the point of all this?  
   
*I have discovered the mAh rating of the 12.6-Volt, 3-cell Lithium-Ion pack within the PB2:  650 mAh.  *
   
  (Because the 4.2V cells are connected in series, the mAh rating of the three-cell, 12.6V battery pack is also 650 mAh.) 
   
  [size=x-small]And if the factory spec holds true - "[/size]More than 20 hours play time with stock OPAMPs" - this means that the PB2 (with stock opamps) pulls a load of only  31 mA (620 mAh / 20h = 31 mA).  That's remarkable!  The original Stepdance has a reputation of being a battery eater and Jan Meier says it pulls about 90 mA (45 mA per channel) - but it's not nearly as powerful as the PB2.  So, again I'll say, it's remarkable that the PB2 can be that efficient, pulling only 31 mA vs. the Stepdance's 90 mA.
   
  Whatever your PB2 play time is with a given set of opamps and headphones, the Energizer XP8000 external battery pack would extend that play time by a factor of 13.3!  (8650 mAh / 650 mAh = 13.3)
   
  If indeed we can get 20 hours of play from the 650 mAh internal battery, the combined play time would be a whopping 266 hours - eleven days straight!  Me thinks the factory specs for the Energizer XP8000 might be exaggerated, however.
   
  20 hours of play time is enough for any day trip, of course, but for an extended backpack, or a car camping trip with no access to 120VAC, the XP8000 could be useful for more than the above-mentioned advantage of providing a constant 15V supply - don't forget it can yield a non-decaying 30-Volt swing with balanced output, while portable, where the internal battery will start out with a swing voltage of 25.2 when fully charged, then eventually fall to 18.0-Volts when the battery is ready for recharging.
   
  When my PB2 actually gets here, I promise to write about it less!   
	

	
	
		
		

		
			




   
  Mike


----------



## SpudHarris

Quote: 





zilch0md said:


> When my PB2 actually gets here, I promise to write about it less!


 
   
  I doubt that very much !
   
  Welcome to the thread Mike. Did you shed you Stepdance in favour of the PB-2 like I did? You won't be disapointed if that is the case. Plus you have a lot of tweakability (is that a word?)... Anyhoo, enjoy!


----------



## zilch0md

Hey Spud!
   
  Thanks for the welcome shout.  I think you may be right about my promise, though.  
	

	
	
		
		

		
		
	


	



   
  I actually have two Stepdances, but I might sell one of them after hearing the PB2 w/ Ron's Topkit into balanced Toxic Cables' Silver Poison > LCD-2.  
   
  I very much respect your opinion (from reading many of your posts, I think we have very similar aural tastes), and I do recall reading that you had gone from Stepdance to PB2, so your testimony was actually a factor in my decision to purchase (among many).
   
  The only apprehension I have is that I don't want to forfeit any of the Stepdance's virtues of transparency, neutrality, and resolving power (detail) just to get what comes with more power (better dynamics, bass control and possibly extension, for example.)  In other words, I may be making another promise I can't keep, but at this moment, not having heard what's coming, I'm steeling myself to be very critical towards not losing ANYTHING of what the Stepdance has so faithfully delivered. 
   
  From what I've read, and believe me, I'm just guessing at this point, I'm eager to try the OPA1612 duals with the dummy adapter buffers (once I get my hands on everything). Everything's been ordered, but the Silver Poison cables will probably be the last component to arrive, as they won't be shipped from the UK for another three or four days yet (Frank is still crafting them.)
   
http://toxic-cables.co.uk/     I ordered 60-inch Silver Poisons, terminated for the PB2 and LCD-2, naked (without the copper braid shielding and fabric sleeve).  Frank (a.k.a. Kabelmeister), has been great to work with, and in my opinion, he offers a lot of value for the money, just like iBasso.
   
  Thanks again!
   
  Mike


----------



## SpudHarris

Your set up sounds close to mine as I too have Toxic Cable for both the LCD and HE-6. Very nice cables and yes he's cool to work with. I've rolled just about every opamp know to man into and out of the PB-2 (and my other amps for that matter) and really, really like the LME49990's with HA5002 Buffers. I do swap out the 49990's now and again but seem to go back after a while. The only other opamp to compete is the ADA4610-2 but unfortunately it makes a very loud thud when turning off which bothers me with my ES5's.
   
  Once you get it, feel free to pm me if you want and opamp info. Oh by the way the OPA1611's / 12's in class A are very very nice. I find the sound a little less fun than the LME49990's but for analytical ears it may be the route to go.
   
  Do post impressions......
   
  All the best - Nigel


----------



## zilch0md

Nigel,
   
  Just knowing that you're a former Stepdance owner gives me great confidence in trying whatever opamps you might recommend, simply because you actually know the sound I'm hoping to get from the PB2.  Add to this the fact that you're using the same cables and that you have the LCD-2, and I'm really keen to respect your advice.
   
  Thanks!
   
  Mike


----------



## zilch0md

I have received my PB2 and yes, all I'm willing to say about it this early in the game is: "WOW!  I'm thrilled!  And it's a lot smaller than I had imagined!"  
	

	
	
		
		

		
		
	


	



   
  But I'm still waiting for my balanced cables.  Joy!
   
  Meanwhile, I made this post to a different thread that concludes with a discussion of how* I will be supplying the PB2 with a regulated, maximum permissible 16V DC, during portable operation - so that I can actually get a swing voltage of 32V p-p all the time - even when not connected to the 16V AC adapter.  *
   
  As mentioned, in my earlier post, above, the PB2's internal 12.6V battery only permits a 25.2V swing, at best, when fully charged, but that begins falling immediately as the battery is used, down to a swing of of only 18.0V by the time the battery is depleted.  The SR-71B suffers a similar fate when using its internal battery, but that battery starts out at 16.8V instead of 12.6V (as it has four cells, instead of three.)
   
  I promised I would write less after getting my PB2.  I kept this pretty short, eh?  
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## Kremer930

If you like the Pb2 now...wait until you try it balanced.....and then wait until you try the HiFlight opamp kits.


----------



## zilch0md

Quote: 





kremer930 said:


> If you like the Pb2 now...wait until you try it balanced.....and then wait until you try the HiFlight opamp kits.


 
   
  Thank you!  I'm already having a good time with the PB2, but yes, I'm still looking forward to more power!
   
  I will say that even single-ended, with the stock op-amps and buffers installed, the LCD-2 (on a stock cable) are exhibiting a readily detectable increase in dynamics with the PB2, relative to the Stepdance with which I'm so familiar.  Detail is a tiny bit compromised, I think - but again, that's with the stock configuration.  
   
  I don't want to start rolling op-amps and buffers until I've got the Silver Poison cables.  It's highly unlikely I'll ever go back to single-ended, once I go balanced, so I've decided not to listen to the TopKit combinations until I've received the cables.  I don't want to influence my impressions using the cable I'm about to retire.  
	

	
	
		
		

		
		
	


	



   
  Waiting...  
   
  Mike


----------



## zilch0md

By the way...  Is this essentially _*the*_ primary thread for the iBasso PB2?   
   
  If so, the PB2 seems to have a really small following.
   
  But that's fine with me - as long as I'm in on what seems to be the best kept secret on Head-Fi.
   
   
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## SpudHarris

Well, in all the time I have had the PB-2 I never even considered using dummy adapters in buffer position 
	

	
	
		
		

		
			





. Until now obviously.....
   
  I use my DB-2/PB-2 mainly as my high quality portable/transportable rig with my ES5's balanced. I have used balanced D7000's and LCD2's at home but prefer the fuller more powerful HifiMan EF-5 for my full sized cans. With the ES5's this sounds considerably more transparent/coherent. More testing is required but my initial thoughts are to leave the dummy adapters in buffer positions and just take some stacked (8 off) BUF634AU's with me when on vacation to use with full sized cans on the evenings.
   
  The other thing which has pleased me no end is without buffers the ADA4610-2BRZ doesn't make that scarey thud/screech when turning of the PB-2. This used to worry me a lot.
   
  Thanks for the heads up Mike, I'm enjoying the PB-2 more than ever!


----------



## zilch0md

Hey Nigel!
   
  Quote: 





spudharris said:


> Well, in all the time I have had the PB-2 I never even considered using dummy adapters in buffer position
> 
> 
> 
> ...


 
   
  That's funny!  
   
  We'd rather add something to our amps, anything at all, than consider leaving any sockets empty.  
	

	
	
		
		

		
		
	


	



   
  You probably saw my post on the opamp thread:
   
   
    
  Quoting zilch0md:
   


> In Headphonia's review of the iBasso PB2, Mike (the article's author) wrote the following:
> 
> Quote:
> 
> ...


 
   
   
  This is still haunting me.  I haven't found anyone yet who can even support Headphonia Mike's statement, much less tell me how much current is lost by removing the buffers.  I don't have a hard time understanding that fewer components could yield a cleaner SQ, but at what cost (to power, for example)?  Personally, I value transparency/detail over dynamics/slam/bass control, so my leaning is to yank the buffers and not worry about a drop in current output, but I don't want to cripple the whole reason I upgraded to a PB2 from a Stepdance - for more power...
   
  I've tried looking for an article or a book that would shed some light on just what a buffer is supposed to be accomplishing and I haven't found anything yet. I don't want to just do the plug and play game, rolling this and rolling that, then listening to various combinations to see what sounds "good," without at least a little understanding of what I'm doing.  
   
  Is it true that buffers increase output current?  If so, how much?
   
  Is it true that removing them improves transparency?  If so, how much current is lost?
   
  Are there any other downsides to removing them?
   
  Is it even "safe" for the amp to run it without buffers when certain opamps are in use?
   
  And while I'm at it...
   
  Is Class A biasing OK when only using resistors to force the op-amp into Class A?  (From what I've read, selecting the right ohm ratings for the opamp in use and other factors is crucial. Too much resistance is just as bad as too little.)
   
  What is meant by using a "bypass" for Class A biasing?
   
  What's with using caps instead of resistors for Class A biasing?
   
  Aren't the risks to SQ of doing Class A poorly far greater than any hoped-for benefits - at least for some opamps that are already great performers when not in Class A?  
   
  What about the heat caused when running opamps in Class A - does this shorten their life - or even cause them to run out-of-spec in terms of SQ?
   
  More questions than answers.  I guess I'd have to learn how to design amps to really understand this stuff, so meanwhile, I suppose I should just put on a dunce cap and start rolling. 
	

	
	
		
		

		
		
	


	



   
  I'm anxious to be something other than clueless, but try searching Google for the word "buffer."  Now try adding some other keywords. 
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## zilch0md

Here's some recommended reading for those like me who are clueless, but curious, about op-amps:  http://www.bcae1.com/opamp.htm
   
  I still don't know what a buffer is good for (except that he says something about how they can help with sources that supply too little current.)
   
  Read the whole thing, but don't miss the section at the bottom of the page on how to interpret Data Sheets.
   
  Mike


----------



## Kremer930

Interesting page. Way over my head but interesting. 

Luckily I can rely on HiFlight to sieve through all of the guff and come up with some awesome kits. 

I do need to learn more about opamps and buffers though so that I can become more confident in rolling through the choices. The normal process for my D12 and now Pb2 is that I roll through all of the combos that I buy, plug in the best and then stick the rest in the box for a couple of months and forget what their strengths and weakness were and hence not roll any further. 

I have three of Ron's combos that I haven't even tried in balanced mode as I didn't have the right cables in the early days.


----------



## zilch0md

I really appreciate your input Kremer930.  I can see myself doing the same thing (not bothering to test combinations that are in my possession.)
   
  In fact, I'm so "biased" toward the OPA1612s (because of my experience with the Meier Stepdance use of OPA1611s and how great that sounds to me with my LCD-2), that I'm really having to fight the urge to just drop Ron's Topkit 1612 duals into the PB2 along with his HA5002 buffers, then close it up and forget about rolling anything else!  
	

	
	
		
		

		
		
	


	




   I can tell you that this is what I plan to do about a week after listening to the stock configuration with the balanced cables for which I'm still waiting. I may not leave the 1612s in there for more than a couple of weeks without rolling something, but just as I'm trying to get really familiar with the sound of the stock PB2, single-ended into my LCD-2 with stock Audez'e cables, I want to change only the cables when I get my balanced Silver Poisons from Toxic Cables (they were shipped from the UK, yesterday).  That way, I'll have had about two weeks with the stock PB2, single-ended before going to the stock PB2, balanced.  
   
  Meanwhile, I'm trying to take a scholarly approach (yeah, right!) by at least getting to the bottom of what the datasheets say for all the op-amps in my tiny collection.  I trust specs.  And if the specs say that THD is such and such at 1Khz (and other criteria), but something significantly worse for a different op-amp, I want to know about it.  (But that article I linked is over my head, too!  So much for the "scholarly approach! )
   
  Maybe I should just trust my ears more than I'm willing. 
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## zilch0md

I'm really not trying to turn this thread into my personal blog...  but now...  some pictures...
   
   
	

	
	
		
		

		
		
	


	



   
 
*Super-Size me!*


----------



## SpudHarris

I didn't listen much to the stock opamps/buffers when I got the PB-2, don't know why?? Probably because I knew I had all these great chips to try and never had much time for OPA604's in the past. I dropped the stock set up back it this evening for fun and it is apparent that ibasso did a great job of selecting the default/stock chipset. Really well suited to my balanced ES5's and I'm going to leave as is for a while, man this is a great amp!


----------



## zilch0md

Nigel,
   
  I'm glad to hear you like the "stock" sound. I'm increasingly disappointed in my PB2, using the stock op-amps and buffers, but I know it's likely due to the fact that I'm still using it single-ended AND/OR that it hasn't had but a week of burn-in.
   
  Still, for the record, with insufficient burn-in and singled-ended, having done a lot of A-Bing with the Stepdance, even running both amps with the same 15V supply voltage, same source (Sony PCM-10 Line-Out), and the LCD-2 with stock Audez'e cables... 
   
  ...  I'm hearing a significant glare with the PB2 - a harshness that's really quite fatiguing.  When I go back to the Stepdance, it's so sweet in comparison that I feel like I can actually enjoy the music instead of fighting to hear it.  
   
  But, I know these impressions are very premature.  More burn-in, balanced cables, etc. and I might yet find the stock op-amps and buffers to be very pleasing - just as you do.
   
  Mike


----------



## Kremer930

I rolled through just about all of the opamp and buffer combinations that I have last night and arrived right back at where I started. I didn't take notes but there is at least one combination of non stock opamps that is very bright but has a very wide soundstage. In the end Ron's recommended combo wins out as it has bass texture and fullness that just about makes me want to go and play a bass guitar or drums. 

One thing that I am findin though is that on some tracks that I may be experiencing some breakup of sound. I don't know if it is the iPod, class or pb2. I don't think that it should be the DT1350 as they are meant to be able to go very loud and whilst I am playing at near live volumes I am not totally negligent to the potential damage to hearing. 

I should try the am plugged in or fully charged and see if this makes a difference.

If all goes well a friend may be bringing over his Dx100 and sennheiser HD25's tonight so that we can compar rigs. I will also dig out my Vmoda M80 for a play too.


----------



## zilch0md

Quote: 





kremer930 said:


> [snip]





> In the end Ron's recommended combo wins out as it has bass texture and fullness that just about makes me want to go and play a bass guitar or drums.





> [snip]


 
   
  You're having too much fun!  OK...  maybe just enough fun!  
	

	
	
		
		

		
		
	


	



   
  Do tell:  What is "Ron's recommended combo" (that's working so nicely with your DT1350)?
   
  Thanks,
   
  Mike


----------



## SpudHarris

I think the last topkit Ron came up with was OPA1612 (Class A Adapter) + HA5002 Buffers closely followed by LT1678 in L/R.
   
  I listened to stock opamps last night with balanced D7000's but ended up stacking buffers which gave the sound a fuller presence. Still OPA604 is a nice chip that I really haven't given much time to. I agree though there is a certain annoying glare after a while.


----------



## Kremer930

I thInk that sounds familiar. They are a great combo. 

With this combination of chips the amp takes on a real fun and energetic sound quality. Even lower quality music takes on a whole new appeal. Sound stage is also right up there. It almost sounds like a three speaker setup.


----------



## zilch0md

Nigel,
   
  Quote: 





spudharris said:


> I think the last topkit Ron came up with was OPA1612 (Class A Adapter) + HA5002 Buffers closely followed by LT1678 in L/R.
> 
> I listened to stock opamps last night with balanced D7000's but ended up stacking buffers which gave the sound a fuller presence. Still OPA604 is a nice chip that I really haven't given much time to. I agree though there is a certain annoying glare after a while.


 
   
  That's the setup I'm dying to try with balanced cables (when they arrive) - OPA1612 with HA5002 buffers, but I'm especially curious to A-B the difference in SQ with and without the Class A adapters.  
   
  Also:  Given that I don't entirely trust my ability to describe what I hear, I'm pleased to see that you, too, can hear an "annoying glare" with the PB2's stock OPA604 setup.  I'm leaving those in however, until I get the balanced cables, because I want to see the difference that the cables alone make vs. single-ended.
   
  Soon...
   
  Mike


----------



## zilch0md

Quote: 





kremer930 said:


> I thInk that sounds familiar. They are a great combo.
> With this combination of chips the amp takes on a real fun and energetic sound quality. Even lower quality music takes on a whole new appeal. Sound stage is also right up there. It almost sounds like a three speaker setup.


 
   
  Joy!!
   
  I can't wait!  (But I must...)


----------



## zilch0md

But waiting for my Silver Poison balanced cables doesn't stop me from taking more pictures.  
	

	
	
		
		

		
		
	


	



  
 I got the XPAL Willy Cable WI16 in the mail today!  Joy!
  
 I hooked it up to the Energizer XP8000 and measured its output (a steady 16.08 VDC) and then used it to successfully recharge the PB2's internal battery (without the AC adatper)! 
  
 I then used it to operate the PB2 - inky black!  No power supply noise - just like my experience with the WI15 cable (15V) when using the XP8000 with my Meier Stepdance.
  
 This rig allows me to operate the PB2 at its maximum permissible input voltage (16.0V), regulated, while portable (transportable.)  And the 16.0V is constant - it doesn't decay during use the way the PB2's internal battery does when it starts out at 12.6V, fully charged, but falls to 9.0V during use, at which point it has to be recharged.  
  
 When using the PB2's internal 12.6V battery, the output voltage swing p-p can't possibly be any better than 12.6V (single-ended) or 25.2V (balanced), and can actually fall to something no better than 9.0V (single-ended) or 18.0V (balanced) by the time the internal battery is ready for recharging.  
  
 The XP8000 + Willy Cable WI16 keeps the PB2 running at 16.0V constantly, as the 5-cell lithium ion pack in the XP8000 discharges from 21.0V (fully charged) to 16.0V, through use, at which point the XP8000 will have to be recharged.  Depending on the op-amps in use within the PB2 and whether they are a rail-to-rail design (where output voltage equals or nearly equals supply voltage), the output swing p-p can be as high as 32V, balanced (per the iBasso spec), while operating portable with the XP8000, and again, it maintains a constant 32V swing p-p even while the XP8000 battery is discharging from its fully charged 21.0 Volts down to 16.0 Volts, thanks to the constant 16V supply coming from the WI16 inline voltage regulator cable.   Joy!
  

  
*My PB2's AC adapter is supposed to be outputting 16.0V, not 16.38V.  *
  

  
*The XPAL WI16 measures 16.08, but it's regulated and steady.*
  

  
*Keep the switch set to 16V for the PB2!   **The switch is fairly stiff, but I wrapped clear packing tape around that end of the barrel to make sure the switch doesn't get changed. *
  

  
*The Energizer XP8000 can deliver 2000 milliamps from its 21V port, so it can easily deliver more than twice the current available from the PB2 AC adapter.  It recharged the internal battery, no problem.*
  

  
 Best of all, unlike the folks who have struggled to come up with the adapters needed to connect an XP8000 to the Meier Stepdance, for PB2 users it's a piece of cake!   The connector on the end of either the WI15 or the WI16 is the perfect size to plug right into the back of a PB2.   No adapters or soldering required!
  
 More Joy!  
	

	
	
		
		

		
		
	


	



  
 Mike
  
  
*UPDATE:  Several people have PM'd me asking how to obtain the WI16 cable.*
  
*You have to go the XPAL Tip Finder site and pretend you are searching for a tip to use with a Panasonic Toughbook CF-270, for example (which is only one of several laptops that require the WI16 cable for use with either the XP8000 or the XP18000).*
  
 http://tipfinder.xpalpower.com/02tip.php?rp=&cno=&did=3&device=Laptop&bid=50&brand=Panasonic&mid=5837&model=Toughbook+CF-270&pid=2&power=XP18000
  
 Then place an order from that page - for just the WI16 Cable, not the adapter shown there.  You won't need the adapter, as the WI16 cable can be plugged directly into the power jack at the rear of the iBasso PB2.
  
 Make sure you select the 16V power setting on the WI16 (because it is also capable of selecting 19V, which is too high a voltage for the iBasso PB2).


----------



## SpudHarris

Quote: 





zilch0md said:


> Nigel,
> 
> 
> That's the setup I'm dying to try with balanced cables (when they arrive) - OPA1612 with HA5002 buffers, but I'm especially curious to A-B the difference in SQ with and without the Class A adapters.


 
   
  The differences between with/without class A adapters are subtle, differences none the less especially for those of us in the Bat Ear Faction LOL.
   
  I have to say recently I have found better results with bypassing. Doesn't work well for everything but something like the OPA827 is transformed with a simple 100nf Tantalum Cap aross + & - pins. I really shouldn't give more fuel to the fire, it's gonna be bad enough for you when you start rolling. What the heck !


----------



## zilch0md

Nigel,
   
  I appreciate your candid comments regarding Class A - I have had my suspicions about its value when used with an op-amp that's already so good, apparently.
   
  But please don't worry about adding fuel to the fire!  I want you to be a fire-breathing dragon!  I really need encouragement to start rolling anything other than the OPA1612.
   
  At this stage of my experience (having not rolled anything), I'm actually reluctant to start popping things in and out, other than to go straight to the OPA1612 / HA5002 (with and without Class A adapters).  Before I even ordered Ron's Topkit, I had read too many positive comments about this combination in the PB2 to have much interest in any of the other combinations. And now, I'm even more convinced, with the very recent comments from you and Kremer930.
   
  Add to all this my having come into the game as a huge fan boy for the Meier Stepdance (OPA1611-equipped), with you telling me that you immigrated from Steplandia yourself, and you might see why I'm all knotted up like a tensed mountain lion in a tree, waiting to pounce on the 1612/HA5002-with-balanced-output that I see coming up the trail ahead of me!  I want to hear this combination in the PB2, balanced - real bad!  (Quivering while drooling...)
   
  And then, if the the unthinkable happens - if the 16V-powered PB2 is not "better" than the 15V Stepdance (with my source, my cables, my phones, my ears, my tastes), there's gonna be a whole lot of rolling going on to see if I can get the PB2 on top - otherwise, I'll be selling a lot of stuff, saving up my pennies and moving on to trial something else a few months from now.  I have had too many countless hours of tremendous listening pleasure with my 15V Stepdance to take a step backward.  
   
  But if the 16V PB2 with 1612/HA5002 balanced blows my 15V Stepdance out of the water, my inner mountain lion is going to be sprawled out in the grass, belly up, basking in the sun on a full stomach!  I will want to leave everything just as it is (no more rolling) for at least a few weeks, to really savor the flavor. 
   
  As I wrote earlier, the single-ended PB2 with stock components has already lost its first battle with the Stepdance.  Ron's Topkit + balanced cables are the PB2's only hope for this customer (my source, my cables, my phones, my ears, my tastes). 
   
  Thanks for all of your enthusiasm and encouragement, Nigel.  
   
  Mike


----------



## jamato8

The HA5002 are very nice and my preference.


----------



## Kremer930

This sounds pretty interesting. I can remember chatting to Zilch' quite some time ago about the virtues of the Stepdance running via 15v power. I will be looking to see how the pb2 compares. I will then be looking to see where he goes after Ron's topkit because anything that tempts him away from that has got to be worth a try in my opinion. 

I wish one of my mates has a RSA71/b to put it up against. 

I will soon get to compare against the DX100 and the alo rx3. Let's see how the value amp goes.


----------



## zilch0md

Quote: 





jamato8 said:


> The HA5002 are very nice and my preference.


 
   
  Thanks for that, jamato8 - this seems to be the consensus, and it really saves me some time in thinking about (or not thinking about) other buffers!
   
  I had thought about running with the dummy buffers, due to Mike (?) of Headphonia writing this text in his review of the PB2:
   
  Quoting the Headphonia article: 





> If you want a more transparent sound and better texture on the bass areas, take out the buffer section and go with a dummy buffer.
> 
> 
> No buffer – Limited current, but still good for HD650, sound is cleaner and more transparent to the actual signature of the op-amp.


 
   
   
  But then I got this response from Mad Max to my having asked the question:  *How much loss of power would you guess is suffered (by using dummy buffers) for the sake of an increase in transparency?*
   
   
   
  Quoting Mad Max's post in The Opamp Thread: 





> The drop is big, most opamps pump out 20-50ma of current while BUF634 pumps out 250ma.  That's 250ma in addition to OPA604 (35ma).


 
   
  So, if the HA5002 are anything like the BUF634 in terms of current output, it seems I would sacrifice a huge loss of current to operate the PB2 without buffers (using the dummy buffers), even though Mike (Headphonia) wrote that the PB2 was still able to drive the HD650 using the dummy buffers.
   
  I've heard from several sources, however, that the LCD-2 wants current more than voltage (both of which produce volt-amps or Watts, ultimately.)   
   
  So, I've now got a total of four combinations I simply must try in the PB2 (with balanced output), ahead of the many other possibilities:
   
  OPA1612 + Class A adapters + HA5002 buffers
  OPA1612 + Class A adapters + dummy buffers
  OPA1612 - Class A adapters + HA5002 buffers
  OPA1612 - Class A adapters + dummy buffers 
   
  I would not be surprised to find that the last combination offers the most transparent (most Stepdance-like) sound quality of the four combinations, but I'm going to be paying extra attention for any loss of dynamics or bass control when operating with the dummy adapters.  There will be an automatic doubling of output swing voltage enjoyed just by going from single-ended to balanced (vs. the Stepdance), so it could be that I will find the very cleanest sound can be had with the reduced current output of using the dummy buffers, while still enjoying a large 
   
  If I can't hear a difference between using HA5002 buffers and using dummy buffers, I'll definitely go with using the HA5002, just on the knowledge that they give me more output current.  
   
  On a somewhat contrary note, if I can't hear a difference between using the Class A adapters and not using them, I'll go without using them, just on the knowledge that they may shorten the life of the 1612 (thanks to the heat associated with Class A.)  But if I can hear an improvement in SQ, I'll definitely run the 1612's in Class A, without concern for longevity - I'll just replace them like burned out light bulbs, if necessary!
   
  Mike


----------



## zilch0md

Quote: 





kremer930 said:


> This sounds pretty interesting. I can remember chatting to Zilch' quite some time ago about the virtues of the Stepdance running via 15v power. I will be looking to see how the pb2 compares. I will then be looking to see where he goes after Ron's topkit because anything that tempts him away from that has got to be worth a try in my opinion.
> 
> 
> 
> ...


 
   
  Thank you Kremer930 - I appreciate your encouragement!
   
  On the subject of SR-71B vs. PB2, I researched this to death before ordering the PB2 three weeks ago, and I did find a couple of posts in various threads made by people who own both amps.  Their feedback seems to match, in that they speak of the SR-71B vs. PB2 with phrases like  "warmer mids", "darker highs,"  "has the RSA house sound," "colored," "more musical,"extended, more controlled bass," etc.  All of which turns me off (admittedly, without having actually heard the SR-71B), with the exception of "extended, more controlled bass."  Thus, I ordered the PB2 (not to mention the price difference.)
   
  Mike


----------



## SpudHarris

Quote: 





jamato8 said:


> The HA5002 are very nice and my preference.


 
   
  Mine also in the PB-2 no contest but I prefer stacked Buf634AU in the Fi-Q  strangely.....
   
  I have a few favourite OpAmps for L/R though and the last couple of days I've been loving OPA1641 again. I believe they are from the same family as the OPA1611/12 but more reliant on a higher voltages. Using a mascot linear regulated 16v adapter seems to be doing the trick!


----------



## Kremer930

Hi Zilch'. I read a lot of reviews about the Pb2 and and 71/b also and agre that the dark RSA house sound seemed to be the majority comment. In the end it was price that made the choice for me. Funny enough, I purchased an Alo Rx2 so that it would match the size and shape of the CLAS rather than stretch the extra to the RSA. 

It was only later when I was browsing the for sale columns and found a second hand Pb2. A new battery later and some of Ron's magic and my Rx2 stopped getting and air time. Then I finally got my balanced cables. It was definitely game over by that stage and my Rx2 got sold to a friend.

The sense of space from the balanced amp seems to be my favorite part of the Pb2. Neither my RA1, iBasso D12, Rx2 had the same sense of wrap around sound that my current Pb2 combo has. 

If only high quality rewires weren't so expensive. Luckily I have already been through quite a few headphones. I would hate to have to pay to have each pair of cans rewired first as I experiment and see which were keepers.

In my last rewired I had my cables terminated in Hirose for both my DT1350 and JH16. I also now have three short adapters thango from Hirose to Rsa balanced, stereo mini and Xlr4. Will make doing amp comparisons nice and easy.


----------



## zilch0md

Kremer930,
   
  One thing's for sure - you guys are very happy with your PB2 rigs - and that's really building my anticipation for going balanced with the PB2 shortly.
   
  I checked your profile because of the cables I see with your DT1350, but I can't find any info saying who made them.  
   
  Was the re-wire done by Frank (Toxic Cables)?  They look like they might be his Silver Poison cables - same as I have ordered for the LCD-2:
   

   
  (I tweaked your photo a bit (opened up the shadow, removed color cast, removed wood stains, etc.)
   
  It sounds like you've got yourself setup pretty well for cables!
   
  Mike


----------



## zilch0md

Quote: 





spudharris said:


> Mine also in the PB-2 no contest but I prefer stacked Buf634AU in the Fi-Q  strangely.....
> 
> I have a few favourite OpAmps for L/R though and the last couple of days I've been loving OPA1641 again. I believe they are from the same family as the OPA1611/12 but more reliant on a higher voltages. Using a mascot linear regulated 16v adapter seems to be doing the trick!


 
   
  I'm putting my hands over my ears!  I don't want to hear you say that you're exploring something other than the 1612s.


----------



## zilch0md

The *Silver Poison* (by Toxic Cables) arrived from London, today.  Awesome sound!  And Frank Donghi's craftsmanship is spectacular.  These cables look like a silver necklace - I'm all about the sound, but man, these things are beautiful to look at. And they are incredibly soft, flexible, and lightweight, and suffer no microphonics.  I LOVE these cables!  Best of all, because they have made the iBasso PB2 sing!  
   
  Admittedly, I'm hearing balanced for the first time, but the PB2, now equipped with these UPOCC (Ultra Pure Ohno Continuous Casting) 99.99998% pure silver cables is, in my experience, the second biggest jump in sound quality I've ever experienced (after the shock of getting the Audeze LCD-2).  I am stunned at what I've been missing!  Going from the Stepdance single-ended to the PB2 single-ended was actually a step-backwards (as mentioned earlier in this thread - at least with the stock opamps and buffers.  But adding these superlative cables and going balanced has already put the PB2 on top.  
   
  Bye-bye Stepance!  I'm gonna miss you!  
	

	
	
		
		

		
		
	


	



   
  How can the SQ keep getting better and better?  Where does it all end?  This is scary!  And I'm still using the stock op-amps and buffers.  I haven't even heard the OPA1612s in Class A with HA5002 yet!
   
  More later, it's very late, but i'll be sleeping with a smile on my face.
   
  Mike


----------



## Kremer930

zilch0md said:


> Kremer930,
> 
> One thing's for sure - you guys are very happy with your PB2 rigs - and that's really building my anticipation for going balanced with the PB2 shortly.
> 
> ...




Mike

The rewire was done by Qusp. It was a full rewire too including all of the internal wires to the drivers. All of this was primarily driven by my purchase of the Pb2. 

I agree with your comments too that the Pb2 certainly picks it up a gear when running balanced.


----------



## zilch0md

I've finally rolled something other than the stock combo into my PB2!  
   
  (WAV > Sony PCM-M10 > iBasso PB2 (with 16-Volt XP8000 battery) > balanced Toxic Cables Silver Poison > Audeze LCD-2)
   
  ---------
   
*I started out by replacing iBasso's stock configuration with OPA1612s + Class A adapters + HA5002 buffers* (all from Ron's Topkit).  
   
  This made a huge improvement across several factors, but best of all, it killed the harsh glare I was getting with the stock combo.  Given that I was in a hurry this evening to try several things, I'm going to refrain from giving any concise impressions until I revisit these combos later.
   
  ---------
   
*I then removed the Class A adapters* and, after re-playing several tracks, I couldn't say for sure that I can hear a difference (believe it or not), so I've left the Class A adapters out, for now.  (I'm very keen on re-testing these, however.)
   
  --------- 
   
*Then I replaced the HA5002 buffers with iBasso's dummy buffers.*
   
  Bingo!  
   
  Da's what I'm talkin' 'bout!  An Uber-Stepdance!  
   
  A beautiful sound (at least for my tastes, anyway.)
   
  I should have mentioned, above, that I had been slightly bewildered with the OPA1612s sounding very slightly veiled (or at least smooth) - definitely not as detailed as the stock combo (which, unfortunately, has a fatiguing glare).  
   
  But now, the veil is lifted - a cornucopia of detail has been revealed, with not quite the neutrality of the Stepdance, but slightly more detail and clarity, plus all that accompanies having more power and a balanced output - improved dynamics, faster/tighter/more extended bass, better separation of voices, etc...   Me like!
   
  Again, please consider these impressions to be premature, as these op-amps have very little burn-in at this point, and for that matter, neither does the PB2 chassis itself, or the Silver Poison cables. 
   
  I've only spent about six hours comparing this combo to the Stepdance (on 15-Volt XP8000), but I'm thinking the PB2 wins, readily!  If anything, this combo in the PB2 is a little more analytical, but not in a way that I would describe as unpleasing - more like unforgiving of bad recordings.  If you prefer a smoother sound, this might not be your cup of tea - use the HA5002 buffers to smooth things over (and, I believe, increase the power output relative to what's had with the dummy buffers.)
   
   

   
     *PB2 with OPA1612s and Dummy Buffers*  (Medium Gain)
   
  As we say in Texas...    Yeeehaw!     
	

	
	
		
		

		
		
	


	



   
  I'm not done rolling, but I'm going to leave this combo alone for a good while.  
   
  Here's a case I came up with for the spare op-amps and buffers:
   

                AlumaWallet  (with foam from the PB2 box)
   

  And now, at roughly 5:15 AM Saturday morning, with dawn fast approaching, it's time for bed!
   
  Mike


----------



## SpudHarris

I'm afraid that you will soon need a bigger box. You my friend have probably just taken your first step onto a very slippery slope hehe


----------



## Kremer930

You have me inspired. I might have a play with that combo too...tomorrow.


----------



## zilch0md

Quote: 





spudharris said:


> I'm afraid that you will soon need a bigger box. You my friend have probably just taken your first step onto a very slippery slope hehe


 
   
*Master,  I am your liege!*
   
  Seriously Nigel, you are sick!   Is there a doctor in the house?   
	

	
	
		
		

		
		
	


	



   
  I'm as envious of your possession of so many op-amps, as I am of your having experienced all their unique sounds!
   
  I don't know whether to follow in your footsteps or take my wee little box down to the lake shore and toss it as far as I can!
   




   
  I remember a few days back, you wrote that you had not considered using the dummy adapters until I mentioned the article by Mike (Headphonia), where he recommended them.  Have you since tried any combos with dummy adapters?  I ask this with respect for all the testing you've obviously done.  
   
  In other words, I want to achieve nirvana without working for it!   
	

	
	
		
		

		
		
	


	




  
   
  Mike


----------



## zilch0md

Quote: 





kremer930 said:


> You have me inspired. I might have a play with that combo too...tomorrow.


 
   
  Oh, please do! I woke up this morning, doubting myself.  I would really appreciate it if somebody can articulate any faults heard while using the 1612s with dummy buffers (and no Class A adapters).   I'm going to listen to this combo for a few days, at least, to really get familiar with it, but my next combination (not tried yet) will be to put the 1612s back on the Class A adatpers, keeping the dummy buffers...
   
  The PB2 is a sojourn!  
   
  Mike


----------



## SpudHarris

Quote: 





zilch0md said:


> *Master,  I am your liege!*
> 
> Seriously Nigel, you are sick!   Is there a doctor in the house?
> 
> ...


 
   
  Haha, thanks Mike... These aren't all for the PB-2 though. I've been Rollin' a few years and at present the Fi-Quest, P4 and EF-5 are all serviced by these. I have to say though there is no such thing as the best OpAmp, I've got LT1122's in my P4 - AD8610's in the Fi-Quest and I'm testing the AD823 in the EF-5 (great OpAmp with a clean power supply). I have had the THS4032 x 2 + HA5002 in the PB-2 for a couple of days and I really like this combo.
   
  I'm still searching for the final chipset for the PB-2 and Fi-Quest. The LT1122's + HA5002 buffers has been in the P4 for a long time and I've yet to find a better chip for the EF-5 than the OPA602CM....
   
  Rollin' Rollin' Rollin' keep those OpAmps Rollin - Head-Fiiiiii !! Yeeehaa !!


----------



## zilch0md

Quote: 





spudharris said:


> I have had the THS4032 x 2 + HA5002 in the PB-2 for a couple of days and I really like this combo.


 
   
  I hear and I obey!   So much for using the OPA1612s with dummy buffers for a few days!   I'm just too curious!
   
  I started by the replacing the OPA1612s with the THS4032 - my first time hearing these.  I really liked the change!   (And I'm so confused!)
   
  Then I replaced the dummy buffers with the HA5002s and things got veiled again.
   
  I went back to the dummy buffers and, just as with the OPA1612s, things got cleaner sounding (more transparent) with the dummy buffers - this is for sure - at least with my source, etc. 
   
*I don't think I'm imagining this - the THS4032 seems to have slightly better dynamics than the OPA1612, but it's just a little smoother / less detail, and it's less neutral - slightly warm - but I like it!  This disturbs me because, intellectually, I don't want to mess with tonal accuracy, even though, emotionally, I'm finding myself attracted to the warmth / heaviness.  THS4032 with dummy buffers sounds a bit like my memory of a a Red Wine Audio iMod I borrowed for a couple of weeks last year.  I'm so conflicted!  Nigel - this is your fault!  You must be contagious!*
   
  There's another aspect of the THS4032 that's really working well with my setup.  My source (the Sony PCM-M10) has been described by those to whom I have lent it (MisterRogers and dj nellie) as being "bright."   I've always thought this has worked well with the LCD-2 rev.1 with stock single-ended cables, because the LCD-2 has the often-discussed "shelved" highs.  But now that I'm using Frank Donghi's Silver Poison (99% silver / 1% gold) UPOCC balanced cables with the PB2, things have sounded brighter than what I'm used to with the Stepdance and single-ended copper cables that came with the LCD-2.
   
  When things get burned-in better, and I've spent many more hours with these various combinations, I might find myself laughing at these premature impressions, but right now, the THS4032 with dummy buffers is sounding awesome!  At this moment, I'm listening to Gerald Albright - "Bobo's Groove" (from "Pushing the Envelope.")   Wonderful.  But will I leave well enough alone?  Unlikely!  
   
  Mike


----------



## SpudHarris

You are smitten!!
   
  I too find the THS4032 addictive. I find that it's a perfect combination between uber detaills and musicallity. In the PB-2 it might just be the Holy Grail, time will tell. I respect Ron's findings regarding ''Top Kits'' but the final call is down to personal preference. For example - Many class the LME49710HA as the be all, end all of OpAmps. Personally I found that the initial ''Hi-Fi sounding'' wow factor soon wore off and I found it metalic and uninspired.


----------



## zilch0md

It seems I'm already falling into the habit of swapping op-amps and buffers to suit various situations.  I was hoping I could settle down on a one-size-fits-all configuration for my PB2 but, like it or not, I'm toggling back and forth between two favorite setups, now:
   
  THS4032 (x2) with dummy buffers (x4)    vs.   OPA1612 (x2) with HA5002 (x4)
   
  The surprise here (to me, at least), is that I've decided I much prefer the OPA1612s with the HA5002s rather than with dummy buffers.  The HA5002s take the edge off the overly analytical quality of the OPA1612s as heard when they are running without buffers -  in combination with with my "bright" source (the Sony PCM-M10) and "bright" cables (Silver Poison) - even though the LCD-2 are known for having "shelved" (reduced) highs.  Note that I don't believe the Silver Poison (UPOCC) cables are overly bright in and of themselves, but they certainly sound brighter than the stock copper cables that came with the LCD-2.  
   
  To my ears, when I'm willing to take the shifter out of neutral, the color imparted by the THS4032 (with dummy buffers) is beautiful - especially with my Sony PCM-M10 source, which is definitely lacking in bass (and which has always left me wondering why everyone praises the bass of the LCD-2.)  Now, with the PB2 running THS4032 and dummy buffers, my LCD-2 are getting better bass extension than I've ever had when portable, and it's a fast bass - lots of detail and texture.
   
  Switching to a desktop source is where the PB2 has really shined, though!   Borrowing my friend's Centance DACport LX (the DACport without an amp), I've been playing my WAV files on an inexpensive Toshiba laptop, running Windows 7, with nothing more spectacular than good old Windows Media Player.  Now hear this:  I have borrowed this very DACport LX in the past, on about three different occasions, a few days at a stretch, but  I was always using it with the LCD-2 single-ended off the Meier Stepdance (albeit with a 15-Volt external XP8000 battery pack).   I had long ago realized that the DACport LX was a far superior source than my portable Sony PCM-M10, but I just can't stand the idea of replacing the easily portable PCM-M10 with a laptop for portable listening - no matter how small the laptop is.
   
  But tonight, the PB2, equipped with OPA1612s and HA5002s is showing off the Centrance DACport LX like nothing I've ever heard before.  I'm ready to take the batteries out of my PCM-M10 and retire it, but for the fact that I want to remain truly portable.  
   
  The synergy of the following combination is simply stunning (easily the best I've ever heard, personally - which isn't saying much because I'm pretty green, but still...):
   
*96/24 or 44.1/16 WAV or FLAC > Windows Media Player (I know...) > Centrance DACport LX > Milian Acoustics SPOFC interconnect > iBasso PB2 w/OPA1612 x2 + HA5002 x4, in Low Gain, powered by a regulated 16.0V Energizer XP8000 external lithium-ion battery pack > balanced Toxic Cables Silver Poison > LCD-2 rev.1*
   
  In the past, when using the DACport LX instead of the PCM-M10 with the Meier Stepdance, I could hear more detail, but now, with the PB2, equipped with OPA1612 + HA5002 and balanced output, the bass extension and control is huge relative to using the Stepdance with the DACport LX.  It's beautiful - it's what I've so often read other people say about the LCD-2, but I'm only just now hearing it.
   
*The PB2 rocks!  As does Ron Kerlin's Topkit!  Thanks for making it so easy Ron - for a newcomer like me to get his PB2 dialed in!*
   
  Now...  How can I go portable with the DACport LX? 
	

	
	
		
		

		
		
	


	



   
  I don't want to be stuck indoors, or even stuck to one location inside my home, tethered to a desktop rig, but I do want the sound I'm getting with the DACport LX + PB2 + LCD-2.
   
*Until further notice, I'll be using the THS4032 + dummy buffers with the PCM-M10, but OPA1612 + HA5002 with the DACport LX (while I'm borrowing it, at least...)*
   
  Mike


----------



## Kremer930

Looking forward to comparing the Pb2 to the new Alo Rx3. I know the iBasso is only half the price but it will be a great challenge either way to see if the iBasso can hold its own.


----------



## zilch0md

Quote: 





kremer930 said:


> Looking forward to comparing the Pb2 to the new Alo Rx3. I know the iBasso is only half the price but it will be a great challenge either way to see if the iBasso can hold its own.


 
   
  Cool!  I'd like to hear that the PB2 can indeed hold its own against a more expensive amp - I suspect it can, as there are a couple of people out there who own both the SR71B and the PB2, that say it can.
   
  I have spent hours and hours now going back and forth with the Stepdance vs. PB2.  Single-ended, Stepdance wins (no contest) vs. the PB2 with stock components, but again, while single-ended, the Stepdance is literally neck-and-neck with the PB2 when using the OPA1612s with HA5002s - I really can't tell them apart.  
   
  Go to balanced output with the PB2, though, and it's all over for the Stepdance.  See ya!   The PB2 steals the day with balanced output, using the OPA1612s with HA5002s or when using the THS4032 and dummy adapters - my two favorite combos for the PB2.  It's a huge, slap you in the face difference.  Given that the two amps cost about the same, the performance advantage of the PB2 comes basically at the cost of getting balanced cables for your headphones + the HiFlight Topkit, but I have no remorse for spending that money - it's a great bang for the buck. 
   
  I'm not familiar with the Alo Rx3.  Does it offer balanced output?  (Too lazy to look it up...)
   
  Mike


----------



## Kremer930

The rx3 is balanced too. Battery life is about 8-10 hours too. It also has a bass adjust function but it is hard to describe how it works as it can also affect treble. I am not an EQ fan but it is pretty interesting. I think that it will knock the Rsa 71/b or Lisa3 off the top spot.


----------



## SpudHarris

Yeah, been thinking about getting one of those to go with my CLAS but I'm a fan of being able to tweak the sound if the mood takes me. I loved the 2Stepdance when I first got it but soon tired of the lack of tweaking haha....


----------



## zilch0md

Heard that!


----------



## Uchiya

RX3 power ratings...a bit dissapointing, shocking for all that hype.


----------



## Kremer930

The Rx3 walks all over the Pb2 in my opinion with my cans. I love the Pb2 but .... The Rx3 is even better.


----------



## zilch0md

Quote: 





kremer930 said:


> The Rx3 walks all over the Pb2 in my opinion with my cans. I love the Pb2 but .... The Rx3 is even better.


 
   
  I can't imagine!  I'd love to hear this, but I'm still on my honeymoon with the PB2 and I want to remain faithful.  
	

	
	
		
		

		
		
	


	



   
  Still, as a relatively green Head-Fi hobbyist, I learned early on that better is always possible.  There's no end to this. So little money, so much time.  
	

	
	
		
		

		
		
	


	



   
  Speaking of things I can't afford, I was just reading a Six Moons review of the ALO Audio Rx-MK3-B, and asking myself,* "When will ALO start working on a balanced version of the Solo?"  My conjecture: Maybe never.*  I read that they have a couple of other projects already underway, and then I read this:
   
   Quoting Ken Ball, of ALO:
   


> "To obtain a balanced working signal, a non-inverting amplifier buffers the input signal. The output of that amplifier is inverted with a unity-gain amp. The balanced signal is then taken from the outputs of both amps which are contained within the same IC. *The worst-case mismatch between inverting and non-inverting outputs is 0.02dB. Going in single-ended is thus no worse than balanced.* The real advantage of the RxMk3-b is its fully balanced amplification circuit and ability to drive all headphones in balanced mode."


 
   
*So much for inserting an iBasso DB2 between the CLAS and a balanced amp.  And so much for hoping that ALO will build a balanced version of the CLAS.  *
   
  Then again, could Ken Ball's statement only apply when using the Rx-Mk3-B?
   
   Quoting one of googleli's posts on the CLAS thread:
   


> After testing, I conclude that I prefer the sound of SINGLE ENDED INPUT on the SR71B, directly from the CLAS, over the CLAS->DB2->Balanced input on SR71B.


 
   
  ----------------------------------------------------------------------------
  Edit:  
   
   googleli changed his mind three days later:
   


> Things have changed since I burnt in the cables and the DB2 for more than a week now. Now I prefer the balanced combo more.


 
   
  Given the Ken Ball quote, above, I'm wondering if googleli might be enjoying changes introduced by the DB2 that have nothing to do with driving the SR71B with balanced input vs. single-ended.
   
  ----------------------------------------------------------------------------
   
  I've been using the excuse that a balanced version of the CLAS may come along any day now - to avoid coming up with the money for a CLAS (and an iPod Classic, and cables).  Now, I'm convinced there's no need to wait for a balanced output CLAS - nor is there any need to consider buying a balanced USB DAC (like the HRT Music Streamer Pro) for balanced input to my PB2.  Single-ended input to the amp seems to be the way to go (saving money with no loss of quality.)  
   
  Is going fully balanced a waste?
   
  Mike


----------



## Uchiya

Quote: 





kremer930 said:


> The Rx3 walks all over the Pb2 in my opinion with my cans. I love the Pb2 but .... The Rx3 is even better.


 
  Direct A/B comparison?  How did you compare them?


----------



## Kremer930

I haven't plugged the Pb2 back in again since getting the Rx3 but bass quantity and spaciousness is significantly improved. 

I will do a proper test soon once my week calms down just in case I am caught up in the moment and also to more accurately compare the two. The Pb2 is still a ripper amp though either way.


----------



## Uchiya

Sounds good.


----------



## zilch0md

Quoting my earlier post: 





zilch0md said:


> [snip]
> 
> *Until further notice, I'll be using the THS4032 + dummy buffers with the PCM-M10, but OPA1612 + HA5002 with the DACport LX (while I'm borrowing it, at least...)*
> 
> Mike


 
   
  Well, I no longer have the use of my friend's Centrance DACport LX, so I'm back to using the Sony PCM-M10, exclusively.  As seems to be the case with some of the more experienced PB2 owners, I'm finding myself unable to leave any particular combination of op-amps and buffers mounted in service for more than a week. I have, however, ruled out the use of several combinations, somewhat permanently.  
   
  Lately, I've been using the THS4032 (x2) with HA5002 (x4) instead of the dummy buffers, in combination with the PCM-M10, Silver Poision cables, and LCD-2 rev.1.
   
  I'm currently liking this combination a lot.
   
  My daughter was visiting for the weekend and I managed to coerce her into participating in a blind A/B comparison of the PB2, powered with an external 16VDC battery pack (XP8000 + WI16 cable), vs. the Meier Stepdance (also powered with maximum permissible supply voltage of 15VDC.)  
   
  Both were sourced with 44.1/16 WAV files from the Sony PCM-M10 with single-ended outputs going to the Audeze LCD-2 rev.1 with stock ADZ-5 cables.
   
  I selected sections of two different songs, using a lapel microphone-equipped Touch and a free SPL metering app by JL Audio, to match the volume controls such that the loops I was playing had peaks at 80 dB from both amps, as measured with the lapel mic trapped between the ear pads when the LCD-2 was resting on the table, prior to testing.
   
  The goal of the experiment was to simply see if my 24-year-old daughter could consistently detect any difference between the two amps.
   
  Here are the results (which was as much as I could accomplish in the time she had to offer):
   

   
  My daughter kept her eyes closed throughout and after listening to a loop play 2 or 3 times, she would decide whether she was listening to the same amp as she had last heard, or the other amp (a different amp).
   
  I had shown her that there were only two amps and she could hear the coin toss that I would do right before switching amps, but I wouldn't tell her the results of the coin toss, obviously.  I had also told her that I would always disconnect and reconnect the cables, whether connecting them to a different amp or back to the amp that she had just heard, so she could not draw any conclusions from the sounds I made when relocating (or not relocating) the input and output cables.  
   
  We did more tests with the second track than the first, only because I wanted to keep going until the coin tossing had produced the same number of Stepdance auditions as PB2 auditions - the purpose of the coin toss being to randomize the sequence, but when it was all said and done, I wanted both amps to have been heard the same number of times.
   
  As you can see, with an admittedly small number of comparisons (a total of 18), she managed to be accurate 66.7% of the time, having decided early on that one of the amps had a "fuller" sound vs. the other's "flat" sound - whatever that means to her.  (She's not familiar with the vocabulary seen here at Head-Fi.)   But if you examine some of the comments she made while deciding if she was listening to the same amp or a different amp as the last one heard, you can see that on occasion, she correctly GUESSED whether it was the same or different amp from what she had just heard, despite having made comments to the contrary!   So, I could argue that her overall score should be lower than what I've tabulated, above.
   
  In any case, whether we score her solely on her ability to correctly select Same or Different, or also look for accuracy in the comments she made as well, she scored less than or equal to 2 out of 3, at best, across 18 comparisons, which is NOT statistically significant, if you're trying to say that she did well at detecting a difference between the two amps.  
   
  This is somewhat subjective, but personally, I'd want to see something like 95% confidence before I'd be willing to say that a subject can consistently tell the difference between these two amps.  66.7% might as well be 50%, in my book - both scores would show no significant discernment.  In other words, she couldn't tell the difference.
   
  For the record, my daughter isn't an "audiophile" and has not sung professionally, but she has been in choirs nearly her entire life, since grade school through university, and has a great ear, not to mention a beautiful voice.  She is immersed in music.
   
  I'm particularly tickled by the results, given that I had decided without blind tests, that I could not tell the difference between the 15V Stepdance and the 16V PB2, single-ended (when equipped with THS4032 and HA5002, as described above.)    You may recall, that when doing "sighted" comparisons of the Stepdance to the PB2 equipped with the default op-amps and buffers, Stepdance was clearly outperforming the PB2, single-ended, at least to my ears.  But it seems the THS4032 + HA5002 combo. had with Ron's Topkit, makes the single-ended PB2 "indistinguishable" from the Stepdance.  (This surprises me given that my initial expectation was that the OPA1612s would bring the PB2 closer to the sound of the Stepdance, with either single-ended or balanced output, but subjectively, this hasn't been the case, at least not when using the PCM-M10 source and LCD-2s.)
   
  I wish I had more time and more people with which to conduct a lot more blind testing. The next series in which I'm interested would be balanced vs. single-ended testing of the PB2. I'm convinced I can hear a big difference, even when the volume levels are matched, but I'd much prefer to find out what blind testing would reveal.
   
  Mike


----------



## zilch0md

Quote: 





kremer930 said:


> I haven't plugged the Pb2 back in again since getting the Rx3 but bass quantity and spaciousness is significantly improved.
> I will do a proper test soon once my week calms down just in case I am caught up in the moment and also to more accurately compare the two. The Pb2 is still a ripper amp though either way.


 
   
  Any news yet?


----------



## Kremer930

Saw your post so thought that I should do a side by side comparison now that both amps are now fully burnt in. 

The fist song up was by the Decemberists and it straight away told me that I needed to take the comparison seriously as the iBasso may have sounded better. 

With this in mind I thought that I better go to a track that I know well and that is well recorded. For this I have chosen one of my favorites, Walk it Off by Angus and Julia Stone. This song has a great range of details from plucking of acoustic guitar strings to awesome female vocals to a punchy kick drum. 

The first qualities that are quickly noticeable are the slightly forward mids of the PB2 as well as great speed on percussion. It has a very clean and fast signature to it. When changing back to the RX3 I notice a slightly heavier bass focus. This is not only in bass guitars and kick drums but also in the depth and thickness of Julia's voice. Julia still retains the slightly nasal tone but you get the feeling of her being more real and less cleansed as she may be in a studio. 

Sound stage is slightly in favor of the RX3 but not an aweful lot in it. I had to check every now and then to check which amp I was using when trying to determine instrument placement etc. 

Wow this is a tough match. 

I think that my preference is going to go to the Rx3 because it has more detail all round. It is not immediately apparent as the slight mid forward of the iBasso innitially make this sound more detailed but once you get used to the increased bass quantity of the Rx3 you do realize that there is not only more bass but more detail across the whole spectrum. 

Considering the cost difference of the two though....the iBasso would win with its clean snappy sound. 

For those that are chasing the ultimate portable though...this round goes to the Alo Rx3.


----------



## zilch0md

Wow!   I'm impressed with how well the PB2 faired against the ALO machine.  I sometimes feel as if I can hear just a wee bit more detail in the Stepdance than I'm hearing with the iBasso PB2, but it's very slight.  Perhaps if I were using LCD-3 instead of LCD-2, a distinction in detail would be more apparent.
   
  I'm curious...  Which of your several sources and headphones were you using for this comparison, and which op-amps/buffers were you using in the PB2?
   
  Thanks!
   
  Mike


----------



## Kremer930

Sorry I forgot to write it on this thread. The iBasso pb2 was running Ron's (HiFlight) opamp kit. The iems used were JH16 with TwAg v2. Both using lossless tacks from iPod 7g classic to CLAS. 

I have just changed back to my usual Piccolino interconnect made by Qusp and I think that it adds slightly more clarity to the Rx3 rig again and would close the gap again with respect to the slight mid focus and speed of attack on percussions. 

But my test was done using a Fiio interconnect so that both amps were evenly judged. 

I am really impressed with how good the iBasso sounded. It has been at least a few weeks since it was used with the exception of a short head meet with another Perth headfier. I wanted to show him how great it is for the cost. He was impressed. No mean feat when his usual rig is the DX100.


----------



## zilch0md

Can you tell me precisely which op-amps and buffers you are using from Ron's Topkit?    
	

	
	
		
		

		
		
	


	




  
   
  Thanks!


----------



## Kremer930

I can't remember what they were called.


----------



## zilch0md

Quote: 





kremer930 said:


> I can't remember what they were called.


 
   
   
  No problem.  I love your honesty, though!   (A rare trait.)


----------



## Mazer

Hi guys, as this seems to be the most current DB-2 related thread I have a power supply question.
   
  In this thread iVinyl said
   
  Quote: 





ivinyl said:


> iBasso confirmed that the charge rate through the USB cannot keep up with the operating current and that the battery slowly depletes.


 
   
  I was looking to use the DB-2/PB-2 combo at times as a desktop from a PC USB and it does not look like this can be left like this for any great length of time.
   
  Could someone confirm the following?
   

 Can the DB-2 be run off the USB power continously while using the USB input for audio (I guess this is no according to the above)?
 Can issue 1 be solved with a Y-connector perhaps?
 Would additional current through the USB line while using it as the audio source line affect signal adversely? (Say at 24bit/96kHz rates)
 Can the DB-2 be run off the USB power continously while using either the toslink or S/PDIF?
 Has anyone hacked up alternative power supply's for the DB-2?
   
  I actually e-mailed iBasso these questions a couple of weeks back but unfortunatly had no reply.
   
  Thanks guys!


----------



## zilch0md

Hi Mazer,
   
  Quote: 





> Originally Posted by *Mazer* /img/forum/go_quote.gif
> 
> [snip]
> 
> ...


 
   
  First, let me suggest that you send iBasso an e-mail a day until they respond.  I have always enjoyed quick responses from iBasso, so I think maybe somebody just "lost" your e-mail before answering it.
   
  Next, I should say that I don't own a DB2, but I do own a PB2 and have a very strong hunch that if you're able to use either a toslink or coaxial connection for data (instead of using the USB port), connecting the external 5V power supply (that comes with the DB2) to the USB port will allow you to operate indefinitely.   Going by what iVinyl was told by iBasso, the USB port of a typical laptop, PC or Mac, can't supply enough current at 5V to operate the DAC -and- recharge the battery at the same time.  But I would be VERY surprised to learn that iBasso's choice of 5VDC power adapters cannot power the DAC via the USB port (while using the coaxial or toslink connector for data) -and- recharge the battery at the same time. 
   
  Consider the PB2's external power adapter.  It supplies enough amps to operate the PB2 and charge the PB2's batteries simultaneously.  Surely, the DB2's AC adapter can supply enough current to do this, too - but I'm just guessing.  While I'm conjecturing, I will stick my neck out further still, by suggesting that it's highly unlikely you could hurt anything by plugging in the AC adapter, turning on the DAC, and turning on the charger all at the same time.  Again, the PB2 permits this, no problem.  
   
  In my opinion, you'd be better off with a coaxial or toslink connection, anyway, as in my limited experience with several USB-powered DACs, they tend to suffer drop-outs due to short intervals of insufficient current from the laptop's power supply - I'm not referring to jiiter, but rather, tiny power outages.  By using the DB2's USB jack exclusively for connecting the external 5V power supply, you'll likely suffer no such power glitches while getting your data from either the coaxial or toslink ports.  
   
  I'm making comments at the edge of my experience, here, so if any DB2 owners can offer corrections to what I've said, please chime in.  I'm eager to learn.  
	

	
	
		
		

		
		
	


	



   
  While I'm conjecturing, you might also want to try using an Energizer XP8000 external lithium-ion power pack to power and/or recharge the DB2 without need of an AC outlet (at least until the XP8000 itself needs recharging):    
   
http://www.energizerpowerpacks.com/us/products/xp8000/
   
  I've been using an XP8000 almost daily for about 18 months, with my Stepdance and, for the past month with my PB2.  I can't say enough about how friendly this device is and how many different voltages you can get out of it, using accessory cables.  You could literally recharge your DB2 and your PB2 simultaneously with an XP8000 - while out and about.
   
  http://www.head-fi.org/gallery/album/view/id/647286/user_id/54793
   
*UPDATE*:  *It's OK to charge two devices simultaneously with the XP8000, but be careful not to establish ANY other electrical connection between the two devices - not even a line out interconnect!*
   
See the post I made a few days later:  http://www.head-fi.org/t/528149/ibasso-pb-2-pelican-fully-balanced-portable-db-2-dac-hiflight-recommended-op-amps-page-16/675#post_8438470
   
  Mike


----------



## SpudHarris

I use mine contiuously while feeding coax from the CLAS.
   
  There is only mini USB charging, no AC Adapter.....


----------



## zilch0md

Yay!  
   
  That definitively answers Mazer's question #4 with a "Yes!"
   
  Regarding the AC adpater...
   
  That's what I get for reading the manual!  
	

	
	
		
		

		
		
	


	



   
  This text led me to believe the DB2 comes with a 5V AC adapter:
   
  Quoting the DB2 manual: 





> _[size=14.0pt]Charging the Batteries:[/size]_
> 
> [size=10.5pt]*Use the furnished AC adapter* or USB cable to charge the[/size]
> [size=10.5pt]batteries. [/size][size=10.5pt]Connect the adapter to the DB2 and turn the[/size]
> [size=10.5pt]charge switch to ON position. [/size]


 
   
  Their main web page for the DB2 also includes this text:
   
  Quoting the DB2 web page: 





> - *Comes with AC adapter*, leather pouch, USB cable, optical cable, 3.5 to 3.5 interconnect, rubber feet, and two extra OPAMPs (LPF).


 
   
  Do they no longer furnish an AC adapter with the DB2?   (Perhaps they just don't include one with orders shipped to countries that can't make use of the one they ship to the U.S.)
   
  In any case, your simultaneous use of the coaxial connection to the CLAS while charging the DB2 via the USB port tells us that a 5V USB charger of sufficient current (AC or XP8000 or ?) would work fine.
   
  If the DB2 really doesn't include an AC adapter, THIS is a great USB charger, that can deliver a whopping 2.1 amps (more than twice the current offered by most USB chargers):
   
*Belkin 2.1 Amp USB Wall Charger (model # F8z630tt04)*
   

   
  I hunted high and low for a USB charger that would deliver enough amps to charge high drain USB devices (portable, Palm OS-based barcode scanners) and this does the trick.  Belkin designed it for charging iPads.
   
_Be careful not to order the weaker version of this charger, that looks the same and costs half as much (model # [size=small]F8Z414ttP[/size][size=small]).[/size]_
   
  Mike


----------



## Mazer

Quote: 





> Originally Posted by *zilch0md* /img/forum/go_quote.gif
> 
> First, let me suggest that you send iBasso an e-mail a day until they respond.  I have always enjoyed quick responses from iBasso, so I think maybe somebody just "lost" your e-mail before answering it.


 
   
  Thanks zilch0md, I wrote right away and had this in my inbox this morning from iBasso:
   
   


> Hi,
> Thank you for your email.
> 1.Can the DB-2 be run off the USB power continously while using the USB input for audio?
> -----Yes, it can.
> ...


 

   
  I have replied to clarify issue 1 as this is somewhat conflicting information and my question could be misinterpreted.
   
  Thanks Guys


----------



## zilch0md

Mazer,
   
  Good news.  I think it's cool that iBasso is willing to say that USB power will impact the DB2's SQ.  Good for them, but I suppose you can always just listen to see if you can hear any artifacts while using USB power with coaxial or toslink data.
   
  Did your DB2 include the 5V AC adapter that's mentioned at the iBasso web site and in the DB2 manual?
   
  Thanks,
   
  Mike


----------



## SpudHarris

Mike, you could be right about the AC adapter. I think mine is probably still in the box! I have a dual USB adapter next to my rig that came with something else so just plug in the cable when it needs it.
   
  It's a great piece of kit.


----------



## zilch0md

I thought that maybe you didn't receive an AC adapter with your DB2 because your AC plugs are shaped differently in Australia.  
	

	
	
		
		

		
			




   
  Mike


----------



## SpudHarris

Hey, I'm from UK not Australia! Is it my text accent that made you think that?


----------



## zilch0md

The Holy Grail combo?
   
*PB2 using OPA1612 x2 for L/R, with AD797 x4 as buffers!*
   
  To my ears, this makes my normally bass-shy Sony PCM-M10 source and LCD-2 sound like HD650s on a transparent source with a transparent amp:  Extended, controlled bass, clean highs, lots of detail across the spectrum, yet still airy and non-analytical.  Not neutral, but fun!
   
  I think this combo works because as buffers, the AD797s are adding bass and warmth, while taking the edge off the top end that comes with the OPA1612s, all without destroying any detail.  It sounds like a really detailed, fast tube amp, with gobs of power controlling the bottom end.
   
  I discovered this yesterday evening and listened to the combo for about three hours.  YMMV.
   
  Mike


----------



## SpudHarris

I will try that Mike!


----------



## zilch0md

Cool!
   
  I can't wait to hear your thoughts - whether they support my findings or not.  
   
  Keep in mind that my chain begins with a "bright" source (the Sony PCM-M10), which is tamed by the LCD-2s shelved highs.  I suspect that if I started with a source that had a flat response, the combo I've recommended might be too dark with my LCD-2s.  
   
  By the way, after about three hours of listening to this combo, the PB2 was warmer to the touch than I've ever seen it. Not hot, just warm, especially on the underside where it was resting on a side table.  I can't imagine why that's happening, but I've never really spent much time listening with the AD797s before - not even on the L/R stage, so maybe they just tend to run hot.
   
  Mike


----------



## zilch0md

Quoting my earlier post: 





zilch0md said:


> Hi Mazer,
> 
> [snip]
> 
> ...


 
   
*Heads up! * 
   
  Just for grins, not having anything else I could use as a source that's USB-rechargeable, I hooked up my Sansa Clip+ to the 5V USB outlet of the Energizer XP8000, having already connected my PB2 to the XP8000 (via the WI16 voltage regulator cable).  
   
  So far, so good, both the PB2 and the Clip+ were charging simultaneously.
   
  But then...   I connected the Clip+ headphone out to my PB2 single-ended input, while both devices were still connected to the XP8000 and still charging.
   
  I put on my headphones, turned on the PB2, then turned on the Clip+ - POP!! - I heard a loud noise and my Clip+ died a horrible death.  Now it makes a rhythmic popping sound that's unaffected by the volume control - no music.  I killed it!
   
  Moral of the story:  I think I created some kind of loop on the power supplies of the Clip+ and the PB2, by having them both connected to the XP8000 -AND- trying to use the Clip+ as the source my PB2.   The funny (not funny?) thing about this is that I had actually hesitated with second thoughts before trying it, but now I know:   *It's OK to charge two devices simultaneously with the XP8000, but be careful not to establish ANY other electrical connection between the two devices - not even a line out interconnect!*
   
  Mike


----------



## Kremer930

Interesting event.  At least you now have an excuse to head out and buy a new source!!


----------



## Kremer930

Quote: 





zilch0md said:


> The Holy Grail combo?
> 
> *PB2 using OPA1612 x2 for L/R, with AD797 x4 as buffers!*


 
  If someone gets a chance to try this combo with an ipod/CLAS source and likes the sound output, I could be tempted to source some of them.  What is the best place to grab them without needing to be able to solder etc?  Cheers


----------



## zilch0md

Quote: 





kremer930 said:


> Interesting event.  At least you now have an excuse to head out and buy a new source!!


 
   
  Ha-ha!  Good one!  Any excuse will do, eh?  
	

	
	
		
		

		
		
	


	



   
  Actually, I've already satiated that desire (somewhat) by ordering another Clip+, just like the one I fried.  (Big spender, not!)  
	

	
	
		
		

		
		
	


	



   
  It will be here Friday, then I have to Rockbox it.  
   
  Joy!
   
  Mike


----------



## zilch0md

Quote: 





kremer930 said:


> If someone gets a chance to try this combo with an ipod/CLAS source and likes the sound output, I could be tempted to source some of them.  What is the best place to grab them without needing to be able to solder etc?  Cheers


 
   
  I wish I had a CLAS with which to answer your question, and more!  
	

	
	
		
		

		
		
	


	



   
  As to how to you might obtain the opamps and buffers: The AD797's are the four blue op-amps that iBasso includes with the PB2 (along with some other pieces in their rolling kit).  So you might already be in possession of the the AD797's.
   
  Here's a picture from Headfonia's review of the PB2 that shows all of the opamps and buffers that iBasso ships with the PB2 - the AD797's are blue:
   

   
  For the OPA1612's, I recommend you contact Ron Kerlin (send a PM to HiFlight) and ask him if he could provide you with a quote for soldering two OPA1612's to the adapters for you - or you could just order his TopKit, which includes the OPA1612s.  Once you have all six parts, you can just open the case and swap them in - no soldering required.
   
  I can send a picture of precisely where to place them, if and when the time comes...
   
  Joy!
   
  Mike


----------



## Kremer930

Hmmm interesting. I may already have them then as I have Ron's topkit already. Will be a big ask for them to knock Ron's kit out of my favorite top spot.


----------



## SpudHarris

I tried the 797's as buffers with 4 x 1611's and while very nice I found that with IEM's the SQ was really grainy. Not noticeable with full sized phones like LCD-2 but a lot of noise with my ES5's
   
  I am happy with my choice of now - 4 x LME49990 and 4 x HA5002 buffers. Clean, quite, transients and tube like micro details to die for..... I listen to a lot of Ambient Trance/Chillout and this combo is just awesome with all my phones apart from HE-6. The PB-2 just doesn't have enough juice to get to a loud enough listening volume, fair play though it doesn't clip, it just doesnt go quite loud enough.


----------



## zilch0md

I was up from 10:00 PM until 3:00 AM last night (this morning) listening to the OPA1612 (L/R) / AD797 (as buffers) combination, again.  
   
  Having written so highly about it yesterday, I had some trepidation as I sat down for another session with this combo, but day two was just as exciting as my first experience.
   
  I LOVE the way this combo sounds in the PB2, balanced out to my LCD-2!  It's PERFECT, for my tastes, anyway.  
   
  Having only had the PB2 for less than two months now, I can't imagine going back to using an amp that can't be rolled.  I've done surprisingly little experimentation compared to several contributors here, but have already latched onto what, for me, is a very satisfying sound quality.
   
  I can't get enough of listening to this rig, but the PB2 continues to get very warm.  I don't understand why this is happening when I've not witnessed this with other combinations (such as the OPA1612s with HA5002 buffers), so it must be the AD797s that are generating all the heat.  I'm thinking of taking the lid off the PB2 when using them - all that heat can't be good for the battery or anything else inside the case.
   
  I just checked the AD797 datasheet - it says that the absolute maximum supply voltage is +/-18V, so my use of a 16V external battery shoudn't be causing any problems.
   
  OK, I just found several posts at various forums saying that it's normal for the AD797 to get warm/hot while running.  No problem (except I'm still thinking of taking the lid off the PB2).  
   
  I wonder if iBasso would sell me another lid, so that I can experiment with drilling vent holes in it...
   
  Mike


----------



## zilch0md

Well, I've solved my overheating problem!
  
 Instead of taking the lid off the PB2 when running AD797s, I've just added a passive heat sink!  Now the AD797s run nice and cool!
  

  





  
 Mike


----------



## Kremer930

And I thought that I got many strange looks commuting with my rig.


----------



## zilch0md

Quote: 





kremer930 said:


> And I thought that I got many strange looks commuting with my rig.


 
   
  If you click on the picture the bubble caption under your mouse reveals that it's meant to be a joke.  But it does look funny sitting there!


----------



## Kremer930

I assumed it to be a joke. We definitely need to get out more otherwise.


----------



## zilch0md

Quote: 





zilch0md said:


> Well, I've solved my overheating problem!
> 
> Instead of taking the lid off the PB2 when running AD797s, I've just added a passive heat sink!  Now the AD797s run nice and cool!
> 
> ...


 
   
  Strangest thing...  I popped the AD797s back into the PB2's buffer stage, along with OPA1612s in the voltage gain stage, just so that I could measure their operating temperature, as requested by iBasso support - only to discover that they are no longer running hot!  
   
  I don't get it.  Maybe they just had to burn-in, literally, for two or three hours.
   
  Last night, using a Raytek MT6 laser thermometer, I ran them for an hour with the PB2 case open and measured temperatures no higher than 40 C - well within the datasheet specified safe operating range, and only about 6 C warmer than using HA5002 buffers.  I then put the lid on the case only to discover that it stayed much, much cooler than it had been the other night when I first tried AD797s in the buffer stage.  
   
  Another unsolved mystery...
   
  Mike


----------



## SpudHarris

Power supply the same?
   
  I nearly sold my DB2/PB2 rig a while back because I was getting more from my CLAS into Fi-Q. I am so glad I kept hold of it because of late I just can't stop listening. I have had the same chipset for a while and I'm no longer in search of the Holy Grail. Yes, I've tried just about every combo you can think of but for my personal flavour I keep coming back to THS4032 (x2) + HA5002 Buffers. To my ears, I don't believe this rig can sound any better, I really don't.....
   
  Ibasso really do sell some bang for buck gear. The P4 for instance is a permanent fixture for my ''quick grab'' portable rig, many have said it is comparable to a 1/2 decent desktop amp and I agree. The DB2/PB2 is just astonishing when you think of how much it costs. I would say that with the addition of the CLAS it is a very decent transportable rig, the truth is it is a decent home rig and portable also (if you can stand the extra 3 stack bulk).


----------



## zilch0md

Nigel,
   
  Yes, I use the XP8000 with WI16 regulator cable, exclusively - to power my PB2.    I give up on why it was running so hot with the AD797s  as buffers (before I decided to protect my gear by pulling them).
   
  Now, they're fine.  Go figure.
   
  Meanwhile, call me fickle - I've decided I don't like their coloration as a rule.  That was a "phase" I was going through, I suppose! 
	

	
	
		
		

		
		
	


	




   But now I own a Raytek MT6 that I'm not sure I'll ever use again, except for fun, and a new PB2 case is already on its way here from iBasso - into which I had planned to drill vent holes.  Now the AD797s are running cool and I don't even like the sound any more.  Sheesh!  
   
  I'm still having fun, though - for sure!
   
  I hear you on the THS4032 with HA5002 - that's a great combo, one that I've gone back to several times.  
   
  I'm currently (until further notice) using the LT1678s with dummy buffers, as I'm back to craving detail and transparency.   I can't decide which offers the absolute greatest detail when used with dummy buffers - the LT1678s or OPA1612s.  I'm thinking the OPA1612s do, but their highs can be a bit edgy at times.  The LT1678s just seem to be a little bit smoother than OPA1612s in the PB2.  My single-ended Stepdance uses OPA1611s, but the highs never sound quite as analytical as the PB2 with OPA1612s and dummy buffers.
  I really appreciate your steadying influence - encouraging me to chill and enjoy my music.  It's funny how you predicted early on that I would go bonkers with rolling!  
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## qusp

they were running so hot because they were oscillating =) perhaps you were in a room that had strong wifi or other HF signal that triggered them. oscillation is not a stable state


----------



## zilch0md

Qusp,
   
  That makes sense, even though I don't know what was causing the apparently temporary oscillations. 
   
  Thanks,
   
  Mike


----------



## HiFlight

It is not uncommon for the AD797 to experience oscillation when used as buffers. There seems to be less tendency for them to oscillate when used as L/R with bypassed buffers. 

The THS4032, LT1678 and OPA1612 are all superb sounding opamps in the PB2 with the ultimate choice being simply a matter of individual preference for the phones being used.


----------



## Mazer

mazer said:


> I have replied to clarify issue 1 as this is somewhat conflicting information and my question could be misinterpreted.


 
   
  Hey Guys,
   
  I haven't had much luck in clarifying the DB-2 power situation from iBasso.
   
  While they said it could be used continuously with a PC USB source they also agree that the battery will eventually run out, so it can't really be used continuously. I suspect I should have used the word indefinitly...
   
  I have written to them 6 times inquiring about the current draw when operating from the USB power supply but I've had no reply.
   
  I assume from SpudHarris' comment about his usage with a USB Y-cable that this configuration gives the extra current needed for indefinite PC based operation?
   
  If anyone has any info on this I'd appreciate it!


----------



## antberg

i was thinking in making about the same question,Mazer,cause as i use to travel from place to place ,every two years more or less,and i was considering a PB2/DB2 combo cause its great power, and mainly because it seems it can be powered from usb directly ,so when you are at home you can use it from Notebook without interfering with the energy amount in the battery,then when on the go you go back on battery use and avoid misuse of the same own battery.
  Is that this true?
  Salute


----------



## HiFlight

antberg said:


> i was thinking in making about the same question,Mazer,cause as i use to travel from place to place ,every two years more or less,and i was considering a PB2/DB2 combo cause its great power, and mainly because it seems it can be powered from usb directly ,so when you are at home you can use it from Notebook without interfering with the energy amount in the battery,then when on the go you go back on battery use and avoid misuse of the same own battery.
> Is that this true?
> Salute




While the DB2 can be powered from USB while in use, the PB2 requires either its battery or AC adapter to be used. USB power is not an option.


----------



## antberg

thanks HiFlight , can wait the moment to buy this combo ,a PB2/DB2 paired with some good Dap should be an hi-end (trans)portable audio equipment.i hope the new Itouch 5 will not disappoint.
  Salute


----------



## Mazer

Quote: 





antberg said:


> i hope the new Itouch 5 will not disappoint.


 
   
  If you are going Apple why not consider CLAS + RXMkIII which would power anything out there? Otherwise the DX100 would actually be a cheaper all in one solution for most phones (availability permitting).


----------



## antberg

Quote: 





mazer said:


> If you are going Apple why not consider CLAS + RXMkIII which would power anything out there? Otherwise the DX100 would actually be a cheaper all in one solution for most phones (availability permitting).


 
  Unfortunately i am not going to buy this "ultimate" hi-fi combo because you cant use it (or at last , the CLAS) with any notebook , even with any MacBook the Clas wont work (witch make sad because would be a perfect size/performance to use at home audio->speakers or headphones).so the IBasso combo seems to be an alternative,obviously not so hi-end and cheaper,for the home and the go simultaneously.anyway thank for the interest.
  salute


----------



## Uchiya

As a previous owner of both the Clas and DB-2/PB-2 combo, I'd say most would be hard pressed to find enough justification in warranting the price difference between the two setups, and that is if you do notice "difference" in quality.  I for one could not, they simply sounded different.  Both do serve respectively uses however.  I do wonder if someday portable audio will be able to create that large, spacious soundstage often attributed to well made desktop amps with their beefy power supplies.


----------



## zilch0md

Hey Nigel,
   
  Quote: 





spudharris said:


> Your set up sounds close to mine as I too have Toxic Cable for both the LCD and HE-6. Very nice cables and yes he's cool to work with. I've rolled just about every opamp know to man into and out of the PB-2 (and my other amps for that matter) and* really, really like the LME49990's with HA5002 Buffers*. I do swap out the 49990's now and again but seem to go back after a while. The only other opamp to compete is the ADA4610-2 but unfortunately it makes a very loud thud when turning off which bothers me with my ES5's.
> 
> Once you get it, feel free to pm me if you want and opamp info. Oh by the way the OPA1611's / 12's in class A are very very nice. I find the sound a little less fun than the LME49990's but for analytical ears it may be the route to go.
> 
> ...


 
   
  I've taken your advice from two months ago and ordered four LME49990MA (singles) from frugaphile (ebay seller) - already soldered on SOIC to DIP adapters.
   
  And now, to await their arrival...
   
  Mike


----------



## SpudHarris

Mike, I think you will like them a lot. I bought them on the advice of Qusp, I really value his advice as he is one switched on chap that really knows his stuff. I am never dissapointed with the sound of the 49990 in anything I dropped it into.
   
  Let us know what you think.
   
  Cheers - Nigel


----------



## zilch0md

Thanks!  Will do!


----------



## zilch0md

Believe it or not, I've gone five weeks without rolling any op-amps - ever since equipping my PB2 with Nigel's recommended LME49990's with HA5002 buffers.
   
  I am content and really don't feel a need to try anything else in the PB2.
   
  Now...  I'm thinking about getting the Boomslang DB2 to use as a desktop DAC.
   
  I'm already using balanced Toxic Cables' Silver Poisons between the PB2 and LCD-2 Rev.1.
   
  I've spent many hours listening to a friend's Centrance DACport LX, but its output is single-ended, of course.
   
  Has anyone got any reservations / opinions / advice about my going with the balanced-out DB2 vs. a Centrance DACport LX, unbalanced (into the PB2 balanced out to LCD-2)?
   
  If the balanced out DB2 sounds as good as the unbalanced DACport LX, I'll be thrilled, but I'm hoping there will be an audible improvement had with balanced input.  
   
  Thanks!
   
  Mike


----------



## SpudHarris

Hey Mike, I'm proud of you my friend. Sounds like you are finally cured haha......
   
  I don't use the PB2 much now but still use the DB2 to feed balanced into the SR71B. The difference between single ended and balanced into the 71B is not huge, it's an improvement sure and I guess taking into account that the DB2 is not expensive, over time it is worth the cost.


----------



## zilch0md

Thanks Nigel!  
   
  Yes, it seems I've followed in your foot steps - first, in trying the LME49990, and then again, in putting an end to trying other op-amps.  
   
  But ultimately, my ears seem to be in agreement with yours, or I'd have gone back to the OPA1612s or something else.  
	

	
	
		
		

		
			




   
  Regarding balanced input...   As I'd told you in a PM, a while back,* I recall reading an interview of Ken Ball, the owner of ALO, regarding their choice to design the ALO Rx MK3 with only single-ended input, despite it having balanced output.  At the time, Ken Ball had said something like, "balanced-output makes a big difference, but that's not so with balanced input."  (I'm paraphrasing, horribly, but that's the gist of what he said.)  Since then, ALO has released the Rx MK3-B - fully balanced from stem to stern.  Surprise!  By popular demand, perhaps?*  
   
  I'll let my ears decide, but unfortunately, I'm really sold on the very neutral, detailed, transparent sound of the single-ended Centrance DACport LX - it offers a great improvement over my portable source, the Sony PCM-M10 - and it sells for $299, the same price as a DB2.   I've heard that the HRT Music Streamer II+ (which is $50.00 richer), has some coloration, that it's darker and perhaps more forgiving, less analytical than the DACport LX - adjectives that might appeal to some people, but not to me.  
   
*Can you (or anyone) describe the sonic traits of the DB2 as being more toward the DACport LX vs. the HRT Music Streamer II+ ?   (More neutral / transparent / analytical / detailed  rather than  colored / dark / forgiving / smoother ?)*
   
  And, dare I ask, can the DB2's characteristics be tweaked by rolling op-amps?  
	

	
	
		
		

		
		
	


	



   
*I would gladly forfeit the somewhat nebulous benefits of balanced output offered by the DB2, if it must come with losing out on the clean, neutral, detailed sound I'm hearing when I borrow my friend's DACport LX.*
   
  It's easy to find a lot of good reviews for the DACport LX, but the iBasso DB2 just seems to be unheralded, in comparison.
   
  Lastly, please keep in mind that I'm only thinking about using it as a USB desktop DAC - I don't really need the portability, nor the coax / toslink inputs offered by the DB2.
   
  Help!  
	

	
	
		
		

		
		
	


	



   
  Thanks!
   
  Mike


----------



## kskwerl

Can the iPod be used with the PB2/DB2 via LOD? or via 30pin iConnector to 3.5mm on the DB2?


----------



## SpudHarris

Yes, both have single ended inputs.


----------



## kskwerl

Quote: 





spudharris said:


> Yes, both have single ended inputs.


 
  Thank you.


----------



## kskwerl

Would there by a significant sonic advantage in use the CLAS with the PB2 instead of an iPod>DB2>PB2 ?


----------



## SpudHarris

You are welcome. In my opinion the addition of the DB2 offers a very small improvement, not sure it justifies the extra cost but it's an improvement all the same.


----------



## SpudHarris

Quote: 





kskwerl said:


> Would there by a significant sonic advantage in use the CLAS with the PB2 instead of an iPod>DB2>PB2 ?


 
   
  Hmmm, that's subjective. They both do a great job.
   
  I have both but I use them together. I feed the ipod into the CLAS>DB2>Balanced into SR71B or PB2


----------



## giveit2menow

i have a d12 and will be feeding from a walkman z into the d12 and ath-es10.
  Im wondering if going to the db2/pb2 instead of the d12 is much of an upgrade in this setup? tx.


----------



## zilch0md

Condensing and rewording a question from my last post...
   
*Can anyone describe the sonic traits of the iBasso DB2 DAC?*
   
*Specifically, which of these characteristics best describes the DB2:*
   
*    neutral / analytical / detailed *
   
*    or*
   
*    colored / forgiving / smooth *
   
*    or*
   
*     something else?*
   
  Thanks!
   
  Mike


----------



## SpudHarris

Hi Mike, sorry, must have missed the question. I slightly prefer the Dac of the DB2 over the Dac section of the clas.

I would say its nicely detailed but still smooth, dual Wolfson chips if memory serves. Of late I have been using the clas and DB2 and it's a fantastic combo.


----------



## zilch0md

Thanks Nigel!


----------



## zilch0md

Well...  
   
  Enough of reading reviews and asking questions.  I'll never know for sure what they sound like without buying them and testing them with my own ears.
   
  I just ordered one of these (iBasso DB2 Boomslang 2)...
   

   
   
  And one of these (JDS Labs Standalone Objective DAC, in the new, shorter, 49mm case)...
   

   
   
  When they arrive, I'll be comparing them with one of these (Centrance DACport LX):
   

   
  I'll be setting up as follows:
   
   
  96 kHz / 24-bit WAV -> USB -> *iBasso DB2 (balanced out) **-*> iBasso PB2 with LME49990 + HA5002 (balanced out)  -> Toxic Cables Silver Poison -> Audeze LCD-2 Rev.1
   
  vs. 
   
  96 kHz / 24-bit WAV -> USB -> *JDS Labs ODAC (unbalanced out)* -> iBasso PB2 with LME49990 + HA5002 (balanced out) -> Toxic Cables Silver Poison -> Audeze LCD-2 Rev.1
   
  vs.
   
   96 kHz / 24-bit WAV -> USB -> *Centrance DACport LX (unbalanced out)* -> iBasso PB2 with LME49990 + HA5002 (balanced out) -> Toxic Cables Silver Poison -> Audeze LCD-2 Rev.1

   
  (I also ordered the iBasso balanced interconnect cable.)
   
  Once I've spent many hours with all three DACs, I'll share my impressions, but I'll post pictures of them together with the DACport LX and other gear when they arrive.
   





   
  Mike


----------



## SpudHarris

You are a trooper Mike. I'd be very interested in your findings. Especially as I already like the DB2 yet a few peeps think single ended into my 71B is the way to go.


----------



## zilch0md

spudharris said:


> Hi Mike, sorry, must have missed the question. I slightly prefer the Dac of the DB2 over the Dac section of the clas.
> I would say its nicely detailed but still smooth, dual Wolfson chips if memory serves. Of late I have been using the clas and DB2 and it's a fantastic combo.




So Nigel,

Are you using this chain?:

iPod Classic -> CLAS (bypassing its DAC) -> DB2 (balanced) -> SR-71B (balanced) -> LCD-2 

I know of several other people doing this. It speaks well of the DB2, given their willingness (your willingness) to bypass the highly acclaimed CLAS DAC - and it makes a strong statement for coming out of the DAC balanced instead of unbalanced. You simply MUST be hearing an improvement over going directly from the CLAS to the SR-71B, unbalanced. 

And that's why I ordered the DB2, instead of confining my upcoming DAC trials to a comparison between just the ODAC and my friend's DACport LX (which currently offers the best sound my relatively inexperienced ears have thus far enjoyed - noticeably better than my portable source, the Sony PCM-M10.)

It's amazing how many people have reduced the $579.00 CLAS to nothing more than a very good way to extract S/PDIF from an iDevice. Again, the DB2 must be pretty special...

Thanks,

Mike


----------



## SpudHarris

Mike, don't get me wrong, the dac in the CLAS is great and better than I was expecting but the DB2 is just that bit better. Not a massive improvement but an improvement all the same. The improvements are mainly soundstage and a little more authority.

Good luck anyhoo with your tests, looking forward to the results.

Cheers - Nigel


----------



## zilch0md

Nigel,
   
  I hadn't imagined that you were disappointed with the DAC in the CLAS.  From all that I've read, it's very highly regarded by nearly everyone who has used it.  
   
  I was just remarking that with your having opted to bypass its DAC for the sake of supplying the SR-71B with a balanced input, I can only be impressed with the DB2, despite having not heard it yet, myself.   
   
  There must be at least a dozen Head-Fi members, like you, who are running the DB2 downstream of the CLAS - people who were very content with the CLAS, before deciding to bypass its DAC for the sake of providing their fully balanced amp with a balanced input.  On using the DB2, they, like you, decide to leave it in the chain.  
   
  To me, that's a strong endorsement of the DB2 - that it can offer something above the CLAS.  Perhaps I just have too high an opinion of the CLAS - all based on nothing more than reading reviews, of course.  
   




   
  Thanks,
   
  Mike


----------



## SpudHarris

Mike, I shouldn't encourage you really but you do know that you can tweak the DB2 slightly with the low pass filter opamps  I've tried it a few times and have to say the changes are subtle and mainly relating to bass response. Enjoy!


----------



## zilch0md

Oh yes!  
   
  A swapping we shall go!  
  A swapping we shall go!
Ee-i, tiddly-i, a swapping we shall go!


----------



## SpudHarris

LOL, you are funny!


----------



## kskwerl

I just got the DB2, I'm having a brain fart....how would I hook up a portable source like an iPod to this thing?


----------



## seeteeyou

.


----------



## Grev

Quote: 





zilch0md said:


> Nigel,
> 
> I hadn't imagined that you were disappointed with the DAC in the CLAS.  From all that I've read, it's very highly regarded by nearly everyone who has used it.
> 
> ...


 
  Along with this, seeing as I've talked to you on the stepdance thread, I would like to know how you rate these iBassos, curiousity is getting to me, I've also got the CLAS with Triad L3 and going to get the RX3 so these comparisons will be very interesting!


----------



## zilch0md

[removed duplicate post]


----------



## zilch0md

Hi Grev,
   
*Regarding the Stepdance vs. PB2...*
   
  I still use the original Meier Stepdance (not the 2Stepdance or the newer offerings) and I drive it with external 15V battery packs (to maximize its output power to the headphones).  I use the Stepdance in my "walkabout rig" - where I want to keep the weight and size of everything to a minimum with this chain:   Sony PCM-M10 -> 15V Stepdance -> headphones 
   
  I love the sound of the 15V Stepdance so much, that I bought another Stepdance, just to keep on hand as a spare, in case the first one dies or gets damaged / stolen / whatever.  I really like the Meier Stepdance and consider it to be far more sophisticated a design than the iBasso PB2.
   
  Where the Stepdance is sophisticated and sounds great, the iBasso is somewhat crude, but can be upgraded to sound even BETTER than the Stepdance WHEN you are using power hungry headphones like the Sennheiser HD650, the Audeze LCD-2 or LCD-3, or especially the HiFiMan HE-6.  
   
  With a 16-Volt external battery pack (not the internal, 12.6-Volt battery) and the use of balanced output to your headphones, the iBasso PB2 is far more powerful than the 15-Volt Stepdance (up to 2500 mW vs. perhaps 900 mW).  
   
  After upgrading the PB2 with the "right" op-amps (which, in my opinion, are the LME49990's and HA5002 buffers), and buying balanced headphone cables (which, in my case, are the Silver Poison by Toxic Cables), the iBasso PB2 definitely SOUNDS BETTER than the 15V Stepdance, into the LCD-2.
   
  It's a matter of MORE POWER plus BALANCED OUTPUT winning the day, with the LCD-2 really coming to life when given sufficient power.  
   
  When using IEMs or far more efficient headphones than the LCD-2 (like my Shure SE530, Sennheiser HD280 Pro, or Philips CitiScape Downtown), the 15V Stepdance has no problem competing with the iBasso PB2.  In fact, I would give the Stepdance the edge in terms of sheer transparency, neutrality, and resolution.  
   
  But overall, I'm willing to suffer a slight reduction in resolution and transparency, as well as suffer the PB2's noisy, archaic, analog volume control, to get the awesome dynamic range, bass extension, and bass control (detail), that comes with running the iBasso PB2 with a 16-Volt regulated external battery pack, LME49990 op-amps, HA5002 buffers, and balanced output to the LCD-2, via Toxic Cable Silver Poisons.
   
  Replace the LCD-2 with efficient headphones, and I'm back to using the Stepdance instead of the PB2.
   
  My interest in USB DACs is strictly for desktop use, where I would always be using the LCD-2, and thus, the 16V iBasso PB2.
   
*Regarding your forthcoming comparisons of the Triad L3 and ALO RX Mk-3...*  
   
  Will you be using balanced output with either of them?  I suspect that singled-ended into power-hungry headphones, they wouldn't be able to compete with the balanced-output,16V-powered iBasso PB2 - but I'm just guessing.  
   
  I'm really looking forward to your impressions.  Will you please send me a PM when you've posted your findings?
   
  Thanks!
   
  Mike


----------



## zilch0md

On the subject of my upcoming comparisons of the Centrance LX vs. iBasso DB2 vs. JDS Labs ODAC...
   
  Back in May of this year, I had posted the following to the CLAS impressions thread, but no one ventured a response:
   
      Quoting my May 2012 post to the CLAS thread:


> I was just reading a Six Moons review of the ALO Audio Rx-MK3-B, and asking myself, *"When will ALO start working on a balanced version of the Solo?"  My conjecture: Maybe never.*
> 
> I read that they have a couple of other projects already underway, and then I read this:
> 
> ...


 
   
  Has anyone here tried feeding either the RSA SR-71B  or  ALO Rx MK3-B  or  iBasso PB2, using the iBasso DB2 with first, single-ended output to the amp, then with balanced output to the amp?  How about in a blind study?
   
  A friend of mine (the owner of the Centrance DACport LX that I've borrowed on several occaisions), will be helping me to perform comparisons of all four of these possibilities:
   
  96/24 WAV -> USB -> DB2 single-ended -> PB2 balanced -> LCD-2
  96/24 WAV -> USB -> DB2 balanced      -> PB2 balanced -> LCD-2
  96/24 WAV -> USB -> DACPort LX (single-ended) -> PB2 balanced -> LCD-2
  96/24 WAV -> USB -> Objective DAC (single-ended) -> PB2 balanced -> LCD-2
   
*Given what Ken Ball says, I'm especially curious about comparing the first two chains, above!  *
   
  Mike


----------



## Grev

The Triad L3 is only a single-ended output as far as I know, maybe others that know more about the technical side of the amp can chime in.  So I have the Norse Audio cables coming in, with balanced and single-ended connections, I will try and do single-ended comparisons first and then go on with balanced.
   
  I am quite interested in the PB-2 though, the voltage and amperage is making me very curious.


----------



## kskwerl

grev said:


> The Triad L3 is only a single-ended output as far as I know, maybe others that know more about the technical side of the amp can chime in.  So I have the Norse Audio cables coming in, with balanced and single-ended connections, I will try and do single-ended comparisons first and then go on with balanced.
> 
> I am quite interested in the PB-2 though, the voltage and amperage is making me very curious.




i have the PB2 and right now I only have a pair of T50RP "Mad Dogs" made by MrSpeakers hooked up single-ended to it and while it can drive them to pretty loud listening levels I feel that there isn't any headroom. I know the "swing" comes when balanced but I have nothing to test it with yet. Was thinking about doing a hardwire split on them to iBasso just to see.


----------



## zilch0md

Hi kskweri,
   
  I realize that you're currently operating the PB2 with single-ended output, but keep in mind that all of these op-amp based headphone amplifiers (single-ended or balanced) offer their highest possible power output (and thus, their best performance) when the supply voltage is at the maximum permitted by the amp's manufacturer.  Not only do they put out higher Watts RMS per channel, a quick look at their datasheets reveals that they all have lower THD and Noise measurements when operated at higher supply voltages.  
   
  For example, the datasheet for OPA1611s documents that they can handle an absolute maximum supply voltage of +- 20V (40V swing), but when used in the Stepdance, Jan Meier mandates that the maximum permissible supply voltage is 15V, not 20V.  When the same OPA1611s (or OPA1612s) are used in the PB2, iBasso says that you can use supply voltages as high as 16V.  The datasheet indicates that THD+N is lowest with a +- 15V supply voltage to the OPA1611.  (That's why I advise people to forget about using the Stepdance' internal 9V battery.)  This is pretty much the case with all op-amps for which I've studied datasheets - you get more Watts with less distortion and noise when operated at or near their absolute maximum supply voltage.
   
  With either amp, the Stepdance or the PB2 (or for that matter, just about any portable headphone amp), you'll not get nearly as much power to your headphones when using their respective internal batteries (9V for the Stepdance or 12.6V for the PB2).  One of the unsung features of the RSA SR-71B is that it has a 4-cell, 16.8V internal lithium-ion battery pack instead of a 3-cell, 12.6V internal battery pack (as with the iBasso PB2).  But even the SR71-B offers its best performance when supplied with a higher voltage from an external supply.    
   
  The hot tip, therefore, is to use an external power supply that provides the maximum permissible supply voltage.  See my photo albums, below, for more info on how to do that and stay portable with the Energizer XP8000 5-cell, external lithium-ion pack, used in combination with the appropriate inline voltage regulator cable.  
   
  One of the not so obvious features of using the XP8000 with a voltage regulator cable is that as the XP8000 discharges from 21.0 Volts when fully charged, down to 16 Volts, the iBasso PB2 will ALWAYS see16 Volts throughout the external battery's discharge cycle.  Compare that to using the internal lithium ion battery, where you start at 12.6 Volts, fully charged, but immediately start slipping to lower voltages until 9.0 Volts is reached and the PB2 shuts off.  Thus, your performance will constantly decay (both in terms of decreased Watts RMS and increased THD+N, when using an internal battery pack, as the battery discharges to lower and lower voltages.  
   
  That does not happen with the XP8000 + inline voltage regulator, where the PB2 always sees the regulated 16 Volts until the battery pack's voltage drops from 21 Volts to 16 Volts through use, at which point, it's time to recharge the XP8000.  
   
  It seems most people who buy portable amps want them to tiny and have batteries that magically last several days. I say forget about convenience!  Give me PERFORMANCE!  Give me a portable amp that has a 5-cell lithium ion battery in it with its own, internal voltage regulator that pushes the op-amps with their highest permissible supply voltage that does not degrade THD+N - all the time - while the battery is fully charged, all the way down to the point where it has to be recharged - giving the op-amps a constant, regulated supply at the ideal voltage.  (Distortion and noise are usually lowest at some voltage just below absolute maximum supply voltage, depending on the op-amp.)  
   
  That way, I wouldn't have to carry an XP8000 and an inline regulator cable with me everywhere I go, with every portable amp I own, just to gain access to everything the amps have to offer.  If an amp's case was large enough to hold a 5-cell lithium-ion battery that delivers four hours of play on a single charge, I'd be content. I don't need even 10 hours of play time, if it can only be had at the expense of a lower than ideal supply voltage!
   
  Enough of building tiny amps with tiny batteries and tiny performance!   
	

	
	
		
		

		
			




   
  Mike


----------



## zilch0md

Hi Grev,
   
  Quote: 





grev said:


> The Triad L3 is only a single-ended output as far as I know, maybe others that know more about the technical side of the amp can chime in.  So I have the Norse Audio cables coming in, with balanced and single-ended connections, I will try and do single-ended comparisons first and then go on with balanced.
> 
> I am quite interested in the PB-2 though, the voltage and amperage is making me very curious.


 
   
  I wasn't sure, but I thought the L3 was single-ended only.  
   
*Can you tell me what the specs are for the L3's internal battery pack?  Volts?  Amp-Hours? *
   
*How about the voltage rating on the external power supply that came with the L3?*
   
  The L3 case is so large, I'm now wondering if it's got a big, high-voltage battery pack in it, instead of the wimpy, lower-than-ideal-voltage battery packs every other amp manufacturer is using.  To my knowledge, only Ray Samuels is using even a 4-cell battery pack (16.8V), but I doubt that it's regulated to some lower, constant voltage, and thus, the performance just decays as the battery pack's voltage drops throughout the discharge cycle.  
   
  Mike
  (Getting off my soap box....)


----------



## Grev

The Triad L3 uses two 9v rechargeable batteries, which I remember even the Tenergy 9v batteries go up to 10v when fully charged, which I also have a set of the Imedion 9.6v (might even get higher voltage) that i might consider changing.  I was also informed that li-ion 9v batteries can be swapped into it too.
   
  The power supplies which is safe for charging and operating is at 24v, which is also the default, but the LLP (L3's official power supply) can go up to 32v output as I was talking to Brad at Triad Audio, and in order to operate at that voltage, you need to take the batteries out.


----------



## zilch0md

Sweet!  
   
  So, going portable, the L3 can at least start out at around 18 Volts (higher than either the PB2's 12.6-volt internal pack or the SR-71B's 16.8-volt internal pack).  But hearing that the designer permits use of a 32-volt external PSU is intriguing!   That tells me that you could theoretically rig up a 32-Volt, regulated external battery pack!   
   
  MO' POW-WUH !


----------



## Grev

Also as a note for 9v rechargeables, I use the Maha Imedion 9.6v ones, and they're 11.3v when fully charged!
   
  http://metaldetectingforum.com/showthread.php?t=118012


----------



## zilch0md

That's 22.6 Volts as you head out the door!  Excellent!  All the more Watts RMS per channel.
   
  Maybe, just maybe, this has a little something to do with why the L3 sounds good with power hungry phones...  
	

	
	
		
		

		
		
	


	



   
  Mike
  (voltage evangelist)


----------



## seeteeyou

.


----------



## zilch0md

Yes!  Lithium-Ion batteries made for RC hobbyists are the least expensive way to go, but they are not nearly as convenient to use as an XP8000 (for voltages up to 21 Volts).   Above 21 Volts, you would have to use something other than the XP8000.
   
  Lithium-Ion battery packs are made of multiple cells.  Each cell has a maximum voltage of 4.2V when fully charged, and 3.0V when fully discharged.  
   
  You do NOT want to discharge a lithium-ion cell below 3.0V, because they can do bad things - like spontaneous combustion - not explosions, just fires that emit toxic smoke and burn whatever's within reach.  
	

	
	
		
		

		
		
	


	



   
  So, if you decide to use a mutli-cell Lithium-ion battery pack with your portable amp, you'll need some way to monitor the voltage of the pack while using it to make sure that you don't discharge it below 3.0V per cell!  
   
  That's a pain, let me tell you, if all you've got is a standard multimeter to carry around with your portable rig.  It can be made easier, however, through the use of one of these:
   
   

   
*                                        Hyperion EOS Sentry*
   
  This sells for about $30 and makes battery monitoring in the field very easy.  It works with five different chemistries, and allows individual measurement of each cell in battery packs having up to 7 cells.  It also calculates disparity between cells - revealing whether one cell is discharging more rapidly than another - which can happen if you don't use a balancing charger, like this $40 Thunder AC 6 (pictured in the following PDF file):
   
http://home.globalcrossing.net/~zilch0/images/Zilch0MD-Stepdance-on-LiPo.pdf
   
   
  For my "Walkabout Rig," where I keep the size and weight down by using 4-cell Lithium-Ion packs with the Stepdance, I fully charge them to 16.8V, then use a feature of my charger to discharge the packs down to the 15.0-Volt maximum allowed by the Stepdance.  In other words, I am pre-discharging the 4-cell battery packs from 16.8 down to 15.0 before I begin using them with my amp. 
   
  Yes, it's a lot of work, but I enjoy the results!
   




   
  Mike


----------



## seeteeyou

.


----------



## zilch0md

I'd be worried about the inverter making noise, but I love the idea!
   
  Mike


----------



## Grev

But need PB-2 impressions!
   
  And portability, whatever YOU want to carry!


----------



## kskwerl

zilch0md said:


> Hi kskweri,
> 
> I realize that you're currently operating the PB2 with single-ended output, but keep in mind that all of these op-amp based headphone amplifiers (single-ended or balanced) offer their highest possible power output (and thus, their best performance) when the supply voltage is at the maximum permitted by the amp's manufacturer.  Not only do they put out higher Watts RMS per channel, a quick look at their datasheets reveals that they all have lower THD and Noise measurements when operated at higher supply voltages.
> 
> ...





I couldn't agree more Mike, I will try your mod when I have some time this weekend.


----------



## cooperpwc

Quote: 





zilch0md said:


> Well...
> 
> Enough of reading reviews and asking questions.  I'll never know for sure what they sound like without buying them and testing them with my own ears.
> 
> ...


 
   
  This may sound crazy but can you please also do:
   
  96 kHz / 24-bit WAV -> USB -> *iBasso DB2 (unbalanced out) **-*> iBasso PB2 with LME49990 + HA5002 (balanced out)  -> Toxic Cables Silver Poison -> Audeze LCD-2 Rev.1
   
   
  I am actually thinking of getting the DB2 as a home DAC to feed my Stepdance and Piano Forte IX. There is much about this DAC that appeals to me even single-ended. The DACport LX is competition. So I am wondering if the DB2 performs well as a single-ended DAC.
   
  Looking forward to your impressions.


----------



## cooperpwc

Quote: 





zilch0md said:


> A friend of mine (the owner of the Centrance DACport LX that I've borrowed on several occaisions), will be helping me to perform comparisons of all four of these possibilities:
> 
> _*96/24 WAV -> USB -> DB2 single-ended -> PB2 balanced -> LCD-2*_
> 96/24 WAV -> USB -> DB2 balanced      -> PB2 balanced -> LCD-2
> ...


 
   
  Oh, so you will do this.  Great!


----------



## kskwerl

So I had a little issue I thought I would just post in here. First off I'm not much of a DIYer at all and I'm weary about taking things apart, I'm scared of electricity because I once grounded myself to a 400w psu to a computer I was building. Anyway..
   
  The PB2 had been plugged into the AC adapter at my computer and I never really used it for portable use yet (I just got it). So I wanted to take it into my bedroom and lay down and listen to some music, it wouldn't turn on with the AC adapter plugged in. I was pretty bummed and contact iBasso immediately, this was last night and I was being impatient so I opened it up and sat there for a second then I detached and re-attached the 4 pin connector for the battery...it worked!
   
  Just thought I'd add that, good thing I tried it before sending it to god-only-knows-where China.


----------



## Grev

Quote: 





kskwerl said:


> Just thought I'd add that, good thing I tried it before sending it to god-only-knows-where China.


 
  A bit of unfounded phobia?  You're sending it to where you got it from...?


----------



## zilch0md

Quote: 





cooperpwc said:


> Oh, so you will do this.  Great!


 
   
  Yes, indeed!  I've already conducted the blind study with a friend's help.  That's a lot of work, by the way - leaving the room each time he re-cabled things, waiting for him to call me, then returning while walking backwards with my eyes closed to take a seat at the table and have another listen.  We managed to get it done, though, and I think you'll be surprised by my findings.  I've been very busy since then, and other than finalizing the spreadsheet where we tracked our results and making a lot of notes regarding my impressions, I've not yet found time to prepare the review I intend to write, but I'm very much looking forward to doing so.
   
  Here's a teaser photo, showing all three DACs side-by-side on my dining table:
   

   
  Surprise! The JDS Labs Standalone ODAC is very small - and when you order "Silver" vs. "Black," you still get a black case - only the end caps of the ODAC are not anodized when you order a "Silver" ODAC.
   
  In their own ways, and for different reasons, each of these DACs offer a lot of bang for the buck - they are all excellent values, but no two of them sound the same.
   
  Stay tuned... 
   




   
  Mike


----------



## kskwerl

Quote: 





grev said:


> A bit of unfounded phobia?  You're sending it to where you got it from...?


 
  Yea pretty much, I've always been scared of electricity for no good reason but then I got zapped by that power supply which strengthened the phobia.
   
  It would just suck very badly to have to pay shipping and tracking to China on a product I just got


----------



## cooperpwc

Quote: 





zilch0md said:


> Stay tuned...
> 
> 
> 
> ...


 
   
  Oh, I will...!


----------



## Grev

Quote: 





kskwerl said:


> Yea pretty much, I've always been scared of electricity for no good reason but then I got zapped by that power supply which strengthened the phobia.
> 
> It would just suck very badly to have to pay shipping and tracking to China on a product I just got


 
  Thing is, if there is a local dealer that's selling them for a bit more than direct, then you should get it through them if these situations ever arise.   I do that, I paid $1300AUD for my LCD-2...


----------



## Currawong

I've moved the review of the three DACs to a new thread:
   
  http://www.head-fi.org/t/626615/centrance-dacport-lx-vs-ibasso-db2-boomslang-2-vs-jds-labs-objective-dac


----------



## zilch0md

Good idea!
   
  Thanks,
   
  Mike


----------



## kskwerl

So I had this issue with the PB2 where it wouldn't turn on unless the AC adapter was plugged into it. I removed the battery and reconnected the 4-pin connector that connects the battery to the PCB and it worked fine for a little. Now today the same thing is happening. Anyone have any suggestions? I've already emailed iBasso and provided them with this video.
   
https://www.youtube.com/watch?v=gud8B5EvS40


----------



## zilch0md

kskweri,
   
  The red LED that we can see in your video, at the rear of the PB2, underneath the power jack, is the LED that lights only when the charger is turned on (via the tiny black switch to the left of the power jack), and even then it's normal for that LED to turn off and stay off once the battery is fully charged.
   
  So...  There's no reason for concern if the red LED on the rear of the PB2 will not stay lit - it just means that the charger is turned off -OR- the charger is turned on, but the battery is fully charged (a good thing.)  
   
  That red LED is only lit when the charger is turned on and the battery is not yet fully charged.
   
*Thus, the video does not demonstrate any problem with your PB2.*
   
*Question:*  *Does the PB2 perform correctly when the battery is connected and the main power switch is turned on at the front of the amplifier, illuminating the blue-white LED underneath the main power switch?*
   
  Thanks,
   
  Mike


----------



## kskwerl

Hey Mike, I forgot to mention that it doesn't turn on unless the a.c. adapter is plugged into the back


----------



## kskwerl

Last I spoke to someone at iBasso they gave me the option of sending me a new battery and sending it time them to be serviced. I think I'm going to request a battery as my gut tells me that's the issue.


----------



## zilch0md

kskwerl,
   
  I understand what's happening now, thanks.
   
  I agree that you should request and wait for the new battery, instead of shipping them your PB2 right away.  
   
  I happen to be sweating it out at the moment, waiting for an acknowledgement from iBasso that they have received a DB2 Boomslang 2 that I returned under their no-questions-asked 14-day money-back-guarantee.  They have acknowledged that my stated shipping date was well within their required 14-day period following the date of purchase, but I shipped it to them two weeks ago and a Chinese woman who works at my local post office (who has family in China) says it should take no more than 10 days to reach Shenzhen via First Class Mail International Parcel.  
   
  My package is 4 days overdue. Not enough to get too very concerned about yet, but hey, it's disconcerting nevertheless. Tick, tock, tick, tock.
   
  I'm assuming my shipment will get there eventually and that I will receive a refund eventually, but I'd much rather be waiting for a new battery coming my way.  
	

	
	
		
		

		
			




   
  I wouldn't send your PB2 to them until you've leaned you have no other option.
   
*Meanwhile:   If you have access to a voltmeter, you could try measuring the voltage of each of the three cells as follows:*
   
  Put the black probe of your voltmeter on the pin for the black wire of the battery, then put the red probe on one of the other pins.
   
  Each cell should measure 4.2-Volts when fully charged, and no less than 3.0-Volts when fully discharged. 
   
  Just keep the black probe attached to the pin for the black wire, as you move the red probe to each of the other pins, writing down the voltage for each of the three cells.
   
  If the total voltage of all three cells is less than 9.0-Volts, I doubt the PB2 would turn on.  In fact, they may use a more conservative figure of 10.0-Volts as the minimum voltage required to operate, which would equate to 3.33-Volts per cell.  A lot of equipment that operates on lithium-ion batteries will shut down at voltages as high as 3.33-Volts per cell, but it's technically safe to operate a lithium-ion cell down to 3.0-Volts. 
   
  Thanks,
   
  Mike


----------



## jamato8

I have had 1st class take 4 weeks. Never as short as what you were told. I have found the mail service to be very good in China, though not always fast. I was in a remote area for about 2 years and got every piece of mail sent to me, which was many. They take pride in their mail service, normally.


----------



## kskwerl

Thanks Mike, they said they are going to ship a replacement to me tomorrow. My buddy down the street has a voltmeter I think I will take some measurements this weekend when I have time so I can compare them with the new battery in case the new battery gives me trouble.


----------



## zilch0md

Quote: 





jamato8 said:


> I have had 1st class take 4 weeks. Never as short as what you were told. I have found the mail service to be very good in China, though not always fast. I was in a remote area for about 2 years and got every piece of mail sent to me, which was many. They take pride in their mail service, normally.


 
   
  Thanks so much for your VERY comforting words!   I can take it easy for a long while yet!   (My new expectation is September 26th - if it arrives sooner than that, all the better.)
   




   
  Mike


----------



## zilch0md

Quote: 





kskwerl said:


> Thanks Mike, they said they are going to ship a replacement to me tomorrow. My buddy down the street has a voltmeter I think I will take some measurements this weekend when I have time so I can compare them with the new battery in case the new battery gives me trouble.


 
   
  It will be interesting to see what you find.  If the battery is discharged, and you're willing to part company with it, I can try to charge it and even recondition it for you with my Thunder AC6 balanced charger then test it in my PB2.  
   
  Just send me a PM if you're interested, but there's no need to feel obligated.  I'll pay the return postage if you can get it to me and I promise to have in back in the mail within 24 hours.  
   
  If it will take a charge after reconditioning, you might end up with two good battery packs.
   
  If you'd rather wait until the other replacement battery arrives, that's fine, too.  I can later try to revive the bad one (assuming it turns out to be the battery that's at fault.)
   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> It will be interesting to see what you find.  If the battery is discharged, and you're willing to part company with it, I can try to charge it and even recondition it for you with my Thunder AC6 balanced charger then test it in my PB2.
> 
> Just send me a PM if you're interested, but there's no need to feel obligated.  I'll pay the return postage if you can get it to me and I promise to have in back in the mail within 24 hours.
> 
> ...


 
  That sounds good Mike, I'm gonna PM you soon


----------



## SpudHarris

Mike, you are a top man! Peeps like you make this forum what it is.


----------



## zilch0md

Thanks Nigel!  
   
  Mike


----------



## kskwerl

Quote: 





spudharris said:


> Mike, you are a top man! Peeps like you make this forum what it is.


 
  I'm gonna have to second this!


----------



## zilch0md

Be careful, I'm beginning to get a big grin on my face!


----------



## kskwerl

Mike, are you still using the PB2? Is that you main rig? My PB2 is currently my main rig. I wanted to get the MK3-B from AloAudio but its pretty expensive me my budget.


----------



## zilch0md

Quote: 





kskwerl said:


> Mike, are you still using the PB2? Is that you main rig? My PB2 is currently my main rig. I wanted to get the MK3-B from AloAudio but its pretty expensive me my budget.


 
   
  Yeah boyee!  It's my best amp, at the moment, and I happen to be using it, right now (balanced out to LCD-2 rev.1 via Toxic Cables' Silver Poison - I'm listening to_ Master and Commander: The Far Side of the World_.)
   
  I haven't heard the Rx-Mk3-B, but for one trait, it can't compete with the PB2 - which allows you to roll op-amps - this can get tedious - but after going two months ignoring Nigel's (SpudHarris) recommendation that I get the LME49990s, my search for the perfect op-amp was over (at least for my tastes, my gear, etc.).  
   
  When you buy an RSA SR-71B or an ALO Rx-Mk3-B, you spend twice as much as what you'd pay for an iBasso PB2, but you get locked into whatever personality those amps offer.  I've never listened to either of them, so _*please*_ take this with a grain of salt and do your own research, but from what I've read, the SR-71B has an "RSA house" sound that's dark and smooth - which I imagine to be similar to my experience with the Red Wine Audio iMod.    
   
  Some people love the musical, colored, sound of RSA gear, but I prefer neutral and transparent - an amp that expresses nothing of itself - just give me more of what the source is providing - the very definition of transparency.   I haven't read enough about the ALO Rx-MK3-B (or its predecessors) to know how neutral they are, but I do suspect that they are extremely well made - much like the Ray Samuels and Jan Meier amps, in that regard.  
   
  Even though I don't know what the more expensive portable, balanced amps actually sound like, I do know that the PB2 can be customized by rolling the op-amps - and the differences can be profound.  All together, I spent about as much on the PB2, opamps, and my Silver Poison balanced cables, as I would have spent on either of those other amps, alone.  The money can add up fast when you go balanced - this makes the PB2 the best value going in portable amps, so far as I can tell.  There are many solid state desktop amps that don't put out as much power as the PB2 - and that translates to awesome dynamics and tight control of the bass - especially when you run the PB2 with 16V external power (AC or external battery pack, your choice).  When iBasso gets your problem fixed, I think you'll be very happy with the PB2.  I know it's a bummer to be sitting on something that's not functioning correctly, but hang in there.  
   
  I'm curious about your tastes in sound.  Do you have a feel for what your personal preferences are?  Neutral vs. warm, dark vs. bright, smooth vs. detailed, etc.?
   
  Thanks,
   
  Mike


----------



## kskwerl

My taste actually changed to very neutral and transparent which is why I moved away from tubes. Mike u can't for the life of me find that opamp post you made for me showing me the buffers and opamps you're using now and where go buy them, I feel like I'm losing my mind.


----------



## Grev

Yo dudes, the RX3 is pretty natural, all that has heard it said that it is one of the best if not the best.   Since I'm an ALO fanboy, I have nearly all of their amps and things like the Triad Audio L3 and the Just Audio AHA-120.


----------



## zilch0md

Grev,
   
  That's nice to hear - I really didn't know what the ALO amps sound like.  And in truth, I rolled op-amps in the PB2, trying several combinations, until I found the combination that made it sound like my beloved Meier Stepdance, but more powerful - neutral and detailed, without being harsh, thin, or dry.  So, if an ALO or Triad amp sounds like that, I'd be OK with not having the ability to roll the op-amps.  (For my tastes, anyway.)
   
  Mike


----------



## zilch0md

Quote: 





kskwerl said:


> My taste actually changed to very neutral and transparent which is why I moved away from tubes. Mike u can't for the life of me find that opamp post you made for me showing me the buffers and opamps you're using now and where go buy them, I feel like I'm losing my mind.


 
   
  LOL - You're not losing your mind kskwel - not any more so than the rest of us!  
	

	
	
		
		

		
			





 
   
  A Head-Fi admin moved that post and several others right out of this thread into a new thread - because he decided that my comparison review of three DACs (and the comments that followed) deserved their own thread.
   
*Here is the post you're seeking:*   http://www.head-fi.org/t/626615/centrance-dacport-lx-vs-ibasso-db2-boomslang-2-vs-jds-labs-objective-dac#post_8672891
   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> LOL - You're not losing your mind kskwel - not any more so than the rest of us!
> 
> 
> 
> ...


 
  Thanks Mike, that explains a lot! LOL


----------



## kskwerl

Stripped a screw pretty good on the DB2 sigh... 

 Anyone know a good way to get that stripped torx out? I was thinking just drill it, I have a nice dremel kit as well.


----------



## zilch0md

Quote: 





kskwerl said:


> Stripped a screw pretty good on the DB2 sigh...
> 
> Anyone know a good way to get that stripped torx out? I was thinking just drill it, I have a nice dremel kit as well.


 
   
  Do you have a pair of needle-nosed vice-grips or forceps?


----------



## kskwerl

No but if that's what will work I can go to home depot and grab a pair or something


----------



## zilch0md

You might want to put some tape on the flat surface of the case (in the area around the bolt head) to protecting the case from scratches as you try to grip and twist the bolt.
   
  Now I know what iBasso generously provides spare bolts with their DB2 and PB2!
   
  Mike


----------



## kskwerl

too late on the scratch, I scratched..actually my stupid ass girlfriend wanted to try and I was like "you're gonna scratch it" and she was like "no I won't"...take a wild guess what happened?
   
   
  Anyway, I got a T8 Torx screw from work. These are T7, the metal is pretty soft so I just jammed the T8 in there and was able to twist it right out. The scratch is a hair line so I'm not too worried lol


----------



## zilch0md

Quote: 





kskwerl said:


> too late on the scratch, I scratched..actually my stupid ass girlfriend wanted to try and I was like "you're gonna scratch it" and she was like "no I won't"...take a wild guess what happened?
> 
> Anyway, I got a T8 Torx screw from work. These are T7, the metal is pretty soft so I just jammed the T8 in there and was able to twist it right out. The scratch is a hair line so I'm not too worried lol


 
   
  All's well that ends well, but if you haven't already, go give her a hug and thank her for trying to help and for showing an interest in things that are important to you.  
   
  So says the guy whose wife shares absolutely none of his interests.  
	

	
	
		
		

		
		
	


	




   But she's awesome, otherwise!  I'm a happy man. 
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> All's well that ends well, but if you haven't already, go give her a hug and thank her for trying to help and for showing an interest in things that are important to you.
> 
> So says the guy whose wife shares absolutely none of his interests.
> 
> ...


 
  lol she knows I love her :3


----------



## kskwerl

I'm looking to place an order for those opamps and buffers Mike, which ones did you happen to like the best. I thought I'd try those first since we have similar tastes.


----------



## zilch0md

http://www.head-fi.org/t/626615/centrance-dacport-lx-vs-ibasso-db2-boomslang-2-vs-jds-labs-objective-dac#post_8672891
   
  In addition to this information (at the link above), let me add that Ron (HiFlight) might be willing to sell you only the *HA5002 buffers (x4)* that he normally includes with his TopKit for PB2.  And you might also ask him if he can supply you with the* LME49990s (singles x4, or duals x2)*, so that you don't have to go to frugaphile (ebay seller) for those, separately.  
   
  Otherwise, you can just take the path I took, by ordering Ron's TopKit for PB2, plus frugaphile's LME49990s - as described in the link above.
   
Send Ron a PM and ask for a quote. He's very knowledgeable, does a great job soldering, and in reality, I don't see him so much as a commercial entity, as just a very nice guy who is providing a great service to folks like us - who can't solder. 
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> http://www.head-fi.org/t/626615/centrance-dacport-lx-vs-ibasso-db2-boomslang-2-vs-jds-labs-objective-dac#post_8672891
> 
> In addition to this information (at the link above), let me add that Ron (HiFlight) might be willing to sell you only the *HA5002 buffers (x4)* that he normally includes with his TopKit for PB2.  And you might also ask him if he can supply you with the* LME49990s (singles x4, or duals x2)*, so that you don't have to go to frugaphile (ebay seller) for those, separately.
> 
> ...


 
  Thanks Mike, I sent Ron a PM and we're working out what I need


----------



## zilch0md

jamato8,
   
  Quote: 





jamato8 said:


> I have had 1st class take 4 weeks. Never as short as what you were told. I have found the mail service to be very good in China, though not always fast. I was in a remote area for about 2 years and got every piece of mail sent to me, which was many. They take pride in their mail service, normally.


 
   
  Quote: 





zilch0md said:


> Thanks so much for your VERY comforting words!   I can take it easy for a long while yet!   (My new expectation is September 26th - if it arrives sooner than that, all the better.)
> 
> 
> 
> ...


 
   
  Good news!  I have received a refund from iBasso, having returned the DB2 and CB08 interconnect under their 14-day no-questions-asked guarantee.  
   
  I mailed it to them 19 days ago, via First Class Mail International Parcel.  
   
  Great service from a great company with great products.  I'm still very pleased with my PB2 amp.
   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> jamato8,
> 
> 
> 
> ...


 
  Glad to hear it Mike!


----------



## zilch0md

Quote: 





zilch0md said:


> Hi Grev,
> 
> I wasn't sure, but I thought the L3 was single-ended only.
> 
> ...


 
   
  Getting back on my soap box...
   
  CEntrance is singing my song in the following statement made in the "27 Sep" entry of their development blog for the forthcoming CEntrance HiFi-M8 portable DAC/amp:
   
   


> HiFi-M8 will feature a very powerful headphone amp. Our customers expect that, since our other products offer that level of performance.* In order to feed that monster and a bunch of digital circuitry to do USB and iPhone connectivity, you need a really beefy battery.  *So we had a to take a compromise between “very small” and “very good.” HiFi-M8′s dimensions are roughly 125x80x30.


 
   
  I would love it if iBasso would get on board with this thinking so that we don't have to use an external LiPO battery pack like the Energizer XP8000 to operate the PB2, for example, at a level of performance that's just impossible with the wimpy, 3-cell, 12.6V internal LiPo battery.  
   
*Big and strong is OK! *  Make tiny portable amps for people who want tiny at the expense of performance, but make big portable amps for people who want big performance - get off the fence.  CEntrance is going to beat out iBasso, in part, just by including a larger, higher-voltage internal battery.  But what will it cost?  As much as I love my CEntrance products (a DACport LX and a DACmin), I also love my iBasso PB2 - on external power, but NOT on internal power.    
   
*I don't need a portable DAC/amp combo like the CEntrance HiFi-M8.  I just want a PB2 successor that contains a 5-cell, LiPo pack internally regulated to a constant 16V, so that as the 5-cell pack discharges with use, with the voltage falling from 21V at a full charge, the amp sees a constant 16V no matter the battery's state of charge - yielding its best possible performance all the time - without using an external source of regulated 16V power.*
   
  Currently, the PB2 starts out with only 12.6V and worse, immediately begins falling toward 9.0V, at which point the internal battery must be recharged.  Yuck!
   
  I hope iBasso reads this post and stops listening exclusively to people who whine about size and play time.  No manufacturer can satisfy both markets with one product.
   




   
  Mike


----------



## kskwerl

Still haven't gotten my replacement battery :'(


----------



## zilch0md

Hmmm...  Did they send you an e-mail saying when it was shipped?   10 days would be more than enough time.


----------



## kskwerl

Quote: 





zilch0md said:


> Hmmm...  Did they send you an e-mail saying when it was shipped?   10 days would be more than enough time.


 
  They did, they had shipped it the 28th. I have a tracking number for USPS but it doesn't seem to be updating


----------



## zilch0md

No worries yet...
   
  It's coming.
   
  I know you're dying to find out if you've got a bad battery, a bad battery connector, a bad charging circuit or whatever.  
   
  Meanwhile, the good news is that the PB2 is rocking on external power, just fine.
   
  Did you get your Milian Acoustics SPOFC interconnect yet?  (And did you order it with the Kevlar sleeve or one of his other offerings?)
   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> No worries yet...
> 
> It's coming.
> 
> ...


 
   

   

   
   
  Yes the same day I placed the order with Milian he was able to send the cable out. I love it and I think it's a great fit. I'm still waiting on my Mad Dogs to get back from BTG audio, I had Brian do a hardwire split to Hirose connector. I'll finally finally be able to test out my rig it's been months in the making lol


----------



## kskwerl

I copied another one of your ideas with that bag lol


----------



## zilch0md

Quote: 





kskwerl said:


> I copied another one of your ideas with that bag lol


 
   
  LOL!   I'm so flattered, I'm going to start calling you Mini-Me!  
	

	
	
		
		

		
		
	


	



   
  Just kidding - every purchase decision you're making is your own - we just think alike!
   
  Nice pictures by the way!  A top loading bag just makes so much sense!


----------



## kskwerl

Quote: 





zilch0md said:


> Nice pictures by the way!  A top loading bag just makes so much sense!


 
  It really does, it was kind of a shot in the dark with the bag but it happened to fit perfectly and it's great for bringing to work or around the house!


----------



## zilch0md

Absolutely! 
	

	
	
		
		

		
		
	


	



   
  I spend a lot of time on my feet around the house, doing chores or whatever, all while wearing the LCD-2 with that gear bag hanging from my shoulder.  I push it around to my back and loop the headphone cable around my neck a couple of turns - good to go.   My wife says I look uber-GEEK, but hey, I'm dialed in.  Excuse me while I enjoy my music on the move!   
   
  Mike


----------



## gikigill

Didnt want to open a new thread so just wondering if someone can answer my query.
   
  How do I got a bit more bass with this combo?
   
  I got the BUF634P/OPA604AP in the PB2 and the blue opamps on the DB2?
   
  I can roll opamps so skill isnt a problem but just wondering if someone has been able to get a bit more bass depth.
   
  Battery life is not an issue but amp stability and protection is.


----------



## kskwerl

Quote: 





zilch0md said:


> Absolutely!
> 
> 
> 
> ...


 
  haha that's awesome, I plan on doing the very same!


----------



## zilch0md

Quote: 





kskwerl said:


> haha that's awesome, I plan on doing the very same!


 
  Let's hope we never run into each other on the street somewhere...   We might be shocked to discover we're wearing the same clothes.


----------



## zilch0md

Listening to Adele on my PB2 -> LCD-2 at the moment.   (She's slowly growing on me...  and *21* has a lot of dynamics.)


----------



## kskwerl

Quote: 





zilch0md said:


> Listening to Adele on my PB2 -> LCD-2 at the moment.   (She's slowly growing on me...  and *21* has a lot of dynamics.)


 
  Adele is pretty nice, love her voice. Think she was on the latest cover on Rolling Stones
   
  The battery finally got to the states! it's at customs in NYC.


----------



## zilch0md

Quote: 





kskwerl said:


> [snip]
> 
> The battery finally got to the states! it's at customs in NYC.


 
   
  Soon we will know if the original battery is junk or if there's a problem with the PB2 charging circuit.  Either way, it was nice of iBasso to send you a free battery.
   
  Tick, tock, tick, tock....
   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> Soon we will know if the original battery is junk or if there's a problem with the PB2 charging circuit.  Either way, it was nice of iBasso to send you a free battery.
> 
> Tick, tock, tick, tock....
> 
> Mike


 
  This is true, I really hope its just the battery. I'll know on Tuesday, I called the post office and it's there but I'm at work today


----------



## kskwerl

Got the battery in the mail today, iBasso actually gave me two replacement batteries. The PB2 works perfectly as it should now!
   
  Finally have my rig together with the new opamps and buffers too


----------



## zilch0md

>


 
   
   
*You may now leave the temple, Grasshopper!  *
   





   
  Seriously!   Check it out! 
   
  You've got the the maximum permissible 16-Volts supplied to the iBasso PB2 from an inline voltage regulator that allows the 5-cell, external LiPo pack to discharge from 21V when fully charged, to 16V - all the while pushing the amp at its maximum performance (with a constant 16V).  
   
  Not only do you have performance that's begins better than possible with the fully charged 12.6V internal battery, it ends at the same voltage where it started - 16V!
   
  Yeah boyeeee!  




   
  Maximum possible power, all the time, while portable!  Add to this the qusp and SpudHarris recommended combo of LME49990s and HA5002s, and you've got a really nice portable amp.
   
  But it gets better.  The Sony PCM-M10 Line Out plays up to 96kHz/24-bit files with gap-less playback, through Sony's proprietary delta-sigma DAC that a couple of Head-Fi members (other than myself) have judged to be in the same league as the HM-801 or HRT Music Streamer II (with less warmth).  And you are surely one of very few Sony PCM-M10 owners who knows how to adapt a 64GB microsSDXC card for use in the PCM-M10 (vs. the 32GB limit of the microSDHC cards).   
   
  Toss an iBasso DB2 in there for ready use with desktop sources and you are definitely ready to leave the temple!  
	

	
	
		
		

		
		
	


	



   
  Congrats on getting two free batteries from iBasso!  That's excellent service, for sure.  
   
  So, you've done your homework and pulled it all together...  How does it sound?
   
  Mike


----------



## Grev

DAMN I SHAT BRIX.


----------



## kskwerl

Mike you have no idea how pleased I am that my rig is finally complete and I have my Mad Dogs back! I never rolled opamps before but man what a difference it made, everything is so much more dynamic and open. So far the battery seems to be working properly and I don't think it's going to give me trouble. I'm also thinking about throwing in a pico slim or something for my IEMs some time down the road.

 Couple questions:
   
  - How do I know that the Energizer pack is On? Should the blue lights be lit up always when it's on? If I keep the Wily cable connected to the Energizer pack and the PB2 will it use the battery even if the PB2 is off?
   
   
   
  Check this out. So I haven't been using the PB2 because I didn't have a good battery and I didn't have any full size cans while I was waiting for my Mad Dogs so I've been using just the Heir 4.Ai's with the PCM-10. Anyway, I got my Mad Dogs back from BTG audio two days ago and plugged them into the PB2 with the order of PCM-10 -> Milian interconnect -> to PB2 and my Mad Dogs were playing sound out of the left headphone only. Immediately I had thought that it was my Mad Dogs because Brian had told me that he could use the Hirose connector for me but had no way to test it. So I emailed Brian and started making plans to send the headphones back to him. I went back into my room and started messing with my gear. After some troubleshooting I came to the conclusion that it was the Milian Acoustic interconnect. So I emailed Brian and let him know it wasn't the Mad Dogs. Then I emailed Maxwell and said once in a blue moon this happens and immediately shipped me out a replacement cable the next day!! So I should get the cable today but I work until 10PM but I'll let you know how it works out. The point of that little story is that MIlian Acoustics support is very very good


----------



## zilch0md

Erich,
  Quote: 





kskwerl said:


> [snip]
> 
> Couple questions:
> 
> ...


 
   
   
  The Energizer XP8000 is always "on," but it won't lose any power unless you attach something to it that pulls a load (just like any battery).  
   
  The red LED on the Willy Cable WI15 will be lit whenever the voltage coming from the battery is high enough for the regulator to send 15V out to your PB2.  If the LED on the WI15 goes out (not lit), then it's time to recharge your XP8000.
   
  The blue LEDs on the XP8000 are never on when using the battery.  They only come on when you are charging the battery, or when you press the little test button next to the blue LEDs!  Had you noticed that button?  If all four LEDs light up, the battery is fully charged.  If none of them light up, it's time to recharge the battery.
   
  By the way, you'll get a lot more mileage out of your XP8000 if you top off the charge frequently, rather than deep-cycling it.  So, it's up to you - you can enjoy the convenience of waiting until it quits before recharging every time - or - you can stretch your money a little further before having to buy a replacement XP8000, by recharging it after every use.  That thinking applies to all rechargeable batteries.  Deep-cycling them shortens their life.  Shallow-cycling is less convenient, but extends their life. 
   
  Lastly:  You should always unplug the WI15 cable from the XP8000 when you are not using it.  The WI15 cable's red LED will drain the battery, slowly, but it will drain it just the same.  When you are ready to use the amp, just plug the WI15 back into the XP8000.  The LED will light up and you will be good to go.
   
  Quote: 





> Check this out. So I haven't been using the PB2 because I didn't have a good battery and I didn't have any full size cans while I was waiting for my Mad Dogs so I've been using just the Heir 4.Ai's with the PCM-10. Anyway, I got my Mad Dogs back from BTG audio two days ago and plugged them into the PB2 with the order of PCM-10 -> Milian interconnect -> to PB2 and my Mad Dogs were playing sound out of the left headphone only. Immediately I had thought that it was my Mad Dogs because Brian had told me that he could use the Hirose connector for me but had no way to test it. So I emailed Brian and started making plans to send the headphones back to him. I went back into my room and started messing with my gear. After some troubleshooting I came to the conclusion that it was the Milian Acoustic interconnect. So I emailed Brian and let him know it wasn't the Mad Dogs. Then I emailed Maxwell and said once in a blue moon this happens and immediately shipped me out a replacement cable the next day!! So I should get the cable today but I work until 10PM but I'll let you know how it works out. The point of that little story is that MIlian Acoustics support is very very good.


 
   
  Yes, Milian Acoustics (Maxwell) offers great support, indeed, but here's the part that kills me:  His quality control must be poor to non-existent because that's EXACTLY what happened to me when I ordered my interconnect from him!   I'm not kidding.  What a shame.  I didn't even think it worth mentioning to you when I recommended Milian Acoustics, but wow...  I can't believe you got a cable with a dead channel, too!   All's well that ends well, I suppose, but you've had more than your fair share of warranty work, lately!
   
  Where did you get that brown cable seen in the photos, above?
   
  Meanwhile - I'm really glad to find out you're thrilled with the sound.  You can't imagine how lucky you are to have fast forwarded past all the hurdles I jumped through to settle down on using a rig like the one you're using now.  SpudHarris helped me tremendously with rolling op-amps and yet I actually ignored his advice regarding the LME49990 / HA5002 combo for TWO months because I thought they were too expensive!  It turns out they are a steal, even at several times the price of other op-amps - a no-brainer.    
   
  Thanks,
   
  Mike


----------



## kskwerl

Quote: 





zilch0md said:


> Yes, Milian Acoustics (Maxwell) offers great support, indeed, but here's the part that kills me:  His quality control must be poor to non-existent because that's EXACTLY what happened to me when I ordered my interconnect from him!   I'm not kidding.  What a shame.  I didn't even think it worth mentioning to you when I recommended Milian Acoustics, but wow...  I can't believe you got a cable with a dead channel, too!   All's well that ends well, I suppose, but you've had more than your fair share of warranty work, lately!
> 
> Where did you get that brown cable seen in the photos, above?
> 
> ...


 
  Mike, I think this may be to how fast he is able to get these custom cables out. Thanks for the info about the battery and deep-cycling/shallow-cycling! I'm very glad I didn't jump through all those hurdles, that's why I love head-fi! Thanks for turning me onto the LME49990/HA5002 combo as well, I'm very happy with my rig for now. I have one final thing to do and that's to send my Mad Dogs (which I just got back   ) to Dan so that he can put on the earpad upgrade I purchased.
   
  As for that brown cable, that's a Norse Audio Norn v2 I got made from Trevor. It's OCC trilevel litz, out of all the MOT Trevor from Norse Audio is the best.


----------



## Grev

The DB-2 will have a new competitor, new CLAS!!!


----------



## seeteeyou

.


----------



## jamato8

I have been using the optical out of the AK100 with the PB2 and the DB2, using HA5002 buffers in the PB2 with really fine results. Going balanced to my LCD-2 is a real treat. Very fine clarity and solid bass.


----------



## zilch0md

Quote: 





jamato8 said:


> I have been using the optical out of the AK100 with the PB2 and the DB2, using HA5002 buffers in the PB2 with really fine results. Going balanced to my LCD-2 is a real treat. Very fine clarity and solid bass.


 
   
  Which op-amps are you using at the moment with the HA5002 buffers (in the PB2) ?
   
  Thanks,
   
  Mike


----------



## goodtill

Just ordered a PB2 and Hiflights Topkit with the AD8599 op amps. Balanced cables for my HD650 are being made over at BTG audio and a adapter from DHA to go back to SE.
  My iMod Ipod will be going to a 64GB SC card this weekend.
   
  Really looking forward to this new portable setup


----------



## zilch0md

Yay!


----------



## goodtill

I have received the PB2 and the Topkit from Hiflight. I let it burn in for about 24hrs with the HA5004 and the AD8599. That combo sounds great on my HD650, just not enough oomph. I am running it at 3o'clock on the knob and it only goes to 5o'clock. I realize there is more power running balanced, but my cables have not come in yet from BTG. I did move the 4 connectors over inside the amp to hi gain.
   
  So what set of amps and buffers will give me the most power in my PB until my cables come in?


----------



## jamato8

Quote: 





goodtill said:


> I have received the PB2 and the Topkit from Hiflight. I let it burn in for about 24hrs with the HA5004 and the AD8599. That combo sounds great on my HD650, just not enough oomph. I am running it at 3o'clock on the knob and it only goes to 5o'clock. I realize there is more power running balanced, but my cables have not come in yet from BTG. I did move the 4 connectors over inside the amp to hi gain.
> 
> So what set of amps and buffers will give me the most power in my PB until my cables come in?


 

 The buf634 has a little more power but not enough to notice and IMO, the 5002 sounds better. Wait for your balanced cables and your 650 will be transformed.


----------



## zilch0md

Quote: 





jamato8 said:


> The buf634 has a little more power but not enough to notice and IMO, the 5002 sounds better. Wait for your balanced cables and your 650 will be transformed.


 
   
  +1 
   
  Singled-ended headphone cables only use 1/2 of the PB2.  Power will double when you get balanced cables.


----------



## goodtill

Thanks guys. I tried double buffering it and it did not sound any louder or better than the HA5004 and the AD8599 combo as suggested by Ron. I do have some LME49990 coming in also to try.
   
  My Fiio E12 came in today and it is definitely louder in SE mode compared to the PB, It needs to burn in before I make a decision on which one sounds better. I actually bought that for my other rig to run some W4R's on lo gain, but it is pretty load on the 650's in hi-gain.
   
  I will wait for my cables from Bruce


----------



## zilch0md

I have received another PM requesting information on* how to obtain the Willy Cable WI16 for use with the iBasso PB2 and Energizer XP8000 external LiPo battery pack (to supply a regulated 16VDC while on the go).   *
   
  So I just updated my original post, here:
   
  http://www.head-fi.org/t/528149/ibasso-pb-2-pelican-fully-balanced-portable-db-2-dac-hiflight-recommended-op-amps-page-16/615#post_8360318
   
   

   

   
  Mike


----------



## smallcaps

Curious if anyone has tried to connect an ALO International to the DB2 in full balanced configuration? I am guessing you would need to make a custom cable?


----------



## goodtill

I know that Double Helix Cables make such and adapter for Hirose to RSA/ALO balanced connector


----------



## seeteeyou

.


----------



## zilch0md

That seems to be how the web page is describing it, yes.   
   
  Mike


----------



## SpudHarris

As the ipod doesn't output a balanced signal I see little point. Might as well buy a normal LOD.


----------



## zilch0md

Good catch, Nigel!


----------



## Uchiya

You know, I'm curious to buy this again for the HD800.  I remember there was nothing I liked about the T1.  It had this unusual, sharp grating sound on nearly everything on my desktop.  Ron's kit, along with the DB-2/PB-2, the T1 was so smooth, almost ortho like.  I'm thinking it might be the fit for the HD800 too without venturing into TOTL setups.


----------



## leesure

Finally have my portable system complete. IPad with CCK>DB2/PB2 (4xOPA627+4x5002 buffers)>LCD-2.1. Great bass, a little sibilant, but the best I have heard the orthos sound thru a portable. Granted, I have not heard the balances offerings from ALO or Ray Samuals, but it's better than the SE portables I have heard. 

On a side note, even the PB2 is virtually unlistenable being fed by the iPod headphone jack. Looks like it's either a CLAS or iMod in the future if I need to go super portable.


----------



## SpudHarris

Quote: 





leesure said:


> On a side note, even the PB2 is virtually unlistenable being fed by the iPod headphone jack. Looks like it's either a CLAS or iMod in the future if I need to go super portable.


 
   
  Feeding line level via a LOD on a normal ipod will be fine. I hardly ever use the headphone jack from any of my portable sources now.


----------



## knights

I have the CLAS and RX combo. Is pb2+db2 better, power-wise?


----------



## gikigill

Pure power would be a yes.


----------



## spurxiii

I just ordered mine pretty blind to use my mad dogs on as a portable. Anyone else use this on the mad dogs. How is the sound? I'm coming from a JDS C5


----------



## gikigill

Maddog and PB2 owner here, even on single ended the headroom is immense and you,ll be deaf before the volume knob is at 12oclock.
   
  Its colder sounding than the C5 though. Stick to medium gain to prevent blowing out yur ears with the Maddogs.


----------



## spurxiii

Haha I like that, blowing out my ears


----------



## spurxiii

Look what came. I'm not sure what I do with the additional chips supplied. It came with no instructions


----------



## zilch0md

Quote: 





spurxiii said:


> Look what came. I'm not sure what I do with the additional chips supplied. It came with no instructions


 
   
  Hey!  Congratulations! 
   
  Take those extra op-amps and ask someone you trust to hide them from you for at least a week, while you get to know the sound of your new amp, with the default configuration.  Then steal your mind in preparation for several weeks of rolling op-amps obcessively!


----------



## spurxiii

Thanks Mike. All those op-amps and buffers look the same, how do you tell what is what. Also, is there a gain switch somewhere because I've got the volume at 90% to get a decent sound?


----------



## zilch0md

For those who are already familiar with the stock op-amps...
  
 I've been using LME49990s in L/R for several weeks now, to drive my LCD-2, either with HA5002 buffers or more recently, with dummy buffers, which sound much more transparent, but less powerful, of course, than the HA5002.
  
 Still, I've come to prefer the clarity of dummy buffers with the LME499990 and there's plenty of headroom left with the fairly efficient LCD-2 (relative to something like the HE-6).
  
 This evening, I finally got to try something I first thought about a couple of weeks ago:  
  
*I'm using LME49990s as buffers, in addition to using them in L/R.*
  
The result is wonderful, for my ears, my tastes, etc.  As buffers, they still don't deliver anywhere near the current that HA5002 would, but they do kick things up noticeably in terms of dynamics and bass control, just the same.
  
 They also add body and fullness to what I was hearing with just the dummy buffers, without any apparent decrease in resolution or transparency.  It's just more of that same LME49990 goodness!
  
 I'm using ebay seller frugalphile's LME49990 singles sold already soldered to SOIC to DIP8 adapters, but his PCBs are longer than the typical Browndog PCBs, so they end up overlapping each other with one row not seating fully into their sockets.  
  
 So...  after trying to shorten the PCBs with a dremel (bad idea, really bad) and ordering another set of four from frugalphile, I decided to stack them atop four DIP8 sockets I ordered from Browndog, so that their PCB length is no longer a problem - they can be fully seated while not running into the other row that's sitting lower down, in L/R.
  
 Joy!
  

  

  
 This sounds great with LCD-2.  Me like!
  

  
 Mike

*
UPDATE: The honeymoon is over! I can't recommend using LME49990 as buffers in the PB2, at least not with LME49990 in L/R. Now, some people might like it, but I've decided, after more hours spent listening, that it's too warm for my tastes AND there is a loss of resolution / low level detail / transparency, as compared to using dummy buffers with LME49990 in L/R. If you're into warm and syrupy sound and/or prefer a slight loss of resolution with absolutely non-fatiguing and airy treble, then you might want to check it out. 8x LME49990 has a thick, warm, and smooth sound.*


----------



## zilch0md

Quote: 





spurxiii said:


> Thanks Mike. All those op-amps and buffers look the same, how do you tell what is what. Also, is there a gain switch somewhere because I've got the volume at 90% to get a decent sound?


 
   
  Have  look at my second picture, above.  Move those jumpers so that they each sitting on the closest pair of pins (closer to the camera when looking at that photo) and you will then be on High Gain.  Move all four jumpers at the same time, while the unit is turned off.  
   
  The photo is showing Low Gain (with the jumpers just resting on one pin - not connecting any pair of pins).
   
  You should be able to find a small Torx wrench (L-shaped) in the stuff that came with the amp.  Use it to remove the top set of screws only (two screws from each end of the amp) and you will then be able to lift off the cover.  Do all of this with it powered off.
   
I'm going to bed now, so more tomorrow, if you have additional questions.  Meanwhile - check the manual (short though it is.) And search this thread.  It's highly unlikely you can ask a question that hasn't already been asked and answered.  
   




   
  But feel to keep asking questions.  I'll help whenever I'm on.
   
  Have fun!
   
  Mike


----------



## zilch0md

Oh, and here's a labeled photo of what's what with the stock op-amps that come with the PB2.
   
   
   

   
  The two columns of op-amps on the right can be put into L/R (the sockets that sit closest to the battery).
   
  The three columns of op-amps on the left are buffers that can be put into the row of sockets that sit closest to the volume control.
   
  The BUF634U have sockets of their own that allow you to stack BUF634P on top of them, if you want to try a different sound.
   
  WARNING:  Make sure that you mount the op-amps with the little half-circle notches facing toward the volume control (away from the battery) - as shown in this picture (again):
   

   
   
  That's it for tonight.    Zzzzzzzzzzzzzzz....


----------



## spurxiii

Thanks Mike. Will do these now


----------



## spurxiii

Just changed the jumpers to high gain and it's not that loud. Still needs about 80% volume to get decent sound on the mad dogs via iphone4s LOD


----------



## boombobby289

Has anyone try to do digital out the Fiio X3 through coaxial output (to bypass the internal DAC) and then line in to iBasso PB2?
  If yes,  is there any significant improvement in sound quality?


----------



## gikigill

Cant connect coax to PB2  but line out will work. Coax is meant for DACs.


----------



## boombobby289

Quote: 





gikigill said:


> Cant connect coax to PB2  but line out will work. Coax is meant for DACs.


 
  Sorry. I mean the DB2 (the standalone DAC) and not PB2.


----------



## spurxiii

Unfortunately I've already succumbed to the opamp rolling. I've swapped to the 797s and the high bandwidth


----------



## spurxiii

The bass definition is better and the upper end is cleaner with the 797s and the high bandwidth buffers. I think I'll keep this till my HiFlight kit comes


----------



## zilch0md

Quote: 





spurxiii said:


> Just changed the jumpers to high gain and it's not that loud. Still needs about 80% volume to get decent sound on the mad dogs via iphone4s LOD


 
   
  That's very astute of you to mention your source, as the input voltage from the DAC does influence the volume heard at the headphones, for any given gain provided by the amp.
   
  So, this is where you need to increase the power output of the PB2 by using HA5002 buffers (which can each provide up to 250 mA of current).  What you choose to put in L/R can have an impact on power output, too, as that top row (closest to the battery) is the input voltage gain stage (affecting voltage, not current).
   
  I vigorously recommend that you send a PM to* HiFlight* (Ron) and ask him to provide information about his "TopKit" for the PB2.  He has assembled, and continues to improve, a collection of some very desirable op-amps that are not included among those that iBasso provides.  Best of all, he does a great job of soldering the SOIC8 packages to DIP8 adapters, so that you can just plug them into your PB2 - no soldering required. Ask him, but I'm pretty sure he still includes the HA5002 buffer, which should help the PB2 to produce more gain.
   
  While you wait for the TopKit to arrive (assuming you order one from Ron), try powering the PB2 with its 16V wall power adapter vs. the 12.6V internal lithium battery.  In any case, no matter what combination of op-amps you roll, 16V power will provide greater dynamics and bass control - _especially for inefficient headphones_ - not at all for the most efficient IEMs.
   
  If you can hear a difference at 16V and are willing to add and carry an external 16V battery pack to your stack for portable 16V operation, just ask for more info. (I'll spare everyone for now.)
   
  Mike


----------



## spurxiii

No need to spare us Mike, your posts are very informative and invaluable to noobs like me. I've learnt everything about portable sound from searching and reading posts like these in the last few of months. The only bad thing is, before I found Headfi in May this year I hardly had any of this gear and I was quite happy with my UE700 IEMs. Anyway, I diverge and I did order the HiFlight topkit from Ron yesterday against your advice from your first post to me. I've also tried the sound out of the 16V battery pack and although it did sound more livelier and dynamic it wasn't large enough for me to say that the improvement was there for sure. Perhaps it was some expectation bias. I have to try it again and give it a bit more time.
   
  I started mentioning souces in my posts because I recently realised that not all sources produce the same amount of output and this was especially apparent when I tried using the pre-outs on my Yamaha AVR as a source for a power amp in a 2 channel speaker setup. The sound was so soft in comparison to a dedicated DAC I had.


----------



## zilch0md

*UPDATE: The honeymoon is over! I can't recommend using LME49990 as buffers in the PB2, at least not with LME49990 in L/R.* Now, some people might like it, but I've decided, after more hours spent listening, that it's too warm for my tastes AND there is a loss of resolution / low level detail / transparency, as compared to using dummy buffers with LME49990 in L/R. If you're into warm and syrupy sound and/or prefer a slight loss of resolution with absolutely non-fatiguing and airy treble, then you might want to check it out. 8x LME49990 has a thick, warm, and smooth sound.


----------



## zilch0md

Hi spurxiii, 



spurxiii said:


> Just changed the jumpers to high gain and it's not that loud. Still needs about 80% volume to get decent sound on the mad dogs via iphone4s LOD




Are your Mad Dogs using balanced cables to connect to the PB2's Hirose connector, or are you driving the MAd Dogs single-ended? If it's the latter, you're only using half of the PB2 amp.

Mike


----------



## spurxiii

No Mike, I had the mad dogs before I purchased the PB2s and they're SE. I bought the PB2s after a couple of recommendations from the mad dogs thread and reading the review of Headphonia. Is that you who wrote the review? Good review if it is. Sorry I'm really new to all this. Thanks for all this help by the way 

 I'm quite happy with the PB2s even as they are now and they have already passed my expectations and even before my Topkit arrives, it already sounds better than my budget desktop setup. 

Would you recommend getting the SE upgraded to balanced if I am already happy with the current sound? i. e. I'm now listening to it at 80% volume on the mad dogs, will it sound the same at say 50%? Or will it be louder and present more dynamically and give me more detail?


----------



## zilch0md

spurxiii said:


> No Mike, I had the mad dogs before I purchased the PB2s and they're SE. I bought the PB2s after a couple of recommendations from the mad dogs thread and reading the review of Headphonia. Is that you who wrote the review? Good review if it is. Sorry I'm really new to all this. Thanks for all this help by the way
> 
> I'm quite happy with the PB2s even as they are now and they have already passed my expectations and even before my Topkit arrives, it already sounds better than my budget desktop setup.
> 
> Would you recommend getting the SE upgraded to balanced if I am already happy with the current sound? i. e. I'm now listening to it at 80% volume on the mad dogs, will it sound the same at say 50%? Or will it be louder and present more dynamically and give me more detail?




Hi spurxii,

I'm a different Mike, but it would be fun to work for Headfonia. 

If you're already happy with SE connection of your Mad Dogs to the PB2, then forget I said anything about balanced cables. I have no experience with Mad Dogs, but generally, the less efficient the headphone, the more it will "scale" to an amp with more power. Efficient IEMs, for example wouldn't likely benefit by going balanced with the PB2, from SE. Something like the notoriously power-hungry HiFiMan HE-6 would, however, appreciate the increase in power. 

i think your Mad Dogs are somewhere in between, so you might enjoy audible benefits or you might not. ???



Mike


----------



## gikigill

The MadDogs soak up power and having the single ended one, the PB2 powers it well but I plan to get the AlphaDogs balanced and expect a significant improvement.


----------



## spurxiii

gikigill said:


> The MadDogs soak up power and having the single ended one, the PB2 powers it well but I plan to get the AlphaDogs balanced and expect a significant improvement.


judging by what others have said about balanced vs SE I wouldn't expect a significant improvement. A significant improvement for me was going from the JDS Labs C5 to the PB2s. I don't expect the same gains or should I? If so I'm in


----------



## zilch0md

I wish I could say.  Ultimately, as with so many decisions in this "hobby" of ours, you'll have to try it to know for sure.  The good news is that spending the money to recable your Mad Dogs will not hurt the SQ in any way.  A small consolation, but true, nevertheless.  There's also the simple contentment of knowing that you would be exploiting 100% of what your PB2 money can deliver, instead of 50%. 
   
  Another point to consider:  Many people argue that going balanced brings more to SQ than just the power offered by running essentially two amps instead of one (or four instead of two, in the case of the PB2's quad design).  But I'm not a big believer in those benefits being truly audible.  I'll admit that with single-ended output, the shared ground can cause impedance fluctuations on one channel to influence what's happening on the other, but is it audible?  I don't think so.  
   
  To my knowledge, the Meier Audio amps, both his portable and desktop designs, are the only single-ended amps that offer what Dr. Meier calls an "Active Balance" feature - where he somehow compensates for impedance fluctuations so that each channel has no awareness of the other, despite sharing a common ground.  As he puts it (paraphrasing), you get the benefit of balanced cables without the expense and hassle.  Still, I can't honestly say I have ever heard these impedance fluctuation gremlins in any single-ended amps, including the Burson Soloist.  So, what good is a balanced design other than the extra power and driver control that can be had with an amp that has twice the components?  
   
  While I'm on a soapbox about balanced vs. single-ended, I'm even less of a protagonist for using balanced sources.  At least with balanced output, you're talking about controlling the moving parts of a transducer that has mass and inertia.  But there's no such equivalent on the source side of an amp.  In my opinion, the only reason to use a balanced output DAC and cable to the amp is for really long cable lengths, where balanced cabling can indeed have a dramatic impact on reducing vulnerability to noise.  In my opinion, for our purposes, especially with portable gear using really short, shielded interconnects, balanced sources are a waste of money.
   
  Ahhh..  I feel much better.  
	

	
	
		
		

		
			




   
  Mike


----------



## spurxiii

Thanks for your thoughts Mike. I'm probably going to wait until gikigill does his re-cabling seeing as he has the same setup in the amp and headphones department. One other benefit of going balanced is that I can use speaker taps to drive my mad dogs off my speaker amps, the same thing I'm going to do with my HE500s. BTW you write like an engineer.


----------



## SpudHarris

Quote: 





spurxiii said:


> judging by what others have said about balanced vs SE I wouldn't expect a significant improvement. A significant improvement for me was going from the JDS Labs C5 to the PB2s. I don't expect the same gains or should I? If so I'm in


 
   
  x2
   
  I've done the SE Vs. Balanced thing with quite a few of my phones and IEMs and what small improvements I thought I heard were just that ''small''. Don't expect day and night differences.


----------



## zilch0md

^ And that's saying a lot coming from Nigel - a guy who has demonstrably good ears!


----------



## SpudHarris

Haha, thanks Mike....
   
  My comments above were aimed at the PB2. I found going balanced via speaker taps of TP60 for certain phones (HE-6) yeilded more noticeable results. Again, not day and night but they were there none the less.
   
  The PB2 is a fantastic amp however you are using your phones.


----------



## zilch0md

Quote: 





spurxiii said:


> Thanks for your thoughts Mike. I'm probably going to wait until gikigill does his re-cabling seeing as he has the same setup in the amp and headphones department. One other benefit of going balanced is that I can use speaker taps to drive my mad dogs off my speaker amps, the same thing I'm going to do with my HE500s. BTW you write like an engineer.


 
   
  Yeah, now THAT is a great reason to get some balanced cables for your Mad Dogs!
   
  I've been heavily pursuing the whole speaker-amp thing, lately.  I even sold my originally $999 Burson Soloist (1.28 Watts into 50-Ohms) in preference for the sound of a $189 Emotiva a-100 Mini-X speaker amp (8.0 Watts into 50-Ohm), in combination with a $597 tube buffer (the Decware ZSTAGE, currently equipped with a NOS Siemens 12AU7) to compensate the Emotiva's somewhat bright and harsh treble.  
   
  Where the Soloist had amazingly smooth yet detailed treble, but was too laid back (tenth-row seating), and somewhat lacking in dynamics, the Emotiva puts you right on stage, with lots of punch and slam dynamics, thanks to 8 Watts vs. 1.28 Watts into the 50-Ohm LCD-2, which can really scale to the power (up to 13 Watts per Audeze support.)  
   

   

   
  More on this subject can be found here:  http://www.head-fi.org/t/649107/speaker-amps-for-headphones/675#post_9711285
   
  I'm now waiting on a $500 TBI Millenia MG3 Class D/B speaker amp that's supposed to ship today.  The amp's designer, Jan Plummer, is also sending me an impedance matching box ($110), with resistor values specific to my 50-Ohm headphones.
   

   

   
http://www.tbisound.com/dsp_products_millenia.asp
   
  The TBI Millenia MG3 will deliver 5.12 Watts into 50-Ohms, but it's said to be extremely musical, natural-sounding, organic, yet detailed, transparent, with great dynamics and having an inky-black noise floor.  Yes, all that!
   
  And it has a battery compartment!  Allowing 12V operation with 8 AA alkaline or lithium batteries for 10 Watts into 8-Ohms (1.6 Watts into 50-Ohms - more than a Soloist's 1.28 Watts)!  Or, better still, you can power it with a 24-Volt battery system for 32 Watts into 8-Ohms (5.12 Watts into 50 Ohms).  Battery power = super clean sound.
   
  Check out these TBI Millenia MG3 reviews from the the venerable John Hoffman of Absolute Sound (a highly trusted source of reviews in HiFi):  
   
  Quoting Positive Feedback Issue 62:


> [size=small]In many respects the Millenia amplifier in battery mode is closer in sonics to my Electra Print 300B SET amplifier than it is any conventional solid-state piece. When revisiting the Lucia Hwong piece I found that high frequency notes had a longer decay pattern and had a greater degree of shimmer. The distinctive tone of the wood flute in the opening passage had gained a higher degree of realism. The vocal passages moved farther back in the sound stage and now floated in a space above the instruments, expressing the surrealistic feel of this composition. These gains in musical reproduction move the Millenia amplifier closer to what the Electra Print amplifier achieves, which happens to be a $4000 amp and preamp package. While the Millenia does not have the harmonic density, or the complete transparency of the SET amplifier, it comes shockingly close. Which is quite an accomplishment for a $500 integrated amplifier.[/size]


 
   
  Quoting Positive Feedback Issue 67 (just five issues later, he felt compelled to revisit this amplifier with another review!: 





> [size=small]The performance gap between my Electra Print amplifier and the Millenia amplifier has rapidly closed, as the latest cluster of improvements that Jan has devised for the TBI amplifier has effectively erased the largest flaws from the previous generation amplifier. Earlier versions of the MG3 amplifier had excellent sound quality for the price point, but there were always a sonic signature that was consistent with the Class D circuit design. Essentially, the music had a smooth and refined sound, but never could quite cross that threshold of realism that separated a SET, push-pull tube amp, or even a well executed solid state design from the chip amp contingent. The 2.0 version of the TBI amp has breached that meridian, and is a legitimate high performance amp that is within the financial reach of most any hobbyist.[/size]


 
   
  Take this amateur's review with a grain of salt, but it's a fun read, just the same: 
   
  Quoting http://www.audiocircle.com/index.php?topic=108242.0:


> Now I won't bore you with these details, but the TBI has the quickness of the best OTL's and Class A's, it has the transparency and detail of the best SET and Class A amps, is has the speed and quickness of the best OTL's and Class A's, it has the smoothness and aliveness of the best Set and OTL amps, it plays vocals like the best SET and OTL's, and it images like the best OTL and SET amps. That is why I call this the JCOTLSETCLASSAPASS amp. If John Curl or Nelson Pass came out with a tube amp, this is what it would sound like. I would love to be Nelson Pass's neighbor and take this wee tiny TBI amp and put it on his monster horns. Even Pass would be surprised.


 
   




   
  I think I'm going to make this both my desktop and my (trans)portable amp! 
   
  OK, that was seriously off-topic!  My apologies.
   
  Mike


----------



## spurxiii

I lost out by $1 on a TBI Millenia on ebay which eventually went for $251. I got so upset, I bought the Topping TP60 on impulse. I have some speaker tap cables coming from BTG Audio to drive my HE500s but won't be able to use it for the mad dogs even with a resistor box because the TP60 does not have a shared ground I believe. To keep this on topic I want to say that the PB2 sounds better than my current desktop setup for both the mad dogs and the HE500s. I hope to have a desktop setup which at least sounds better than my PB2 in the TP60.
   
  Nigel, do you reckon I will get much of an improvement in SQ from my PB2 with a TP60 on my HE500s since you've used them with the HE6s it might give me some insight into what to sort of expect.


----------



## SpudHarris

Quote: 





spurxiii said:


> Nigel, do you reckon I will get much of an improvement in SQ from my PB2 with a TP60 on my HE500s since you've used them with the HE6s it might give me some insight into what to sort of expect.


 
   
  Definately.... I still use my TP60 when I fancy a change from my HP-8 with my HE-6. For the price it is an astounding amp. It can't compete with the HP-8 in true terms but it does make me smile when listening via the TP60 because it's not a million miles away but costs five times less. There's something nice about knowing you have a quality piece of kit punching above it's price point.
   
  I've used the HE-6 balanced with the PB2 to good effect but the TP60 just makes them sing. Expect a bigger, fuller sound with improved dynamics and extension. It needs a decent input, rubbish in = rubbish out.


----------



## spurxiii

Thanks Nigel. Its a good feeling to know the TP60s won't sound like rubbish. I almost regretted buying it until I plugged them into my speakers and my speakers have never sounded better. It seems I hear so much more detail from the speakers with the TP60 over my Home Theatre AVR. Am I right in saying that the TP60 will also present lots of detail to my head phones via the speaker taps? I found the sound from the speaker to be very very neutral and linear and somewhat cold and dry.


----------



## SpudHarris

No worries....

The TP60 will offer lots of detail for your HE-500's, I very much doubt you will be disappointed. Have you taken into account the resistors required across + and - ? I added a 10ohm (7 watt) across mine for the HE-6.

Hey we are all family here! What do we call you?

Cheers - Nigel


----------



## spurxiii

Quote: 





spudharris said:


> No worries....
> 
> The TP60 will offer lots of detail for your HE-500's, I very much doubt you will be disappointed. Have you taken into account the resistors required across + and - ? I added a 10ohm (7 watt) across mine for the HE-6.
> 
> ...


 
  Hi, just realised I've never advertised my name before on this forum. You guys can call me Tom, my Vietnamese name is a bit difficult to pronounce so Tom's easier.
   
  I'm going to try it out without any resistors in place and take some care with the volume. Do the resistors give you improved SQ or is it to allow better adjustment of the volume?
   
  Tom


----------



## SpudHarris

You might want to look into the reasoning behind the resisters shorting + & - on the TP60 Tom. I'm no expert but it's something to do with reducing the load to 8 ohms (I think?). I would hate for you to fry your HE-500's for the sake of a little research.
   
  This is a pic that was sent to me....


----------



## spurxiii

Quote: 





spudharris said:


> You might want to look into the reasoning behind the resisters shorting + & - on the TP60 Tom. I'm no expert but it's something to do with reducing the load to 8 ohms (I think?). I would hate for you to fry your HE-500's for the sake of a little research.
> 
> This is a pic that was sent to me....


 
  Thanks Nigel, I'll look into it. Glad I asked.


----------



## spurxiii

Nigel, after reading the first few pages of the speaker amps for headphones thread I think I'll go get a couple of 10ohm 10w resistors and perhaps 10ohm 7w like yours to try out. Thanks for the heads up.
   
  Tom


----------



## SpudHarris

No worries pal. I only went with 7w because they didn't have 10w at the time. If you go lower than 10w you just need to check the heat and ensure they are not changing colour.


----------



## zilch0md

Tom and Nigel,
   
  I barely have a grasp of this stuff myself, but I've been studying this subject quite a bit lately and can say with some certainty that the following statements are true.  (How's that for a disclaimer?) 
	

	
	
		
		

		
			




   
  1)  Amps don't mind seeing a greater load (running uphill), but can be damaged by seeing a load that's less than that for which they are designed (running downhill).  So... you don't have to add resistance in parallel (across the + and - of each channel), for the sake of protecting an amp that's designed for the 4- or 8-Ohm load of speakers from the greater impedance (i.e. 38-Ohms) of a headphone.   *For the amp's sake, it's perfectly OK to run without adding parallel resistors to a load that has a higher impedance than that which the amp expects.*
   
  2) Headphones, like speakers, can tolerate only so many watts peak from any given amp.  *If the amp can produce more power than the headphone can handle, it's a good idea to add parallel resistors - for the sake of the headphones, not to protect the amp. * I've just read that the HE-500 has an impedance of 38 Ohms, but I can't find a specification for the number of Watts it can handle.  The Audeze LCD-2, can handle up to 13-Watts rms (where rms is typically about 70% of peak) into its 50-Ohm load.  *You need to find out how many watts your HE-500 can handle into its 38-Ohm impedance.*  If the amp does not exceed this rating into 38-Ohms, you don't need to add parallel resistors for the sake of protecting the headphones.
   
  3) *How do you translate a power rating into 4- or 8-Ohms into that for a higher impedance (i.e. 38-Ohms)?*  For most amps, the relationship between power out and impedance of the load is not linear, but we can get in the ballpark by using an inverse proportion.  The TP60 is rated at 80 Watts (rms) into 4-Ohms, but the HE-500 presents a 38-Ohm load.
   
*Power Rating of Amp * Expected Impedance / Actual Impedance = Watts into Actual Impedance *(approximate)
   
  80 Watts *  4-Ohms / 38-Ohms =  8.42 Watts (into 38-Ohms)
   
  So, if the HE-500 can handle 8.5 Watts into 38-Ohms, there's no need to add parallel resistors for the sake of protecting the headphones, but you may want to do so for the sake of tailoring the sound, because the amp might actually sound better, or at least different, by adding parallel resistors (or for that matter, by adding series resistors). More on that in the next points...
   
  4)  Keeping all of the above in mind, even if you don't need parallel resistors to protect the headphone from excessive power, you can use parallel resistors to tailor the sound.  *Adding parallel resistors will make the amp sound more aggressive or sharp, less muddy or fuzzy, generally speaking.* *The parallel resistance should be 1/10th to 1 times the impedance of the headphones - to decrease the effective output impedance.* The lower the value of the parallel resistors, the harder the amp has to work to deliver the same SPL at the headphones.  So when you add parallel resistors, SPL at the headphones will increase.  It may seem counter-intuitive, but you're allowing the amp to see less total impedance, not more (just as when switching in two pairs of 8-Ohm speakers instead of one pair, on an amp that offers the ability to drive two pairs simultaneously, presents a 4-Ohm load to the amp, not a 16-Ohm load.)  A lower value of parallel resistance gets closer to being as if there's no parallel resistor. (Duh!)  Increasing the value of the parallel resistor _decreases_ the effective output impedance, but don't bother going any higher than the impedance of the headphones.
   
  5) And now let's talk about series resistance... * If you want your amp to sound less aggressive or sharp, more relaxed, you can add series resistors to the + side of each channel - to increase the effective output impedance*. *The series resistance should be 1 to 3 times the impedance of the headphones.* Once a series resistor hits a value that's 3 times the headphone driver impedance, you've done all the good you're going to do in terms of reducing an aggressive sound by increasing output impedance.  Increasing the series resistance to values higher than three times the headphone impedance will only make things worse, with insufficient damping factor making things muddy.  But there's more...
   
  6) Understand that with dynamic headphones, _when adding series resistors_, you will also be changing the frequency response, because impedance is not flat across the frequency spectrum with dynamic headphones.  With planars, which have a purely resistive impedance, their impedance is flat across the frequency spectrum, and thus, you will not get a shift in frequency response by adding series resistors.
   
  Wow... I wrote a book - a  book that's completely off-topic for this thread. Sorry!
   




   
  Mike


----------



## SpudHarris

Mike, for someone who has barely got a grip you certainly seem to know ten times more than me 

Don't ask me to explain but I tried the LCD2 with the TP60 and they sounded weird and not in a good way. The HE-6 on the other hand was the best I'd heard them sound (until getting the HP8).

I don't mind going off topic a bit so we shouldn't get too bent out of shape. However, due to activity back on this thread I decided to get the PB2 out again and see what it was that made me keep it over the SR-71B. I took my son for his life guarding lesson and relaxed poolside for 45 mins.... This is a truly brilliant amp, I am sticking with my chipset even though runtime is sacrificed. 4 x AD743 + 8 x BUF634 is my choice.

Since I've become satisfied (for now) with my home listening I have given less time to portables. I think I could be happy with just the PB2 now as the form factor and SQ is well suited to my iPod Classic. I think I will shed some portable stuff as the cash would come in handy for my new house move. I just need to pull together a transportable rig for vacations etc.... I think the iCan + CLAS would work for this.

I am quite content at the moment


----------



## zilch0md

Thanks Nigel,
   
  I'm a teacher at heart (not for a living), but teachers will tell you that explaining stuff to others is the best way to learn the material yourself.  I swear I couldn't have told you all of that standing face-to-face.  I had to pull it from several sources to make sure it was correct, and even now, I invite anyone who can find fault with it to set me straight, because I don't want to lead anyone astray.  In other words, that dissertation, above, is really at the limits of my understanding - not at the forefront.  
	

	
	
		
		

		
		
	


	



   
  I hear you regarding the PB2 - I tried replacing dummy buffers with another row of LME49990, but didn't like how "rich" it sounded, nor the slight loss of transparency.  We all have our unique tastes, of course, so I'm back to digging on 4x LME49990 in L/R + dummy buffers sounding great with my PCM-M10 as source and LCD-2 rev.1.  
   
  Like you, however, I'm sometimes amazed at just how satisfying this little portable amp can be - holding its own very well against my Emotiva a-100 Mini-X + Decware ZSTAGE tube buffer - lacking some of the dynamics that come with 8 Watts per channel, but not suffering any of the negative traits I'm hearing with the desktop rig (bright and harsh treble without the tube buffer -or- a loss of resolution and low level detail with the tube buffer).  If only I could find an op-amp as powerful as the HA5002, that's more transparent, I think my PB2 would be "perfect."
   
  Mike


----------



## SpudHarris

You are a bad man! You know I now have to try your chipset :rolleyes:

Tonight is the night I may fall off the Rolling wagon. My name is Nigel and I'm a recovering rollerholic


----------



## spurxiii

Wow Mike you could write a thesis on this. I'll take my time to read this later as I just quickly skim read this. I kind of had a feeling this might have worked without resistors but now I feel better in giving thus a go. Mind you my cables don't come for another week so I'm pretty stoked. Malveaux on the other thread connected the HE500s to the Emotiva which is rated at a similar 50w into 8ohms so I believe I should be ok. Gotta go to work 

Tom


----------



## spurxiii

Hi guys, just had quick listen to the TP60s via the speaker taps I received today and I think they're awesome. Night and day for me. Everything sounds so much more open, cleaner and clearer. I get so much detail now. I'm running it with no resistors and had the volume at 10 o'clock so I don't believe I will fry these. It sounds like it can take more than my ears can. I'm so happy.
   
  Tom


----------



## zilch0md

That's awesome, Tom!  
   
  I love seeing a content audiophile!   Rarer than hen's teeth.  
	

	
	
		
		

		
		
	


	



   
  Enjoy!


----------



## spurxiii

zilch0md said:


> That's awesome, Tom!
> 
> I love seeing a content audiophile!   Rarer than hen's teeth.
> 
> ...


Thanks Mike and Nigel for all your help with this new hobby of mine. Am I to expect big changes like this on the PB2 when the Topkit arrives? I hope so because the mad dogs are sounding a little flat after hearing the speaker taps


----------



## zilch0md

Quote: 





spurxiii said:


> Thanks Mike and Nigel for all your help with this new hobby of mine. Am I to expect big changes like this on the PB2 when the Topkit arrives? I hope so because *the mad dogs are sounding a little flat after hearing the speaker taps*


 
   
  Haha!  
	

	
	
		
		

		
		
	


	



   
  You're suffering from the phenomenon of "adaptive hedonism" - that tendency of human nature to quickly adapt to new, higher standards - which applies to any and all things that are found pleasurable - such that going back to a lesser quality experience is next to impossible.  
   
  I have to look no further than my coffee-drinking habit to acknowledge the truth of adaptive hedonism.  I can no longer stand to drink the stuff they brew in the employee break room at work, but I used to drink it all the time.  And the list goes on forever, to include just about everything we enjoy in life!
   
  But do not despair regarding your PB2. I'm really glad you ordered Ron's (HiFlight) TopKit for PB2. Isn't he a great guy?
   
  You're in for a wild ride of op-amp rolling!  Sorry about all the free time you used to spend doing other stuff!  
	

	
	
		
		

		
		
	


	




  I was truly obsessed with rolling op-amps in the PB2 for about three months, going just a few days at a time with each of several combinations.  *Ask Nigel to show you a picture of his op-amp collection!  *He has really been there and done that!
   
  Nigel and I just recently discussed how we are sometimes amazed at how well the little PB2 competes with our desktop rigs.  I've yet to build any rig, either desktop or portable, in which I cannot find room for improvement.  My iBasso PB2 equipped with LME49990 and dummy buffers, when used with my source, my headphones, and for my personal tastes, is nearly "perfect" except for its inability to compete in terms of dynamics and bass control that my speaker amp's 8 Watts into 50-Ohms can deliver with the LCD-2, which scales very nicely to the additional power.  But man, the PB2 with LME49990 is nearly flawless in every other regard and the dynamics it delivers, as is, are superior to what I experienced with the Burson Soloist's 1.28 Watt's into 50-Ohms.  The Soloist is too laid-back (10th-row seating) and unassertive for my tastes.  I kid you not, the PB2 (with LME49990), balanced out to LCD-2, smokes the Soloist, in my opinion - and that's without buffers!
   
  I don't really know what Ron (HiFlight) is including with the TopKit for PB2, lately, as he constantly improves the selection of op-amps, but you haven't begun to hear what the PB2 can do for you until you've moved past the stock op-amps that iBasso ships with it.  I'm pretty sure Ron now includes a slightly more powerful and less analytical-sounding version of the LME49990 in his TopKit - the *LME**49860*.  If you put those in L/R and drop his TopKit's *HA5002* in as buffers, I think you'll find that a hard combination to beat, in terms of power and dynamics from a little portable amp.  
   
  And then, of course, there's the improvement you could hear when going balanced - to get the benefit of twice the power that you have now - which again, only reveals itself with headphones that can scale to more power - which you've now proven is the case with your Mad Dogs and speaker amp.
   
  Mike


----------



## SpudHarris

Mike, I thought I had tried the 49990's with dummy buffers. I gave in to temptation last night and rolled that configuration. Now I don't know what has changed since I tried that combo but I don't ever recall it sounding this good. I even tried different buffers but they all seemed to add a veil of some degree. Without the buffers the PB2 does offer amazing transparency with the LCD-2 in balanced mode. I am content to leave it set up like this for a while, it may suffice as both portable with my ES-5's and transportable with LCD-2's.
   
  Man I forgot how good this amp is!!


----------



## zilch0md

Nigel!   I had figured our different assessments were just a difference in taste, so either way, I respect your preferences, but it's GREAT to hear you like the LME49990's with dummy buffers.  As you've reiterated, I can't find a real buffer that doesn't take away some transparency.  Without question, the HA5002 are the best, but even they smother the micro details that add so much to imaging and sound stage.  Dummy buffers let us hear nothing but what the op-amps in L/R have to offer and in the case of the LME49990, that's a lot.
   
  Thanks to Ron (HiFlight), I'm now resisting the urge to try what he prefers over the LME49990.  (Will the rolling of op-amps ever come to an end?)  
   
  He says the *LME49860* duals offer about 20% more current and have a more analog, less analytical sound.  That might be great for headphones other than the Audeze offerings - for something like AKG 5xx or 7xx, or some of the ATH, or Beyerdynamic offerings - but I'm thinking it might be too tube-like for my tastes with LCD-2, which sound "perfect" to my ears with the more analytical LME49990.  But I'm thinking about trying them just the same.
   
  Have you ever tried LME49860 in the PB2?
   
  Mike


----------



## SpudHarris

Haha, got them in now!
   
  Report back later....


----------



## spurxiii

Quote: 





zilch0md said:


> Haha!
> 
> 
> 
> ...


 
  Adaptive hedonism, quite an interesting concept but I guess its true. Does it apply to the wife also? 
	

	
	
		
		

		
		
	


	



   
  All this op-amp rolling talk has got me quite scared actually. What have I gotten myself into.
   
  Can I safely say that my desktop setup is now better sounding than any portable setup I could achieve (assuming the same headphones)?


----------



## SpudHarris

Mike, I bet you have sat there biting your nails waiting to hear about the LME49860. 

Well, rest easy pal. To my ears the 49990 is still king, although it's close. Indeed the 49860 is nice and will appeal to some over the 49990 as it is slightly more laid back but with the LCD2's at least, the 49990 nails it. Transients in electronica/psy(dub/trance) are unmatched as is soundstage. The 49860 is more analogue but also more personal, probably more suited to IEM's which is a shame given it's increase in current over the 49990.

Anyhoo, if you are curious? Ping me your address and I will send you a couple to test.

Listening with LCD2's (balanced) and PB2 with 49990 and dummy buffers in high gain (20db) and I doubt the LCD2's have sounded much better. 

I feel another beer coming on


----------



## zilch0md

Sheesh!  That's great news!  Your description of the LME49990 reinforces my perception with the LCD-2.  So, I find your assessment of the LME49860 to be very credible - good enough to forgo testing them myself - but thanks so much for volunteering to lend them to me (all the way from the UK, no less!)


----------



## Uchiya

With the dummy buffers, are the op-amps in L/R pushing less than the 2w of current?


----------



## zilch0md

I suspect that most combinations of op-amps in the PB2 (not using dummy buffers) supply less than 2W per channel into balanced headphones (despite iBasso's unqualified spec of 2.5 Watts.)

But, for sure, dummy buffers supply zero current gain.

What headphones are you thinking of using?


----------



## Uchiya

I was going to try pairing the HD800 in the future.


----------



## zilch0md

Uchiya,
   
  You might want to run with HiFlight's favorite op-amp - the recently discussed (above) LME49860.  The HD800 will appreciate the more analog sound and the additional power of the the LME49860 (over the more analytical sounding LME49990 that works so well with the LCD-2.)
   
  Send a PM to Ron (HiFlight) and ask him to send you his TopKit for PB2 (which I think will include the LME49860 and HA5002 buffers, as well as some other op-amps you can try), but ask him what he thinks would work best in the PB2 with the HD800.
   
  Mike


----------



## spurxiii

Just got the Topkit and as you can see I've dropped in the LME49860s and the buffers included. Can someone tell me what the left over chips are. Also have I installed it correctly? 
Thanks, Tom


----------



## zilch0md

Here's a chart I created when I bought one of Ron's TopKits a couple of years ago. There may be some overlap with the op-amps you've received, so try to match the appearance, but your best bet is to just send Ron a PM and ask him what you've got in the latest version of his kit (which constantly evolves).



If you want to know others' opinions of each, just search this thread or the op-amp thread.

So, how does the currently mounted set sound?

Mike


----------



## spurxiii

zilch0md said:


> Here's a chart I created when I bought one of Ron's TopKits a couple of years ago. There may be some overlap with the op-amps you've received, so try to match the appearance, but your best bet is to just send Ron a PM and ask him what you've got in the latest version of his kit (which constantly evolves).
> 
> 
> 
> ...


Just had a quick 1 minute listen and it definitely sounds fuller. The bottom end sounds wider, the mids have smoothed out and sounds more mellow, less cold and metallic and less fatiguing.


----------



## spurxiii

I've just given the top kit a bit more of a listen and noticed the volume isn't greater than with the stock setup. It is clearly less fatiguing and the extended bass isn't more extended than the stock setup as what I first thought. The sound isn't really too different, slightly more smoother and less cold. I was expecting a bigger change.


----------



## zilch0md

I learned to listen during my three months of incessant op-amp rolling with the PB-2. I can assure you that the more time you spend trying different combinations, with at least a couple of days listening to each, their distinctions will become a lot more obvious.


----------



## spurxiii

zilch0md said:


> I learned to listen during my three months of incessant op-amp rolling with the PB-2. I can assure you that the more time you spend trying different combinations, with at least a couple of days listening to each, their distinctions will become a lot more obvious.



I'll give it a go. I'm already enjoying this setup more and more


----------



## zilch0md

"Enjoying" is the good word in that sentence.  
	

	
	
		
		

		
			




   
  As much as I was hoping to explain that the difference between op-amps becomes more obvious with experience, I should be celebrating your ability to just enjoy the music, without getting caught up in analysis of the sound.  
   
  35 years ago, I had a HiFi system that, today, would cost at least $50,000.  I had the best of the best from Carver, Hafler, Dahlquist, etc.  A very good friend of mine had an old Fisher console (a single piece of furniture with a "record changer" + AM/FM radio + two speaker cabinets built into either end.)  That Fisher console was the worst of the worst in terms of sound quality.  The speakers literally knocked in their surrounds because the foam had decayed, the amp snapped, crackled, and popped, and a constant high frequency hiss, but Craig, my friend, enjoyed music like no one else I've known before or since.  He had a  M A S S I V E  collection of LPs and loved nothing more than taking me on "tours" of various artists - he was my music appreciation guru.
   
  The first time he heard my over-the-top system, he was truly awe-struck.  His LP's were so scratched, I had replaced a $250 Audio-Technica AT20SS MM cartridge with a $60 Shure before playing any of them on my turntable.  Despite the scratches heard in the records he had brought with him, he sat there with his jaw hanging open, nearly speechless.  After that one Saturday, listening to my system, he chose to never come back because he didn't want to get jaded to the sound quality.  Thereafter, we did all of our joint listening at his place.  He died of a heart attack, after multiple surgeries, at the age of 27 (congenital heart failure).  
   
  Moral of the story - I'd rather you be more like my friend Craig, than like me - there's a lot more pleasure in enjoying the music than there is in being a gear tweaker.  
	

	
	
		
		

		
		
	


	



   
  Mike


----------



## spurxiii

Sounds like Craig enjoyed life before he died, and although sad, a good story. I think I enjoy the music more than the gear and I know I'm enjoying it when I get goosebumps listening and I've gotten more goosebumps lately than I ever have so its a good experience. I'm guessing the better gear allows me to "enjoy" it more which makes this journey so well worth it and the most enjoyable hobby I've ever experienced.
   
  I only found headfi recently but through headfi I've gotten the gear and the advice in music that I would never had thought of listening to. You know I only heard Pink Floyd for the first time in May this year and Dire Straits also. When I heard Mark Knoflers guitar for the first time in Money for Nothing I nearly fell off my seat. And this is all just a few months ago. I was listening to some uplifting trance music walking home from work on the PB2s and it sounded so good I was literally danced home from the station.
   
  Although you're obviously a gear tweaker (the biggest tweaker I've read about here), you must also "enjoy" the music otherwise there's no point right? 
   
  Tom


----------



## spurxiii

Quote: 





zilch0md said:


> "Enjoying" is the good word in that sentence.
> 
> 
> 
> ...


 
  I just realised what you wrote here. Wow, I could never dream of having anything like that, do you still have it or something similar?


----------



## zilch0md

Heee-hee!  I wish!  
   
  Back then, I was making a lot of money for a guy my age (in a fire equipment business, of all things). I had a modest apartment and a modest car, but a killer stereo system, killer clothes (Bill Blass, Yves St. Laurent, etc.) and a killer girlfriend!
   
   
	

	
	
		
		

		
		
	


	



   
  I ended up selling all of it (not the clothes or the girlfriend - I married her) for about half what I had paid for it all, just five years after I had begun building and upgrading the system.  A single buyer took everything except my LPs and cassettes.  He wanted to make sure he could get the exact same sound at his place.  
   
  I've never since gone back to Hi-Fi.  Headphones (and the girlfriend who turned into a wife and mother) are expensive enough.  
   
  Mike


----------



## spurxiii

zilch0md said:


> Heee-hee!  I wish!
> 
> Back then, I was making a lot of money for a guy my age (in a fire equipment business, of all things). I had a modest apartment and a modest car, but a killer stereo system, killer clothes (Bill Blass, Yves St. Laurent, etc.) and a killer girlfriend!
> 
> ...




And I had thoughts of you being a multi millionaire with a 60 foot yacht driving around in a Bentley


----------



## Uchiya

With that much money he wouldn't need to have headphones, because he wouldn't need to hear at all.


----------



## spurxiii

uchiya said:


> With that much
> money he wouldn't need to have headphones, because he wouldn't need to hear at all.




Lol great response


----------



## zilch0md




----------



## spurxiii

I've been Opamp rolling, damn its so hard not to do. I've got the case screws permanently off now with the PB2 tied around my iphone with 2 Fiio Bands. I've tried the stock 797s as buffers, at first I liked it but eventually it became too warm and fuzzy for my tastes. I've also been switching between the LME49860 and the 797s as opamps and the keeping the topkit HA5002 as buffers and to me they sound very similar, but both very good. I might listen to each for a couple of days and see how I go. Everything else is too bright for me.
   
I'm trying out the 797 (blue opamps) and HA5002 buffers first, it suits the mad dogs and the Gr07s I use as portables.


----------



## zilch0md

Haha!  I love that you've decided to leave the case open!  Good one!  You're into it now, Tom!
   




   
  Yeah, you can drive yourself nuts popping them in and out too quickly.  That's exactly what I did at first.  But different tracks will reveal stuff that other tracks won't, so going a couple of days or even a week with a given combo is a lot smarter, in my opinion.  
   
  Another tactic is to try, and this can be hard for me to do, at least, try...  to ignore the technical analysis and just ask yourself if you are _enjoying_ the music.  If there's something technically annoying about the combination of op-amps you're using, it will be obvious to you without "looking" for it.  Just get to know a set and enjoy the music - the technicalities will make themselves known automatically and your assessment of the technicalities will be more accurate than if you try to deliberately analyze it.
   
  Lastly, switching back to the set you had used previously (a few days earlier) can be very very revealing - because you are already familiar with that signature, you'll recognize its distinguishing traits more profoundly than you did when you heard it on the first pass.  Right then and there, after listening to a few well-known tracks, is where you should take some notes.  Then move on to a new combination.  
   
  Mike


----------



## spurxiii

Mike, you were 100% right about the amps sounding different. Switching between all the buffers and opa-amps and even using the amps as buffers reveal totally different sounds. After yesterdays session my ears are fried and need a break. I'll now stick with one configuration for a while to see which one I enjoy more. Problem is its too hard as there are too many configurations I enjoy and they are good for different genres and phones. I'm trying to find one that is good for all things and leave it at that.


----------



## SpudHarris

spurxiii said:


> Mike, you were 100% right about the amps sounding different. Switching between all the buffers and opa-amps and even using the amps as buffers reveal totally different sounds. After yesterdays session my ears are fried and need a break. I'll now stick with one configuration for a while to see which one I enjoy more. Problem is its too hard as there are too many configurations I enjoy and they are good for different genres and phones. I'm trying to find one that is good for all things and leave it at that.




Tom, the closest I got to a chipset to suit all was Opa1611 (class A mod) x 4 + BUF634AU x 4....


----------



## SpudHarris

Oh, sorry to add fuel to the fire!


----------



## spurxiii

Quote: 





spudharris said:


> Oh, sorry to add fuel to the fire!


 
  Not at all Nigel, another configuration I've got to try so thankyou. I'm not after perfection, I'm just after general enjoyment
   
  Have you heard the OPA2134? What do you think of them?
   
  Also, what's a class A mod? Is it an adapter?
   
  Tom


----------



## spurxiii

I'm after a sound that's slightly warmish in the low end but clear in mids and highs and bass does not bleed into the mids. I really liked the sound of the stock chips AU797 x 4 and the BUF634P but it had a mettalic twang in the bass on some tracks which I didn't like about.
   
  Tom


----------



## Makiah S

Well I to am selling my Slate JDS Labs C5, to buy this amp xD, going to run a Beyer Dt 880 Pre 600 ohm portable balanced [mine's already been recabled] out of a Hm 801 and then into this
   
  What would be the leanest set of Op amps and Buffers, The Hm 801 is going to have all warmth I need now I just want the amp to be as clean lean and tight as I can get er! 
   
  Also any one selling one ;3


----------



## SpudHarris

The class A mod is in the form of a DIP socket with a resistor across two pins (4 and 7???). Sorry Tom it's been a while :rolleyes:.

Not sure I have pics on this Ipad but will post some for sure if not from the home PC.

I think that configuration will cover your needs and you can always swap the buffers for stacked BUF634P if you need to smooth it out slightly.


----------



## Makiah S

Quote: 





spurxiii said:


> I'm after a sound that's slightly warmish in the low end but clear in mids and highs and bass does not bleed into the mids. I really liked the sound of the stock chips AU797 x 4 and the BUF634P but it had a mettalic twang in the bass on some tracks which I didn't like about.
> 
> Tom


 
  You know... looking at your portable rig are your using an iPhone as a source? That Metallic Twang is something I heard when I owned and amp'd my old iPod Nano... if you want a slightly warmish sound but clear mids and highs... try going for a Hifiman DAP. The bass is nice and smooth Great speed and tightness with a warm sound to it, mids r touch forward and a little sparkle in the treble. The DAP might be a tad to warm for the mad Dogs, but honestly i'd imagine a better source might yeild better results, if your feeding your amp a sub par signal, there's nothing the amp can do to make crap into gold 
   
  I used to own a iDevice and the sound pretty bleh, Still I'm happy to hear the stock sound at the very least has that issue to it, the Dt 880s have such a big fat resonnace in thier low end some metallic twang might balance em out lol


----------



## spurxiii

mshenay said:


> You know... looking at your portable rig are your using an iPhone as a source? That Metallic Twang is something I heard when I owned and amp'd my old iPod Nano... if you want a slightly warmish sound but clear mids and highs... try going for a Hifiman DAP. The bass is nice and smooth Great speed and tightness with a warm sound to it, mids r touch forward and a little sparkle in the treble. The DAP might be a tad to warm for the mad Dogs, but honestly i'd imagine a better source might yeild better results, if your feeding your amp a sub par signal, there's nothing the amp can do to make crap into gold
> 
> I used to own a iDevice and the sound pretty bleh, Still I'm happy to hear the stock sound at the very least has that issue to it, the Dt 880s have such a big fat resonnace in thier low end some metallic twang might balance em out lol


funnily enough I actually like the warmth of the bass on the iPhone but it just won't give me the volume for that mad dogs. I've run the PB2 via the pc and I believe the metallic twang is from the PB2. Non of the amps I've tried from the iPhone had this sound. I really did like the warmish bass when I used the 797 op-amps as buffers but the bass ate into the mids too much and I lost all details in the mids and highs


----------



## Makiah S

Quote: 





spurxiii said:


> funnily enough I actually like the warmth of the bass on the iPhone but it just won't give me the volume for that mad dogs. I've run the PB2 via the pc and I believe the metallic twang is from the PB2. Non of the amps I've tried from the iPhone had this sound. I really did like the warmish bass when I used the 797 op-amps as buffers but the bass ate into the mids too much and I lost all details in the mids and highs


 
  again if ur using the on board mother board sound your not going to have any details to begin with, but you might be right. Still any one have pictures of what the OP amp swaping and Buffer swaps look like? How would I change the op's and buffers in my unit? [Obviosuly open it up but aside from that then what...]
   
  In addition I always found the Mad Dogs to be really  warm... and hearing that a Fully Balanced Amp results in losing detail in the mid range and highs sounds alittle off... Still I'd like to tinker with it my self, although I hold to the idea that the iPhone and the Pc [if your using the Stock DACs in both] are teh culprit.
   
  My old iPod had no mid or high details, and my on board pc audio was the same. You really need a better source to accurate judge the sound of an amp as nice as that. But if all you have is Stock Mother Board Sound and n iPhone it's not a wonder you'r having issues with quality.


----------



## spurxiii

mshenay said:


> again if ur using the on board mother board sound your not going to have any details to begin with, but you might be right. Still any one have pictures of what the OP amp swaping and Buffer swaps look like? How would I change the op's and buffers in my unit? [Obviosuly open it up but aside from that then what...]
> 
> In addition I always found the Mad Dogs to be really  warm... and hearing that a Fully Balanced Amp results in losing detail in the mid range and highs sounds alittle off... Still I'd like to tinker with it my self, although I hold to the idea that the iPhone and the Pc [if your using the Stock DACs in both] are teh culprit.
> 
> My old iPod had no mid or high details, and my on board pc audio was the same. You really need a better source to accurate judge the sound of an amp as nice as that. But if all you have is Stock Mother Board Sound and n iPhone it's not a wonder you'r having issues with quality.




I was using the audio gd 15.32 as a dac via usb. It drives the HE500s via the Topping TP60 really well.


----------



## Makiah S

hmm and there was no mid detail... did u check ur gain my matrix gets a thick bass n no details when i run my beyers at 18 gain... n they r 600 ohms at that


----------



## Makiah S

spudharris said:


> The class A mod is in the form of a DIP socket with a resistor across two pins (4 and 7???). Sorry Tom it's been a while :rolleyes:.
> 
> Not sure I have pics on this Ipad but will post some for sure if not from the home PC.
> 
> I think that configuration will cover your needs and you can always swap the buffers for stacked BUF634P if you need to smooth it out slightly.




Spud what combo of ops n buffers would yeild the most linear sound


----------



## spurxiii

Sorry meant to expand a bit on that. I have that metallic artificial twang sound in the bass with the PB2 even though connected to a the Audio GD DAC via USB from my PC so I don't believe its the source. For me trying to reduce the twang (not sure if its even a word but you understand right) increases the warmth in the bass which I like but it ends up always affecting the mids and highs.
   
  My topping TP60 (speaker taps) via the same source beats the PB2 in every way via the same source and headphones (HE500s). I didn't like my old ipod nano either (no mids and no highs) and didn't like the sound of the iphone 5 (bass is bloaty and it clips on some of my iems), I'm not sure if there are any differences inside but I actually like the iphone 4 and 4s which I use both as a standalone player and to drive the PB2s. I might purchase another DAP but at this stage I still like the iphone 4 and will later consider an upgrade once I feel like I'm ready.


----------



## spurxiii

Damn it Mshenay, now listening to my desktop rig again, you got me thinking I might need a new DAP. Any recommendations on a decent DAP that will do the PB2 and Mad Dogs justice? The bigger the storage available the better also.


----------



## SpudHarris

Class A DIP mod for Dual and single OpAmps


----------



## spurxiii

Geez, I better learn how to solder


----------



## SpudHarris

Haha, the top ones were done recently, the bottom ones were done as I was learning, I really enjoy tinkering  I have some spares lay around, if you ping me your address I'll pop a few in the mail for you....

The OpAmps that seem to benefit the most are the OPA1611 (singles) and LT1678 (duals). Both of which have been in the Top Kit at some point.


----------



## spurxiii

Wow Nigel, you're so kind. I might take you up on that offer to try but not until I sort out my DAP otherwise I'm not doing them justice. Any recommendations?


----------



## Makiah S

Quote: 





spudharris said:


> Haha, the top ones were done recently, the bottom ones were done as I was learning, I really enjoy tinkering
> 
> 
> 
> ...


 
  Hell I'd pay for some of those [SHIPPING COSTS <3]
   
  Better question, how does the PB1 compare to the PB2 Sonically and power wise?


----------



## spurxiii

Quote: 





mshenay said:


> *Hell I'd pay for some of those* [SHIPPING COSTS <3]
> 
> Better question, how does the PB1 compare to the PB2 Sonically and power wise?


 
  So would I


----------



## Makiah S

Quote: 





spurxiii said:


> So would I


 
  More importantly [some one is selling a Pb1] so how does it compare to the Pb2?


----------



## spurxiii

Quote: 





mshenay said:


> *Well I to am selling my Slate JDS Labs C5*, to buy this amp xD, going to run a Beyer Dt 880 Pre 600 ohm portable balanced [mine's already been recabled] out of a Hm 801 and then into this
> 
> What would be the leanest set of Op amps and Buffers, The Hm 801 is going to have all warmth I need now I just want the amp to be as clean lean and tight as I can get er!
> 
> Also any one selling one ;3


 
  Lol I'm also selling my JDS C5. But I aint selling my PB2, she's a keeper. This amp rolling is addictive


----------



## Makiah S

Quote: 





spurxiii said:


> Lol I'm also selling my JDS C5. But I aint selling my PB2, she's a keeper. This amp rolling is addictive


 
  Thankfully I have headphones to sell with mine <3 that and I have the orignal Box and paperwork [HA]
   
  But I might try the Pb1, it seems cheap enough and should have more power than ANYTHING in it's price range [sub $200] I also hear people whining about the mids being to controlled, and not lush enough [YES]
   
  And while Op rolling is addicting, I don't feel like DEALING with it, and while 3 gain JUMPERS is great I'd rather have a SWITCH -.-
   
  That being said I do like the Simple'r approach of the Pb1 but ofc I'm sure at some point <.< I'd want that POWER of the pb2 
   
  So I'm still un sure


----------



## SpudHarris

Quote: 





mshenay said:


> Hell I'd pay for some of those [SHIPPING COSTS <3]
> 
> Better question, how does the PB1 compare to the PB2 Sonically and power wise?


 
  Let me have a look and see what I have and I'm sure I can sort you out. I've got hundreds of plain adapters and 2.2k resistors so I could always knock a few up. I'm guessing you guys would want 4 x singles and 2 x duals?
   
  Never had the PB1 but can't imagine ibasso would replace it with something inferior....


----------



## Makiah S

Quote: 





spudharris said:


> Let me have a look and see what I have and I'm sure I can sort you out. I've got hundreds of plain adapters and 2.2k resistors so I could always knock a few up. I'm guessing you guys would want 4 x singles and 2 x duals?
> 
> Never had the PB1 but can't imagine ibasso would replace it with something inferior....


 
  Indeed, and Pb1 one owners tell me the build quality of it was kinda meh and it was only half as powerful
   
  and these are op amps where are talking about right


----------



## zilch0md

mshenay said:


> again if ur using the on board mother board sound your not going to have any details to begin with, but you might be right. Still any one have pictures of what the OP amp swaping and Buffer swaps look like? *How would I change the op's and buffers in my unit? [Obviosuly open it up but aside from that then what...]*




Here you go....

http://youtu.be/46QoCeD_du8

Warning: you wouldn't know it from watching this video, but the pins can be easily bent or broken if you handle the op-amps the way this fellow does. Go easy...

Mike


----------



## Makiah S

Quote: 





zilch0md said:


> Here you go....
> 
> http://youtu.be/46QoCeD_du8
> 
> ...


 
  Ahh indeed, and yea he was a little rough, I work on computers so trust me... I got lot's dem tools and I love me some desk space to work with... might need some small pliers or something but not a big deal
   
  what I REALLY need is some one to SELL another pb2 >.> or at LEAST some one to sell one used!


----------



## SpudHarris

mshenay said:


> and these are op amps where are talking about right




The adapters not the actual OpAmps....


----------



## Makiah S

Quote: 





spudharris said:


> The adapters not the actual OpAmps....


 
  I figured as much thanks. Can any one tell me what the HifiKit is for the Pb2? I assume it includes these adapters and some additional OP amps
   
  Although I did just buy a fully functional Pb1 for $55, that being said... does the Pb1 and the Pb2 use the same balanced out? The pictures make it appear that it indeed does, so I got a Pb1 for $95 [including the balanced converter cable I need for my 4pin terminated dt 880s] 
   
  Either way I am excited, now let's assume the pb1 sucks and I hate it terribly
   
  the Pb2 where dose one get the HifiKit? And what does it include


----------



## spurxiii

mshenay said:


> I figured as much thanks. Can any one tell me what the HifiKit is for the Pb2? I assume it includes these adapters and some additional OP amps
> 
> Although I did just buy a fully functional Pb1 for $55, that being said... does the Pb1 and the Pb2 use the same balanced out? The pictures make it appear that it indeed does, so I got a Pb1 for $95 [including the balanced converter cable I need for my 4pin terminated dt 880s]
> 
> ...


PM HiFlight, Ron sells 

IMO the stock op-amps aren't bad 

Ron's TopKits are good but it's not a night and day difference for me, just a chance to try a different sound


----------



## eversuvok

great.Now we just need to advance 10 years into the future where these things can fit in thinner chassis


----------



## CharliePolk

want to try this to, I like sound character from iBasso's amp.


----------



## Mooses9

I've been thinking of the pb2 but the ibasso p4 warbler had been more than powerful enough and I have a ton of opamps for it. at 600mw+600mw I feel it's more than powerful to drive iems. That and I have been able to recreate the sound of my sr71-b with the p4 and some opamps actually to my ears the p4 sounds better but the sr71-b still has some majic to It. 

Im heavy thinking of the pb2 but ron said single ended to single ended he would choose the p4 and im not unsatisfied with the p4 so I will jist have to wait and see if one pops up for a decent ammount pr just be satisfied if possible in this hobby lol


----------



## Makiah S

charliepolk said:


> want to try this to, I like sound character from iBasso's amp.


 
  
 got my pb1 in today, I like it.


----------



## zilch0md

Joy!


----------



## mkinmkin

Hello.
  
 I am a new comer and have not owned any protable amps yet. I have ordered DX50 3rd batch and waiting to receive it. My present gear is Cowon J3, TF 10 pro (change to E5C housing) and a custom made cable.
  
http://imgur.com/O25l56R
  
 I am interested in PB-2 or DB-2, but have no idea which model is more suitable for DX50 and my IEM.
  
 Would you please give me some advice?
  
 Thanks~


----------



## spurxiii

I have also ordered the dx50 on the third batch and planning on running my pb2 from them. The db2 is a standalone DAC, the PB2 is a standalone Amp.


----------



## spurxiii

I hear that the dx50 is made for IEMs so you probably won't be needing an amp. Try it before you buy the amp. I need the PB2s because I'm driving kind of hard to drive headphones


----------



## mkinmkin

spurxiii said:


> I hear that the dx50 is made for IEMs so you probably won't be needing an amp. Try it before you buy the amp. I need the PB2s because I'm driving kind of hard to drive headphones


 
  
 Thanks. Yes, I will wait for the DX50 and test it on my IEM before I buy any AMPs. But as a IEM such as TF10 Pro or SE535....etc, is it necessary to have a AMP as upgrade?


----------



## spurxiii

mkinmkin said:


> Thanks. Yes, I will wait for the DX50 and test it on my IEM before I buy any AMPs. But as a IEM such as TF10 Pro or SE535....etc, is it necessary to have a AMP as upgrade?


 
  
 I've got a UE900 and an amp doesn't improve it much. Just because its expensive doesn't mean its better


----------



## Mooses9

Ive converted my whole portable rig over to use with the db2 and pb2

Got a Iriver ihp140 optic out to db2 optic in using a sys_concepts custom cable, ibasso balanced from the db2 to pb2 then balanced out with toxic silver poison to westone w4r. I havent gotten all parts in but all are on there way

Im also getting a toxic silver poison ibasso balanced to rsa balanced to use with my toxic silver poison westone cable.

Im coming from the algorthyhm solo dac to the db2 dac hopefully I like it lol I made a ton of previsions for the use of both the db2 amd pb2. Should be a pretty powerful portable rig/ desktop replacement

Will also be using the db2 with ny sr-71b


----------



## zilch0md

Planning is half the fun, eh?


----------



## Mooses9

Yeah its the little things that give you hickups like needing to convert the cd11 from ibasso balanced to xlr to ibasso balanced rsa.

Then needing to get a ibasso balanced to rsa balanced cable made so I csn use my rsa with the db2


----------



## Makiah S

zilch0md said:


> Planning is half the fun, eh?


 
  
 I totally agree


----------



## Mooses9

Can anyone give me their opinion on the db2 sound? Im so eager to give the setup a listen and they came in the post but im at the hospital girlfriend is getting shoulder surgery......I dont think she would understand if I left to audition my audio equipment LOL


----------



## Makiah S

mooses9 said:


> Can anyone give me their opinion on the db2 sound? Im so eager to give the setup a listen and they came in the post but im at the hospital girlfriend is getting shoulder surgery......I dont think she would understand if I left to audition my audio equipment LOL


 
  
 Agree'd STAY BY HER
  
 The Db1 has a nice sound, spacious. Well detailed, wonderful sound stage ofc! I would hope the DB2 would sound the same of better 
  
 Ironically though the pb1 is laid back compared to the clean lean and spacious db1


----------



## Mooses9

hey can anyone confirm something for me. when you plug in a optical cable to the ibasso db2, is it supposed to light up red? i plugged my sys-concepts custom cable in and get nothing no light or anything. am i doing something wrong? or am i only supposed to  get the optical light from the dap?
  
 edit nevermind.
  
 but for reference if you are using a iriver ihp-120-140 go to settings>controls>optical out>yes/no?>yes and your optical output is now on.
  
 pardon me, i have just gone from a ipod touch to the iriver which imo the iriver ihp-140 is much more control based vs the ipod where ipod is just plug and play really not alot of controls
  
 on another note, i got most of my setup in, pb2>db2>sys-concepts custom optical cable>ibasso balanced cable>iriver ihp-140>westone w4r
  
 i feel its pretty impressive although i am currently only using the stock cable vs my toxic silver poison per the toxic cable being terminated in rsa balanced. so i am going to have a ibasso balanced to rsa female cable made so i can use it with this setup.
  
 however even with the stock cable, it sounds very good on first listen, its warm per the stock cable, i think once i get my toxic cable in the mix it will brighten up the sound a bit


----------



## jamato8

That is a nice combination.


----------



## msromike

I searched the forum for 10 mins because I know it's in there, just couldn't find it.
  
 When using the DB2 with the external power supply do you leave the charge switch on or off?
  
  I am assuming if the charging switch is on you get the 14V from the battery at the amp section and the charge is keeping the battery topped off.  Then if you set the switch to off, it bypasses the battery and you get 16v to the amp.
  
 Did I get it right?


----------



## SpudHarris

msromike said:


> I searched the forum for 10 mins because I know it's in there, just couldn't find it.
> 
> When using the DB2 with the external power supply do you leave the charge switch on or off?
> 
> ...




For certainty just unplug the internal battery and try the on off switch with charge switch on and off also. I did this ages ago but can't remember the results doh!

I think that it may well take power from the external power pack no matter if in charge or off position....

Let us know what you find, I may even get mine out and test again.


----------



## zilch0md

I had the DB2 at one time and I still have the PB2.  I think they work the same in this regard...  
  
 When the AC adapter is plugged in, the amp will operate at 16V whether or not you have also turned on the battery charger.  It's impossible for the amp to operate at less than 16V when the AC adapter is connected.
  
 Hint:  Pay careful attention to how bright the *front* LED is when the amp is turned on, comparing the brightness when operating from the battery with no AC adapter attached vs. from the battery with the AC adapter attached and charger turned off.  A brighter LED indicates a higher operating voltage.  (This is true for a lot of portable amps.)
  
 Then again, with the AC adapter attached, comparing charger turned off vs. charger turned on.   
  
 I predict you will see only two degrees of brightness (bright and not so bright), where the brighter of the two happens whenever the AC adapter is plugged in, whether or not the charger is turned on, and the darker of the two when the AC adapter is not plugged in - when operating only on battery power.
  
 Mike


----------



## puskuruk

What do you think about:

 x3(I already have) /dx50/qa350+db2+o2(I already have) /pb2/aha 120/predator 

Or

HDP-R10

Which is the best sq for iem?


----------



## zilch0md

I'm thinking DX50 headphone out straight to the IEM...


----------



## Mooses9

Doesnt make muxh sense to buy a decently expensive dap not to use it as a media carring device. Because once you arent I using it for the dac or amp it really serves no purpose.

Im using the ihp-140 dap to fiber optic cable to db2 and then to pb2 thats a little dofferent as im using the dap for its fiber optic capabilites.


----------



## Wyd4

Hi All,
  
 First of all my setup.
  
 AK100>ADL interconnect>PB2 (stock OP-AMPs and the dummy buffers)
  
 I was wondering what recommendations you have for OPAMPs and Buffers.
  
 The sound as I have it now is nice and clear etc, however I was wondering if there are better options (I am sure there are).
 I want the amp to be as true to source as possible, however with nice bass extension/impact.
  
 I currently have the gain set to high.
  
 I did try the BUF643P WB but I wasn't fussed on the sound, not sure why, just didnt sit well.
 In saying that, my amp is basically new so it will require some burn in no doubt.
  
 Thanks in advance, I am new to this Op-Amp/Buffer business.
  
 Scott


----------



## Mooses9

wyd4 said:


> Hi All,
> 
> First of all my setup.
> 
> ...


 
 i think a exceptional opamp for L & R is LME49990  and buffers the HA5002.
  
 To me the LME49990 is probably the top of the line opamp. i ALWAYS come back to it, no matter what other opamp i use. its so good. i was using it in the ibasso p4 warbler, im using it in the ibasso pb2 pelican. just a all around phenomenal opamp


----------



## Wyd4

mooses9 said:


> i think a exceptional opamp for L & R is LME49990  and buffers the HA5002.
> 
> To me the LME49990 is probably the top of the line opamp. i ALWAYS come back to it, no matter what other opamp i use. its so good. i was using it in the ibasso p4 warbler, im using it in the ibasso pb2 pelican. just a all around phenomenal opamp


 
 These?
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=170986338704
  
 Are these a dual channel jobby or do I need 4?  Sorry, noob here and I couldnt find anything to say one way or the other.
  
 What are the characteristics of this op-amp?
  
 Thanks for the suggestion 

 Scott


----------



## spurxiii

mooses9 said:


> i think a exceptional opamp for L & R is LME49990  and buffers the HA5002.
> 
> To me the LME49990 is probably the top of the line opamp. i ALWAYS come back to it, no matter what other opamp i use. its so good. i was using it in the ibasso p4 warbler, im using it in the ibasso pb2 pelican. just a all around phenomenal opamp


 
 I agree. I been on the PB2 stock kit for many months and I just put the Top Kit back in now and it does sounds phenomenal. It didn't sound so good when I had the PB2 paired with the iPhone 4s but with the DX50 upstream it does make it a lot better


----------



## spurxiii

The topkit does sound good from this configuration


----------



## Mooses9

wyd4 said:


> These?
> http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=170986338704
> 
> Are these a dual channel jobby or do I need 4?  Sorry, noob here and I couldnt find anything to say one way or the other.
> ...


 
http://www.ebay.com/itm/2pcs-LME49990-DIP8-ADAPTERS-/190897296160?pt=US_Amplifier_Parts_Components&hash=item2c725d9320
  
 those are the singles, there are also doubles on the DIP8's
  
 I would say its very transparent, some might say it has a extremely clean sound, some might say almost to the sterile point but to me overall its completely clean, mids are crisp, high are crisp, vocals are very clean. IMO you should try it out.  its pretty amazing opamps, many will agree.
  
 there is a slight step down that isnt are sharp slightly rounder edges to the frequencies. thats the lme49860


----------



## Dopaminer




----------



## Dopaminer

I just can`t decide which to get:


----------



## Mooses9

i see your dilemma!


----------



## jamato8

Choices, it is all about choices.


----------



## casper3127

Hi there,

I've recently purchased a pb2. Since I'm going to connect it single-ended to my dap, I wanted to know if I can output it balanced to my hd650s.

Thanks in advance.


----------



## zilch0md

Absolutely!   In fact, there are a lot of people (like me) who argue that even though balanced cables out of the amp (to the headphone) can provide audible benefits had with more power (with some amps, as with the PB2) and no cross-channel impedance fluctuations (suffered when left and right transducers are influencing each other via a shared ground), going balanced out of the DAC (to the amp) is only beneficial for long cable runs between the DAC and the amp, where common mode noise can become an issue and where there's a low signal-to-noise ratio with the lower voltage between DAC and amp, vs. the higher voltages between amp and headphones.
  
 So, yes!  Feel free to supply your PB2 Pelican with a single-ended DAC, while using balanced cables out to your headphones.
  





  
 Mike


----------



## casper3127

Thank you so much Mike! I've been thinking for a while that I had bought a silver dragon balanced cable connecting my pb2 to the hd650 for nothing!! 

The point is that I cannot go balanced from my digital audio player but WANT a balanced sound in my delicious hd650. 

Warm regards! What a relief, mate...


----------



## zilch0md

Thanks!
  
 Enjoy!


----------



## Mooses9

im lovin my pb2/db2 combo, but it doesnt seem like its that popular of a amp. probably because it isnt exactly ''portable''


----------



## zilch0md

THIS isn't exactly portable...


----------



## Mooses9

zilch0md said:


> THIS isn't exactly portable...


 
 yeah someone see that...some kind of arrested you would be getting LOL


----------



## gikigill

People carry around full blown tube amps and the PB2 is considered not portable? 
Must be opposite day.


----------



## Mooses9

Well what I meant is its not as portable as say a head stage arrow, jds labs c5, pico slim and the likes.

Personally I use my pb2 for home use so portable or not it doesn't matter to me.

I love the lme49990 opamps and the ha5002 buffers +10 gain/+20 balanced is how I rock mine.


----------



## casper3127

> Personally I use my pb2 for home use so portable or not it doesn't matter to me.


 
  
  
 That's really the point Mooses. When I see a bundle of four small bricks considered as portable...


----------



## zilch0md

mooses9 said:


> Well what I meant is its not as portable as say a head stage arrow, jds labs c5, pico slim and the likes.
> 
> Personally I use my pb2 for home use so portable or not it doesn't matter to me.
> 
> I love the lme49990 opamps and the ha5002 buffers +10 gain/+20 balanced is how I rock mine.


 
  
 I'm really OK with not you not thinking of your DB2/PB2 stack as "portable."   I want to defend your right to say this, so that I can defend my right to call my travel rig "portable."  
	

	
	
		
		

		
		
	


	



  
 And yes, the LME49990s with HA5002s are a great combination.  With more efficient phones, where you don't need the current gain of the buffers, but want a little more transparency, I like the LME4990s with dummy buffers.  
  
 Enjoy!
  
 Mike


----------



## Mooses9

zilch0md said:


> I'm really OK with not you not thinking of your DB2/PB2 stack as "portable."   I want to defend your right to say this, so that I can defend my right to call my travel rig "portable."
> 
> 
> 
> ...


 
 hmmm i might have to give that a go. i have tried i would say a decent ammount of  opamps and buffers....and came to the conclusion that the lme49990 is bar none IMO, and the ha5002 the best buffer offering great current gain.....with the gain setting on high and that combo, you have a seriously powerful amp.


----------



## Makiah S

mooses9 said:


> hmmm i might have to give that a go. i have tried i would say a decent ammount of  opamps and buffers....and came to the conclusion that the lme49990 is bar none IMO, and the ha5002 the best buffer offering great current gain.....with the gain setting on high and that combo, you have a seriously powerful amp.




Im getting one of these new in the next week or so. Ill most likly b usung dummy buffers as i have a bwlnced D2k that doesnt nrrd much powet

which dummy buffers r most transparent n where do i get a quad of lme49990s ... and do i need n adapter :3


----------



## jamato8

mshenay said:


> Im getting one of these new in the next week or so. Ill most likly b usung dummy buffers as i have a bwlnced D2k that doesnt nrrd much powet
> 
> which dummy buffers r most transparent n where do i get a quad of lme49990s ... and do i need n adapter :3


 
 A dummy buffer is just a bypass to the socket so all you have is a wire going from one point to another. There are no chip in place.


----------



## zilch0md

mshenay said:


> Im getting one of these new in the next week or so. Ill most likly b usung dummy buffers as i have a bwlnced D2k that doesnt nrrd much powet
> 
> which dummy buffers r most transparent n where do i get a quad of lme49990s ... and do i need n adapter :3


 
  
 You can buy two (2) of these (one for each channel) from the ebay seller named "frugalphile" - I've done business with him several times and have always been very impressed by his soldering skills and his business practice.
  
http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER-/190999739495?pt=US_Amplifier_Parts_Components&hash=item2c7878bc67
  
 They include the DIP8 adapters (again, nicely soldered.) 
  
 IF you would prefer a quad of singles (instead of two duals), you can order two (2) of these from the same seller, instead:
  
http://www.ebay.com/itm/2pcs-LME49990-DIP8-ADAPTERS-/190897296160?pt=US_Amplifier_Parts_Components&hash=item2c725d9320
  
 Mike


----------



## Makiah S

jamato8 said:


> A dummy buffer is just a bypass to the socket so all you have is a wire going from one point to another. There are no chip in place.


 
  
  


zilch0md said:


> You can buy two (2) of these (one for each channel) from the ebay seller named "frugalphile" - I've done business with him several times and have always been very impressed by his soldering skills and his business practice.
> 
> http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER-/190999739495?pt=US_Amplifier_Parts_Components&hash=item2c7878bc67
> 
> ...


 
 so for a low gian balanced set up, it would be best to get maybe a quad of those LME 49990 adapters and install the dummy buffers, and ofc have the gain set to low 
  
 what are the variable gain settings, I'd like to keep it at... at most 3 for balanced out, My w1000x is sensitive :x
  
 hoping in the next week to maybe find a used Pb2, and not have to buy new, but I can afford new if need be plus I've got a pb1 so I have the adapter, already so what $325 + $35 for the 4 opamps + shipping would be around $400 or so for a new amp, not bad $100 less than an RSA F-35 and  I don't need another adapter


----------



## zilch0md

My opinion:  
  
 Always select the lowest gain that allows sufficient volume with your headphones - even if you have to turn the knob well past 12 o'clock.
  
 This does two things for you:  It gives you the lowest noise floor during silent portions of your music -and- it gives you more finesse to fine tune the volume than you would have at a higher gain setting, where the volume control has to stay closer to the zero position.
  
 The iBasso PB2 has four sets of jumpers, each with three possible postions - Hi / Med / Low gain.  See the manual for a diagram of how to set the jumpers (on Low, to start with).  Again, if that gives you sufficient volume, you're done - leave it on Low gain.
  
 Mike


----------



## Makiah S

zilch0md said:


> You can buy two (2) of these (one for each channel) from the ebay seller named "frugalphile" - I've done business with him several times and have always been very impressed by his soldering skills and his business practice.
> 
> http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER-/190999739495?pt=US_Amplifier_Parts_Components&hash=item2c7878bc67
> 
> ...


 
 I'm going to quote it as often as I can so I don't forget it [or email to my self herp derp] 


zilch0md said:


> My opinion:
> 
> Always select the lowest gain that allows sufficient volume with your headphones - even if you have to turn the knob well past 12 o'clock.
> 
> ...


 
 Yea I want LOW Gain, my pb1 is set to high gain ... permantly due to the smashed Gain Pins on the bottom [my fault / crappy build quality] so... well I paid $60 for it and it's my HIGH GAIN OH YEA amp, it works nicely with the DT 880 600 ohm, noise is low and I do NOT like loud volume but some ppl do, had a guy MAX out my pb1 yesterday [in balanced out] he was... happy
  
 non the less I want LOW LOW LOW gain for my Dynamics, the 32 ohms ones. I've got my wanted add posted, so let's see what happens
  
 thank you for the link to the opAmps as well.


----------



## Mooses9

mshenay said:


> Im getting one of these new in the next week or so. Ill most likly b usung dummy buffers as i have a bwlnced D2k that doesnt nrrd much powet
> 
> which dummy buffers r most transparent n where do i get a quad of lme49990s ... and do i need n adapter :3


 
 Check out HIFLIGHT on here he makes great kits for the pb2.


----------



## zilch0md

I don't think Ron (HiFlight) offers LME4990s currently, or I would have mentioned him.  Ron is certainly a great guy to deal with and has bent over backwards for me a couple of times, helping me with problems.  
  
 In fact, Mshenay might want to send Ron a PM with photos of his damaged gain jumpers, to see if Ron might be willing to give a quote for fixing them.  He's in Florida - not China.  
  
 Mike


----------



## Makiah S

zilch0md said:


> I don't think Ron (HiFlight) offers LME4990s currently, or I would have mentioned him.  Ron is certainly a great guy to deal with and has bent over backwards for me a couple of times, helping me with problems.
> 
> In fact, Mshenay might want to send Ron a PM with photos of his damaged gain jumpers, to see if Ron might be willing to give a quote for fixing them.  He's in Florida - not China.
> 
> Mike


 
 Nah It's time to upgrade my amp truth be told :3. I wanted the pb2 but I settled for the Pb1, so I'd like to try the LME 49990 Pb2 as my upgrade for this Spring 
  
 but a good idea thank ya


----------



## highfell

I asked somebody whether he could make a balanced cable for me to my Sennheiser 600HD and he made the following comments.

The trouble is this is not a true balance system as Sennheiser has only 2 terminal per channel - ground and positive.

A balnced cable needs - Ground - Positive - Negative - wired the same at both ends whhich is why it is called balanced.

http://www.scotaudio.com/wiring.htm

The iBasso link shows a connector that is XLR (ground and positive for each channel) which is essntially the same as the one I made for you except I used a mini jack connector rather than XLR.

I can make one of these up for you but do be aware it is not really a balanced cable.

Does this matter?


----------



## zilch0md

I'd say it doesn't matter, given that I can't think of a single headphone that has three wires going to each transducer! 

I'm sure that fellow is right so far as how to wire 3-pin XLR connectors between a balanced DAC and a fully balanced amp, for example, but eventually, you've got to get down to only two conductors per channel - for headphones or speakers. So, for most people, it's OK to call a four-wire headphone cable "balanced," while a 3-conductor headphone cable is called "single-ended" (or "unbalanced").

Try http://toxic-cables.co.uk - he won't get tripped up in semantics. 







Mike


----------



## Makiah S

zilch0md said:


> I'd say it doesn't matter, given that I can't think of a single headphone that has three wires going to each transducer!
> 
> I'm sure that fellow is right so far as how to wire 3-pin XLR connectors between a balanced DAC and a fully balanced amp, for example, but eventually, you've got to get down to only two conductors per channel - for headphones or speakers. So, for most people, it's OK to call a four-wire headphone cable "balanced," while a 3-conductor headphone cable is called "single-ended" (or "unbalanced").
> 
> ...


 
 Ugh yea dude Frank know's his stuff also... is that an LCD being driven by the PB2 :O... me gusta
  
 Honestly some one needs to mod a pb2 to have adjustable gain on the Fly like the PB1 did, it's a shame you have to open it to adjust gain :/ 
  
 still I also want a white one my self


----------



## Mooses9

i use the pb2 with +10 gain and have pitch black imaging and silent floor...but it could be the use of balanced mode and using the db2 boomslang, i use a decent ammount of iems on this setup.


----------



## jamato8

I think the PB2 and DB2 are one of the most overlooked combos or even individual pieces of electronics in the high end portable market. People just don't realize until they use them how good they are and frankly, at a bargain price for what you are getting.


----------



## Makiah S

mooses9 said:


> i use the pb2 with +10 gain and have pitch black imaging and silent floor...but it could be the use of balanced mode and using the db2 boomslang, i use a decent ammount of iems on this setup.


 
 Nice, the hm801 may not be as quiet as the DB2, how ever my pb1 isn't noisy, it just lacks any Volume control. There's way to much gain to be able to adjust the volume suitably, and I have a lot of classical and EDM so... :/


----------



## zilch0md

mshenay said:


> Ugh yea dude Frank know's his stuff also... is that an LCD being driven by the PB2 :O... me gusta
> 
> Honestly some one needs to mod a pb2 to have adjustable gain on the Fly like the PB1 did, it's a shame you have to open it to adjust gain :/
> 
> still I also want a white one my self


 
  
 Yeah, that's the LCD-2 rev.1 on a PB2, balanced out.  
  
 I leave the PB2 on Low Gain for the LCD-2, and I don't have any phones that need more power, so I never have to open the case just to change the gain, but I hear you - it would be nice if there were an external switch for gain.
  
 Mike


----------



## jamato8

I tape one side of the case, so it makes a hinge and use one screw in on the back of the case. Very fast and easy to open the case. I have rarely changed the gain though. 
  
 What also helps with the DB-2 is that it used a battery for the digital section and one for the analog, giving you an even better SN ratio. It also gives you better dynamics and separation.


----------



## Makiah S

jamato8 said:


> I tape one side of the case, so it makes a hinge and use one screw in on the back of the case. Very fast and easy to open the case. I have rarely changed the gain though.
> 
> What also helps with the DB-2 is that it used a battery for the digital section and one for the analog, giving you an even better SN ratio. It also gives you better dynamics and separation.


 
 I have a 600 ohm dt 880 and a 23 ohm w1000x... you see my particular delima here lol
  
 one likes HIGH gain the other likes SUPER LOW gain xD


----------



## zilch0md

jamato8 said:


> I tape one side of the case, so it makes a hinge and use one screw in on the back of the case. Very fast and easy to open the case. I have rarely changed the gain though.
> 
> What also helps with the DB-2 is that it used a battery for the digital section and one for the analog, giving you an even better SN ratio. It also gives you better dynamics and separation.


 
  
 I love the taped hinge idea, but then I'd be back to rolling op-amps 'til the wee hours of the morning, weekdays and evenings.  It's a wonder I haven't sealed my PB2 with Loc-Tite, just to keep myself out of it!


----------



## Makiah S

$300 later I got a Pb2 with a LME 49990 set, in silver the color I wanted!


----------



## Mooses9

mshenay said:


> $300 later I got a Pb2 with a *LME 49990 set*, in silver the color I wanted!


 
 now just get the HA5002 Buffers are ur set. best buffer imo.


----------



## Makiah S

mooses9 said:


> now just get the HA5002 Buffers are ur set. best buffer imo.


 
 well I'm using the Dummy Buffers, as I do not need the additional power... or do i? 
  
 No I don't. keeping it around for my D2k and W1000x, both of which do NOT need a lot of power!


----------



## zilch0md

mshenay said:


> $300 later I got a Pb2 with a LME 49990 set, in silver the color I wanted!


 
  
  


mshenay said:


> well I'm using the Dummy Buffers, as I do not need the additional power... or do i?
> 
> No I don't. keeping it around for my D2k and W1000x, both of which do NOT need a lot of power!


 
  
 And what do you think of the sound (with which DAC and headphones)?


----------



## turboman808

I got this last night and I am pretty impressed.  I've had a set of hifiman headphones for a few months but nothing seemed to work well with them.  This amp made them sound really good.  
  
 I see it came with all these different omp amps.  Do they all sound different?  I didn't see any guide telling me the different characteristics of them.  
  
 Should have my alpha dog and audeze lcd-xc headphones next month.  Hope they sound even better.


----------



## Makiah S

zilch0md said:


> And what do you think of the sound (with which DAC and headphones)?


 
 I just paid for it today xD, shipped from China, it's in good condition I got extensive pics
  
 and what do I think? well the only DAC it's going to be used with is the HM 801
  
 btw, the LME 49990 are rather warm tbh, are there any... op amps that sound like the pb1? The hm801 is already thick warm and lush, I'd like really something like an LME 49720HA, something more on the SPEED and CLEAR side than warm. 
  
 I had an LME 49990 in my Matrix M Stage and it sounded very good, but again the hm801 is already warm, I've got the HiFilight Top Kit and the entire Stock kit at my disposal


----------



## Mooses9

mshenay said:


> I just paid for it today xD, shipped from China, it's in good condition I got extensive pics
> 
> and what do I think? well the only DAC it's going to be used with is the HM 801
> 
> ...


 
 your the only person i have heard say the lme49990 is warm, the ive had the p4 warbler and the pb2 pelican and the lme49990 is to me, bright or maybe alot of clarity which makes it seems bright. and i find it to be very analytical, i dont find my pb2 to at all be warm. maybe its just me.
  
 but you have to take into consideration the circuitry of the matrix m and maybe it made it sound warm?


----------



## Makiah S

mooses9 said:


> your the only person i have heard say the lme49990 is warm, the ive had the p4 warbler and the pb2 pelican and the lme49990 is to me, bright or maybe alot of clarity which makes it seems bright. and i find it to be very analytical, i dont find my pb2 to at all be warm. maybe its just me.
> 
> but you have to take into consideration the circuitry of the matrix m and maybe it made it sound warm?


 
 IT could very well be just that :3


----------



## Mooses9

mshenay said:


> IT could very well be just that :3


 
 you might wanna try the LME49860NA it has a similar sound as the lme49990 but its a bit warmer in the IBASSO Amps...that is if you find the lme49990 to be analytical or bright.
  
  
 i have a question for anyone.... what are your guys opinion on the DB2 BOOMSLANG using the upgrade LPF opamp.. i personally think it does add a bit of depth to the bass. just wondered what others thought.


----------



## Makiah S

mooses9 said:


> you might wanna try the LME49860NA it has a similar sound as the lme49990 but its a bit warmer in the IBASSO Amps...that is if you find the lme49990 to be analytical or bright.
> 
> 
> i have a question for anyone.... what are your guys opinion on the DB2 BOOMSLANG using the upgrade LPF opamp.. i personally think it does add a bit of depth to the bass. just wondered what others thought.


 
 WHOA NOOOOO
  
 To bright is not in my Vocab, I drive a DT 880 with an Audio GD 10ES2, thats a bright amp and a bright can


----------



## Mooses9

birds of a feather haha, i too like bright, but i think its more analytical than bright, or maybe its clarity that is perceieved as bright.
  
 i have the er4s/er4p and the hf2 alot of people consider those iems bright but i find them perfectly detailed and accurate. warm signature imo withholds detail in the track, and thats not my taste.
  
 i have cables like the Hybrid peptide symbiote silver plated copper cable for my se535, i also have the toxic cable silver poison for my westone w4r i have the toxic silver poison pure silver interconnects... have rsa male to hirose male toxic silver poison interconnect for the amp to dac....im into anything that is going to bring out max detail.
  
 and now saying that i might be perceiving all that clarity,detail,brightness,analytical sound from all that silver......but i still think the LME49990+HA5002 is hands down the best combo, maybe the muse01 or muse02 might sounds better, but those cost a penny or 2, and im not opposed to spending the money i dont care, i just havent really heard alot about those opamps and if they will yeild what i am looking for, again i have tried a ton of opamps and the lme49990 just does it for me, but everyone is different.


----------



## jamato8

The 5002 to my ear, is the cleanest background and allows the most detail of the buf634 or 5002. I have used the 5002 stacked, though they do produce some heat.


----------



## Makiah S

mooses9 said:


> birds of a feather haha, i too like bright, but i think its more analytical than bright, or maybe its clarity that is perceieved as bright.
> 
> i have the er4s/er4p and the hf2 alot of people consider those iems bright but i find them perfectly detailed and accurate. warm signature imo withholds detail in the track, and thats not my taste.
> 
> ...


 
 I see no reason to use the buffers tbh, the hm801 is very warm and likes a BRIGHT amp, that said it has a clean line out :3 best of all it all cost me $280! For my Pb2 and hiFilight Kit with lme 49990 and some other buffers, it will be here in 2 weeks!


jamato8 said:


> The 5002 to my ear, is the cleanest background and allows the most detail of the buf634 or 5002. I have used the 5002 stacked, though they do produce some heat.


 
 I never had any issues with background noise even on my pb1, the background is black out of the balanced out with my D2k


----------



## Mooses9

different strokes different folks, if it works for you


----------



## Dopaminer

DHL just delivered my pb2.  I`ve downloaded the pdf from ibasso; could someone here direct me to additional instructional information, like an FAQ or something?  
  
 Many thanks,
  
 d


----------



## Mooses9

dopaminer said:


> DHL just delivered my pb2.  I`ve downloaded the pdf from ibasso; could someone here direct me to additional instructional information, like an FAQ or something?
> 
> Many thanks,
> 
> d


 
 what exactly are u looking for?


----------



## zilch0md




----------



## Dopaminer

Thanks guys,
  
 The basics of op-amp rolling, in general and specifically on the pb2. Those visuals are cool.  I`ll guess I`ll just start in with switching things out.  Is there some systematic way to go about it?  I`m interested in gain variations - I`ll mostly be using the amp with balanced shure se846 (9ohm and hiss like hell from the ibasso dx50 headphone out) but would also like to try my hd800s with it as well. . .


----------



## Makiah S

dopaminer said:


> Thanks guys,
> 
> The basics of op-amp rolling, in general and specifically on the pb2. Those visuals are cool.  I`ll guess I`ll just start in with switching things out.  Is there some systematic way to go about it?  I`m interested in gain variations - I`ll mostly be using the amp with balanced shure se846 (9ohm and hiss like hell from the ibasso dx50 headphone out) but would also like to try my hd800s with it as well. . .


 
 Whoa from iems to the HD 800... let us know how that works
  
 I'm going to be using mine with LME 49990 OP Amps and Dummy Buffers, gain set to low
  
 it should drive all my headphones nicely! And I'm the owner of an HE 4 now, so I'm going to need every bit of current the pb2 can drive :3 my pb2 is already here, but I've yet to pick it up... should have it in hand tommorow


----------



## Mooses9

mshenay said:


> Whoa from iems to the HD 800... let us know how that works
> 
> *I'm going to be using mine with LME 49990 OP Amps and Dummy Buffers, gain set to low*
> 
> it should drive all my headphones nicely! And I'm the owner of an HE 4 now, so I'm going to need every bit of current the pb2 can drive :3 my pb2 is already here, but I've yet to pick it up... should have it in hand tommorow


 
 You are going to need the HA5002 Buffers and gain set on high for hd800


----------



## jamato8

The buf634 will work fine for the HD800. They have a little more power output than the HA5002, not really noticeable to me but either will work fine and to my ear the 5002 are just slightly more transparent.


----------



## Mooses9

jamato8 said:


> The buf634 will work fine for the HD800. They have a little more power output than the HA5002, not really noticeable to me but either will work fine and to my ear the 5002 are just slightly more transparent.


 
 True, i would perdsonally take the transparency vs output. but thats just my opinion.
  
 reason being is the added transparency plus the lme49990 = a amazing opamp setup 
  
 since running the lme49990 + ha5002 i havent rolled any other opamp


----------



## zilch0md

Or for a little more warmth with the HD800:   *LME49990 in I/V with Muses 02 as buffers* - and the gain set as low as possible while still achieving a sufficient listening level.  
  
*The lower the Gain setting that can achieve adequate volume levels, the lower your noise floor.  *
  
 Note:  I don't have the Muses 02 yet, but going on everything I've read, I'm pretty sure they would be a better match for the HD800, as buffers in the PB2, than the HA5002.  
  
 But yes, I agree with LME49990 + HA5002 buffers, in the absence of Muses 02.  I've tried LME49990 + HA5002 with the HD800 (which is plenty loud on Low gain) and it sounds _really good _when the PB2 is getting a _warm signal_ from my Bushmaster MkII DAC's analog Line Out - a _slightly_ _warm source_ - not as warm or dark as the iBasso DB2 Boomslang2, but with a lot more detail and just the right amount of sparkle.
  
 I didn't like the DB2 Boomslang2 > PB2 for use with my LCD-2, because it was too warm and dark, so I returned it, but now that I have the HD800, I suspect the DB2 Boomslang2 > PB2 would be a good match to tame the HD800's brightness, but I'm not going to order it again to find out. 
	

	
	
		
		

		
			




  
 As I've already said, the _slightly warm_ Bushmaster MkII DAC > PB2 with LME49990 + HA5002 buffers is a pretty good match with the HD800, for my tastes, definitely better than when using any of my other DACs that are more neutral than the Bushmaster MkII (CEntrance LX, CEntrance DACmini CX, or Concero). 
  
 Thus, I have a hunch, but haven't tested, the Muses 02 as buffers with the LME49990 in I/V _might make_ the PB2 just about right for the HD800 when using a neutral DAC.
  
 Sticking with a neutral DAC > 16V-powered PB2 with LME49990 + dummy buffers > the HD600 is also looking for warmth (in my opinion) - as could be provided perhaps with the Muses 02 as buffers , and I suspect with the HD650, it would be even better (more like my LCD-2 with a neutral DAC > 16V-powered PB2 with LME49990 + dummy buffers).
  
 Note:  My comments above were made while powering the PB2 with an external XP8000 battery pack, regulated to 16V (the maximum permissible voltage for the PB2), not with the PB2's internal, 12.6V LiPo battery. This translates to better dynamics and bass control than can be had with lower swing voltages at the rails.  
  

  

  
 Using the PB2's internal 12.6V battery pack, the voltage, and thus the performance, decays with use following a fresh charge, until the battery gets down to about 9V, at which point the PB2 will stop operating.
  
 Using the XP8000 battery pack with an XPAL WI16 inline voltage regulator, the PB2 _always sees a constant 16V, even as the external battery pack's output decays with use from 21V to 16V_, when the regulator will shut down.  Thus, the PB2's optimal 16V performance remains constant, completely unaffected, as the external battery pack is consumed!
  

  
 Mike
  
*UPDATE: * I have to add that I have *never* heard an op-amp used as a buffer in the PB2, that is as clean and transparent as dummy buffers in the PB2.  I just broke out my PB2 and HD800, to validate what I've written above, and although I find the HA5002 buffers to provide the additional warmth needed by the HD800, replacing them with dummy buffers increases the transparency and detail - allowing me to hear the LME49990s without "corruption," but, of course, this reduces the current gain offered by the HA5002s - reducing total power output to the headphones - making the use of dummy buffers a better match for the HD650, for example, than for the less efficient LCD-2 or HD800.   
  
 In the past, I've tried all of my meager inventory op-amps as buffers in the PB2, even using LME49990s as buffers with LME49990s in the input voltage gain stage (LME49990 x 8), but nothing beats using dummy buffers for resolution and transparency.  That's going to be the first thing on which my attentions will be focused if I ever get around to orderings some Muses 02 for use as buffers.
  
 UDATED UPDATE:  All the more reason to push the PB2 with 16V power instead of 9 to 12.6V power...  Listening to the LCD-2 on LME49990 + dummy buffers with a neutral DAC right now, is sublime - just as I concluded after about three months of rolling op-amps.  (Feel free to substitute HD650 for LCD-2!)  So...  you don't necessarily need the extra power afforded by using op-amps as buffers (instead of using dummy buffers), when using a 16V supply voltage AND taking advantage of balanced output (one last piece of the puzzle) that always gives you 2x the power you'd get when using the PB2's TRS (single-ended) headphone jack.
  
 There, I think I'm done with this dissertation.


----------



## Makiah S

zilch0md said:


> Or for a little more warmth with the HD800:   *LME49990 in I/V with Muses 02 as buffers* - and the gain set as low as possible while still achieving a sufficient listening level.
> 
> *The lower the Gain setting that can achieve adequate volume levels, the lower your noise floor.  *
> 
> ...


 
 Well that is going to make my Portable stack EVEN thicker but... oh well ;3 I guess I'll have to live with it and invest in bigger pockets 
  
 and guys I'm not driving a HD 800, I'm diriving an HE 4, entirely different monster, in which Low Gain is best for maxium current output into the HE 4. as in Hifiman HE 4
  
 I might pick that enegizer unit up here in a week or so! 
  
 So where did you find the XPAL Williy WI16, I found one site in Chinnese that sold it... but without a price :\
  
 And that combo unit is almost as much as the Pb2 it self <.< [or a used one] but if it's worth it. Maybe I'll sntach it up next Fall  
  
 Also, the Battery pack seems like a Power Conditioner for portable gear, smart thinking, I have a conditioner sitting in between my wall and my NFB 10ES2 and it did increase over detail retentension and clarity


----------



## zilch0md

Hi,
  
 I've never heard the HE-4 and I don't know how efficient it is, but if it's as efficient as the HD600, you're not likely to hear a big improvement in bass control or dynamics, just by using 16V power - and maybe not even by using balanced output from the PB2 vs. single-ended.
  
 But there's a very easy test for determining whether or not you will hear any improvements using the XP8000 + WI16 Willy Cable...  
  
*Just listen to your PB2 + HE-4 while using the PB2s AC adapter.  It outputs 16V just like the XP8000 + WI16. If you decide you can hear an improvement on 16V power vs. the internal battery's 9V to 12.6V, then the XP8000 + WI16 would be the way to go for portable use.*
  
 See this post for more information and WI16 ordering instructions:   http://tinyurl.com/kvmjnj2
  
 Mike


----------



## Makiah S

Efficiency: 86 DB
  
 The HE 4 is rated at 86 DB efficeny and 32 ohms
  
 It's almost has hard to drive as the HE 6... almost. And I find that all of my headphones, my D2k and W1000x and Beyer DT 880 all benifit sonically from the Balanced out of the Pb1, which is why I bought the Pb2 to get a sonic upgrade to my Pb1
  
 That said, nice test! I might just save the money and not worry about it, seeing as the only time I'm really portablt, or walking with headphones on and gear in pocket is when I'm traveling and surrounded by noise. My portable set is mostly for when I'm not at home, but still sitting down in a some what quiet enviorment


----------



## zilch0md

You're set then.  Good!


----------



## Mooses9

i found while the pb2 pelican is a excellent amp, when using the er4s with the lme49990 + ha5002 + +10 gain i was over in the 1 o clock ish range for medium to loud, i would have expected the volume pot to be smaller given the pb2's power?


----------



## zilch0md

mooses9 said:


> i found while the pb2 pelican is a excellent amp, when using the er4s with the lme49990 + ha5002 + +10 gain i was over in the 1 o clock ish range for medium to loud, i would have expected the volume pot to be smaller given the pb2's power?


 
  
 I hear you, but those are among the most inefficient IEMs available: 
  
  Quoting http://www.headphone.com/headphones/etymotic-er-4s.php
  


> Somewhat inefficient and power-hungry at a stiff 100 Ohms impedance, listeners should consider a headphone amp for maximized detail with iPod/iPad/iPhone and portable sources -- or select the low-impedance ER-4PT model for non-amped mobile applications.


 
  
 Mike


----------



## jamato8

The more travel you use with the volume anyway. The less resistance in the path, from the volume pot, the better.


----------



## Makiah S

Got my pb2, on Low Gain the Pb2 could not drive my Dt 880 600 ohm, I got sound in only one channel 
  
 I fiddle'd with the gain jumpers till I got even sound in both channels, [using the balanced out ofc]
  
 that said does ANY one have a GRAPH or some kind of picture for adjusting the Gain Jumpers 
  
 so apprently no Jumpers = low gain 
  
 I found the PDF for it 
  
 0XX =High
 xx0= Medium
 000=Low 
  
 XX being the jumper


----------



## highfell

mshenay said:


> Got my pb2, on Low Gain the Pb2 could not drive my Dt 880 600 ohm, I got sound in only one channel
> 
> I fiddle'd with the gain jumpers till I got even sound in both channels, [using the balanced out ofc]
> 
> ...




My PDF suggest it's the other way round between medium and high gain ie 

0XX =Medium
XX0= High
000=Low 


But it does depend on which way you are looking at them !!


----------



## Makiah S

highfell said:


> My PDF suggest it's the other way round between medium and high gain ie
> 
> 0XX =Medium
> XX0= High
> ...


 
 I may have mis read if, though when is that for each pin on each of the 4 channels? When I got my amp it appeared to be set to high gain, yet I had channel imbalance issues 
  
 well she's set to 0 and... wow man I'm liking this! Really cleaned up the bass on my D2k with my hm801 :3 can't wait to get my d2k rebalanced and try out that balanced connector , although +6 gain on the balanced out might still b a touch to much >.>, I'm sitting at 9:30 o Clock on 0 gain with my SE D2k xD


----------



## highfell

mshenay said:


> Got my pb2, on Low Gain the Pb2 could not drive my Dt 880 600 ohm, I got sound in only one channel
> 
> I fiddle'd with the gain jumpers till I got even sound in both channels, [using the balanced out ofc]
> 
> ...






My PB2 with jumpers on medium gain


----------



## jamato8

In general, I think the DB2 and PB2 are overlooked and not too many realize how good they can sound. The DB2 does an excellent job of getting to the music without sound digital. I was using it yesterday, letting it warm up for about an hour and the sound was extremely good, fed by the DX50, it was much better than the AK100 or anything around that sound range. Sure, not as portable but if you are looking for a small package for balanced sound, it is hard to beat. The DB2 has a separate battery for the digital and analog section and that gives it a real advantage in s/n, dynamics and overall quality of sound.


----------



## highfell

After much deliberation and reading of both this and the Opamp threads - thanks all - I have decided on my OP Amp rolling path for the PB2.


1. Lme49990 OPamps x 4 bought off a reputable EBay seller - they have arrived in the UK from the US and awaiting delivery from Customs.
2. MUSES02 X2 awaiting stock (expected any day now)
3. Topflight kit bespoked by Ron in view of the above choices. Ha5002 buffers x4 , plus 4x single Opamp class A adaptors and plus 2x dual Opamp class A adaptors.

I already have two OPA627s, so I suspect I may be tempted to buy 2 more to try them out as well in due course but I want to try the Lme4990 & Ha5002 combination, also a MUSES choice and then to see if Class A biasing makes much of difference.

Reviews to follow when they have arrived.


----------



## SpudHarris

highfell said:


> After much deliberation and reading of both this and the Opamp threads - thanks all - I have decided on my OP Amp rolling path for the PB2.
> 
> 
> 1. Lme49990 OPamps x 4 bought off a reputable EBay seller - they have arrived in the UK from the US and awaiting delivery from Customs.
> ...




Well, you have done your homework pal. Well done 

I've had my PB2 for a long time and I've ended up where you are starting. Enjoy...


----------



## highfell

spudharris said:


> Well, you have done your homework pal. Well done
> 
> I've had my PB2 for a long time and I've ended up where you are starting. Enjoy...


)

LOL - let's hope I share yours & others tastes -

Famous last words, but I kind of think that in terms of Amplifiers I am nearing the end of my search now and that with the having the ability to switch to differing OPamps, it will mean that I will have no need to change the Amplifier, as I will have enough choice to satiate me. 

I am also waiting to receive a balanced cable from toxic cables. I am looking forward to hearing how big a difference balanced to single ended is going to be. I just hope it can hear a difference ...


----------



## SpudHarris

The difference between SE and Balanced isn't massive but it is an improvement all the same. Frank makes very high quality cables, I have quite a few and have not once been disappointed.


----------



## chiman

highfell said:


> 1. Lme49990 OPamps x 4 bought off a reputable EBay seller - they have arrived in the UK from the US and awaiting delivery from Customs.
> 2. MUSES02 X2 awaiting stock (expected any day now)


 
 You got links to the sellers please?  Thanks.


----------



## highfell

chiman said:


> You got links to the sellers please?  Thanks.




1. http://www.ebay.co.uk/itm/190897296160

Note that these are sold as a pack of two singles, so you will have to order 2 of them in order to have four. The seller was recommended on here. And certainly the communication was excellent. Not received them yet.

2. I am being offered the MUSES as a bit of a favour - they normally wouldn't sell to the public - in fact we haven't even discussed a price yet, so I would prefer not to share the details the actually deal is done and then I will ask them if they are happy for me to pass their contact details on. Sorry.


----------



## zilch0md

Ebay seller frugalphile also offers duals:   http://www.ebay.co.uk/itm/190999739495
  
 It's really two singles mounted on one PCB - with one on top and the other underneath.
  
 The PB2 can use either four (4) singles or two (2) duals in L/R, but if you want to try them as buffers you'll need to get four (4) singles.
  
 I've made several transactions with frugalphile and have no complaints at all - his soldering is really clean, too.
  
 Mike


----------



## zilch0md

By the way, the 2x Muses02 that I ordered from Mouser.com (now in stock) came on a little strip of foam packing, inside a zip-loc bag, packed loosely in an over-sized box for shipping.
  
 See:  http://www.mouser.com/ProductDetail/NJR/MUSES02/?qs=%2fha2pyFaduiBH%2f%2fkpIrdkJVU%252b1ReE4c5hUkfZAV1m%2fo%3d
  
 No harm done, but I'm pointing out that Mouser.com did not include the nice jewel boxes that SpudHarris has received when ordering Muses01 and Muses02 from the "official e-bay seller for Audiotrak, Gyrocom":
  
 See:  http://www.ebay.com/itm/AUDIOTRAK-MUSES-02-OPAMP-High-Quality-sound-bipolar-input-dual-oerational-amp-/111080427256
  
 And:  http://www.head-fi.org/t/432749/the-opamp-thread/4620#post_10189334
  
  
 Mike


----------



## highfell

highfell said:


> After much deliberation and reading of both this and the Opamp threads - thanks all - I have decided on my OP Amp rolling path for the PB2.
> 
> 
> 1. Lme49990 OPamps x 4 bought off a reputable EBay seller - they have arrived in the UK from the US and awaiting delivery from Customs.
> ...




OK the LME49990s have arrived and I have now had time to review them. First of all, just to confirm that they were packaged well etc., so the seller is certainly to be recommended.

They are very musical. They have a clear, lively sound with a seemingly transparent approach. So the detail is there but not too bright, harsh or shrill though. They seem to bring out the musical quality of the DX50. I can understand why others seem to like them. 

They play well across the musical spectrum of heavy rock, prog rock & classical - they are a keeper.

My MUSES02 are about to be sent to me and also I am being allowed a couple of 01s to try as well. Excited or what.

[ now playing - Ritual by Nemrud ]


----------



## zilch0md

Joy!


----------



## SpudHarris

My additional Muses 01/02 arrived today, damn you Parcel Farce! Had to pay another £35 for customs and VAT. £35 for 2 OpAmps is a fair amount but that's just additional cost :rolleyes:

That said, they are absolutely worth the money. Believe me these are end game OpAmps. In the PB2 I am preferring the 01 (sorry Mike) but to be truthful I need more time with each to offer a solid comparison, it could be a combination of San Miguel and Music Choice but at the moment I just want to keep listening with the 01. In other amps I have to say the 02 was my favourite but give me a week or so and I should be able to offer some comparisons.

Either way the 01 and 02 are world class....


----------



## jamato8

Just be careful of the legs when you take them out. They bend easily and a few times would be enough, if bent far enough, to snap them off. Nice soft copper. No other op-amp I know of used copper like this, very nice.


----------



## SpudHarris

jamato8 said:


> Just be careful of the legs when you take them out. They bend easily and a few times would be enough, if bent far enough, to snap them off. Nice soft copper. No other op-amp I know of used copper like this, very nice.


 
  
 Thanks John for the tip. I figured this and for the purpose of evaluation I have stuck them all in DIP sockets. Have you tried the 01 in your Fi-Q?


----------



## highfell

spudharris said:


> Thanks John for the tip. I figured this and for the purpose of evaluation I have stuck them all in DIP sockets. Have you tried the 01 in your Fi-Q?




Does it matter which ones you use? They seem dirt cheap on Amazon - so can I order any?


----------



## zilch0md

spudharris said:


> My additional Muses 01/02 arrived today, damn you Parcel Farce! Had to pay another £35 for customs and VAT. £35 for 2 OpAmps is a fair amount but that's just additional cost
> 
> 
> 
> ...


 
  
 My only reason for putting Muses02 in the PB2 was to see if they could warm the HD800 - and they do.  From what I've read, I wouldn't prefer the Muses01 for that task, but I strongly suspect I would prefer the Muses01 with the LCD-2 - where I get all the color I want from the headphone itself, preferring a neutral DAC and amp.
  
 With Muses02 in L/R, I'm still rolling buffers. Uggh!  Life goes on hold when I take the lid off my PB2.  
	

	
	
		
		

		
		
	


	



  
 Mike


----------



## SpudHarris

zilch0md said:


> My only reason for putting Muses02 in the PB2 was to see if they could warm the HD800 - and they do.  From what I've read, I wouldn't prefer the Muses01 for that task, but I strongly suspect I would prefer the Muses01 with the LCD-2 - where I get all the color I want from the headphone itself, preferring a neutral DAC and amp.
> 
> With Muses02 in L/R, I'm still rolling buffers. Uggh!  Life goes on hold when I take the lid off my PB2.
> 
> Mike




Understood and you are absolutely right, my experience with the 01 has only been with the LCD2/3. Will have to do a bit more rolling to see the effect the 02 has on the HD800 :rolleyes:

Darn it, no sleep again tonight! :angry_face:


----------



## SpudHarris

highfell said:


> Does it matter which ones you use? They seem dirt cheap on Amazon - so can I order any?




Are you referring to Muses or DIP sockets?

If DIP sockets? I don't think it makes a great deal of difference, I personally go for gold plated. When I find a permanent home for the Muses I will install without additional DIP sockets, just trying to reduce risk whilst evaluating....


----------



## zilch0md

Yeah, that's what I did with the Muses02, also - I put them straight into DIP sockets when they were new.


----------



## jamato8

spudharris said:


> Thanks John for the tip. I figured this and for the purpose of evaluation I have stuck them all in DIP sockets. Have you tried the 01 in your Fi-Q?


 
 I have tried them and they sound good but haven't taken the time to compare the 01 and 02 for sound difference. The 02 seems to be a little more transparent but need more time.


----------



## highfell

spudharris said:


> Are you referring to Muses or DIP sockets?
> 
> If DIP sockets? I don't think it makes a great deal of difference, I personally go for gold plated. When I find a permanent home for the Muses I will install without additional DIP sockets, just trying to reduce risk whilst evaluating....




Yes I was referring to DIP Sockets. If you have a link to your gold plated ones that would be helpful.


----------



## zilch0md

zilch0md said:


> [snip]
> 
> With Muses02 in L/R, I'm still rolling buffers. Uggh!  Life goes on hold when I take the lid off my PB2.
> 
> ...


 
  
 Across several sessions, and a whole lot of time this weekend, I've concluded that the Muses02 sounds best with dummy buffers (in the PB2).  
  
 That seems to be my preference for every op-amp in L/R - using them with dummy buffers.    
  
 The best op-amp (other than dummy buffers) that I heard with the Muses02 in L/R was using LME49990 as buffers (from among my modest collection), but as usual, there's a loss of transparency and resolution.  And since I'm trying to use the Muses02 with the HD800, I prefer the cleaner sound of dummy buffers.
  
 I also did a lot of A/B (as fast as I could) between Muses02 and LME49990 in L/R (both with dummy buffers).  Conclusion:  I prefer the Muses02 with HD800, but the more neutral LME49990 with LCD-2 rev.1 - balanced out in both cases.  Try as I might, I can't ignore the fact that the Muses02 is expensive.  I'm not sure I'd recommend it over the LME49990 for anything other than "cold" sounding headphones, like the HD800, AKG K550, T1, etc. - that do better with tubes.  The LME49990 is still king of the hill for my LCD-2 rev.1, as the headphone itself gives me all the color I want.  YMMV
  
 Mike


----------



## highfell

zilch0md said:


> I'd say it doesn't matter, given that I can't think of a single headphone that has three wires going to each transducer!
> 
> I'm sure that fellow is right so far as how to wire 3-pin XLR connectors between a balanced DAC and a fully balanced amp, for example, but eventually, you've got to get down to only two conductors per channel - for headphones or speakers. So, for most people, it's OK to call a four-wire headphone cable "balanced," while a 3-conductor headphone cable is called "single-ended" (or "unbalanced").
> 
> ...




Thanks Mike.

I went to Frank at Toxic Cables and now have just received a beautiful looking balanced cable. No question that it is a work of Art.

Time to try it out to see if it sounds as good as it looks.


----------



## zilch0md

Congratulations!  Yes, Frank does fine work.


----------



## highfell

If I use the PB2 in the single ended mode, rather than balanced, can I get away with fitting only two single OPamps rather than four?

If so, into which sockets would I put them.

Thanks


----------



## pitsel

highfell said:


> If I use the PB2 in the single ended mode, rather than balanced, can I get away with fitting only two single OPamps rather than four?
> 
> If so, into which sockets would I put them.
> 
> Thanks




I always use in single mode with 2 buffer and 2 single TO-99 opa637


----------



## spurxiii

pitsel said:


> I always use in single mode with 2 buffer and 2 single TO-99 opa637


 
 That surely can't be how the OPAMPS are installed right? My OPAMPS are installed as below


----------



## highfell

pitsel said:


> I always use in single mode with 2 buffer and 2 single TO-99 opa637




Cool. Thanks. I can try my 2x OPA627s


----------



## zilch0md

spurxiii said:


> That surely can't be how the OPAMPS are installed right? My OPAMPS are installed as below


 
  
 You are using duals in L/R with singles as buffers.  But if you're using the TRS jack for single-ended cables, you could pull the first and third buffer op-amps (counting from left to right in your photo) and you wouldn't hear any difference.
  
 Pitsel's photo is proof that using the PB2 single-ended gives us only half the power of going balanced with this design - but its still two-channel stereo, even with half as many op-amps.


----------



## spurxiii

zilch0md said:


> You are using duals in L/R with singles as buffers.  But if you're using the TRS jack for single-ended cables, you could pull the first and third buffer op-amps (counting from left to right in your photo) and you wouldn't hear any difference.
> 
> Pitsel's photo is proof that using the PB2 single-ended gives us only half the power of going balanced with this design - but its still two-channel stereo, even with half as many op-amps.


 
 Thanks Mike!


----------



## zilch0md

spurxiii said:


> Thanks Mike!


 
  
 You're welcome,
  
 Those look like HA5002 as buffers, but what are those duals you're using?
  
 Mike


----------



## spurxiii

Yes Mike they are the HA5002 buffers. Those duals are LME49860 which is from the topkit in Aug last year


----------



## highfell

highfell said:


> Cool. Thanks. I can try my 2x OPA627s




But they will have to wait my newly arrived 2x Muses 01


----------



## zilch0md

Joy!
  
 It seems I'm hopelessly addicted to dummy buffers (at the expense of additional current) but, depending on your headphones, you might find you can better hear what the Muses01 brings to the table, at least for a little while, if you go "bufferless."  
  
 This is analogous to something I once read at the forums of CoffeeGeek.com (paraphrasing): _ If you really want to know what your non-dairy creamer is doing to the flavor of your coffee, just fill your mug with hot water - not coffee, then add the usual amount of creamer and drink up. Keep doing this until you find one that doesn't taste nasty. And by the way, good luck with that!_
  
 I have yet to find an op-amp that is as transparent as a dummy buffer. That's actually a gross understatement, given that a dummy buffer is nothing more than conductors, but the transparency is just as obvious to my ears as the understatement is to my eyes.  Even my best-sounding buffer (the HA5002) has a slight veil, best heard with something like the HD800 and a really noise-free DAC, like the Beresford Bushmaster MkII.
  
 Lastly, just running the PB2 balanced out instead of single-ended gives me plenty of power (from two duals or four singles) for my LCD-2 or HD800.  With the LCD-2, I typically run the volume knob somewhere between 9 and 11 o'clock, but let me be the first to say that I'm probably forfeiting some dynamics and bass control by running dummy buffers, as the planar magnetics prefer power (volts * amps) that comes from amperage (via buffers) rather than from voltage (via the op-amps in L/R).  
  
 And in truth, the LCD-2 is not ultra resolving, so I can tolerate the "veil" of the HA5002 when using the LCD-2, but I try to keep the lid closed on my PB2 - to protect my sanity from the incessant rolling of op-amps. I could easily get into pulling the HA5002 in and out, in and out, with the changing of headphones.  
  
 It's all I can do to keep the lid closed.  As yet, I haven't resorted to putting Loctite Red on the case screws... 
  




  
 Mike
 (Currently running 2x Muses02 with dummy buffers, after several months using 4x LME49990 with dummy buffers).


----------



## highfell

zilch0md said:


> Joy!
> 
> It seems I'm hopelessly addicted to dummy buffers (at the expense of additional current) but, depending on your headphones, you might find you can better hear what the Muses01 brings to the table, at least for a little while, if you go "bufferless."
> 
> ...




Good idea. I will try replacing with dummy buffers.

Silly question - if you have no buffers at all what happens ???


----------



## turboman808

Hey Guys.  I just got the hiflightaudio kit yesterday and I really don't have a clue what I am doing.  I use my amp with my alpha dogs and hifiman headphones.  I also should have a DB2 coming in pretty soon.  Plan to run everything balanced.  
  
 Anyways I see pictures of different things, I see hiflight pictures but they all look different.  Mine came with 4 chips with diodes on them. I put all those in the second row from the jumpers.  I then put 2 of the larger chips in near the jumpers.  I didn't like the way the first set seems to be breaking up in the highs.  I think it had white paint on them.  I then put in the set with red paint and it sounds much better.  
  
 I can take a picture tonight but I would really like to just set this up and leave it alone.  Any advice would be much appreciated.  Thanks Nate


----------



## highfell

turboman808 said:


> Hey Guys.  I just got the hiflightaudio kit yesterday and I really don't have a clue what I am doing.  I use my amp with my alpha dogs and hifiman headphones.  I also should have a DB2 coming in pretty soon.  Plan to run everything balanced.
> 
> Anyways I see pictures of different things, I see hiflight pictures but they all look different.  Mine came with 4 chips with diodes on them. I put all those in the second row from the jumpers.  I then put 2 of the larger chips in near the jumpers.  I didn't like the way the first set seems to be breaking up in the highs.  I think it had white paint on them.  I then put in the set with red paint and it sounds much better.
> 
> I can take a picture tonight but I would really like to just set this up and leave it alone.  Any advice would be much appreciated.  Thanks Nate




Download the PB2 "manual" at the bottom of this page

http://ibasso.com/en/products/show.asp?ID=70

Don't the chips have markings on them to identify them? And then read this thread, there are some more details about the Topflight kits


----------



## zilch0md

highfell said:


> Good idea. I will try replacing with dummy buffers.
> 
> Silly question - if you have no buffers at all what happens ???




Silence.


----------



## zilch0md

Hi Turboman808,




turboman808 said:


> Hey Guys.  I just got the hiflightaudio kit yesterday and I really don't have a clue what I am doing.  I use my amp with my alpha dogs and hifiman headphones.  I also should have a DB2 coming in pretty soon.  Plan to run everything balanced.
> 
> Anyways I see pictures of different things, I see hiflight pictures but they all look different.  Mine came with 4 chips with diodes on them. I put all those in the second row from the jumpers.  I then put 2 of the larger chips in near the jumpers.  I didn't like the way the first set seems to be breaking up in the highs.  I think it had white paint on them.  I then put in the set with red paint and it sounds much better.
> 
> I can take a picture tonight but I would really like to just set this up and leave it alone.  Any advice would be much appreciated.  Thanks Nate




The first thing to do is to identify all the op-amps in your possession so that you can take notes and share comments with others and receive opinions from others. Then, remove the top four screws from your PB2 case, remove the lid, plug in the cables and headphones of choice, and start listening and rolling, listening and rolling. 

If you have single-ended cables, you can speed up the rolling process by using half as many op-amps, like pitsel does:



pitsel said:


> I always use in single mode with 2 buffer and 2 single TO-99 opa637




If you want to skip all that trial and error, go with the opinions of others by telling us which op-amps you have.


----------



## pitsel

If you have single-ended cables, you can speed up the rolling process by using half as many op-amps, like pitsel does:



pitsel said:


> I always use in single mode with 2 buffer and 2 single TO-99 opa637




If you want to skip all that trial and error, go with the opinions of others by telling us which op-amps you have.

[/quote]

Hi,
For single-ended cables, ^ ^ with standard BUF634 and "Single" op-amps OPA637 



And below same for single-ended cable, with Dummy buffer and "Dual" LME49720HA, i more prefer than opa637


Thanks


----------



## turboman808

Thanks I will have to take some pictures and write down what they are tonight.


----------



## HiFlight

Perhaps I can add a bit of clarification here.... buffers are primarily current devices rather than voltage devices, so by bypassing them, one will lose some output power, but this will likely be a non-issue unless attempting to drive extremely challenging phones or listening to music with a very wide dynamic range, such as some hi-rez files. More importantly, buffers function as impedance-matching devices. When bypassing them, some phones will sound just fine while others will have the frequency balance affected to some degree or another. 

Regardless of what type of buffers are used, they will add their own signature to that of the L/R opamp(s) which can be either a positive or a negative, depending on your personal preferences. 

Topkits include more than one set of L/R opamps to enable the user to optimally match their musical tastes as well as find the best synergy between the amp and a particular set of phones. 

As far as choosing a "best" combination, TRUST YOUR EARS!!!


----------



## Makiah S

SO guys I have a bit of an issue, and a question for you all?
  
 My pb2 has a White Battery inside of it, not a HUGE blue one and I've also got a capcitor Sitting atop of the Blue sodder joints that lead into it's soddered in with a right angle plug
  
 more importantly, I've been having some issues with my left channel, first of all the CB11 that I got died on me, it wsn't running the left channel at all, now I've got a new adaptor and all is well except that... if I bump the amp [which I don't often do] I get a click or a pop on my left channel :/
  
 what is that, should I be worried? Do I need to purchase a new pb2 at some point to avoid this one dieing q.q, should I find my Warrenty card, which may now be expired since I got it second hand >.> lot's o questions I have
  
 also I found a FREAKING hair inside my amp... which I didn't know was there, I removed it. But I am worried that it may have lead to the death of my last adapter and it my have been the cuase that developed this left channel clicking due to movement from the amp
  
 IF I tap on the chassis I get some MAJOR Mirconphonics and the left channel again goes super silent... what the heck <.< this is a freaking SOLID state device, and why does the internals of mine not look like what you guys have pictures of up there q.q
  
 yea if I thunk it to hard no left channel... if I thunk it with just ONE finger, the left channel comes back... what the heck >.>


----------



## SpudHarris

mshenay said:


> SO guys I have a bit of an issue, and a question for you all?
> 
> My pb2 has a White Battery inside of it, not a HUGE blue one and I've also got a capcitor Sitting atop of the Blue sodder joints that lead into it's soddered in with a right angle plug
> 
> ...


 
  
 My first thought would be to ensure your OpAmps are sat correctly in the sockets. Post a pic if you think yours is different....


----------



## Makiah S

spudharris said:


> My first thought would be to ensure your OpAmps are sat correctly in the sockets. Post a pic if you think yours is different....


 
 they are and have been I can check again


----------



## HiFlight

mshenay said:


> they are and have been I can check again




Sounds to me like a cracked/incomplete solder joint on one of the opamps. NEVER insert them by pushing down on top of the opamp. Press gently around the edges of the adapter. The SOIC solder joints are very small and very fragile. 

I would try changing L/R opamps one at a time. Doesn't matter at this point if they are all the same, you are just looking to find the one that is faulty.


----------



## Makiah S

ewww thanks for tellin me that... I used tweesers today on the tops... super gently! but actually one of the pins was slighty bent. Ive never removed thr op amps or buffers before but i reseated them all today straightend the pin with a tweezer. took me 2 painful mins

but everythings all clear now. I appreciate u respobding. Ive got a quad of lme 49990s. If the problem appears again n reseating the doesnt fix it ill buy new op amps first

but removeing n reinsrting all 8 op m buffers solved the noise issues!


----------



## HiFlight

mshenay said:


> ewww thanks for tellin me that... I used tweesers today on the tops... super gently! but actually one of the pins was slighty bent. Ive never removed thr op amps or buffers before but i reseated them all today straightend the pin with a tweezer. took me 2 painful mins
> 
> but everythings all clear now. I appreciate u respobding. Ive got a quad of lme 49990s. If the problem appears again n reseating the doesnt fix it ill buy new op amps first
> 
> but removeing n reinsrting all 8 op m buffers solved the noise issues!




Glad to have been able to help!


----------



## Lohb

Anyone know how this compares to RSA F35 in stock form and with any other upgrade kits in it (LME49990 etc) ?
 ...and is it a compromise to use it as your main desktop amp as well @ about $400 inc. upgrade chips/shipping ?
 I'll be running it off a Bushmaster Mk2 downstream.


----------



## Uchiya

lohb said:


> Anyone know how this compares to RSA F35 in stock form and with any other upgrade kits in it (LME49990 etc) ?
> ...and is it a compromise to use it as your main desktop amp as well @ about $400 inc. upgrade chips/shipping ?
> I'll be running it off a Bushmaster Mk2 downstream.


 
 Something like an Asgard2 would better serve you if you're using it purely as a desktop amp.


----------



## Lohb

uchiya said:


> Something like an Asgard2 would better serve you if you're using it purely as a desktop amp.


 

 Thanks, was looking to share mobile and desktop....more money for more cans !


----------



## Uchiya

lohb said:


> Thanks, was looking to share mobile and desktop....more money for more cans !


 
 There are limitations to what portable amps can do, nice as they are.  If you hear your cans on a desktop setup and can live with the compromise in sound from a portable amp, go for it.


----------



## Makiah S

lohb said:


> Thanks, was looking to share mobile and desktop....more money for more cans !


 
 I think it's more [well with the HiFlighKit] capable of being a desktop and portable amp. Granted it'll push about 2.5wpc into 32 ohms [that asumming you've got the right BUffers and op amps and max gain]
  
 But if we assume at least 1w pc [worst case scenario] it'll work nicely with the the New Hifiman Orthos, the Mr Speakers Ortho's and any Dynamic headphones. 
  
 So it should be decently capable.


----------



## spurxiii

I think the PB2 sounds about as good as a desktop amp that's probably half the price to be honest. You pay for portability. My HE500s sound just as good out of my PB2 or my AGD 15.32


----------



## highfell

Rolling Muses01 and Muses02 in a Pb2 powered by a DX50.

I can confirm that they have very bendy legs 

What did the they sound like? First, when I turn my PB2 on with the Muses01 I get the biggest "pistol shot thump" that I have heard from any of my other OpAmps and yet with the Muses02, I don't hear anything.

The Muses01 don't seem bright to me at all, even though I was expecting them to. They are detailed for sure but not harsh sounding. Very musical across the range from rock to classical. Vocals are forward and very apparent eg listening to SigurRos live, his tenor style voice sounds mesmerising. They also have an ability to respond well to the deep notes of a bass guitar. I found the Muses01 dynamic in style and frankly great to listen to. They are my "goto" OPamps.

Highlight's Topkit of HA5002 Buffers adds some more oomph and dynamism. (now to try them in class A biased sockets)

For the Muses02, I was slightly disappointed but probably only in their comparison to Muses01. They are definitely warmer sounding which I generally prefer, but I found a slight muddiness that surprised me. They still sound very musical but compared to Muses01 they lack sparkle & sound slightly lifeless. As a little aside , I also had some electronic noise interference on my commute into work which I haven't had with the Muses01.


----------



## Makiah S

spurxiii said:


> I think the PB2 sounds about as good as a desktop amp that's probably half the price to be honest. You pay for portability. My HE500s sound just as good out of my PB2 or my AGD 15.32


 
 I agree, while my NFB 10ES2 has a slighty better sound, the Pb2 is darn close! and it's about 1/10 the size and weight


----------



## spurxiii

mshenay said:


> I agree, while my NFB 10ES2 has a slighty better sound, the Pb2 is darn close! and it's about 1/10 the size and weight




Yup portability costs. But can't believe I can hear what I'm hearing sitting next to some stranger on the train. Most of the time I'm using it to drive my TH600 because they're closed. Most of the beats people give me weird looks they're probably thinking I got some cheap ass can on my head. Little do they know I'm in sonic heaven while they only think they are


----------



## Bugdozer

Will you guys please stop!! About a year ago I sold my DB2/PB2 combo with a whole boatload of OPAs and buffers thinking I wouldn't miss it.  I was wrong, I was honorably wrong but right now I can't afford to replace it.  All this talk is making me want them back.  Where is that damn unsubscribe button.


----------



## highfell

bugdozer said:


> Will you guys please stop!! About a year ago I sold my DB2/PB2 combo with a whole boatload of OPAs and buffers thinking I wouldn't miss it.  I was wrong, I was honorably wrong but right now I can't afford to replace it.  All this talk is making me want them back.  Where is that damn unsubscribe button.




Come back home - this guy posted on the dx50 thread that he was selling this.

http://www.head-fi.org/t/714271/wts-ibasso-pb2-silver-few-weeks-old


----------



## Makiah S

highfell said:


> Come back home -
> 
> 
> 
> ...


 
 YOU BUY NOW
  
 I actually have the Hifi Flight Kit, I only use the Dummy Buffers and LME 49990 Quads, so take those out of the equation and I'd be more than happy to sell you the other OP amps and buffers in the Kit I don't use


----------



## zilch0md

mshenay said:


> * I only use the Dummy Buffers and LME 49990 Quads*


----------



## HiFlight

mshenay said:


> YOU BUY NOW
> 
> I actually have the Hifi Flight Kit, I only use the Dummy Buffers and LME 49990 Quads, so take those out of the equation and I'd be more than happy to sell you the other OP amps and buffers in the Kit I don't use




FWIW, I do not include the LME49990 opamps in the PB2 Topkit. With bypassed buffers, the output power is considerably reduced. Not an issue with sensitive phones but could be problematic with phones that are challenging to drive.


----------



## burdie

hiflight said:


> FWIW, I do not include the LME49990 opamps in the PB2 Topkit. With bypassed buffers, the output power is considerably reduced. Not an issue with sensitive phones but could be problematic with phones that are challenging to drive.


 

 Ya, Lately Hiflight include LME49860 in the Topkit.


----------



## Makiah S

Ahh... either way I'll Post what I have here soon enough!
  
 Thankfully both of my portable woodies, are 32 ohm highly sensitive headphones, so power wise I don't need much. 
  
 My HE 4 isn't good for any where outside of home, seeing as it's open ya know!


----------



## Makiah S

zilch0md said:


>


 
 Guys SHAME ON ME
  
 there is an ACTUAL record Shop, and apprently a rather famous one near me called
  
 Killgor Troue, here in Myrtle Beach sc :O.
  
 I've NEVER been and I'm TOTALLY going to go in there in about the next hour! With my POrtable gear with me :3. Let's hope I can find some AudioPhiles there ^^


----------



## zilch0md

Memories!  I'm envious!


----------



## Mambosenior

Who sells the ibasso pb2? Was it replaced with a newer model?


----------



## zilch0md

It's still manufactured and sold directly, by iBasso.  
  
 Here's the link:  http://ibasso.com/en/products/show.asp?ID=70


----------



## Lohb

Anyone know what a comparable SQ desktop amp would be to the PB2 with the LMExxxx opamp kit ?


----------



## Lohb

If anyone has an xpal willy 15 volts lying around that they no longer use with their PB2, please let me know if it is for sale.
 I just picked up the XP8000 battery pack the other day.
 15 volt one not the 16v one.


----------



## zilch0md

I can't help. but I'm curious why you want the 15V version for your PB2.
  
 Mike


----------



## Lohb

zilch0md said:


> I can't help. but I'm curious why you want the 15V version for your PB2.
> 
> Mike


 

 It is for another amp 15v max just now and then can use with PB2 later.


----------



## zilch0md

Smart!


----------



## zilch0md

I've ordered a pair of NE5532AP at $1.08 each. (Big spender!)

I'm just curious because I keep reading about how they've been used in so many audio devices, but there seems to exist a consensus of disapproval for them - mostly for lack of detail - but I want to hear them, just the same.

Mike


----------



## Makiah S

On a positive note, I used my pb2 today with my hm801, LME 49900 op amps and dummy buffers, the positive here is I used a Hirose 6pin to Dual Female XLR Dual Pin, and now get this on LOW gain, the iBasso pb2 didn't show any signs of power lagg, or ANYTHING when driving two dynamics [30ohms 95+ sensitivity], Which impressed me, in the past when I would Spilt the 3.5mm out into 2 headphones it was Quieter and I lose head room, now spilitting the balanced out... THE pb2 DONT CARE lol, she's got the same grunt and power into 2 dynamics on LOW gain with DUMMY buffers as when driving a single headphone,
  
 either way I'm really glad I got this amp :3, and to think I was going to spend $600 on an RSA balanced amp ^^, for half the price I think what I have is just as good if not better


----------



## zilch0md

zilch0md said:


> I've ordered a pair of NE5532AP at $1.08 each. (Big spender!)
> 
> I'm just curious because I keep reading about how they've been used in so many audio devices, but there seems to exist a consensus of disapproval for them - mostly for lack of detail - but I want to hear them, just the same.
> 
> Mike


 
  
 Don't bother with the NE55532AP.  The "AP" is allegedly the low-noise version of the "P", costing a few cents more per op-amp, but it's horribly lacking in detail, sounds compressed and lifeless, with excessive bass energy, that's very woolly. In fact, the whole spectrum is woolly.  Yuck!  
  
 I can only conclude that these op-amps have been used in literally millions of audio devices because they're inexpensive, not because they sound good.
  
 I'm glad the experiment only cost me about $6.00 with shipping, but I'm also glad I heard these, as it establishes a reference that highlights just how much better something like an OPA1611 or LME449990 or Muses 01 really is.
  
 Mike


----------



## zilch0md

mshenay said:


> On a positive note, I used my pb2 today with my hm801, LME 49900 op amps and dummy buffers, the positive here is I used a Hirose 6pin to Dual Female XLR Dual Pin, and now get this on LOW gain, the iBasso pb2 didn't show any signs of power lagg, or ANYTHING when driving two dynamics [30ohms 95+ sensitivity], Which impressed me, in the past when I would Spilt the 3.5mm out into 2 headphones it was Quieter and I lose head room, now spilitting the balanced out... THE pb2 DONT CARE lol, she's got the same grunt and power into 2 dynamics on LOW gain with DUMMY buffers as when driving a single headphone,
> 
> either way I'm really glad I got this amp :3, and to think I was going to spend $600 on an RSA balanced amp ^^, for half the price I think what I have is just as good if not better


 
  
 Hey, congratulations on getting a PB2 - with LME49990 and dummy buffers, no less.  
  
 It's an amazing little amp and I know from having had one that the PCM1792UK Line Out of the HM801 is wonderful.  
  
 Which headphones are you using on the balanced output of the PB2?
  
 Thanks,
  
 Mike


----------



## Makiah S

zilch0md said:


> Hey, congratulations on getting a PB2 - with LME49990 and dummy buffers, no less.
> 
> It's an amazing little amp and I know from having had one that the PCM1792UK Line Out of the HM801 is wonderful.
> 
> ...


 
 I guess I forgot to mention that, I used my Modded Denon D2k it's got Lawton Pads, Cocobolo Wood Cups and Lawton Driver Mods, and I also used my W1000x, L3000 Pads and purrin mods, both have Copper OCC cables from BTG


----------



## zilch0md

Nice!


----------



## zilch0md

Is anybody thinking about buying four LME49990 for their PB2?
  
 http://www.head-fi.org/t/724174/4x-lme49990-op-amps-on-dip8-adpaters-4x-dip8-sockets-includes-shipping-and-fees


----------



## ati832

Practical Devices XM6 or the ibasso what you guys think has the most power out of these two.


----------



## zilch0md

ati832 said:


> Practical Devices XM6 or the ibasso what you guys think has the most power out of these two.


 
  
 I have no experience with the XM6, but going only on this description from their website...
  
  Quoting http://www.practicaldevices.com:
  


> ... made possible by the XM6's *two-chip ultra-low-distortion FET amplification stage*, mated to a separate* two-chip output buffering stage *...
 
  
I would be surprised to learn that the XM6's single-ended output, using only four op-amps (two per channel), could be as powerful as the iBasso PB2's balanced output, using eight op-amps (4 per channel).
  
 That's a generalization, of course, because power output will vary with the type of op-amp being used and the supply voltage, but I'm still confident that a really power-hungry headphone would be happier with eight op-amps (balanced) than with four op-amps (single-ended) - even with some variation in performance of the op-amps chosen.
  
 What headphones are you planning to use?
  
 Mike


----------



## SpudHarris

I used to have an XM6. Lots of features but not the best amp. Not bad, just nothing special IMO.


----------



## ati832

thanks guys for the input. I am needing an amp for the t1's might just buy the ifi idsd


----------



## steam412

Well buyed PB2, buyed NJM2068x2 and with hard but find LT1010.
  
 Well what can say: if use NJM2068 with stock buffers you already start see what pb2 play better scene more width.
  
 With LT1010 you will heard fast real bass this like in bass in live rock concert.
  
 Can say what stock pb2 vs pb2 up this real more diferents.
  
 NJM2068 this real max neutral opamp how and sayed Ron. LT1010 this real good buffer for that headphones how isodynamic.
  
 Ron thank you real for advice what better play this real fantastic (I"m sorry what not buyed you kit. But you sayed No...but you respect.)


----------



## privilege15

No really, who can tell if there's another highly customizable balanced portable amplifier capable of 2.5 watts per channel?
 So far I am crazy about it:

 Also ordered iBasso Hirose balanced connector. Going to try out my soldering skills by making a balanced cable for DT150 myself. Luckily for me DT150 have two physical wires for each channel. Just need to solder them to the correct pins.


----------



## Dopaminer

Isn`t it awesome ?  
 I have a balanced hirose cable for my HD800, and it makes for the ultimate transportable system.


----------



## zilch0md

dopaminer said:


> Isn`t it awesome ?
> I have a balanced hirose cable for my HD800, and it makes for the ultimate transportable system.


 
  
 What DAC and which op-amps are you using for your HD800, Dopaminer?
  
 Thanks!
  
 Mike


----------



## zilch0md

Spoiler: stillevil's still at it



Quote: 





stillevil said:


> No really, who can tell if there's another highly customizable balanced portable amplifier capable of 2.5 watts per channel?
> So far I am crazy about it:
> 
> Also ordered iBasso Hirose balanced connector. Going to try out my soldering skills by making a balanced cable for DT150 myself. Luckily for me DT150 have two physical wires for each channel. Just need to solder them to the correct pins.





 
  
 I really dig your enthusiasm stillevil. 
	

	
	
		
		

		
			




  
 If anybody on this thread hasn't seen it yet, check out this stillevil creation:
  
  




  
 http://www.head-fi.org/t/507835/meier-audio-quickstep-also-stepdance-and-2stepdance-discussion-and-impressions-thread/2805#post_10997869


----------



## Dopaminer

zilch0md said:


> What DAC and which op-amps are you using for your HD800, Dopaminer?
> 
> Thanks!
> 
> Mike


 

 I use the iBasso DB2.  It`s a `fully balanced` system.  So far I`m using the stock OPA604 opamps but with the BUF634P 180MHz buffers, the ones with the little capacitor cylinders or whatever they are soldered on.  (See pic below).  Also, no gail jumpers, so +6db gain in balanced mode according to the iBasso pdf.  With these opamps and gain setting, I get comfortable listening levels with my HD800 from 11o`clock to 3o`clock on the volume dial.  (as a side note, when I tried the HE-560 single ended from this system at the Tokyo show last month, I buried the volume knob at max and it wasn`t enough)
  
 I found this headfonia page really helpful. 
  
 d


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## zilch0md

^ OK, I'm very, very intrigued by your use of the DB2 in that rig!  
  
  Nice shot!
  


>


 
  
 Before I had the HD800, I long ago ordered the DB2 and ended up returning it under iBasso's generous 15-day trial guarantee.  I've been very reluctant to order it since then, because if I again don't like it, I'd want to take a loss and sell it on the used market, rather than returning it again, and frankly, the DB2 is not a very popular DAC.  
  
 But my experience with the DB2 is haunting me because, at least with my LCD-2 rev.1 on the PB2, balanced out, I found the dual-Wolfson equipped DB2 to be too dark for my tastes.  Now that I have the HD800, I love the idea, at least, of using a dark DAC with a highly resolving, transparent, and powerful portable amp.  
  
 So, I've been looking for a used DB2, for quite some time now, but they just don't come up - as I don't think there are all that many of them out there. 
  
 Meanwhile, I really believe that in addition to the desireable "darkness" of the DB2 for the HD800, your choice of op-amps in the PB2 is actually _softening_ things for the HD800 - taking away some of the edginess that can be heard with so many tracks, using the unforgiving HD800.
  
 Currently, my favorite portable chain for the HD800 is:
  
*FiiO X5 PCM1792A DAC Line Out > iBasso PB2 with 4x LME49990 and dummy buffers balanced out > Toxic Cables Silver Poison > HD800*
  
 For my tastes, this is still too bright (too much energy in the highs), but it retains all the other traits of the HD800 that I like.  
  
 So... the hunt for a used DB2 continues, as I do not want to buy a new one and take a loss selling it used, if I don't like it...
  
 Mike


----------



## Dopaminer

zilch0md said:


> ^ OK, I'm very, very intrigued by your use of the DB2 in that rig!
> 
> 
> Before I had the HD800, I long ago ordered the DB2 and ended up returning it under iBasso's generous 15-day trial guarantee.  I've been very reluctant to order it since then, because if I again don't like it, I'd want to take a loss and sell it on the used market, rather than returning it again, and frankly, the DB2 is not a very popular DAC.
> ...


 
  
 I always thought the reason used DB2s don`t come up for sale very often is because their owners love them too much !  
 The DB2 is really amazing, with it`s true balanced structure, including 2 batteries...  As for shrillness of the HD800, I have always been transported by my HD800, and any music file that that I own which sounds bad with it, I replace with a better version.  I have steadily replaced my music library with better / different versions of the recordings.  For example, I have multiple versions of Massive Attack albums, from my own CD rips, to 24bit `needle drops`, DVD-A rips.  With modern jazz, I have recently been exploring all the SACD rips flooding the sharing sites, and I am always on the lookout for a viable PS3 to rip my own.  Plus, I have joined every single Hi-Res download site I can find, get their samplers, create mixes of my faves.  I simply don`t listen to youtube, or spotify, or iTunes, or MP3 even.  I believe there is a sonic difference between lossy and lossless files, and I believe dsd does have something special.  
  
 I also believe in the placebo effect and am not bothered if that is what I am enjoying.  
  
 My desktop / main headphone amp is a locally-made 3w tube amp, so maybe that`s why I enjoy the DB2 so much.  
  
 Fiio X5 is interesting.  With my db2/pb2 I used the iBasso dx50 as transport, with their short digital interconnect.


----------



## zilch0md

Haha!  Maybe you're right about why the DB2 never comes up for sale - it's not because nobody bought any - it's because they don't want to sell them!  
	

	
	
		
		

		
		
	


	



  
 It sounds as if you are way more aggressive than most people at finding high quality recordings - good for you!  I haven't invested as much _time_ as I should to that endeavor, but I'm sure it's very rewarding.
  
 It's beginning to look like I'm just going to have to buy another DB2 to hear it with my HD800... 
  
 Mike


----------



## spurxiii

I must make a new cable with hirose connector for my HD800s


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## burdie

spurxiii said:


> I must make a new cable with hirose connector for my HD800s


 
 What I did was made a universal Hirose to full size XLR adapter cable ready to accept any custom cable terminated with XLR at one end (SE535, HE-500, LCD 2.2 etc)

 The coaxial cable from iBasso DX50 (right angle 3.5mm) to DB2 (right angle RCA) is RG179 75 ohm flexible cable, tiny and just right size for 3.5mm plug

  
  
 DB2/PB2 combo with balanced mod AKG K712 via universal hirose to XLR > XLR to mini XLR > mini XLR to mini XLR


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## spurxiii

burdieOoooh nice 

I've already got a hirose to XLR adapter. I wanted an excuse to make a straight through to hirose 1.5m HD800 cable so I can put the rig in my pocket or bag and walk around with it if I wanted to


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## burdie

spurxiii said:


> @burdieOoooh nice
> 
> I've already got a hirose to XLR adapter. I wanted an excuse to make a straight through to hirose 1.5m HD800 cable so I can put the rig in my pocket or bag and walk around with it if I wanted to


 
 @*spurxiii*
 True also, hirose to FULL SIZE XLR is not meant for portable usage.


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## Dopaminer

zilch0md said:


> It sounds as if you are way more aggressive than most people at finding high quality recordings - good for you!  I haven't invested as much _time_ as I should to that endeavor, but I'm sure it's very rewarding.


 
  
 I have the advantage of extremely fast internet connection, with NO limit on data download.  Also, a kind of OCD/Fetish for seeking out better and better and better sounding recordings.  (It`s the endless hedonic treadmill, I know).  At least I am confident that the HD800 is as good as I will ever need.  
  
 Probably. 
  
 You should get another DB2 !   One thing I`ve never tried is filter-rolling to adjust the sound sig.  Maybe soon. . . 
  
 d


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## Dopaminer

spurxiii said:


> @burdieOoooh nice
> 
> I've already got a hirose to XLR adapter. I wanted an excuse to make a straight through to hirose 1.5m HD800 cable so I can put the rig in my pocket or bag and walk around with it if I wanted to


 

  Burdie that rig looks just like mine !  Is that dx50 or dx90 ?  
  
 The orange-ish balanced cable you guys see above on my HD800 is 1.5m. It is two completely separate cables joined at the hirose connector.  I had it made originally for my Shure 846, but I now know there is way too much hiss with the PB2 and those 9-ohm iems.  I also had one of those Furutech single-ended HD800 cables laying around, with the carbon fiber connectors, so I had a local shop solder them on to the 846 cable,  and voila!


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## spurxiii

dopaminer said:


> Burdie that rig looks just like mine !  Is that dx50 or dx90 ?
> 
> The orange-ish balanced cable you guys see above on my HD800 is 1.5m. It is two completely separate cables joined at the hirose connector.  I had it made originally for my Shure 846, but I now know there is way too much hiss with the PB2 and those 9-ohm iems.  I also had one of those Furutech single-ended HD800 cables laying around, with the carbon fiber connectors, so I had a local shop solder them on to the 846 cable,  and voila!


 
 Wow that's nice. I'm still waiting for my paracord to arrive before I can make mine


----------



## Dopaminer

I wish I could make stuff . . . 
  
 You guys are cool.


----------



## burdie

dopaminer said:


> Burdie that rig looks just like mine !  Is that dx50 or dx90 ?
> 
> 
> 
> ...


----------



## Makiah S

zilch0md said:


> ^ OK, I'm very, very intrigued by your use of the DB2 in that rig!
> 
> 
> Before I had the HD800, I long ago ordered the DB2 and ended up returning it under iBasso's generous 15-day trial guarantee.  I've been very reluctant to order it since then, because if I again don't like it, I'd want to take a loss and sell it on the used market, rather than returning it again, and frankly, the DB2 is not a very popular DAC.
> ...


 
 haha yea I use the same rig with my Cans, though the X5 sounds terrible. compared to my old HM801, I found it to be shrill and with very little sound stage or air for that matter 
  
 Get your self a hifiman DAP it will sound amazing with your HD 800, as it does with all of my very BRIGHT headphones 
  


burdie said:


> @*spurxiii*
> True also, hirose to FULL SIZE XLR is not meant for portable usage.


 
 I use it on the go lol 
  


dopaminer said:


> I have the advantage of extremely fast internet connection, with NO limit on data download.  Also, a kind of OCD/Fetish for seeking out better and better and better sounding recordings.  (It`s the endless hedonic treadmill, I know).  At least I am confident that the HD800 is as good as I will ever need.
> 
> Probably.
> 
> ...


 
 Yea I also have such a connection, though I still think my HM 901 LIne out is a GREAT way to Feed my iBasso PB2


----------



## spurxiii

mshenay said:


> haha yea I use the same rig with my Cans, though the X5 sounds terrible. compared to my old HM801, I found it to be shrill and with very little sound stage or air for that matter
> 
> Get your self a hifiman DAP it will sound amazing with your HD 800, as it does with all of my very BRIGHT headphones
> 
> ...




I used to use it on the go until I reterminated my TH600 to hirose. I didn't like carrying around an extra XLR connector. I just now need to make a hirose female to XLR adapter to use the TH600 with the Master 9


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## Makiah S

spurxiii said:


> I used to use it on the go until I reterminated my TH600 to hirose. I didn't like carrying around an extra XLR connector. I just now need to make a hirose female to XLR adapter to use the TH600 with the Master 9


 
 Nice stuff, though shame on my, as my pb2 doesn't as much use since I got my 
  
 hm901 and MS1i-W :/ I'm a filthy non Line Out using Casual when I'm on the go now
  
 though in all honestly, I use the Pb2 mostly when I'm sedentary, which I'm not as much any moar


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## privilege15

So today I received a spare cable for my headphones, cut its 3.5mm jack and attached the "balanced" plug to it.
  
 I thought there would be 4 separate wires inside DT150 cable but I was wrong. There were 3 wires only - red for the right channel, blue for the left and orange for "neutral". Here's what I figured out how to solder them to the connector:
  

  
  
  
 I managed to solder everything properly from the second try only. I'm not goot at it at all but it works.
  
 Here are some pictures:




  
 It works!)


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## Dopaminer

People I`ve decided to betray this whole PB2/DB2 system : I just bought the ak120ii.
  
 My complete ibasso rig is for sale in the FS section, including interconnects, a SE-adaptor, a case, and an HD800 cable.  
  
 Would love it to go to a good home . . . .   
  
 David


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## zilch0md

stillevil said:


> So today I received a spare cable for my headphones, cut its 3.5mm jack and attached the "balanced" plug to it.
> 
> [snip]
> 
> It works!


 
  
 Good for you!  Nicely done!


----------



## burdie

stillevil said:


> So today I received a spare cable for my headphones, cut its 3.5mm jack and attached the "balanced" plug to it.
> 
> I thought there would be 4 separate wires inside DT150 cable but I was wrong. There were 3 wires only - red for the right channel, blue for the left and orange for "neutral". Here's what I figured out how to solder them to the connector:


 
 You are actually having common ground for balanced Left & Right channel at which if i not mistaken, shouldn't be ground together as left and right channel have separated circuit and by doing so, risk burning your PB2


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## privilege15

I agree that one should't use common ground but that's the start at least as I don't have any other cable at my disposal. The power is doubled and this is what I was looking for until I find a better cable. The quality is noticably better than that of a single ended output and as for know it is on par with Corda Quickstep but still need more time to listen.

My analysis after a day of listening is the following:

PB2 (balanced and modded with opamps) at 16v is equal or better than Qickstep at 15v. Still listening for this.
PB2 (single ended and modded with opamps) at 16v is worse than Quickstep at 15v and the difference is noticable. That's why until I went balanced with PB2 I had kept it my drawer preferring Quickstep.
PB2 with stock opamps... well... if you don't plan to change opams and go balanced it's better to spend the same money on Quickstep.


----------



## burdie

stillevil said:


> I agree that one should't use common ground but that's the start at least as I don't have any other cable at my disposal. The power is doubled and this is what I was looking for until I find a better cable. The quality is noticably better than that of a single ended output and as for know it is on par with Corda Quickstep but still need more time to listen.


 
 Go ahead and balanced mod your DT150 to experience the real balanced out


----------



## privilege15

burdie said:


> Go ahead and balanced mod your DT150 to experience the real balanced out


 
  
 Yeah, I will. Today it struck me. I don't know why I didn't think of this before but as a network engineer I have several UTP patch cables (24 AWG) in the inventory. The colours are little too bright but who cares. At least I will not have to spend a fortune on fancy audio cables. I'll make the real cable when I return home.


----------



## burdie

stillevil said:


> Yeah, I will. Today it struck me. I don't know why I didn't think of this before but as a network engineer I have several UTP patch cables (24 AWG) in the inventory. The colours are little too bright but who cares. At least I will not have to spend a fortune on fancy audio cables. I'll make the real cable when I return home.


 
 24 awg audio cable not really that expensive (for DIY). Canare star-quad ofc cable cost few dollars for a meter, 2-3 meters basically long enough. The Hirose connector even cost more. Some more there are a lot of choices like mogami, van damme, belden etc with difference conductor like silver plated copper, ultra pure ofc etc


----------



## Vo2max

Has anyone tried rolling opamps in these configuration;
  
 XXOO
 XOXO
 XOOX
  
 where:
 X - opamp A
 O - opamp B


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## privilege15

After 4 hours and 2 burnt fingers I came up with a true balanced cable made of Cat5 UTP 24AWG:


----------



## zilch0md

stillevil said:


> I agree that one should't use common ground but that's the start at least as I don't have any other cable at my disposal. The power is doubled and this is what I was looking for until I find a better cable. The quality is noticably better than that of a single ended output and as for know it is on par with Corda Quickstep but still need more time to listen.
> 
> My analysis after a day of listening is the following:
> 
> ...


 
  
 All of this makes sense to me (as a Stepdance and PB2 owner).  I've yet to find a combination of opamps for the PB2, however, that can compete with the 15V-powered Stepdance for transparency - but it takes the likes of an HD800 to hear the difference (when the PB2 is populated with OPA1612 and dummy buffers).  When the PB2 is configured like this, it's at its most neutral and transparent, but I've yet to find a portable DAC that satisfy the the HD800's revealing nature when using perfectly neutral and transparent amps.  
  
 For less demanding headphones (everything else?), to my ears, the PB2 sounds best with LME49990 and dummy buffers (or HA5002 buffers if the extra power is really needed) - sounding less analytical than the OPA1612.
  
 Mike


----------



## zilch0md

vo2max said:


> Has anyone tried rolling opamps in these configuration;
> 
> XXOO
> XOXO
> ...


 
  
 I haven't.


----------



## zilch0md

stillevil said:


> After 4 hours and 2 burnt fingers I came up with a true balanced cable made of Cat5 UTP 24AWG:


 
  
 That's beautiful - and I really like the way you admit to burning your fingers!  LOL  (Me too. I hate soldering. I'm all thumbs, but they never get burnt.)
  
 With only three pins at the headphone connector, aren't you still bringing the grounds together (at the other end of the cable instead of at the Hirose connector)?
  




  
 Mike


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## privilege15

zilch0md said:


> That's beautiful - and I really like the way you admit to burning your fingers!  LOL  (Me too. I hate soldering. I'm all thumbs, but they never get burnt.)
> 
> With only three pins at the headphone connector, aren't you still bringing the grounds together (at the other end of the cable instead of at the Hirose connector)?
> 
> ...




Hi Mike,

There are 6 pins at headphone connector originally: R+, R-, L+, L-, Mic+, Mic-

Byerdynamic DT150 is a micless version so the last two pins are not used. The negative R- and L- pins are soldered together as a factory default to provide common negative ground.

See the pic below:



Sry for the quality, I made it for myself as a backout plan.

What I did when making the true balanced cable is that I separated the negative pins from each other by removing the original factory solder between them and solderd R- and L- as per the pin separately.


----------



## Vo2max

zilch0md said:


> I haven't.


 
 Somehow, someone has to do it. 
	

	
	
		
		

		
		
	


	



  
 Btw, is there really a remarkable difference in using the LME49990 / dummy buffers over the AD797 / dummy buffers?
 I am running balanced on HD650
 I won't be asking this question if the LME49990 can be easily obtained on my end here. It is a hazzle to have one here actually.


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## privilege15

vo2max said:


> Somehow, someone has to do it.
> 
> 
> 
> ...


 
  
 Yes, there's is audible difference over stock opamps. I have ordered my LME49990 from a very nice seller on ebay frugalphile who sent me a free replacement for a couple of damaged on the way opamps as two of them arrived with bent legs and it was impossible to recover them. If you can't use ebay, there's an option to contact Hiflight member on this forum or go straight to his web site at www.hiflightaudio.com. Although he does not include LME49990 in his set but still goes with very interesting opamps and buffer combinations to influence the sound signature to your liking.


----------



## zilch0md

vo2max said:


> Somehow, someone has to do it. :etysmile:
> 
> Btw, is there really a remarkable difference in using the LME49990 / dummy buffers over the AD797 / dummy buffers?
> I am running balanced on HD650
> I won't be asking this question if the LME49990 can be easily obtained on my end here. It is a hazzle to have one here actually.




I'm going to play it safe and say it's a subtle difference. If you've rolled a lot of op-amps, it might seem a little more dramatic.


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## Vo2max

@stillevil @zilch0md thanks for chiming in.
 I think i have to give it a try. i was expecting/looking for a "remarkable" but i know that is a tall order just by changing opamps.
 "audible" or "subtle" difference would be fine for me.
 I simply cannot ignore what most head-fiers are saying.


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## zilch0md

I'm cautious in answering questions about the impact of a component change because several months of rolling op-amps in the PB2 actually trained me to listen critically (for which I have no regrets, I have to say), but it's difficult for me to know if another person's ear is as well-trained as my own - and I still see my ear as a work in progress. I know for a fact that other people at Head-Fi are much better at discerning sonic traits than I am.
  
 In the beginning, however, it was really hard for me to detect any differences when rolling op-amps, because at that stage of my "development," I was all about enjoying the content of a recording, without much ability to detect differences in sound quality. I could easily detect differences between headphones, but it was not so easy to detect differences between op-amps. Ignorance was bliss. Adaptive hedonism had not taken me very far at that point.  
  
 So, for someone who hasn't rolled op-amps in their PB2, for example, I make the assumption that they, too, might find it difficult to detect differences at first.  I have to remind myself of this when I read a post where someone says that all cables sound the same to them, or all DACs, and even all amps!
  
 My daughter is a skilled musician, but she seems to listen to music entirely for its content, with what I see as a fascinating ability to completely ignore the quality of reproduction. She has almost no capacity or interest in listening analytically. I envy her, in a way, as it has taken me a while to learn how to effectively disable my analytical listening, when I just want to enjoy the music.  I actually have to willfully focus on the emotional aspects of a recording long enough to fall into that head-space where I am no longer focusing on sonic traits. I can transition very quickly now, but there was a time, thanks to my op-amp rolling experience, when it wasn't so easy.  
  




  
 Mike


----------



## spurxiii

Stop being so modest Mike, we all know that the LME49990s and dummy buffers provide at least a 167% improvement in soundstage, 243% better separation and 98% bass impact


----------



## zilch0md

^ Haha!  Those were the exact numbers I had in mind!


----------



## Vo2max

zilch0md said:


> I'm cautious in answering questions about the impact of a component change because several months of rolling op-amps in the PB2 actually trained me to listen critically (for which I have no regrets, I have to say), but it's difficult for me to know if another person's ear is as well-trained as my own - and I still see my ear as a work in progress. I know for a fact that other people at Head-Fi are much better at discerning sonic traits than I am.
> 
> In the beginning, however, it was really hard for me to detect any differences when rolling op-amps, because at that stage of my "development," I was all about enjoying the content of a recording, without much ability to detect differences in sound quality. I could easily detect differences between headphones, but it was not so easy to detect differences between op-amps. Ignorance was bliss. Adaptive hedonism had not taken me very far at that point.
> 
> ...


 
  
 I am not an audiophile by any means. Listening analytically has never been my forte as i simply love to listen to good music. Simply put, as anything that satisfies my stomach is good food, same goes for anything that satisfies my ear is good music, 
 I have no specific taste as i go from Metal to Classical and anything in between that.
 The PB2 came in late to me considering that the rest of you guys have probably have thousands of hours on their PB2. But i have no escape, sort of, as i have changed the cable of HD650 to a Hirose connector ready for the PB2 a year ago. Boy it was a long wait!!!
 Although these is the first time i rolled op-amps, changing from the stock 604/634 to AD797/dummy showed a very discernible change. No analytical listening involved but my ears simply love the latter combination right off. It was like soloing on the guitar without even thinking where to put ones fingers on the fretboard. The choice came out natural/automatic without even thinking.
 I have backread the entire thread and i can say that i enjoy reading your inputs.


----------



## Vo2max

spurxiii said:


> Stop being so modest Mike, we all know that the LME49990s and dummy buffers provide at least a 167% improvement in soundstage, 243% better separation and 98% bass impact


 
  
 I have a feeling that those numbers won't change once i got the LME49990/dummy buffer installed on mine..


----------



## zilch0md

^  LOL  
  
 You surely won't be disappointed.


----------



## Makiah S

dopaminer said:


> People I`ve decided to betray this whole PB2/DB2 system : I just bought the ak120ii.
> 
> My complete ibasso rig is for sale in the FS section, including interconnects, a SE-adaptor, a case, and an HD800 cable.
> 
> ...


 
 I'm sorry to hear that, Though I am currently using my HM901 n Classic Card with my MS1i-W on the go, as when I'm out of the house I'm listening in noisy enviorments
  
 Though I've not heard a lot of positives about the Sound of the AK120ii when compared to the HM901, and my second point is the PB2 Balanced out with LME 49990 and Dummy Buffers sounds better both SE and Balanced than the hm901 Classic or Standard card
  
 my Ultimate point being, I think you may find the AK120ii to be lacking in terms of quality. Though I've not heard the DB2 so I'm not sure how it sounds in comparison to the AK 120ii or the HM901 
  


zilch0md said:


> I'm cautious in answering questions about the impact of a component change because several months of rolling op-amps in the PB2 actually trained me to listen critically (for which I have no regrets, I have to say), but it's difficult for me to know if another person's ear is as well-trained as my own - and I still see my ear as a work in progress. I know for a fact that other people at Head-Fi are much better at discerning sonic traits than I am.
> 
> In the beginning, however, it was really hard for me to detect any differences when rolling op-amps, because at that stage of my "development," I was all about enjoying the content of a recording, without much ability to detect differences in sound quality. I could easily detect differences between headphones, but it was not so easy to detect differences between op-amps. Ignorance was bliss. Adaptive hedonism had not taken me very far at that point.
> 
> ...


 
  
 Yea I agree, I find the LME49990 and DUmmy Buffers to be very ideal for HIGH sensitivity and Low Impedance Headphones [everything I own minus the HE 4] so with both of my Grados, my LA D5k and my W1000X, I find the pb2 with those op amps and buffers to really be a very good listen! Even more I can drive both my LAD5k and W1000X balanced out without the PB2 showing any sign of fatigue or strain [on low gain] with the LME 49990 OP amps and Dummy Buffers 


spurxiii said:


> Stop being so modest Mike, we all know that the LME49990s and dummy buffers provide at least a 167% improvement in soundstage, 243% better separation and 98% bass impact


 
  
  


zilch0md said:


> ^  LOL
> 
> You surely won't be disappointed.


 
 No you won't, I've found the Differances between the Balanced out of my Audio GD NFB10ES2 and the LME 49990/Dummy PB2 to be very minor, granted the NFB10ES2 has more power [much more] so it drives my HE 4 better, but for all of my Dynamics, the sound is very simmilar, with only the NFB10ES2 having a tighter Sub Bass and a touch more space in terms of sound stage, but these differances aren't VAST with any of my Open or Closed Back Dynamics, granted with an HD 800 yea I might here a little bit more, Though my W1000X is pretty transparent, the w1000x is why I sold my hm801 and got an hm901, the my 801 was too slow and sluggish with the W1000X [which is how the player sounds] so I choose to upgrade to get a cleaner and more dynamic and just faster sound, and I was not disappointed in my decision
  
 so my point here is, if you feed the PB2 [Lme 49990/Dummy] Combo a Good Signal [shame on me I use the SE portion] you will get a very good sound
  
 and for the record, I do think the slight differances in "space" can be atributed to differances in the Dac of each unit, the NFB10ES2 feeds it balanced signal right to it's amp sections, I use the SE out of the amp to feed into the Pb2, so if I used my 3pin XLR out on the NFB10ES2 I may get the same level of sound stage, though the Nfb10ES2 will have the tighter sub bass due to a cleaner amp section all together, though were talking an amp 3-4 time larger than the pb2, so for it's size it's a real bargin with the LME 49990/Dummy Combo


----------



## WhiskeyJacks

Okay serious  question to those PB2 owner's that have had more time with their PB2 balanced amplifier. Now from what I am seeing on the specs that it uses for single or mono opa chips? not dual opa's? along 4 buffers? I am wanting to know to see what kind of OPA chips I can buy to roll with. I have used the OPA604 and the 797s


----------



## WhiskeyJacks

Also, from what I am seeing via this thread that it is okay to install two Dual OPA LM4562's for example instead of 4 LME 49710s? I believe that would be fine as long as I plugged them into the right place on the dip8 slots.


----------



## 7keys

mshenay said:


> I'm sorry to hear that, Though I am currently using my HM901 n Classic Card with my MS1i-W on the go, as when I'm out of the house I'm listening in noisy enviorments
> 
> Though I've not heard a lot of positives about the Sound of the AK120ii when compared to the HM901, and my second point is the PB2 Balanced out with LME 49990 and Dummy Buffers sounds better both SE and Balanced than the hm901 Classic or Standard card
> 
> ...


 
 Mshenay
  
  
 I'm wondering why you stopped communicating with me since you PM'd me that you received my headphones for testing?
  
 What's up with that.


----------



## Makiah S

7keys said:


> Mshenay
> 
> 
> I'm wondering why you stopped communicating with me since you PM'd me that you received my headphones for testing?
> ...


 
 7Keys Hmm I've not been on head fi for like a week now, still thanks for derailing the thread


----------



## SpudHarris




----------



## 7keys

mshenay said:


> 7Keys Hmm I've not been on head fi for like a week now, still thanks for derailing the thread


 
 You're very welcome!


----------



## Makiah S

whiskeyjacks said:


> Also, from what I am seeing via this thread that it is okay to install two Dual OPA LM4562's for example instead of 4 LME 49710s? I believe that would be fine as long as I plugged them into the right place on the dip8 slots.


 
 and yea it should be fine, I think you can seat two op amps across two of the 4 sockets and still get a balanced amplification check the user manual for insctruions, I'm pretty sure iBasso has a PDF of it


----------



## privilege15

whiskeyjacks said:


> Also, from what I am seeing via this thread that it is okay to install two Dual OPA LM4562's for example instead of 4 LME 49710s? I believe that would be fine as long as I plugged them into the right place on the dip8 slots.


 
 Yes, it is ok to install two dual opamps in proper places as per the manual to supply balanced output. If you intend to use SE output it is also ok to install only two single opamps and two buffers only.
  
 PS It very easy to forget if you went for he second option with SE. After a while when you decide to go balanced you might find the sound really strange with missing opamps  I even had to resolder the connector only to find out that nothing changed until I remembered that a couple of opamps were missing to complete the balanced output set.


----------



## Makiah S

mshenay said:


> and yea it should be fine, I think you can seat two op amps across two of the 4 sockets and still get a balanced amplification check the user manual for insctruions, I'm pretty sure iBasso has a PDF of it


 
  
  


stillevil said:


> Yes, it is ok to install two dual opamps in proper places as per the manual to supply balanced output. If you intend to use SE output it is also ok to install only two single opamps and two buffers only.
> 
> PS It very easy to forget if you went for he second option with SE. After a while when you decide to go balanced you might find the sound really strange with missing opamps  I even had to resolder the connector only to find out that nothing changed until I remembered that a couple of opamps were missing to complete the balanced output set.


 
 yea just remember what you did lol, other wise it might sound really wonky! I tried it and It threw me for a loop lol


----------



## WhiskeyJacks

Sounds good, I ordered some 49710s that were on sale, was lookning for the 49990s on the adapter to 8pin that I had installed in both my cmoy bb, blue bird, and m-stage.


----------



## Makiah S

cool let us know how you like it when you get them


----------



## WhiskeyJacks

also any suggestions on upgrades for buffer chips? I would appreciate any advice on that, or if you feel like they are not worth upgrading, please let me know your guys subjective opinions on this
  
 Also I will let you know how the LME49710's sound with the pb2


----------



## zilch0md

+1  
  
 I would love to find a buffer op-amp that does not reduce the transparency - I want the transparency of a dummy buffer with the current gain of an HA5002.  (I can dream...)


----------



## Vo2max

I was thinking what would i do next to my current set-up (Fiio X3.>Ibasso PB2 >HD650/ATH-IM70):
  
 - replace the X3 to DX90 (DX90>PB2>HD650/IM70)
 or
 - retain the X3 and add Ibasso DB2 (X3>DB2>PB2>HD650/IM70)
  
 retaining the X3 and adding DB2 would make the stack nicely as all 3 would be W55 x L100 with X3 just 1/4" protruding lengthwise.
  
 Which option would be better in terms of sound reproduction?
  
 I can of course forego the uniform stack if the sound of the DX90>PB2 would have a big improvement over the latter even if the stack has the DX90 wider by 9mm. Sound over aesthetic that is.


----------



## privilege15

So now I have improved the cable from this...
  

  
 to this...
  

  
 Here are some tips for those who would like to make his/her own cable for PB2 balanced output:
  
 1. Be not afraid! It's simpler than it looks.
  
 2. Make sure, your headphones support 4 wires (R+, R-, L+, L-). You can go with 3 wires (R+, L+, common R- L-) as well because you will still get double power but some people say it's not good for PB2 in the long run. Personally my opinion, your PB2 will be fine anyway but you may not want to take the risk. I did and nothing happened. If you go with 3 wires you may stop reading here as further goes explanation how to make a 4 wire cable) 
  
 3. The easiest way to obtain 4 copper wires is from a UTP patch cord (an Ethernet cable) which you will need to tear apart. It's good to have practice with and very cheap. In the long run you may want to get a better cable. At least you will have experience up to then.
  
 4. Braid the wires the following way (click the image to enlarge).

 5. Before you solder the Hirose HR10A-7P-6P connector, make sure you have pushed onto the cable a couple of heat-shrinks and whatever you need on the cable before you solder a connector to it. Think twice because when you solder connectors from both sides it would be too late to pull anything on the cable.
  
 6. Disassemble HR10A-7P-6P connector and solder the wires the following way:
  

  
  
 7. Assemble the connector.
  
 8.For sleeving I used Techflex. It's not expensive and can be bought on ebay. You can push it on the cable even with connectors already soldered as Techflex is expandable in diameter. I used the following Techflex type for my cable: *6.4mm x 3m Length - Techflex Flexo PET Expandable Braided Cable Sleeving*

  
 9. Use a fan or a lighter to heat the heat-shrinks and make the final looks.
  
 10.Enjoy!))


----------



## Vo2max

@stillevil
 Tks for taking the effort on the recabling tips. I might try it one day.
 Any tips on how to solder the wires to the Hirose connector.


----------



## privilege15

Hirose connector = HR10A-7P-6P. Pls check my tips, it's all there with only exception that I didn't write how to actually operate a soldering iron. There are plenty of manuals in the Internet, you can handle it)


----------



## spurxiii

And the female version to make an adapter is the HR10A-7J-6S. Wish I could find one in Oz


----------



## WhiskeyJacks

So this is an update of the installation and daily use of the LM49710's equipped inside the PB2. I will say that at first, I loved the sound, and now...still do. Lol, they have a very immersive sound is as best as I can describe not really warm more neutral sounding, but not neutrality to the point of sterile, very life like sound when installed in the PB2 and paired with the dx90 and the Fidue A83 and SM64 v2. Both A83 hyrbrid IEMs and the SM64 3 with their ba drivers sounds really good with the pb2 normally, the lm49710 is no exception. If anything I believe the fidue a83 sound better with these opamps installed when using the dx90 as source then before.
  
 I believe I prefer the LM49710 for my own sonic preferences, do not get me wrong this still sounds like the PB2, but it just has a more lifelike tonality I feel with these 4 mono opamps installed, which is a big preference of mine. I really hope some other people give it a  try, I got these 4 as a bundle on ebay for I want to say 9$ was able to make a lower offer which they accepted.


----------



## WhiskeyJacks

http://www.ebay.com/itm/251206622371?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 Link for 2x national semiconductor LM49710s(you need to purchase two of the x2 for the Ibasso pb2 if you are new to opamp rolling.


----------



## zilch0md

whiskeyjacks said:


> http://www.ebay.com/itm/251206622371?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> Link for 2x national semiconductor LM49710s(you need to purchase two of the x2 for the Ibasso pb2 if you are new to opamp rolling.




What are you using as buffers?

Thanks!


----------



## burdie

The female version HR10A-7J-6S is available in Oz, but immediate stock will be the crimp type HR10A-7J-6SC.
 http://au.rs-online.com/web/p/industrial-automation-circular-connectors/7645029/
  
 and HR10A-7J-6S solder type required back order, but estimated despatch date on 29 Jan 2015
 http://au.rs-online.com/web/p/industrial-automation-circular-connectors/7645026/
 I've been waiting for this connector as well for a very long period.
  
 Mouser have it, but need to pay shipping.


----------



## spurxiii

burdie said:


> The female version HR10A-7J-6S is available in Oz, but immediate stock will be the crimp type HR10A-7J-6SC.
> http://au.rs-online.com/web/p/industrial-automation-circular-connectors/7645029/
> 
> and HR10A-7J-6S solder type required back order, but estimated despatch date on 29 Jan 2015
> ...




I need to wait til then before I can use my TH600 with certain amps


----------



## zilch0md

Hi all,
  
*Here's a short review of the LT1028ACN8 as a buffer in the iBasso PB2:*
  
 I've done a lot of A/B testing with the iBasso PB2 this morning, to compare the LT1028ACN8 as buffers vs. dummy buffers and the popular HA5002.
  
 The LT1028ACN8 is absolutely the the "cleanest sounding" buffer op-amp I've ever used in the iBasso PB2 - noticeably better than the HA5002 for resolution and transparency, but offering less advantage in terms of current gain.
  
 For transparency and resolution, however, the LT1028ACN8 is not the equal of using dummy buffers in the iBasso PB2.
  
 Here's the chain I use to test resolution and transparency of op-amps in the PB2:
  
*FiiO X5 Line Out > iBasso PB2 on 16V battery power (not the switchmode PSU) balanced out > Toxic Cables Silver Poision cables > HD800*
  
 My most detailed and transparent op-amp for use in I/V is the OPA1612.  The LME49990 is "prettier" sounding, but not as analytically detailed and neutral as the OPA1612.  
  
 With the OPA1612 in I/V for the above chain, I can easily detect the degradation of resolution caused by the HA5002 relative to using dummy buffers. It's night and day with that chain.  Not so if I use my lower-resolving LCD-2 rev. 1, which really appreciates the extra current provided by the HA5002.
  
 But the HD800 thrive on voltage - they don't need a boost in current (as had with the HA5002 vs. dummy buffers), and they're so revealing they can detect any loss of transparency.
  
 Despite my conviction that the LT1028ACN8 is not as transparent as dummy buffers, the difference is subtle - which is saying a lot. In fact, with dummy buffers in place, switching from the OPA1612 to LME49990 in I/V imposed about the same, small reduction in resolution as was imposed by going from dummy buffers to LT1028ACN8 when the OPA1612 were in I/V.
  
 When I then switched to using LME49990 in I/V, to compare the LT1028ACN8 to dummy buffers, the reduction in resolution imposed by the LT1028ACN8 was less noticeable than when using OPA1612 in I/V.  I had to go through several of my favorite resolution-testing tracks before I started finding some sections where the difference was great enough to convince that I wasn't imagining things.
  
 So that says a lot for the LT1028ACN8's abilities, but I have to ask what benefit is providing?
  
 I've scoured the LT1028ACN8 datasheet, found here:  http://cds.linear.com/docs/en/datasheet/1028fc.pdf
  
 Sadly, I am unable to find _*any* _reference to max. output current in that datasheet.  There are several references to the word "current" and "mA," but I cannot find any specs or charts that I, at least, can clearly interpret to discern how much current the LT1028ACN8 can deliver.  They provide max. output voltage, max. input offset current, max. supply current, but not the all-important max. output current.  (Perhaps I need another cup of coffee, but I just can't find it.)
  
 That said, I have no use for the LT1028ACN8, especially given that adding them to the PB2 (vs. dummy buffers) _did not allow me to turn down the volume, due to any increase in SPL_.  In terms of added power, they almost seem to be inert when used with the HD800, where the HA5002 make a much bigger difference in providing additional power to the current-hungry LCD-2 rev.1, which again, can't really appreciate the resolution advantage of the LT1028ACN8.  *I'd rather run HA5002 buffers with the LCD-2 (with LME49990) and stick to using LME49990 and dummy buffers for the HD800.*
  
 But... For headphones that don't thrive on power as much as the LCD-2, nor thrive on transparency and resolution as much as the HD800, the LT1028ACN8 is definitely "cleaner" than the HA5008, and no doubt provides more power (how much?) than dummy buffers.
  
 And you can't beat the price of the LT1028ACN8.
  
*Lastly, I'll add that some HD800 owners might want to deliberately "soften" the HD800's analytical nature just a wee bit, to reduce fatigue, and for that, I would say the LME49990 with LT1028ACN8 is a great combination - because it's subtle - not as drastic a "softening" as that caused by HA5002.   * 
  





  
 Mike
  
 UPDATE:  I've just realized, having previously concluded that using the LT1078ANC8 as buffers would work well with headphones that don't need the resolution demanded by the HD800 or the current gain demanded by the LCD-2, they would probably sound great with the relatively efficient and not exceptionally detailed OPPO PM-1 / PM-2 / or PM-3.  But I've already put everything away, with the PB2 holding LME49990 and dummy buffers.  LOL


----------



## privilege15

Thanks for the summary Mike. That's a nice overview of LT1028ACN8.
  
 Actually today I have ordered two dual MUSES01 and 4xLT1028ACN8. I have noticed people characterise MUSES01 as neutral, transparent with huge soundstage. Well, I guess that I want to try and experience the new sound eventually some time in January when they arrive and if I find it more than subtle compared to LME49990 and dummy buffers I will certainly write about it here.
  
 PS Spending a lot of dollars for the sake of mere experimenting with uncertain results is kinda weird to most people, but you never know until you try)


----------



## zilch0md

Do tell when you try the Muses 01.


----------



## privilege15

zilch0md said:


> Do tell when you try the Muses 01.


 
 BTW did you try using your MUSES02 as buffers with LME49990?


----------



## zilch0md

stillevil said:


> BTW did you try using your MUSES02 as buffers with LME49990?




That can't be done. They are duals and the buffer row only accepts singles.


----------



## mayassa

Sorry a little off topic, where can I buy one only from Ibasso? and is the PB-3 just around the corner?
 PB2


----------



## privilege15

mayassa said:


> Sorry a little off topic, where can I buy one only from Ibasso? and is the PB-3 just around the corner?
> PB2


 
 You can pick one up at a dealer at the same price iBasso has. I'm sure there are at least a couple of dealers who sell iBasso stuff where you live. I don't think PB3 is any close to be around the corner. At least in 2013 iBasso had no plans for PB3.
  
 I find that PB2 still has a lot of potential, just make sure you have enough money for buying and trying more superior opamps)) If you don't plan to replace stock opamps in PB2 I would consider it a waste of money purchasing it. The same goes to using balanced output only.


----------



## jamato8

I do not agree that the stock op amps and buffers that come with the PB2 are a waste of money. The amp performs, IMO, very well with them. Everyone has a little different taste in what they want to hear. The PB2 has a lot of power and a nice voltage swing and there is nothing I own that it won't power and do it very well.


----------



## mayassa

Thanks for the replies, I can't find a dealer in the US so I will probably order one from the site after the holidays.  I received my DX90 today I'm pretty impressed.


----------



## privilege15

mayassa said:


> Thanks for the replies, I can't find a dealer in the US so I will probably order one from the site after the holidays.  I received my DX90 today I'm pretty impressed.


 
  
 DX90 is a very nice source)) Personally I'm waiting for release of Fiio X7 in 2015 with a balanced output and ESS9018 as DAC to upgrade from my X5. Balanced source + balanced PB2 as amp + balanced headphones will be a killer combo I think. Although the price for X7 is promised to be around 700$. Already started to save money)


----------



## highfell

zilch0md said:


> +1
> 
> I would love to find a buffer op-amp that does not reduce the transparency - I want the transparency of a dummy buffer with the current gain of an HA5002.  (I can dream...)




For a really transparent opamp (maybe not a buffer) try some JRC2068s. Ron (hiflight) sent me some and they are so clean sounding. I was realy surprised when I started to use them.

There is something beguiling about them. There have a a real clarity and transparency. I have been listening to the Naive Vivladi editions and the music just flows like a stream of liquid glass and is as smooth as silk. Great mids and highs, but what I find surprising is that even the deeper bass notes are resolved well , which surprised me.

They are definitely worth trying.


----------



## taz23

Hi everyone, I just got a PB2.  Congrats to myself!  
	

	
	
		
		

		
			




  
 May I ask what configuration(s) is/are recommended for HE-560 with the PB2?  I understand that high current is required for the HE-560 to sound dynamic.
  
 Thanks!


----------



## privilege15

I took the parcel from post today with 2xMUSES01 (from janeh2100) and 4xLT1028ACN8 (from goldy0903).
  
 I have some doubts about LT1028ACN8 as I'm not sure whether it's genuine or not because it's kind of too sensitive to electrical currents in my PB2 and doesn't work well with some opamps due to extreme levels of interference but still you can hear that it sounds great, so it might be genuine but of a different make, who knows. Maybe they need some burn-in. We'll see. I almost ordered another 4 of them from a different seller but changed my mind as after my last insertion, the interference decreased so much that you can barely hear it with MUSES01.
  
 Ok, since I got the chips I've been testing the following combinations for 5 hours in a row:
  
 1. MUSES01+dummy buffers is worse than LME49990+dummy buffers. IMHO you should not use dummy buffers with MUSES01 as you feel lack of power and drive compared to LME49990+dummy buffers.
 2. MUSES01+LT1010CN8 (from Ron's kit). It just doesn't work. There's audible distortion (yes, I mean sound distortion, not interference) that you can't listen to this combination. It's interesting that LME49990+LT1010CN8 does not have any distortion or interference at all, it is as quiet as graveyard at night, smooth but not as transparent as dummy buffers.
 3. MUSES01+all other buffers that came with PB2. No interference or distortion of any kind at any volume levels. Works well but it does not sound well enough to satisfy my ear.
  
 Now for the most interesting part))
  
 4. LME49990+LT1028ACN8 doesn't work because of interference.
 5. MUSES01+LT1028ACN8. My last insertion of the bufferes eliminated almost any type of interference (and I mean interference, not distortion like with LT1010CN8). Don't ask me what I did to achieve this result, I just couldn't figure this out as I've been swapping them for a hundred times maybe)). You still can hear it at 12 o'clock volume level when you pause the song but it's very very quiet. I also found the source of interference when you use LT1028ACN8 - it's external power supply. If you supply PB2 with 16V of power it's more audible when no music is being played, that's why I switched to 15V of power to decrease it. You will not hear any noises if you disconnect all sources of external power.
  
 At first I thought my LT1028ACN8 buffers were fake but I seem to like the sound very much, so they might be genuine after all but of a different make. Maybe later, I will order another 4 from a different seller when I have more money to spend to compare.
  
 As for the sound quality of MUSES01+LT1028ACN8 I can say that it's neutral and transparent as expected and sounds very much like LME49990+dummy buffers but seems like it's more transparent and spacious. The sound seems to me more balanced with a little less of deep soft bass than LME49990 but with more punch and more reverberation from musical instruments (including bass guitars) which makes them sound more lively and engaging.
  
 I'll keep this combo in my PB2 for further listening but almost feel like I'll be using it for a long while since now.
  
 If you wish to try this out please be aware the difference between LME49990+dummy buffers and MUSES01+LT1028ACN8 is not day and night, some may think it's just a little different but I almost sure it's different to better sound. The first thought that came into my head when I inserted this combo and turned on the first song is "What a nice reverberation is there from musical instruments!". So the difference might not be subtle after all but... )))
  
 DISCLAIMER: My brain may be playing with my perception, also wishful thinking and excitement should be taken into consideration 
  
 PS. My setup is Fiio X5 - Black Dragon interconnect - PB2 - handmade balanced headphone cable - Beyerdynamic DT150 (250 Ohm) headphones. PB2 is powered by 15V by Energizer XP8000.
  
 PS2 I'm not the first one to say but MUSES01 have extremely bendy legs. I almost killed one of them so take extra caution messing with them.


----------



## zilch0md

^ That's a very credible summary, stillevil - thank you!

I really like how cautious and moderate you are in describing what you hear. 

I've heard of other op-amps that are sensitive to PSU noise, so I always use portable gear with external or internal battery power. The Energizer XP8000 with the Willy Cable WI15 (inline voltage regulator) have been used by a lot of Meier Stepdance owners, as you know, but for the sake of other readers here, I want to point out that it has always been described as a completely noise-free external power source - obviously better than the switch-mode PSU, the likes of which we see with a lot of audio gear.

Your Muses 01 account leaves me still curious, but has reduced the likelihood that I will ever buy them (for which I'm grateful - again, because I find you to be so credible.) I need a more dramatic distinction from the LME49990 to warrant spending $150 for a pair of Muses 01. 

Thanks,

Mike


----------



## privilege15

I'd like to note mostly for other forum members that 2xMUSES01 cost $150 only if you buy them from official website or source. This is the price you have to pay if you want to make sure it is 100% genuine. Chinese guys have their own shady ways to obtain the same opamps from factories that produce genuine MUSES01 which results in half the price on ebay. They do this all the time with much more costly equipment and sell for half the price at gray market, I know  The risk to buy fake goods increases of course but you can use google at least to check the seller.
  
 I bought mine for half the price about $40 each. Anyway I would not pay $150 out of curiosity for MUSES) but 80$ is more affordable.


----------



## privilege15

The rest of the time today I spent comparing LME49990+dummy buffers and MUSES01+LT1028ACN8 with different music genres: Rock, Classic Rock, Heavy Metal, Atmospheric Black Metal, Black Metal, Dark Metal, Death Metal, Doom Metal, Gothic Metal, Instrumental, Jazz, Pop-Rock and Synth-Pop.
  
 I can make some conclusions now based on what I heard.
  
 LME49990+dummy buffers sound very lively - the music has drive, punch and seems more forwardy sacraficing transparency and spaciousness (if we compare it to Corda Quickstep/Stepdance amp or Muses01 opamp) which is welcomed by many metal and rock heads. This combo goes nice with rock and heavy metal music or when you are in the mood to have some drive. The downside is that it causes fatigue in the long run. It seems to me that it is not neutral but slightly coloured going into lows thus making it appealing to most listeners.
  
 MUSES01+LT1028ACN8 are more transparent and crystal than LME49990+dummy buffers although with less bass punch. I consider it balanced and neutral sounding. It deals better with music that needs space and where highs should not be outperformed by lows nor lows outperformed by highs keeping everything in balance. It's less fatiguing to listening to jazz (like Ahmad Jamal Trio) because the cello does not make as much pressure to ears as with the other combo. Or, e.g. if we take black metal and take the song Puritania by Dimmu Borgir. There's tons of drums which you don't want to be prevailing all the time because you will get tired very quickly so listening to the recording with muses01 you feel perfect balance between the drums, guitars and vocals. Let's take Depressive Suicidal or Atmospheric Black Metal anything from Woods of Desolation/Thranenkind/Annorkoth etc. Listening to this genre you don't need drive, it is very very sad music you need balance between guitars and vocals without running too much into lows and leaving whether they are which is a perfect genre for Muses as well.
  
 I can go on and enumerate examples from other genres but the key here is that Muses01 make it all balanced. Many of you have heard recordings which have so many lows that you can't listen to them for long. Muses don't emphasize lows and leave them as is, like it was intended.
  
 The more I listen to them the more I think this is the true neutral and uncoloured sound with straight EQ line.
  
 So both opamps are worthy. It's all about listener's preference in the end.


----------



## jamato8

The PB2 is a great testing device, and listening as well. I have found that it really changes with what you put in it. Seems to hold up well to the test of time. So many choices on op amps now. stillevil, thanks for your insight.


----------



## SpudHarris

I tried the LT1028 as buffers + Muses01 and couldn't listen due to the worst interference ever. Tried several phones but it was unbearable. Don't you guys have this issue also?


----------



## zilch0md

I've never had the Muses 01 - I don't know what would happen in my PB2...


----------



## SpudHarris

Can't be the muses as I have used them in the PB2 with other buffers. Must be the LT1028's.... Gone back to AD797's + BUF634 x 8 which is my favourite combo for the HD800.


----------



## privilege15

spudharris said:


> I tried the LT1028 as buffers + Muses01 and couldn't listen due to the worst interference ever. Tried several phones but it was unbearable. Don't you guys have this issue also?


 
  
 Yes, I have issues with interference also but I managed to minimize it to comfortable level by switching LT1028 places and trying different combinations of those until I found which one has the minimum of it. Some combinations are unbearable. You still hear a small amount of hissing and radio like interference when turning the volume level up and down but it's ok because you hear it only when no music is being played.
  
 To my ear Muses01+LT1028 are so great that it beats the interference issues because I find myself enjoying the music a lot more. I don't remember turning my player on while at home so often and working in my headphones for hours in a row. I think it's worth it.
  
 I would have switched to other buffers without interference that I tried but LT1028 are the best I heard with Muses.


----------



## SpudHarris

Thanks stillevil for the reply. I hear you and will give it another go but am worried that this combo will be a no go with IEM's as I can't even get it to play nice with full sized phones.....

The AD797 + 8 x BUF634 is an amazing combo and one I keep going back to for my balanced transportable / vacation rig.


----------



## privilege15

You know, I was going to give up with LT1028 because of interference once I tied them many times in different positions and gaining very little progress. The level of interference and the quality of it changed after each swap but still was not any good for listening. It's when I told myself I'll try one last time, swapped them at random... And it worked like a charm.
  
 Right now, just to make sure the place matters, I switched two of them places and this audible interference appeared again, so I switched them back. I don't know why it influences the sound as buffers are all the same, I just don't know.


----------



## privilege15

zilch0md said:


> I've never had the Muses 01 - I don't know what would happen in my PB2...


 
  
 Mike, when you tried your LT1028ACN8 with LME49990 did you hear any interference?
  
 I'm asking this because I hear it with LME49990 as well.
  
 If you don't hear it could you pls take a picture of your LT1028?
  
 Mine look like this:


----------



## privilege15

spudharris said:


> Thanks stillevil for the reply. I hear you and will give it another go but am worried that this combo will be a no go with IEM's as I can't even get it to play nice with full sized phones.....
> 
> The AD797 + 8 x BUF634 is an amazing combo and one I keep going back to for my balanced transportable / vacation rig.


 
 Just now I figured out that you can't get rid of interference in any way if you use SE output, that is if you connect your headphone via 3.5mm jack. You should use balanced output only.
  
 UPDATE. SE output interference disappears completely after 3-5 minutes after turning on PB2.


----------



## taz23

taz23 said:


> Hi everyone, I just got a PB2.  Congrats to myself!
> 
> 
> 
> ...


 

 Anyone with HE-560 can provide some advise for a newbie?
 Many thanks!  And Happy New Year!


----------



## highfell

spudharris said:


> Can't be the muses as I have used them in the PB2 with other buffers. Must be the LT1028's.... Gone back to AD797's + BUF634 x 8 which is my favourite combo for the HD800.




Not sure about that.

When I tried out Muses01 and 02 (my post on page 74 mentioned this) :

"As a little aside , I also had some electronic noise interference [with Muses 02] on my commute into work which I haven't had with the Muses01"

Whilst, I haven't used Muses02 since then, I obviously did suffer some interference with 02 but never with 01.


----------



## highfell

taz23 said:


> Anyone with HE-560 can provide some advise for a newbie?
> Many thanks!  And Happy New Year!





I have a pair of Sennheiser 600 so not too far removed from your HE560s. 

In addition to the stock OPamps, that came with the Pb2 I have purchased the following and here is my experience : 


1. Lme49990 OPamps x 4 
2. MUSES01 & 02 X2 
3. Ha5002 buffers x4.
4. JRC2068

LME49990s are very musical. They have a clear, lively sound with a seemingly transparent approach. So the detail is there but not too bright, harsh or shrill though. They seem to bring out the musical quality of my DAP. I can understand why others seem to like them. They play well across the musical spectrum of heavy rock, prog rock & classical - they are a keeper.

Muses01 and Muses02 review :

What did the they sound like? First, when I turn my PB2 on with the Muses01 I got the biggest "pistol shot thump" that I have heard from any of my other OpAmps and yet with the Muses02, I don't hear anything.

The Muses01 don't seem bright to me at all, even though I was expecting them to. They are detailed for sure but not harsh sounding. Very musical across the range from rock to classical. Vocals are forward and very apparent eg listening to SigurRos live, his tenor style voice sounds mesmerising. They also have an ability to respond well to the deep notes of a bass guitar. I found the Muses01 dynamic in style and frankly great to listen to. They are my "goto" OPamps. And Highlight's Topkit of HA5002 Buffers adds some more oomph and dynamism.

For the Muses02, I was slightly disappointed but probably only in their comparison to Muses01. They are definitely warmer sounding which I generally prefer, but I found a slight muddiness that surprised me. They still sound very musical but compared to Muses01 they lack sparkle & sound slightly lifeless. 

For a really transparent opamp try some JRC2068s. Ron (hiflight) sent me some and they are so clean sounding. I was realy surprised when I started to use them.There is something beguiling about them. There have a a real clarity and transparency. I have been listening to the Naive Vivladi editions and the music just flows like a stream of liquid glass and is as smooth as silk. Great mids and highs, but what I find surprising is that even the deeper bass notes are resolved well , which surprised me.
They are definitely worth trying.

Hope this helps.


----------



## privilege15

I'd like to tell a story of mine about my listening experience. I was and still am a big fan of earbuds because I hate IEMs. Although somehow all of them became my wife's possession now)). Anyway, the first decent pair of earbuds which I bought were called Hisoundaudio PAA-1 Pro. I've been listening to them for a long while until I decided to upgrade to Blox ANV3 which cost about $70 some years ago. When I received them and eventually tried, the sound did not appeal to me at first but there was something about them that made me listen to them more and more until they completely replaced PAA-1 Pro. After a while any attempt to return to PAA-1 Pro was met by negative reaction from my brain because I realised Blox ANV3 presented more natural and uncoloured sound, they were miles ahead in musicality after PAA-1 Pro. Why did it take a while for me to realise this? I guess it's human nature to get used to things sometimes even worse things and hard to switch to something different even if it's better.
  
 The story continues after I gave PAA-1 Pro to my wife because I didn't need them any longer. After a while when I offered her Blox ANV3 for a try she turned them down making all excuses that PAA-1 Pro sounded better (that rings a bell, isn't it?)). I've been using Blox ANV3 for the rest of the time until I completely switched to full sized cans. I had nothing to do with Blox so I've given them to my wife as well. Can you imagine what happened next? She's gone through exactly the same accustomization as I did. As a result now Hisoundaudio PAA-1 Pro are collecting dust on the shelf.
  
 Wait, it's not the end of the story. One day she managed to break a wire inside the cable of my beloved Blox ANV3 after which one ear went silent. I told her to go back to PAA-1 Pro until I fix it. And she just couldn't go back, because you can't go back to something that doesn't appeal to your taste any longer when you tried something better and brought your taste standards to a new level. So she waited several days without listening to music at all until I fixed the cable of Blox ANV3 and returned them to her.
  
 What I want to say by this is that at first your brain might object to different or even better things if they are simply new to you but your subconsciousness if there's something to it will keep telling you "Go ahead! Don't listen to your brain there's more to this than it sees at first glance." And the subconsciousness is generally right.
  
 So things that seemed controversial at first sight might become completely different when you judge them again in the long run of experience 
  
 I still have this gut feeling caused by audio nirvana that I can't get enough of Muses01 after I conquered interference with LT1028  buffers and wish to listen to them more more every day throughout the day which never happened to me before. They sound so musical.
  
 Returning to the previous poster, I also have JRC2068 opamps from Ron but I can't say that I feel the same about them. And I'm talking exactly about the feeling that sound gives to me and not its objective qualities like transparency, airiness or whatever. I guess it's all individual and you never know what you feel until you try as you can't predict your emotions to something that is merely described by someone else, just like if I described a girl to someone. Would he fall in love with her based on verbal description only? I don't think so. It's the same about the sound.


----------



## SpudHarris

I picked up 2 x JRC2068's and have been auditioning one in my P4 today. First impressions are quite nice. I was considering getting rid of the PB2 but am now trying to find reasons to keep it :rolleyes: let's see what it delivers with the 2068's tonight. If Ron is recommending them, there must be a reason, I've trusted his judgement for years.....


----------



## jamato8

The PB2 has held up to the test of time. Just because an amp is a few years old doesn't mean it no longer sounds good or can compete. I find that it is up there with the best and you can play with even newer op amps.


----------



## zilch0md

The PB2 is indeed a keeper. I just can't bring myself to sell it, even though it's redundant to other solutions. Its power, transparency, the option of fully balanced operation, and its ability to support rolling a lot of different op-amps makes it a lot more precious than the $250 cash I might get selling it used. 

I cling to my Meier Stepdance, which, on close examination, is more refined in terms of build quality and it's my personal benchmark for neutrality and transparency, but I only have to drop OPA1612s and dummy buffers into the iBasso PB2 and I've got the same sound quality - a sonic clone of the Stepdance, with the option of going balanced!


----------



## taz23

Thanks a lot for the detailed description, highfell!
  
 I see in your signature that you have OPA627 in your Leckerton.  How does the 627 fare in the PB2, as compared to the 4 opamps you mentioned. 
  
 Quote:


highfell said:


> I have a pair of Sennheiser 600 so not too far removed from your HE560s.
> 
> In addition to the stock OPamps, that came with the Pb2 I have purchased the following and here is my experience :
> 
> ...


----------



## highfell

I am yet to try them. Not sure why in a way as, although I only have two of them, I could still listen to them single ended in the PB2.

I guess the reason is that I really enjoy listening to the Leckerton with the 627s - and despite my love of the PB2 - the sound of Leckerton is still the one that I somehow fall back on, and the sound of the 627s is synonimous with the Leckerton. The Leckerton is also a well built and well dsigned Amp.

I find the 627s very musical, maybe slightly coloured in a warm, tubey kind of way. I can only assume that they would also sound very good in the PB2.


----------



## taz23

Thanks, highfell! 

Yes, the Leckerton is a great amp. But I needed more power for my HE 560. 

Looks like I should try the 627 opamps in the near future.


----------



## highfell

spudharris said:


> I picked up 2 x JRC2068's and have been auditioning one in my P4 today. First impressions are quite nice. I was considering getting rid of the PB2 but am now trying to find reasons to keep it :rolleyes: let's see what it delivers with the 2068's tonight. If Ron is recommending them, there must be a reason, I've trusted his judgement for years.....




How are you finding them ?

I have just swapped out dummy buffers for HA5002s - seems to add a little more oomph & depth and reduce the occasional thinness of the sound , whilst not compromising the transparency of the 2068s


----------



## SpudHarris

They are really great, I am still evaluating them. I want to try them with different buffers though...

Have ordered some LT1010's and some more LME49600's. The 49600's may need a little alteration to fit the PB2 as the footprint is slightly larger than a DIP8.


----------



## Mooses9

ive tried both the muses and the lme49990 and to me the 49990 were the best that i tried and i tried ALOT of opamps with my pb2 and db2.  the lme49990 is just too good imo, i kept going back to them no matter what i tried they always ended up back in my amp. of course. everyones miles may vary as peoples sound preferences are different.


----------



## privilege15

mooses9 said:


> ive tried both the muses and the lme49990 and to me the 49990 were the best that i tried and i tried ALOT of opamps with my pb2 and db2.  the lme49990 is just too good imo, i kept going back to them no matter what i tried they always ended up back in my amp. of course. everyones miles may vary as peoples sound preferences are different.


 
 Out of curiosity, there are at least 4 types of Muses that I know form the top of my head. Which ones did you try?


----------



## Mooses9

stillevil said:


> Out of curiosity, there are at least 4 types of Muses that I know form the top of my head. Which ones did you try?


 
 MUSES 01 204.
  
 But to me the lme49990 just was so sweet, i had probably  50+ opamps maybe more and to think of all the combonations, nothing sounded better at least to my ears than the 49990.


----------



## privilege15

You are right, LME49990 have this distinguished sound that you can definitely say from other opamps and like. MUSES01 are different I agree.
  
 Sometimes this crazy thought comes into my head to try Burson Supreme Sound Discrete Opamp one day:
  
 
  
 Official marketing stuff: 
  

  
 The size does not matter))


----------



## jamato8

I have always wondered about those, how they sound.


----------



## Mooses9

i wonder how they would sound also. they arent price bad if the sound is right.


----------



## privilege15

Yeah the price is $140 for a set of 2 x Dual Opamps. Affordable at some point.


----------



## highfell

mooses9 said:


> MUSES 01 204.
> 
> But to me the lme49990 just was so sweet, i had probably  50+ opamps maybe more and to think of all the combonations, nothing sounded better at least to my ears than the 49990.




I realise now that I have never evaluated the lme49990s at all as my Muses arrived at the same time. Crickey, best of 50, I need to try them......

Do you use them with dummy buffers or something else?


----------



## highfell

stillevil said:


> You are right, LME49990 have this distinguished sound that you can definitely say from other opamps and like. MUSES01 are different I agree.
> 
> Sometimes this crazy thought comes into my head to try Burson Supreme Sound Discrete Opamp one day:
> 
> ...




How would you fit them in? Could you fit them in with the top Lid closed?


----------



## privilege15

highfell said:


> How would you fit them in? Could you fit them in with the top Lid closed?




With the lid closed? Not a chance) Aren't you just curious?


----------



## highfell

stillevil said:


> With the lid closed? Not a chance) Aren't you just curious?




For sure. Tempted to buy them to try them out.

Also realistic, if there isn't a plug & play solution available then it will beyond my "pay grade".


----------



## SpudHarris

I am really curious about them but they certainly won't fit in any of my portables and my main Amp is an Oppo HA1 which really requires no improvement for out put and the HP out is discreet anyway...

It would mean using with portables (PB2/P4/Fi-quest) with open cases which is inviting external interference. So although very curious I personally can't justify the purchase. That said, I would love to hear from anyone who has made the leap


----------



## zilch0md

Yeah, those discrete component op-amps would make your PB2 almost as top-heavy as my PB2:
  

  
 Mike


----------



## Mooses9

Thats crazy haha


----------



## zilch0md

I had just sat that heat sink there to make a funny photo.


----------



## Mooses9

Awsome heat sink none the less. I miss my pb2 and db 2


----------



## jamato8

spudharris said:


> I am really curious about them but they certainly won't fit in any of my portables and my main Amp is an Oppo HA1 which really requires no improvement for out put and the HP out is discreet anyway...
> 
> It would mean using with portables (PB2/P4/Fi-quest) with open cases which is inviting external interference. So although very curious I personally can't justify the purchase. That said, I would love to hear from anyone who has made the leap




Since I use stuff at home a lot I may try them. Why me. . lol Hasn't anyone tried these? At home the case open is no big deal and Superfon used to like to use acrylic cases for this reason, finding the sound to imrove, and I agree.


----------



## oldmate

I have been using the iBasso D6 since late 2011. At 1st it was attached to a 5th gen iPod Video and now it resides stacked with my X5.
  
 I did have the Fiio E12 with the X5 at 1st but purchased it on a whim when I got the X5 and subsequently swapped it out for the D6. I want to use the D6 as a desktop amp/dac with my pc so I'm looking for another amp for the X5.
  
 I was originally looking at the Pure II but it's just a little exie for me ($700+ AUD) so was thinking of grabbing the PB2 ($369 AUD) to pair with the X5. Initially it will be used as a single ended amp but down the track I will definitely try the balanced out with some new cans at some stage as I'm curious about it having never had a balanced solution. In addition swappable opamps vs the none changeable SQ of the Pure II.
  
 Any reason not to go this way??


----------



## HiFlight

oldmate said:


> I have been using the iBasso D6 since late 2011. At 1st it was attached to a 5th gen iPod Video and now it resides stacked with my X5.
> 
> I did have the Fiio E12 with the X5 at 1st but purchased it on a whim when I got the X5 and subsequently swapped it out for the D6. I want to use the D6 as a desktop amp/dac with my pc so I'm looking for another amp for the X5.
> 
> ...




The PB2 is an excellent amp, especially when driving from the balanced outputs. Although it has a single-ended output, it was primarily designed for use as a balanced amplifier. I'm not sure if the SE output can match that of the Pure II, but with the right opamp configuration, it is hard to beat for balanced use. A balanced source is not required as it has internal circuitry to derive a balanced output from a single-ended input.


----------



## oldmate

Wow!!. Mr HiFlight. I have read many of your posts re iBasso and I have to say you speak from the head and not the heart. You have given people here some great advice and are the reason I went with the D6 back in 2011.
  
 Thanks.
  
 Cheers.


----------



## HiFlight

oldmate said:


> Wow!!. Mr HiFlight. I have read many of your posts re iBasso and I have to say you speak from the head and not the heart. You have given people here some great advice and are the reason I went with the D6 back in 2011.
> 
> Thanks.
> 
> Cheers.




Many thanks for the kind words!


----------



## Denzelwng4

Hi all,

I'm a newbie, do you know where I can buy opamps for my pb2?
I lost the whole box including the opamps or anyone selling here?
Pls PM me. Thanks!


----------



## Mooses9

denzelwng4 said:


> Hi all,
> 
> I'm a newbie, do you know where I can buy opamps for my pb2?
> I lost the whole box including the opamps or anyone selling here?
> Pls PM me. Thanks!


 
 contact *Hiflight *On here he can make you a whole box of whatever you need


----------



## SpudHarris

IBasso would be the best bet...


----------



## Denzelwng4

spudharris said:


> IBasso would be the best bet...


 
 i have been emailing them but no reply


----------



## jamato8

denzelwng4 said:


> Hi all,
> 
> I'm a newbie, do you know where I can buy opamps for my pb2?
> I lost the whole box including the opamps or anyone selling here?
> Pls PM me. Thanks!


 

 They are on vacation. I would  contact HiFlight anyway. Very reasonable and very good choices.


----------



## privilege15

I thought somebody might be interested in my humble research as far as the pair MUSES01 + LT1028ACN8 is concerned. Ever since I plugged in all of them and found the best possible combo with LT1028 buffers to decrease the interference as much as could, I continued to search for a solution that would eliminate the interference completely. Recently I ordered another pack of ACN8 and CN8 series of LT1028 from Ebay and tried them in. CN8 goes to the bin straight away but as for the new set of ACN8 they are much better. I still shuffled them a little and finally got 0 interference through both balanced and SE outputs. There's one condition to it though - a source device must be plugged in with its AUX cable into PB2.
  
 So if anyone goes for MUSES and LT1028, buy more LT1028 than required preferably from different sellers.
  
 Beware you can burn your fingers if you touch them during playback (hot,hot,hot) 
	

	
	
		
		

		
		
	


	




  Wondering what's the maximum operating temperature they can handle?
  
 Gimme a radiator like this one pls)))
  

  
*UPDATE* From the datasheet: "Operating Temperature Range: LT1028/LT1128AC, C (Note 11) ............–40°C to 85°C". So it seems within the range.


----------



## Paul - iBasso

stillevil said:


> I thought somebody might be interested in my humble research as far as the pair MUSES01 + LT1028ACN8 is concerned. Ever since I plugged in all of them and found the best possible combo with LT1028 buffers to decrease the interference as much as could, I continued to search for a solution that would eliminate the interference completely. Recently I ordered another pack of ACN8 and CN8 series of LT1028 from Ebay and tried them in. CN8 goes to the bin straight away but as for the new set of ACN8 they are much better. I still shuffled them a little and finally got 0 interference through both balanced and SE outputs. There's one condition to it though - a source device must be plugged in with its AUX cable into PB2.
> 
> So if anyone goes for MUSES and LT1028, buy more LT1028 than required preferably from different sellers.
> 
> ...


 

 That is a lot of work you did. I am glad you are enjoying the music!


----------



## privilege15

Who may have thought that DIP-8 heat sinks actually exist but here they are at my disposal with adhesive thermal conduct:
  

  
 Hmm, maybe a mini fan would be nice in the long run. I need to think about it and after I attach the heat sinks to the buffers I need to check if there's enough space for it so that I'm able to mount it inside PB2 and power via USB from XP8000 external battery which I always carry with me.


----------



## privilege15

paul - ibasso said:


> That is a lot of work you did. I am glad you are enjoying the music!


 
  
 Thanks Paul. Can we expect any updates to the hi-end customizable portables amps series lineup in the future? Although it seems there's hardly anything left to update from the sound perspective as I find it already extremely good at the moment but still curious)


----------



## Paul - iBasso

stillevil said:


> Thanks Paul. Can we expect any updates to the hi-end customizable portables amps series lineup in the future? Although it seems there's hardly anything left to update from the sound perspective as I find it already extremely good at the moment but still curious)


 

 Yes.


----------



## ebe2000

Has anybody tried OPA633KP as buffers yet?


----------



## privilege15

More pictures:


----------



## HiFlight

ebe2000 said:


> Has anybody tried OPA633KP as buffers yet?




Given the very high quiescent current draw, battery runtime would likely be very short. The 633 is probably best used for desktop application using the charger/power supply. Based on the current draw, I would expect them to run warm. For these reasons, I have not used them in either the P4 or PB2.

Both the LT1010 and LME49600 have lower distortion and higher output, however both need to be modified for use in the PB2, as the pin basing of the LT1010 is non-standard and the case style of the 49600 is not compatible with a DIP socket. Modification of both opamps for PB2 compatibility is a task requiring a fair amount of technical skill, however the results are well worth the effort!


----------



## zilch0md

stillevil said:


> More pictures:
> 
> 
> 
> ...


 
  
 I really dig your passion, stillevil.


----------



## Denzelwng4

that's a nice cut-out on your pb-2 ....


----------



## privilege15

I wouldn't bother with all the upgrades unless I was digging this thunderstorm lively sound out of this tiny little box.
  
 Unfortunately there are certain drawbacks to it though as very soon you start to realize that some once loved albums actually have a mediocre mastering and sound quite congested compared to good recordings with wide dynamic range. You start to value dynamic range which you didn't notice before when all recordings sounded almost the same on old setups. Now they don't. This made me delete some albums from my DAP because it's no longer a pleasure to listen to some of them.
  
 The surprising thing is that the same recording can sound well on not so sophisticated setups. Amazing, isn't it, when you can listen to it on a casual stereo system but can't tolerate the mastering which is audible through such a portable setup because now you are able to hear the difference coherently.


----------



## ebe2000

I just cant help it, but must try more to upgrade this little PB2 jewel. How about the Burson discrete opamps? Is the PB2 power section able or will it need upgrading too? (Just cant get rid of this upgrade urge)


----------



## privilege15

ebe2000 said:


> I just cant help it, but must try more to upgrade this little PB2 jewel. How about the Burson discrete opamps? Is the PB2 power section able or will it need upgrading too? (Just cant get rid of this upgrade urge)


 
  
 I'd recommend three sets as the summary of my trial an error)
  
 1. *LME49990* (sold separately) + *dummy buffers* (included in the package with PB2) - recommended for anyone as it is the easiest to install (plug and play) and has a very nice sound quality.
 2. *HiFlight's kit* which is not pricey but offers good quality op-amps and buffers for any sound signature you'd prefer (cold, neutral, warm)
 3. *MUSES01* + *LT1028ACN8* - recommended for crazy ones only like me as it has A LOT of caveats and conditions to work properly inside PB2 including appropriate power supply, location, heatsinks, and other dependencies. Failure to comply with them will give you the worst sound you've ever heard but if you are successful you'll get the best sound you've ever heard. Although the sound signature is more neutral from No1 variant (beware it has less bass but sounds a lot more hi-fiish to my ears) so apply with caution or better not even try if you're scared... 
  
 As for Bursons, the specification seems fine to me, they should work with PB2 without power tweaks but they are huge. I would try them if I were not completely satisfied with my current setup. I can't imagine there's room for improvement.
  
 And advice by default: balanced connection only and good headphones is a must, else you'll not hear any difference between almost any upgrades or they will be just minimal.
  
 PS Today I've found the topic about *iBasso P5 Falcon* (http://www.head-fi.org/t/752829/fresh-from-the-oven-ibasso-p5-falcon)which is a fresh portable amp soon to appear on the market. This one will supposedly be good with non-balanced headphones.


----------



## ebe2000

Thanks Stillevil, have been through all above, have the LME49990 in now and just ordered 2 dual Burson's. There are 35 mm extension wires available for the DIM sockets, long enough to piggyback the Bursons horizontally on top the case. I'll just cut a hole for the wires. Hope the power section is stromg enough, but I also have an external 16V/24000 mAh battery. All that for my long distance flights.


----------



## ebe2000

My T5p headphone is wired balanced, unfortuately not the CKR9 and IE800.


----------



## privilege15

ebe2000 said:


> ... and just ordered 2 dual Burson's...


 
  
 You are the man! 
	

	
	
		
		

		
		
	


	



  
 Please tell us about your experience when they arrive.


----------



## ebe2000

Had a quick look at P5, not for me, I stay balanced ( unless I am too drunk )


----------



## ebe2000

I shall do so, am travelling next 2 weeks, so it will be some time


----------



## HiFlight

There is now a Topkit Ultra available for the P4/P5 and PB2. It uses custom buffer modules for increased output current and extended bandwidth. 



stillevil said:


> I'd recommend three sets as the summary of my trial an error)
> 
> 1. *LME49990* (sold separately) + *dummy buffers* (included in the package with PB2) - recommended for anyone as it is the easiest to install (plug and play) and has a very nice sound quality.
> 2. *HiFlight's kit* which is not pricey but offers good quality op-amps and buffers for any sound signature you'd prefer (cold, neutral, warm)
> ...


----------



## ebe2000

hiflight said:


> There is now a Topkit Ultra available for the P4/P5 and PB2. It uses custom buffer modules for increased output current and extended bandwidth.


And what is included in this top kit?


----------



## ebe2000

stillevil said:


> You are the man!
> 
> 
> 
> ...


 

 Well, I got back home, the Burson´s were here and in the PB2 before I could even say hello to my wife. Wow, am really glad I did go this way. Out of the box, what an improvement, in absolute everything. Fully worth the money. I don´t think there can be anything better out there - mobile. Probably gets even better after burn in. Enough power with the dummy buffers. I shouldn´t say more, otherwise all the amp manufacturers want sell their stuff anymore. This is rather High-end then Hifi.


----------



## privilege15

Thanks for the input. When the time comes I'll try them as well.


----------



## Paul - iBasso

ebe2000 said:


> Well, I got back home, the Burson´s were here and in the PB2 before I could even say hello to my wife. Wow, am really glad I did go this way. Out of the box, what an improvement, in absolute everything. Fully worth the money. I don´t think there can be anything better out there - mobile. Probably gets even better after burn in. Enough power with the dummy buffers. I shouldn´t say more, otherwise all the amp manufacturers want sell their stuff anymore. This is rather High-end then Hifi.


 

 Do you have any images to post? Glad you are enjoying the PB2.


----------



## ebe2000

Sorry, no better quality pic at 01:30AM, but this is showing the Bursons on "stilts". Have to find a way to cut out two holes for the cables and piggyback the Bursons somehow.


----------



## ebe2000

stillevil said:


> Thanks for the input. When the time comes I'll try them as well.


 

 Be careful though, you might not want to get your headphones off anymore.


----------



## privilege15

ebe2000 said:


> Sorry, no better quality pic at 01:30AM, but this is showing the Bursons on "stilts". Have to find a way to cut out two holes for the cables and piggyback the Bursons somehow.


 
  
 The burson opamps must come in aluminum tubes. I would make the holes for extension cords, then fasten the tubes on the body of the amplifirer and then put the bursons inside them to protect.


----------



## privilege15

FYI, you can stack sockets to make them stand upright above the battery like in the picture:


----------



## privilege15

ebe2000 said:


> Be careful though, you might not want to get your headphones off anymore.


 
 Which retailer did you buy burson opamps from? The only one I found which does international worldwide shipping is http://www.partsconnexion.com/. Are there any alternatives on the market?


----------



## ebe2000

stillevil said:


> Which retailer did you buy burson opamps from? The only one I found which does international worldwide shipping is http://www.partsconnexion.com/. Are there any alternatives on the market?


 

 I bought them from Partsconnexion, they are the official Burson dealer. The Burson´s come with a life time guarantee.


----------



## ebe2000

stillevil said:


> The burson opamps must come in aluminum tubes. I would make the holes for extension cords, then fasten the tubes on the body of the amplifirer and then put the bursons inside them to protect.


 

 Good idea. I think I will actually lay them horizontally onto the PB2 top lid and use silicon as a glue and insulator. Their diameter is slightly more then the PB2´s width.


----------



## batracom

Apologies if this sounds simplistic or has been answered before, but am looking to get the LME49990 on a DIP8 adaptor for my PB2. Would a "dual" configuration, such as this one:
 http://www.ebay.co.uk/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER-/201320580342?pt=LH_DefaultDomain_0&hash=item2edfa444f6
  
 be fine, or should I get four singles, 
 http://www.ebay.co.uk/itm/2PCS-LME49990-SINGLE-DIP8-ADAPTERS/201213280939?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140328180637%26meid%3Da77cbdc0a048494d9d52b76a7ade20d7%26pid%3D100009%26rk%3D2%26rkt%3D5%26sd%3D201320580342
  
  
 Many thanks for any assistance!


----------



## zilch0md

Hi batracom,
  
 Quote:


batracom said:


> Apologies if this sounds simplistic or has been answered before, but am looking to get the LME49990 on a DIP8 adaptor for my PB2. Would a "dual" configuration, such as this one:
> http://www.ebay.co.uk/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER-/201320580342?pt=LH_DefaultDomain_0&hash=item2edfa444f6
> 
> be fine, or should I get four singles,
> ...


 
  
 There's a slight consensus in favor of using two duals rather than four singles, but some would argue that you won't hear a difference. I bought singles, but if I were going to buy more, I would get duals - it's a little less expensive and, if there is a sonic advantage, I believe the duals would have the edge.
  
 Frugalphile (eBay seller) is a good source for them, as his soldering is very nicely done, but those blue PCBs he uses are a little too large to avoid running into the op-amps that occupy the buffer row.  
  
 To avoid that problem, when you order either the duals (2x) or the singles (4x) you can write him in advance and ask him if he can trim the length of the PCB's before shipping them to you.  I know of a Head-Fi member who thought to ask first, and frugalphile trimmed the PCBs at no extra cost.
  

  
 I tried using a Dremel tool and cutting disk to do this myself once, with four singles.  Chalk it up to poor vision or just being all thumbs when it comes to DIY efforts, I managed to cut through a trace on all four of them!  
  
 Ron (HeadFi member: HiFlight) came to my rescue by volunteering to solder jumper wires across the junctions that I had severed! They worked fine afterward.  
	

	
	
		
		

		
			





 
  
 If you are located in the States, sending a PM to Ron, to get a quote for the LME49990s, would have you getting DIP8 adapters that fit inside the PB2 without modification.  Ron does a great job and he has a reputation for excellent customer service.
  
 Mike


----------



## privilege15

One can avoid cutting the edges by using additional DIP8 sockets. They will raise LME49990 above any obstacles.


----------



## zilch0md

Indeed!
  

  
  
 Dinner is served!


----------



## rebelme801

Does anyone have problems with hissing noise?  I have a hissing coming from the right side when hooked up to my hd650 with balanced cable.  Sorry if this was addressed already.  Also, this amp sounds great (minus the hissing) with the Theorem 720 --> So far this is my ultimate <trans>portable rig.


----------



## SpudHarris

Sounds as though an OpAmp isn't quite seated correctly...


----------



## Paul - iBasso

rebelme801 said:


> Does anyone have problems with hissing noise?  I have a hissing coming from the right side when hooked up to my hd650 with balanced cable.  Sorry if this was addressed already.  Also, this amp sounds great (minus the hissing) with the Theorem 720 --> So far this is my ultimate <trans>portable rig.


 

 Please switch the op amps or buffers to see if that is the problem. It could be as mentioned above, that one is not seated correctly.


----------



## rebelme801

Thanks, problem fixed.


----------



## Makiah S

rebelme801 said:


> Does anyone have problems with hissing noise?  I have a hissing coming from the right side when hooked up to my hd650 with balanced cable.  Sorry if this was addressed already.  Also, this amp sounds great (minus the hissing) with the Theorem 720 --> So far this is my ultimate <trans>portable rig.


 
 Yea it's an issue with the amp. About every 6 month's I remove my Op Amps [Lme 49990 an Dummys] from the sockets check for any debris or dust an reset everything. 

 The only issue I still have is I get a slight hiss on the right side when I change the volume. I've not re seated my Lme 49990 from the Riser they sit in [DIP 8] so that might be an issue there, Though I'm reluctant to do that without a set of proper tools atm so I'm dealing with the hiss when I change volume [not a huge deal imo]

 But I'm happy to here others have dubbed the pb2 as a Ultimate Trans[Portable] Amp :3, I use mine with my HM 901 an it sounds just as good as my NFB 10ES2. Only issue I have with the pb2 is it doesn't quite have the head room my NFB10ES2 does with the HE 4, but thankfully I don't use my HE 4 portable so it's never an issue


----------



## eboch

Anyone have problems with the headphone jack self destructing?
  
 Trying to figure out if there is some easy solution other than rip/replace jack.
  
 Thx!


----------



## zilch0md

^ bummer.

Send an email to iBasso. They might send parts for free, even if it's out of warranty (if you can solder.)


----------



## eboch

Thx!  Good news for me is that I can solder 
  
 Will contact iBasso and post result.  
  
 Better to go back to OEM for sure....I hate trying to find general market alternative to parts - since the replacement may be better part, but unless it's an EXACT replacement, the part generally looks like a kludge.


----------



## zilch0md

Roger that! I can't say for sure that they'll send the part for free, but I can assure you it will be inexpensive.

I wanted to drill vent holes in my PB2 case and was amazed to find they sold me a complete case (top and bottom), screen printed as usual, for only $20.00. 

Mike


----------



## privilege15

Just wanted to return to this thread and say that since I started using MUSES01 opamps I still think PB2 is one of best portable amps I've ever listened to. No other portable or desktop amp (even over $1000) I tried satisfied my audio tastes as this one.
  
 Funny thing is that it is generally considered that MUSES01 is light on bass or fairly neutral. One day I offered to listen to my FiioX5 -> PB2 -> IE800 setup to one of my mates, for what he replied he didn't like that there was too much bass. LOL what?!


----------



## zilch0md

I would love to hear Muses01 in my PB2, but I've told myself I've got to find a buyer for my Muses02 first.


----------



## Makiah S

stillevil said:


> Just wanted to return to this thread and say that since I started using MUSES01 opamps I still think PB2 is one of best portable amps I've ever listened to. No other portable or desktop amp (even over $1000) I tried satisfied my audio tastes as this one.
> 
> Funny thing is that it is generally considered that MUSES01 is light on bass or fairly neutral. One day I offered to listen to my FiioX5 -> PB2 -> IE800 setup to one of my mates, for what he replied he didn't like that there was too much bass. LOL what?!


 
 you wanna hear something crazy, upgrade out of the Fiio X5 into something like a Hifiman HM901 an you'll REALLY see how good the PB2 does! to my ears, the HM901 an PB2 are sonically on par with my Audio GD NFB10ES2. Only difference is the NFB10ES2 has more head room with my HE 4, aside from that the two are damn near sonically the same! [is this is a fully balanced 30lb amp that cost me $600, vs the like 3lb portable at like $1300 xD, 1/10 the weight an double the cost]


----------



## zilch0md

My PB2 is still proving it can add value:
  
 http://www.head-fi.org/t/633511/pictures-of-your-portable-rig-part-xvi/18450#post_12113811


----------



## oldmate

zilch0md said:


> My PB2 is still proving it can add value:
> 
> http://www.head-fi.org/t/633511/pictures-of-your-portable-rig-part-xvi/18450#post_12113811


 
 I've just hooked up my iBasso D6 to my Galaxy S3 and I'm absolutely stoked with the sound quality. Older iBasso AMPS/DACS are still very relevant today. My Oppo HA-2 whilst very good is now having a rest whilst I enjoy the rather pleasant sound signature of the dual wolfson DAC's.
  
 I can't believe I had it for sale on eBay twice and nobody purchased it. I'm definitely hanging on to it now. It's an ugly stack compared to the oppo but man it sounds good. I think I may end up with the D14 as well!!


----------



## Makiah S

Just hooked my PB2 up to my HM901/NFB10ES2 an remembered why I own it, honestly the SE out is a step above that of my NFB10ES2 the balanced out isn't as good on the NFb10ES2 but considering the size I'm ok with that. I'm still just shocked at how clean an quick the Single End output side is! I know with my NFb10ES2 the SE is very slow compared to the Balanced out, though that's a Balanced Dac/Amp so I can understand that
  
 How ever, driving the PB2 with a SE cable yeilds an excellent quality of sound out of BOTH connectors, the Balanced out is still the best output, how ever the SE doesn't fall to far behind [like the NFB10ES2 Single End does compared to it's balanced out]


----------



## Makiah S

Holy crap D: I basso Changed their web site up AN they don't directly sell this bad boi any more! This puppys gone extinct! I really feel like a lotto winner having gotten mine while they were in production <.< I'm still impressed how amazing the SE output on this sounds! It's MUCH blacker an more detailed than the very poor SE out on my NFB10ES2 [though tbh it's a fully balanced Dac/Amp, the SE is just there for... well to be there lol]


----------



## privilege15

It seems like the web site is not complete yet. In any case I seriously consider buying a second PB2 as this amplifier is one of a kind, extremely versatile and will never get old.


----------



## Makiah S

stillevil said:


> It seems like the web site is not complete yet. In any case I seriously consider buying a second PB2 as this amplifier is one of a kind, extremely versatile and will never get old.


 
 well design wise it may never age  but for the moment it seems to be a challenge to find a new one <.< do you know of any one who can soder the LME 49990 to the 8pin adapters. I'd love to get a second one my self too >.>


----------



## Makiah S

Here's some MAJOR nostalgia!
  
 In 29 days my PB2 will be TWO years old Dx that's so crazy I forget that I've had it that long!


----------



## ebe2000

[/quote]

Same here, sadley mine sits around collecting dust as I use the ifi idsd exclusively nowadays due to its long lasting battery on my long flights.


----------



## zilch0md

Sell it!
  
 I should talk - I've got stuff that hasn't been powered on in over a year.


----------



## ebe2000

Am rather into buying not selling unfortunately, always collecting - that´s what attics are for


----------



## Makiah S

Same here, sadley mine sits around collecting dust as I use the ifi idsd exclusively nowadays due to its long lasting battery on my long flights.[/quote]

 long battery life? My iBasso PB2 last me like 12 ish hours how longs the iDSD


----------



## ebe2000

mshenay said:


> long battery life? My iBasso PB2 last me like 12 ish hours how longs the iDSD


I do two 8 hour flights every 6 weeks and the IDSD has never empted. (16 hours). Plus should I need a top up, I can recharge via USB from power bank which I carry anyway with me. Can't do that on PB2


----------



## WhiskeyJacks

Do you have the Micro idsd or the nano? And I can understand that, I use the Pb2 most of the time when using portable amp because it sounds really awesome with my he-560s(balanced out) and my Earsonic SM64v2(SE out) but I have also read and heard from peoples whose ears I trust that the Idsd sounds pretty awesome. One of the best DACs heard under 500$


----------



## ebe2000

whiskeyjacks said:


> Do you have the Micro idsd or the nano? And I can understand that, I use the Pb2 most of the time when using portable amp because it sounds really awesome with my he-560s(balanced out) and my Earsonic SM64v2(SE out) but I have also read and heard from peoples whose ears I trust that the Idsd sounds pretty awesome. One of the best DACs heard under 500$


I have the Micro IDSD and absolutely enjoy it


----------



## zilch0md

*I can't believe how good this sounds.*
  
 The Burson V5 discrete op-amps (fed by the Oppo HA-2's ESS9018K2M DAC) have a very natural, _pleasureful_ sound that works very well with the HD800, yet with lots of detail and an inky black noise floor.The V5s are keepers (more on that in a moment) and I actually like them more with LME49990 as buffers than using dummy buffers - which is kind of a first for me, as I usually prefer using dummy buffers to squeeze out the last bit of transparency and detail, but together, in this configuration, everything is gelling very nicely with the HD800.
  
 I've got a spare case for my PB2 that I'll be taking to a machine shop to have holes cut, through which the Burson V5 Duals can protrude - something like this mockup I've attempted to draw:
  

  
 This combination of the Oppo HA-2 > iBasso PB2, equipped as shown, sounds so good with the HD800, I'm starting to think I should just sell my desktop gear:
  

  
 Really, not even my beloved Metrum Acoustics stack sounds as good with the HD800 as this portable rig - it can't compete in terms of dynamics or detail, but is perhaps a little less fatiguing with "coarse" recordings like Adele's stuff.  Soundstage, imaging, and overall natural "rightness" is just superb with the PB2 configured this way.  
  
*Sadly, I have a warning regarding Burson's op-amps:  *
  
 They are having quality control issues and seem to think it's OK to suffer their customers with problems like dripping epoxy (as reported in the Burson V5 thread) and misaligned DIP8 pins relative to the orange plastic case -because- they have a 30-day return policy and lifetime guarantee.  
  
 That's all well and good, but the fact remains that  I'm not looking forward to re-packaging my great-sounding, burned-in V5 Duals, taking them to the post office, filling out customs declarations, paying postage, and waiting another two-weeks for a pair of op-amps that do NOT look like this (below) and...  might not sound as good!
  

  

  
 Neither of them are square inside their outer cases.  Even the one on the left is twisted a little bit - not ideal, but the one on the right is ridiculous.
  
*Why should we be inconvenienced by such easily avoided negligence - lifetime guarantee or not?*
  
 I'm not going to cut holes into the spare PB2 lid to accommodate these twisted V5s, so I've got no choice but to return them and ask for a hand-picked pair that are actually aligned with and centered beneath their cases.
  
 Mike


----------



## privilege15

No surprise PB2 is capable of a lot. Unfortunately it is so underestimated and becoming forgotten. I sold all my other amplifiers leaving only this one and not planning to change it. It's much more powerful out of balanced port than even it's neighbour P5 with external power supply. In fact, since it is no longer manufactured and almost disappeared from the shelves I almost bought a second PB2 recently just in case my current one will get broken but my new money sink into DIY multicopters stopped me from buying it.


----------



## zilch0md

^ It's nice to see someone so passionate about audio exhibiting an interest in other hobbies.  I'm sure a lot of us are that way, but it's hard to tell, reading these threads.


----------



## HiFlight

Absolutely great work!!!! The PB2 is a great amp that was overlooked in favor of the boutique stuff.


----------



## zilch0md

You've been a faithful and very helpful advocate of iBasso's gear for a long time, Ron. I very much appreciate your enthusiasm and generosity, especially in my early days of rolling op-amps.  
  
 Thanks!
  
 Mike


----------



## FallenAngel

zilch0md said:


>


 
  
 Seeing that photo made me think : at what point of upgrade-itis do you just say "maybe I should get a different amplifier"


----------



## zilch0md

^ I feel so silly now. What was I thinking?


----------



## Makiah S

zilch0md said:


> ^ I feel so silly now. What was I thinking?


 
 no no, you get another amp when iBasso makes a pb3 xD 
  
 I still love mine!


----------



## zilch0md

I've added Edna SILMIC II 35V 10uF caps to DIP8 extenders that I can insert or remove from beneath the Burson V5s, at will.  
  
 (This was the idea of Head-Fi member "pelopidas" on the Opamp Thread - soldering the caps to the extenders instead of to the op-amps themselves.)
  




  
  

  

  

  
 Improved dynamics!  
  
 I can't believe there was room for improvement, but now I understand why Burson has a web page describing this mod and why so many people like it.
  
 (YMMV depending on how your amp's power supply is designed.)
  
 This was my second attempt at soldering anything other than power cables.  My first attempt was a disaster  
	

	
	
		
		

		
		
	


	




  
  
 It helps to wear two pair of reading glasses and use lots of Scotch Tape.  Doh!  
	

	
	
		
		

		
		
	


	



  
 Mike


----------



## privilege15

Why are you doing this to me? Lol


----------



## zilch0md

Good one!  
	

	
	
		
		

		
		
	


	



  
 I'm always chasing someone else, so you might as well do the same!  
  




  
 At least this is an affordable experiment (compared to the many audio components I've bought that didn't pan out.)
  
 Start by just trying the caps soldered to extenders for insertion beneath whatever op-amps you're currently using.
  
 http://www.ebay.com/itm/10-PCs-ELNA-SILMIC-II-10uF-35V-ELECTROLYTIC-CAPACITORS-NEW-/191772894800
  
 http://www.ebay.com/itm/8-Pin-Round-DIP-Socket-For-DIP8-Package-Pack-of-5-/300922720329
  

  

  
  





    <--- Top-down view
  
  
 Note:  The photos above show the DIP8 socket upside-down, on its back.  So pay attention to where the notch is when looking at this diagram, immediately above.
  
 For single op-amps, you use different pins:
  
<--- Top-down view
  
  
 I'm really a novice at soldering, but I managed to do it.  
	

	
	
		
		

		
		
	


	



  
 Mike


----------



## WhiskeyJacks

I really wish the Burson V5's were not so tall and large, I would love to use them in my PB2 when I would get the money for them, currently I am using 4x LM49710  opamp and the dummy buffers. Pairing this with the iBasso DX90 and the Oppo PM-3 has been a delight thus far.


----------



## zilch0md

^  I hear you!  I'm having a difficult time even getting a quote from a water jet cutting service to precisely cut two rectangular holes in the spare lid of my PB2.  They want nothing to do with it, saying, "You only want one of them done?  The job is too small.  We're booked."  
  

  
 Three different local companies here in the Dallas area have turned me down - they won't even give me a quote with my having said, "Give me a *crazy* number. You might be surprised what I'm willing to pay." 
  
 So now I'm looking for an "old-school" machinist who thinks he can drill and cut without messing it up.  I know I don't have the skill, so I'm not about to attempt it myself.
  
 No lid means it's not transportable.  Ugggh!    
  
 But man, does it sound great!
  
 Mike


----------



## Makiah S

zilch0md said:


> Good one!
> 
> 
> 
> ...


 
 I'm wondering how that would sound, with the LME 49990 Op amps, having the addition of the capcitors


----------



## zilch0md

Hi Mshenay,
  
 Somehow, I overlooked your post, above.  I've never tried the caps with the LME49990, and unfortunately, I've just spent about six hours wearing out my ears with testing the Sparkos SS3602 Duals vs. the Burson V5 Duals, in my PB2, so I will have to test the LME49990s with and without caps, some other day.  
  
 Meanwhile, for the sake of the guys on the Gustard H10 thread, where many of them use the Burson V5s that have been melting left and right, here's a link to my post discussing the SS3602 with the PB2:
  
 http://www.head-fi.org/t/735828/gustard-h10-high-current-discrete-class-a-output-stage-headphone-amplifier/5040#post_12629394
  

  
 Mike


----------



## Lohb

Hi, guys looks like this thread just sprung to life after I finally picked up a PB2.
  
 Following Zilch0md's advice before,I picked up the xpal battery pack with LPS 16 volts plug and already have a set of 4 Burson V5i new generation opamps coincidentally that I was going to use elsewhere.
 I'll have to get the Hirose connector from ebay and make everything balanced.
  
 I wish the gain switches were on the outside as I'd really wanted to share it between IEMs and my LCD 2.1s and Fostex planars. But if I only use it with planars fair enough.
 From all that has been written about this amp (desktop class but transportable), they should NEVER have discontinued it, but taken it to a sleeker V2 unit design....tut tut !! 
	

	
	
		
		

		
		
	


	




 
  
 Does anyone know if it takes a single-end DAC input and makes it fully balanced end-to-end like the RSA F-35 ?


----------



## Lohb

...and I wonder if anyone is running a decently priced 16 volts linear power supply (ebay etc)  into their unit for desktop usage ?
 As it would save the battery cycle life and avoid the stock inferior SMPS usage.


----------



## zilch0md

Hi Lohb,

Welcome to PB2 land! Yes, it's sad that the trend shifted from separate components to all-in-one uber-DAPs, especially when you consider the ridiculously buggy UIs found in every DAP other than those made by Sony, which themselves suffer from having only 10- or 15mW peak output into 16-Ohms. Our choices, today, are confined by the ignorance of the masses and manufacturers' reasonable desire to meet the demands of the majority.

But those of us who have an understanding of the audible benefits of mix-and-match separate components, no tolerance for poor software, headphones that come to life only when given 300mW into 32-Ohms or more, and a willingness to carry and use the now unfashionable "bricks" of stacked gear, which have been branded as "inconvenient" by the legions of former Beats owners, whose highest priority remains rooted in fashion as they consider size and battery life (diametrically opposed objectives) to be more important than anything else... We still have yesteryear's hardware at our disposal, obsolete and unappreciated though it may be!

Wow, that dounds horribly elitist, reading it back, but I'll let it stand. I do my best to educate the newcomers, but the lure of the herd is difficult to overcome. I did, very recently, manage to convince a PB2 owner not to sell it (via a PM exchange), despite the fact that I would love to have a 2nd PB2, in reserve, should mine fail irreparably, in some way.

The PB2 is not just a great balanced amp, it's a veritable laboratory. I've learned so much and my ears have become quite experienced at critical listening - a skill attainable by anyone with healthy hearing, if they put in the time - rolling op-amps with various headphones.

My OPA1611-equipped Meier Stepdance is still going strong, but it's a one trick pony, despite its superlative transparency and neutrality - it is all you could want in an amp for use with many combinations of DAC and headphone, but certainly not all, most prominently excluding the Senn HD800, AKG K550, and Beyer DT880 600 and T1, among headphones I've owned, unless you use a DAC that smears or colors the signal coming into the Stepdance (a deplorable practice, in my opinion, seen far too often, as with people using the Schiit Vali with an HD800, morphing it into something less than it's capable of being.)

The PB2, on the other hand, is a lump of clay, ready and willing to to play whatever role you ask of it. Well, it does have some limitations.  OK, that's enough of my tribute to the PB2.

Regarding fully balanced operation, you will have to use the balanced input of the PB2, not the TRS input, but I am strongly of the opinion that using balanced-output DACs is a waste of money, even for desktop amps, unless the distance to the amp is greater than three or four meters, where the benefits of common-mode noise rejection can actually be heard - or so they say, as I've never experienced going from a balanced DAC to unbalanced and back over a long cable run to the amp. I did so, using very short cables with the iBasso DB2 and could hear no benefits. The shorter your line level cables, the less benefit there is to going fully balanced, even theoretically, much less audibly.

Add to this my conviction that amps with both TRS and balanced output can sound better using balanced cables almost entirely due to the power increase had with going balanced, and not due to the mostly imagined benefits of common-mode noise reduction or cancellation of cross-channel impedance fluctuations. I genuinely believe such impairments to sound quality actually exist, as evidenced by Jan Meier's innovative implementation of his "Active Balance" feature in the Stepdance - where he injects a nulling signal to each transducer, to cancel the impedance fluctuations "felt" across the shared ground wire that can modulate the frequency response of dynamic headphones (not so much with the almost purely resistive planar magnetic headphones), BUT... I have never read any reviewers of any of the many uber-expensive desktop amps having only TRS output, tube or solid state, owned and loved by experienced afficianados of high-end gear, write anything close to a lament of this nature: "If only this otherwise supurb headphone amp had a balanced output to eliminate the cross-channel impedance fluctuations I'm hearing! It's got plenty of power, but the lack of common-mode noise rejection (on six-foot headphone cables) is another factor that earns this amp a big thumbs down!" Seriously, nobody complains of hearing these undesirable anomolies with single-ended amps. It's the benefits of additional power that people are hearing and enjoying by switching from a TRS jack to a 4-pin jack on amps that offer both, and even then, the power increase is audibly benefecial only when the transducers are sufficiently inefficient to perform their best with the power offered at the TRS jack. 

The extremely popular and affordable Chinese-made Gustard H10 desktop amp offers both balanced and unbalnced inputs (for the sake of compatibility), yet only a TRS output! Bravo! They get it! But people wonder why it lacks balanced output! Ken Ball, of ALO, is on record as having defended his first portable amps, that had balanced input, but no balnced output, saying that the balanced input was just for compatibility with balanced portable DACs, while balanced output was unnecessary, given the amp's power at the TRS jack. He later succumbed to market pressure applied by the ill-informed masses, to produce amps with balanced output. 

There are legions of very experienced, very satisfied, well-heeled users of single-ended amps that provide plenty of power for their headphones of choice, who couldn't care less about balanced output, much less, fully-balanced operation - because the benefits of sufficient power far outweigh any benefits of balanced operation, especially with short cable runs.



Mike


----------



## zilch0md

Oh, and regarding the use of a 16V LPS, for desktop purposes, I routinely power the PB2 with my Energizer XP8000, equipped with the 16V XPAL Willy Cable, all the while leaving the XP8000 attached to its AC charger.  
  
 I can think of two DACs, one of which I own - the French-made Audiophonics PCM5102 - and one I've never heard, but that's much better known - the Ciúnas DAC -  where the (independent) designers have included battery packs inside the DACs, while simultaneously encouraging users to leave the DACs connected to external power supplies.  DACs are notoriously sensitive to ripple noise from power supplies, but here we have two examples of designers who are believe that battery packs do a great job of eliminating power supply noise, even that from switched-mode power supplies.  JKenney, of Ciúnas, has even published a DIY mod for theUptone Audio USB Regen, which he believes can improve the quality of the USB signal it delivers to your DAC of choice, by bypassing what Uptone has said is one of the highest quality, low-noise, voltage regulators they could find for driving the 3.3V circuits within the USB Regen. I've not tried it, nor do I have any interest in doing so, but JKenney advises opening up the USB Regen and soldering leads from an external battery pack that's trickle-charged with any old 5V LPS of your choosing, that is itself regulated by any old 3.3V regulator of your choosing. So, the external battery pack is plugged into a noisy 5V supply that's regulated down to 3.3V with a potentially noisy regulator, to keep a nominally 3.7V battery pack trickle charged at a constant 3.3V, with sufficient amps to meet the diminutive 40mA load of the USB Regen's internal circuits. And voila, he claims the battery pack will eliminate any and all noise coming from either its AC charger or the external voltage regulator that holds the voltage coming into the external battery pack at 3.3V - at least to a degree that outperforms the noise generated by the USB Regen's own, internal, state-of-the-art 3.3V regulator. And Uptone Audio (Alex and John) admit that the internal voltage regulator generates noise of its own, but they tested many possibilities before settling on that one and have only pointed out that doing such mods would violate their warranty.
  
 My point in sharing all of this is to put your mind at ease about powering the PB2 with an AC-attached XP8000 + 16V Willy Cable.  The inline voltage regulator offers a much greater threat to achieving a low noise floor than does leaving the XP8000 attached to its AC charger, and the question becomes: Can you find a regulated, 16V LPS that is as quiet as the XP8000 + inline regulator?  I don't feel any incentive to go hunting for a solution to that "problem," because, in my experience and that of many other people, whatever is inside those inline Willy Cable regulators is pitch black, in terms of impact on noise floor - even with the Stepdance and noise-sensitive IEMs - where the Stepdance bypasses its internal battery pack entirely, once connected to external power. Some people have even noticed external noise coming from their Willy Cables - like a high-pitched whine - not loud enough to interfere with even the most open headphone designs, as long as you don't hold the Willy Cable right next to your head - but some people have used these "whining" Willy Cables with the Stepdance, reporting no signal noise, whatsoever.  
  
 I really don't know what's available, but I think you'd have to get into some big bucks to find a 16V LPS that's as quiet as an XP8000+Willy Cable, with or without the AC charger attached.  You can easily test the (zero) impact of the AC charger, by disconnecting and reconnecting the charger while listening to the PB2 with a track that has a lot of recorded "silence."  (Again, people are designing DACs with batteries inside, just to filter LPS noise.)
  

  
 Mike


----------



## Lohb

Thanks for all the balanced/battery input Mike.
  
 I know the Bakoon current drive amps uses a similar internal battery schematic as you describe.
 I'll just skip the LPS I had bookmarked - they give you a custom plug for the device you need to power -
  
 16 volts set unit with correct power plug length/breadth
 http://www.ebay.co.uk/itm/112007457911?_trksid=p2060353.m1438.l2649&var=410948176767&ssPageName=STRK%3AMEBIDX%3AIT
  
 But as you say, the Energizer XP8000, equipped with the 16V XPAL Willy Cable will be hard to beat even with an entry-level LPS.
  
 Looking forward to trying the V5i Burson chips in it with dummy buffers I guess, as the seller has the stock opamp kit and I remember you used your LME49xxxx opamp chips in the dummy buffer slot with your V5 Bursons before the heat issues cropped up with those V5 units.
  
 I just saw the gain difference between balanced and unbalanced output on the iBasso PB2 instruction PDF.
 So maybe I can find a sweet-spot for IEMs and planars (maybe medium gain) but I doubt it....I'd only get Fostex T20Mk2 and IEMs in a kind of extreme low/high volume dial range but getting IEMs and LCD 2.1s to work on same jumper setting will be near impossible !
 I'd like to strip the unit down and anodize it like ALO stuff, but fear breaking something in the process.


----------



## zilch0md

Hi Lohb,
  
 I've not had any heat problems with the Burson V5 Duals in the "topless" PB2.  The only problem I've had after getting two that were not defective on arrival is that they were too tall to close the lid.     I still love their sound, but so far, I like the Sparkos SS3602 a little more.
  
 The V5i should be a much better fit for the PB2 than either the V5 or the Sparkos op-amps, so I might try those eventually.
  
 For only $55 U.S., you've really got me interested in that 16V LPS, now.  It has an R-Core transformer, which is typically quieter than EI or toroidal transformers.  A lot of guys on the computeraudiophile.com USB Regen thread are big fans of some of these Chinese R-Core LPS units.  
  
 Have a look at this one:   http://www.ebay.co.uk/itm/30VA-30W-115V-230V-To-DC18V-HiFi-Linear-power-supply-Regulated-PSU-CL-219-/111558067765
  
 Here's a 2x enlarged crop from one of the photos in that listing, which shows a little brass screw on a white component, next to the voltage regulator's heat sink.  
  





  
 That's where you can adjust the output voltage yourself (be careful what you touch with the screwdriver), while referencing the handy, built-in voltmeter display.
  
 I'm chuckling at myself for having been so dogmatic about the XP8000 + Willy Cable, but if you've a mind to experiment and you can't hear any change in the noise floor, this would be a little tidier on your desktop.


----------



## Lohb

I'm currently waiting on an answer from iBasso on the PB2 plug width/length.
 The ebay one is
  

  
 """ DC cable head size: 5.5*2.1mm  ( if you need other size. Please contact us) """


----------



## Lohb

zilch0md said:


> Hi Lohb,
> 
> I've not had any heat problems with the Burson V5 Duals in the "topless" PB2.  The only problem I've had after getting two that were not defective on arrival is that they were too tall to close the lid.     I still love their sound, but so far, I like the Sparkos SS3602 a little more.
> 
> ...


 

 I'm surprised you never gave the Caiman Mk2 DAC a shot after the Bushmaster Mk2....
 Been following Caiman Mk2 DAC on another forum, he keeps improving the unit via chip FLASH updates.


----------



## zilch0md

^ I was desperately trying to satisfy my HD800 at the time and went in the direction of NOS DACs for awhile. I remain curious about the Caiman Mk2, so I might give it a try sometime.


----------



## ph0n6

Since iBasso is planning on releasing the PB3, can someone tell me what's the original price of the PB2 since I believe it will be priced the same as the previous gen. Or looking at their current lineup I would say it would belong to the 3-400$ price range hopefully.


----------



## zilch0md

Really!   I had no idea there was a PB3 coming!  Cool!
  
 I think the PB2 sold for $399.


----------



## zilch0md

ph0n6 said:


> Since iBasso is planning on releasing the PB3...


 
  
 OK - now I need a reference, please.  I can't find any mention of the PB3 other than people wishing it were coming - since way back.


----------



## ph0n6

zilch0md said:


> OK - now I need a reference, please.  I can't find any mention of the PB3 other than people wishing it were coming - since way back.


 
 https://www.facebook.com/iBassoAudio/?fref=ts
 Here's the official iBasso product page, they update it frequently so definitely check it out. Also the new PB3 despite the name take quite a different approach compared to the PB2 with slimmer and more compact design so no more opamp rolling, make sense as the P5 is an upgrade to the PB2 already.


----------



## Lohb

ph0n6 said:


> https://www.facebook.com/iBassoAudio/?fref=ts
> Here's the official iBasso product page, they update it frequently so definitely check it out. Also the new PB3 despite the name take quite a different approach compared to the PB2 with slimmer and more compact design so no more opamp rolling, make sense as the P5 is an upgrade to the PB2 already.


 

 No opamp rolling then it is only PB in name.
 The core of it is the opamp rolling/SQ dialing and the sheer balanced power for hard to drive headphones.


----------



## ph0n6

The P5 doesn't have balance in or output but is pretty much the PB2 upgraded so I don't think it makes sense to make 2 similar product, especially considering how small the marketshare for portable amp is.


----------



## zilch0md

ph0n6 said:


> https://www.facebook.com/iBassoAudio/?fref=ts
> Here's the official iBasso product page, they update it frequently so definitely check it out. Also the new PB3 despite the name take quite a different approach compared to the PB2 with slimmer and more compact design so no more opamp rolling, make sense as the P5 is an upgrade to the PB2 already.


 
  
 Thank you, ph0n6!
  
 Yes, it seems to be designed to suit the masses...  
  
 /sarc/
  
 We want everything to be slickly styled, smaller, lighter and more convenient, with USB charging and a longer battery life!  
  
 Oh wait...  All of those must-haves will compromise power output and sound quality! Oh well! That's what we want! Give it to us!
  
 /end sarc/


----------



## Lohb

P5 internals.
  

 "We haven’t seen a dedicated amp from iBasso for a while now, and the *P5 is the successor to the old P4."*
 http://www.head-fi.org/products/ibasso-audio-p5-portable-amplifier/reviews/14027


----------



## Makiah S

zilch0md said:


> Thank you, ph0n6!
> 
> Yes, it seems to be designed to suit the masses...
> 
> ...


 
 UGH a pb3 without opAmp Rolling >.> 
  
 well on the plus side, I've decided I'm going to do an ASC in EET here in the fall, as there's a part of me that's terrified about not being able to fix my own gear! So much so I think I'd like to move into that feild
  
 either way, I've still got my PB2, an it's been running like a champ for maybe 3 years now! I've never had an issue with it. Here's to hoping they make a Modular PB3, though I doubt they will. "Audio phile" is getting popular, and with that popularity I think there's an increase in the number of customers who want a simpler product [IE less options/tinkering] which is a shame


----------



## Lohb

Confirmed the power plug on PB2 is 5.5*2.1mm with iBasso so that LPS posted previously will work with it.


----------



## Lohb

If bypassing the internal PB2 battery with a desktop LPS and a linear external battery ( Energizer XPAL ) is it best to fully charge it or fully discharge the original internal battery, if is not going to be the primary power source ?
 Also, can it be removed easily ?
 That would give more room for a caps upgrade and in Zilch's case, the Sparkos would fit, IF it operates normally with external power only.


----------



## zilch0md

lohb said:


> If bypassing the internal PB2 battery with a desktop LPS and a linear external battery ( Energizer XPAL ) is it best to fully charge it or fully discharge the original internal battery, if is not going to be the primary power source ?
> Also, can it be removed easily ?
> That would give more room for a caps upgrade and in Zilch's case, the Sparkos would fit, IF it operates normally with external power only.


 
  
 Hi Lohb,
  
 Li-Ion and LiPo batteries should be discharged to a voltage of 3.8V per cell before putting them away in storage.  They will have a voltage as high as 4.2V per cell when fully charged.  
  
 The battery pack in the PB2 has a 3 cells, so when it's fully charged, it would measure as high as 12.6V (4.2V per cell) and when you store it, it should measure exactly 11.4V (3.8V per cell).
  
 It can be easily disconnected, but I think it has some double-sided tape on the underside, because it doesn't come loose easily.  I've never tried to actually remove it completely - I've only noticed that I cannot wiggle it or lift it.
  
 And therein lies my advice - I would just leave it alone. Battery packs are known for eating power power supply noise.  JKenney, maker of the Ciunas DAC, uses LiFePO4 cells inside his DAC to power it, but he encourages his customers to leave the DAC connected to its AC-powered charger.  I have the French-made Audiophonics PCM5102 DAC, which has a really small Li-Ion battery inside, that couldn't possibly power the DAC for longer than about an hour, if that. But that's not the intent. The battery is only there to filter noise. They too, say to operate the DAC with the charger connected at all times.  In their case, they don't provide a power supply - you have to go get one of your choosing.  Weird.  I no longer have it, but for a while I had an inexpensive NOS DAC, also from France, called The Battery DAC.  It had rechargeable batteries inside, but I couldn't hear any difference switching the mains power in and out to charge the batteries during use. But in their case, they encourage the idea that it will be quieter when operating without mains power.  Ironically, the noise floor was so high from using a cheap Philips NOS DAC chip, that using battery power is next to pointless, except for enjoying portable operation, but it was almost too big for that.  
  
 So, when using the PB2 as a desktop amp, I run it with the charger switch turned on while supplying it with 16V from the XP8000 + Willy Cable, and - _surprise_ - I leave the XP8000 plugged into its charger.    It's so easy to test for noise - just find an excellent recording that has lots of black silence in it, and try listening carefully, even with the volume cranked up a little higher than you would normally listen.  Try removing the XP8000 from its charger, then plugging it back in, then taking it back out.  You won't hear any increase or decrease in noise.  I can't, anyway.  Then leave the XP8000 plugged into the AC and try unplugging the Willy Cable from the back of the PB2, out and in, out and in.  No changes in the noise floor.  With two batteries in between the mains and your PB2, you've got twice the filtering, assuming there's anything to be said for how JKenney and Audiophonics promote leaving their battery-powered components plugged into the chargers.
  
 Mike


----------



## Lohb

Thanks Mike, as thorough as ever !
 I'm going to go through the Pelican case dimensions next for it as sometimes I have water bottles in my sling/torrential rainy season downpours etc.
 Will add any information to the PB2 database. Currently using this for DAC and IEMs.

  
 Pelican 1050 for PB2 with an Energizer/XPAL external battery combo by the looks of it....


----------



## Lohb

Just received my PB2.
 It's about 50% of the cubic volume I'd imagined it to be. But that is a good thing.
 Now to see if I an get these four single v5i opamps to fit inside.
  
 Nope V5i singles are a no-go. I think duals would just squeeze in.


----------



## Lohb

Ah yes, having a little 'zen' moment here.
 This little amp is lovely with my other equipment.


----------



## Lohb

zilch0md said:


> Mike


 
 Mike are you running dummy buffers with the Sparkos ? I think I need to get Sparkos duals, no way to fit the Burson singles ;-(
 Do you know what is best to put in the buffer socket to not stand in the way of current for planars...dummies, buffers or actual opamps ?
  
 Currently using the AD797 and wideband buffers with caps due to the V5i's not fitting.


----------



## chiman

Lohb, I've been running the duals for a week or two now. They're a tight fit, but I don't have any jumpers plugged in



Here's a bad pic taken with my phone.


----------



## Lohb

chiman said:


> Lohb, I've been running the duals for a week or two now. They're a tight fit, but I don't have any jumpers plugged in
> 
> 
> 
> Here's a bad pic taken with my phone.


 

 Nice, how you finding them vs the stock kit ?
 I just got told by Burson to try elevating 2 chips with dip adapters of the 4 singles to get then fitting in the PB2.
 If no joy, on to Sparkos it is for me.
  
 I'm finding the higher gain settings on PB2 have more bite/attack dynamics but on a thread as old as this it no new information I guess.
 Anyway, with these new discrete OPAMPs new to the market they will be taking the SQ of PB2 to a higher level again, hopefully.


----------



## Lohb

chiman said:


> Lohb, I've been running the duals for a week or two now. They're a tight fit, but I don't have any jumpers plugged in
> 
> 
> 
> Here's a bad pic taken with my phone.


 

 By elevating yours, I guess you will be able to use the gain jumpers again.
 I see you are not using dummy buffers. Did you roll in a few combinations before choosing an OPAMP in the buffer slots ?
 I'm still trying to get to grip with the benefits/drawbacks of different chips in the buffer slots...BUF634P WB gave the 797's a meatier sound, though less clearer from what I can remember.


----------



## zilch0md

lohb said:


> Mike are you running dummy buffers with the Sparkos ? I think I need to get Sparkos duals, no way to fit the Burson singles ;-(
> Do you know what is best to put in the buffer socket to not stand in the way of current for planars...dummies, buffers or actual opamps ?
> 
> Currently using the AD797 and wideband buffers with caps due to the V5i's not fitting.


 
  
 Hi Lohb,
  
 Yes, I always use dummy buffers in the PB2, when using it with the HD800 or with my recently acquired DT880 600-Ohm (modified by BTG-Audio to use balanced cables).
  

  
 I would love to have the current gain offered by using "real" buffers in the output stage, but the noise floor is _*always*_ lower when I use dummy buffers - as heard with highly resolving headphones. When using the LCD-2 rev.1, HD600, and HD650, for example, I cannot hear the increase in noise floor that comes with using "real" op-amps in the buffer stage - so with those headphones, I can enjoy the extra power that comes with using buffer op-amps, without feeling as if I am having to compromise the noise floor.  
  
 And speaking of power vs. noise... check out the comparison chart Sparkos Labs has published:
  

 Source:  http://sparkoslabs.com/wp-content/uploads/2014/06/SS3601_SS3602.pdf
  
 Take this chart with a grain of salt, if you like (with it showing the SS360x having *more power and lower noise* than the other op-amps listed), but I can attest that not only does a pair of SS3602 duals in my PB2 (with dummy buffers) exhibit an audibly lower noise floor than the Burson V5 duals in the same chain, they can drive my 600-Ohm balanced-cabled DT880 with terrific authority. The SS3602 is powerful, even with only the +/- 16V supply voltage of the PB2.  The SS3602 is just coasting along with a +/-16V supply voltage (with the PB2 on external 16V power), given that they can handle supply voltages as high as +/- 22V (compared to the current edition Burson V5's +/-17V).
  
 In looking at the data sheets of a lot of different op-amps, I've noticed that most op-amps tend to yield their lowest noise levels not at their absolute maximum permissible supply voltage, but rather at supply voltages that are roughly 85% to 90% of absolute maximum. Yes, they will give you more output power to your headphones if you can give them their absolute maximum supply voltage, but they will be noisier at their maximum permissible voltage.  Consider how good a match the +/- 16V supply voltage of the PB2 is (on external power), with high gain, to the +/- 22V maximum supply voltage of the Sparkos, vs. the +/-17V maximum supply voltage of the Burson V5. Take note that I am assuming these two discrete op-amps behave a lot like most IC op-amps in terms of low noise at less than maximum power, which might not be the case, but in general, it just makes intuitive sense to me that an op-amp which is not maxed out will generate less noise. 
  
 The DT880 600 sounds a little compressed and has slightly uncontrolled bass when using only half of the SS3602 Duals via the TRS jack of the PB2, but when I switch to balanced cables, using the PB2's Hirose jack, the DT880 600 comes to life, finally getting enough power to be all it can be - with the tightest, most textured and detailed bass I've ever heard - way better than my LCD-2 rev.1 in terms of control and texture, even when the LCD-2 is connected to my Oppo HA-1's 4-pin XLR jack, that puts out 2000 mW into 32-Ohms. The bass energy (amplitude) of the DT880 600 is not as great as that of the LCD-2 rev.1, but that's a good thing, as I've long since "matured" in terms of how much bass energy sounds natural and real vs. simply "fun."  The HD800 weaned me of my lust for bass, but the DT880 600, with balanced cables _*and*_* *Beyer's pleather pads (instead of the velour pads), is "just right," as Goldilocks would say. I can also say that the Sparkos SS3602 plus DT880 600 has a more "musical" bass. The warp of a tympani drum, for example, is awesomely slurred through a range of low frequencies rather than sounding like a brief honking at a single frequency. I realize that I'm pitching the DT880 600, here, as much as I am the Sparkos SS3602, but the fact is, I don't get this level of performance with other op-amps in the PB2.  After getting my DT880 600 back from BTG-audio having installed mini-XLR jacks for balanced operation, I ran through some of my favorite opamps with the DT880, not wanting to overlook any special synergies that might exist.  Forget about it.  The Sparkos SS3602 wins!
  
 Basically, thanks to the Sparkos SS3602 duals, my precious PB2, and balanced output to the DT880 600, my HD800 is gathering dust (at least for the moment).  Oh, the HD800 sounds great with the SS3602s but, it just can't muster the bass energy of the $220 DT880 600 with the $70 mod performed by BTG-Audio and Beyer pleather pads. The detail from top to bottom is spectacular. The noise floor is really low. And the treble doesn't have the smoothing "glow" around every note that the (too tall) Burson V5 Duals have. The Sparkos SS3602 yields so much blackness around even the lowest-energy signals, that the soundstage just blossoms. Micro-details against inky black backgrounds are the building blocks of soundstage - they map out the dimensions of the space in which the music was recorded, revealing the weakest of natural reverbs. The DT880 isn't known for having the big soundstage of the HD800, but thanks to the low noise of the Sparkos, the width and depth of the soundstage is surprising.  The Sparkos also place you a lot closer to the stage, where the dynamics are more impactful and vocals more intimate and close (all but feeling the singer's breath on your face) than the Burson V5, where you find yourself sitting farther back from the stage - more laid back,less dynamic, with less "slam."  I attribute the superior dynamics, the bass control and and the authority of drum hits and bass kicks to the SS3602's raw power.  I'm running them with the PB2 jumpers set to high gain.  If I were using much more efficient headphones, these power-related attributes wouldn't be as noticeable relative to the Burson V5s, but the difference in noise floor would be even more noticeable.  
  
 Note, however that* I am unable to fully seat the SS3602 into the PB2 sockets*:
  

  
 This has proven to be perfectly OK. They are staying put, with no evidence of rising up out of the sockets on their own, but *I have affixed a section of thick packing tape above the Sparkos op-amps, on the underside of the PB2's cover*, to provide a non-conductive surface, just in case the SS3602s would touch the bare aluminum.  I've used them with the lid on, without the packing tape, but I feel better having added the packing tape.  There is no room under the PB2's closed case to insert a DIP8 extender.
  
 All that said (I can't help myself thanks to be a fast typist), if I were using the Sparkos SS3602 with less than highly resolving headphones, I wouldn't hesitate to at least try using "real" buffer opamps - to get even more power (through additional current gain), but I would make some careful comparisons while listening with a track that has a lot of silence in it.  I'm pretty sure "real" op-amps could be used instead of dummy buffers, without running into the SS3602s, but I haven't tried it.    
  
 Here's a recording with some silent spaces that really allow the Sparkos SS3602 to show off:   _Heart Beat_ by Antonio Forcione Quartet
  
 Mike


----------



## zilch0md

chiman said:


> Lohb, I've been running the duals for a week or two now. They're a tight fit, but I don't have any jumpers plugged in
> 
> 
> 
> Here's a bad pic taken with my phone.


 
  
 Wow, those sit really close to the exposed gain pins, but I guess nothing is going to move about in there, so if you were going to have a short, it would have happened already.  In truth, they fit better than the Sparkos SS3602, but I would want to use the high gain jumpers.


----------



## zilch0md

Here's an interesting white paper from Sparkos Labs (for the very curious):
  
 http://sparkoslabs.com/audio-op-amps-gain-seek-bandwidth/
  


> Can we get an op amp with 2 pole compensation and have massive loop gain and a reasonable bandwidth?  Yes we can, but you won’t find it in a monolithic IC.


 
  
 Mike


----------



## Lohb

Looking good Mike regarding the OPAMP technical stuff....
  
 I just picked up a better quality than generic printer cable, and after half-an-hour, worked the 4th pin completely out with a razor and tweezers as per your data-only USB plug method for split USB cables.I used tape for the 4th pin on another previous cable, but it never lasts when you remove the USB cable from the port daily.

  
 http://www.head-fi.org/t/647693/sonic-satori-hrt-levels-the-field-with-the-microstreamer/1155#post_12640560
  
 Will have my Hirose male plug fitted on an 8-line Sterling Silver IEM cable by tomorrow locally....
 But I know I cannot AB exactly, even taking account for volume. I find the middle/high gain adds more *bite/attack/dynamics* to the presentation for some reason, and I think it is not purely volume but the impedance or something is working with the end IEM/headphones to present it slightly differently....I think that came up in the H10 thread as well.
  
 Have yet to see if the base of the case can screw off, if yes, may anodize it or power-coat upper and lower case and leave the rear and front as it is.
  
 Just pulled the AD797...found them too dry in the mids/treble...now using OPA604 + dummy buffers which has a richer tone and fuller sound than AD797... until I can get my hands on DIP8 units to raise 2 of the Bursons up and keep 2 low.


----------



## Makiah S

has any one yet to well rebuild a PB2? Like from stratch, I wonder what it would cost to manufactor a clone with a larger space for opAmps. Granted that might bump into some copy Right infiringments, but I keep getting the sense that we all really need just more space in this Amp to work, an there has to be a better solution than what were currently doing imo 
  
 with regards to the sound of the different gain settings, I've also enjoyed running low gain on all my dynamic headphones, on my HE 4 Medium gain sounds the best imo, still I'm enjoying the LME 49990s as I always have, my only issue has been and will always be there's a touch of noise when I adjust the volume, I clean the amp out from time to time and re seat the amps, and it kinda helps, but I really just need to get new opAmps and with 8pin DIP adapters, 
  
 either way still enjoying this little amp an awful lot ^^ I'm excited as my Hm901 and PB2 combo has been getting more head time recently


----------



## Lohb

I notice a pop on or off, so no earphones in the 3.5" when switching on or off...I roll the volume to zero before removing inserting IEMs.
  
 A mute relay would have helped unless that is just the used amp's style  I picked up.


----------



## Lohb

mshenay said:


> ...my only issue has been and will always be there's a touch of noise when I adjust the volume, I clean the amp out from time to time and re seat the amps, and it kinda helps, but I really just need to get new opAmps and with 8pin DIP adapters,


 

 Roll the volume pot from zero to 100% many times while switched off. That may loosen any dirt/dust and fix the issue.


----------



## zilch0md

lohb said:


> Looking good Mike regarding the OPAMP technical stuff....
> 
> I just picked up a better quality than generic printer cable, and after half-an-hour, worked the 4th pin completely out with a razor and tweezers as per your data-only USB plug method for split USB cables.I used tape for the 4th pin on another previous cable, but it never lasts when you remove the USB cable from the port daily.
> 
> ...


 
  
 Hey, good job on getting rid of the 4th pin.  Replacing the tape is a nuisance, for sure.
  
 In Europe, there are several people who really like this product for accomplishing the same thing - the *SBooster VBus2 Isolator*:
  
 https://www.sbooster.com/sbooster-tweaks/sbooster-vbus-isolator?language=en
  
 Unfortunately, they refuse to sell directly to wanna-be customers in the States, but you can ask them for the contact info of a "dealer" here in the States who will do business with you by email - no website, not even a Facebook page, quotes by email and he uses his girlfriend's PayPal address to take payments.  Very flaky - no thanks.  (Just my opinion, having never actually done business with him, stopping short at receiving his unprofessional, hastily thrown together emails.) 
  
 SBooster has some very highly regarded LPS, also, but just try and buy one.
  
 ---
  
 It's sounds as if you're going to have a nice cable when it's done.  Enjoy!


----------



## zilch0md

@Lohb   And, by the way, you should write iBasso and ask them if they have any spare part cases for the PB2 lying about.  For real.  They sent me a top and bottom - no end plates, for only $20.00 U.S., shipping included.  That was about eighteen months ago, so I don't know what they still have in the way of inventory, but it's worth asking, and that way, you can try anodizing without risking the original parts.


----------



## Lohb

zilch0md said:


> @Lohb   And, by the way, you should write iBasso and ask them if they have any spare part cases for the PB2 lying about.  For real.  They sent me a top and bottom - no end plates, for only $20.00 U.S., shipping included.  That was about eighteen months ago, so I don't know what they still have in the way of inventory, but it's worth asking, and that way, you can try anodizing without risking the original parts.


 

 Nice. I still want to pull the original battery and load a nice juicy cap in that space....hahaha.
 But I won't, after your previous post on how it can affect things adversely.


----------



## Makiah S

lohb said:


> Roll the volume pot from zero to 100% many times while switched off. That may loosen any dirt/dust and fix the issue.


 
 thank you, I'll have to do that right away 
  


zilch0md said:


> @Lohb   And, by the way, you should write iBasso and ask them if they have any spare part cases for the PB2 lying about.  For real.  They sent me a top and bottom - no end plates, for only $20.00 U.S., shipping included.  That was about eighteen months ago, so I don't know what they still have in the way of inventory, but it's worth asking, and that way, you can try anodizing without risking the original parts.


 
 mmhmm I may do that as well, just to have the parts for my self too


----------



## privilege15

lohb said:


> Thanks Mike, as thorough as ever !
> I'm going to go through the Pelican case dimensions next for it as sometimes I have water bottles in my sling/torrential rainy season downpours etc.
> Will add any information to the PB2 database. Currently using this for DAC and IEMs.
> 
> ...


 
  
  
 It’s been quite some time since I retired from searching for the right sound that would soothe my ears after spending thousands of dollars on various buys and tries. Since I found the right one I rarely pay visit to head-fi, only to scan through interesting updates on the market. Non spotted though)
  
 Although I don’t think I shared one of pictures on how I actually store my setup which might be useful to someone. I bought this waterproof pelican case last year for this very purpose. It’s a 1075 pelican case with foam inside:
  

  
 I put the relevant sticker on it which was lying around:
  

  
 And that's how everything is organized inside:
  

  
 I do really think that the PB2 is the heart of the whole system. The DAPs are replaceable, there's plenty and one on the market but PB2 is the only and almost extinct powerful beast. It will never get old and most of the time (depending on what internals you have...obviously there must be something better than the stock ones) it will beat all those fancy new super duper portable amps and a good deal of the desktop headphone amps.
  
 If you have one, never lose it.


----------



## Lohb

Yeah, it is a superb amp, and I like that case you have but for me I think the 1060 will do it for my needs...another energizer LPS user I see


----------



## Lohb

@stillevil what chips did you finally settle on ?
  
 I'm running the OPA604 OPAMPs + dummy buffers which I found the best of the stocks chips for my own taste and IEMs. I read the 604 comes alive the more voltage you feed it up to a point.
  
 Anyone looking at the new Burson V5i chips, get dual chips for PB2, not singles like me....doh !
 I just could not estimate their size from the website photos.


----------



## privilege15

lohb said:


> @stillevil what chips did you finally settle on ?


 
  
 I'm running with *MUSES01* opamps and *LT1028ACN8* buffers with 8-pin DIP heatsinks because the buffers become pretty hot.
  
 I read on some other DIY forum for hi-fi/hi-end electronics that LT1028ACN8 go really well with MUSES01. That's how I tried this combination which eventually appeared to be the final one.
  
 I thought of trying Bursons or Sparkos but then I asked myself "What's the point?" as I already have one of the best sounds for my taste by comparing it to many of the setups I tested, be it my own or someone else's or demo samples in stores.
  
 I tried running MUSES01 with dummy buffers at first. The sound was NOT as good as with LME49990 opamps+dummy buffers which I previously used so I rolled back and put the MUSES01 aside in the drawer. At the same time I ordered LT1028ACN8. When the set of new buffers arrived I inserted MUSES01 and LT1028ACN8 and that's when I had my jaw dropped to the ground. When I found it, I already knew this is it, that's exactly what I needed.
  
 Don't get me wrong LME49990 is a good opamp but I did not feel that I was completely satisfied with it. Something was missing/weird/strange but I could not say what exactly so I kept searching. Eventually my brain got in total harmony as soon it heard the combination of *MUSES01* and *LT1028ACN8* and of course balanced *Beyerdynamic DT-150* headphones (250Ohm) plugged into PB2 with handcrafted with my own hands custom cable, the search was over. After this I sold most of my other audio stuff as considered to my tastes to be inferior to my current one.
  
 DISCLAIMER: everything said is strictly regarding my taste


----------



## Lohb

stillevil said:


> I'm running with *MUSES01* opamps and *LT1028ACN8* buffers with 8-pin DIP heatsinks because the buffers become pretty hot.


 
 What is the sound signature like on that combo ?
 2 dual Muse ?
 I see multiple product number codes online.


----------



## privilege15

All MUSES01 are dual...I think. At least I never heard about the single ones. The codes on the chip itself might be different. It's better to order from Japan. There are many fakes around.
  
 As for the sound signature it's completely neutral and crystally transparent for me with on the spot amount of bass and on the spot middle and highs. It's almost like if you imagine the flat frequency curve in 2D as a square metal plate through which you can't see but then imagine that this plate turns into crystal glass reveling every hidden nook behind it. I felt like there was no more fog, not even a haze to hide anything from me while being 1 on 1 with the composition.
  
 That's approximately how sound signature looks like


----------



## Lohb

stillevil said:


> It's almost like if you imagine the flat frequency curve in 2D as a square metal plate through which you can't see but then imagine that this plate turns into crystal glass reveling every hidden nook behind it. I felt like there was no more fog, not even a haze to hide anything from me while being 1 on 1 with the composition.
> 
> That's approximately how sound signature looks like


 

 Haha, I say that kind of stuff to my friends and they are like "W.H.A.T. ?"


----------



## Makiah S

stillevil said:


> It’s been quite some time since I retired from searching for the right sound that would soothe my ears after spending thousands of dollars on various buys and tries. Since I found the right one I rarely pay visit to head-fi, only to scan through interesting updates on the market. Non spotted though)
> 
> Although I don’t think I shared one of pictures on how I actually store my setup which might be useful to someone. I bought this waterproof pelican case last year for this very purpose. It’s a 1075 pelican case with foam inside:
> 
> ...


 
 ooh does the 1075 come in bricks like that? I've mutilated a few cases trying to cut out foam with the right shape
  
 I might have to pick one up if it comes with removable foam bricks! 
  
 an yea the PB2 is still one of my favorite amps! It sounds better than a LOT of desktop amps I've had over the years


----------



## Lohb

Just picked up the Pelican Micro 1060 hard case for my PB2 audio chain. More manageable in a sling with notebook.
  
 I like the idevice white case (1010i) but Pelican seem to only make 1 white case.


----------



## Lohb

Just picked up adapters to elevate dual V5i's after my inability to fit the singles on PB2.
  
 Should elevate them above the gain plastic plugs main body pushed in the gain sockets just behind the DIP sockets.


----------



## Lohb

Surprised that Pelican 1060 BARELY could fit everything. As tight packed as it gets.
 Trying to stack everything so it does not need to come out the box...like an UBER-MOJO...haha.

  
 Frothing at the mouth for my Burson V5i duals to finish everything off...


----------



## zilch0md




----------



## Lohb

Would 4x LME49600 be an improvement over dummy buffers after the V5i slots for planars...more current right ?


----------



## Lohb

Pure Sterling Silver 8-line Hirose balanced MMCX 1.1M cable for sale if anyone interested, before I convert it back to single-end....


----------



## zilch0md

lohb said:


> Pure Sterling Silver 8-line Hirose balanced MMCX 1.1M cable for sale if anyone interested, before I convert it back to single-end....


 
  
 I wish I actually needed it.


----------



## Lohb

_Burson have been excellent with re-shipping out duals_ after I could not get singles in the PB2 due to the extended lip stopping correct insertion next to each other of 4 singles....
 Just got some V5i duals in again and they need elevation with dip8 sockets, and now I'm having vertical fitting issues (vs horizontal) with the top of the amp barely pushing into place.
 I think the V5is just have to ship without the EMI cap - bare like all other chips.

  

  
  
 Screw hole not lining up unless I push the lid down that last 1%, which may cause undue pressure on the circuit board...it would in effect turn the lid into a direct heatsink with full contact to it from the chip EMI cap .....which would be good, if it fit 100%.

  
 Also have Sparkos on the way to test the 2 out together A|B (with V5i open lid).
 Just read that there is noticeable burn-in with the V5i on the opamp thread, so I'll get looping the loops with my amp top off in the meantime.
  
  
 I'm still resisting pulling out the stock battery to get a stack of caps in that space. Need to speak to an amp design guru I know locally to see if it will be safe and improve the sound again.
 Need to build a balanced cable for my planars now. To experience this little monster balanced, feeding all that juicy goodness to Audeze/Fostex planars.


----------



## Lohb

Regardless of fitting, this is one amazing amp chip (V5i) OOTB.....transparancy/dynamics/bass control and depth......a veil gone.
 I guess the case lid could get the DAP bands treatment for those that don't want to pay over $69 for new chips to give their PB2 a new lease of life.


----------



## Lohb

Did anyone dig up low-profile jumper tabs that will allow the new generation Burson V5i and Sparkos opamps to sit correctly in their slot.
 I imagine some place will have tiny jumper tabs and that the spacing may be a universal standard.
  
  
 Got my Sparkos sitting at home and travelling with my V5Is just now, but I'd love to get the Sparkos sitting correctly in their DIP slots....


----------



## northendjazz

On the short jumpers they came from a computer/electronics shop they are called "Miniature Pin Jumper" there was only long and short in the shop so I guess there a common size.
  
 Hope this helps


----------



## Lohb

northendjazz said:


> On the short jumpers they came from a computer/electronics shop they are called "Miniature Pin Jumper" there was only long and short in the shop so I guess there a common size.
> 
> Hope this helps


 

 Can the latest Neco Soundlab V5 dual mono take amp chip rolling or are they soldering the chips in now ?


----------



## northendjazz

The V5 does not allow op amp rolling, which helped me keep the V4 and searching for PB2 I found powdered peanut butter 
	

	
	
		
		

		
		
	


	




.


----------



## SpudHarris

northendjazz said:


> On the short jumpers they came from a computer/electronics shop they are called "Miniature Pin Jumper"there was only long and short in the shop so I guess there a common size.
> 
> Hope this helps




I just took off the top off the original ibasso jumpers. Seemed to have picked up a few over the years having owned P3, P4, and PB2...


----------



## Lohb

spudharris said:


> I just took off the top off the original ibasso jumpers. Seemed to have picked up a few over the years having owned P3, P4, and PB2...


 

 You mean you cut off the top plastic bendy part ?


----------



## SpudHarris

lohb said:


> You mean you cut off the top plastic bendy part ?




Yes...

Of course if aesthetics are less important you could use fuse wire or a bent paper clip.


----------



## Lohb

spudharris said:


> Yes...
> 
> Of course if aesthetics are less important you could use fuse wire or a bent paper clip.


 

 Thanks, worked a treat ! No tilt to the amp chips, no DIP 8 adapter needed and the jumper tabs are in there all snipped on mid-gain.
 Lid closes too....a new lease of life for an excellent amp !


----------



## privilege15

If anyone have been wondering about new Burson V5i opamps, I tested them in my iBasso PB2:
  

  
 I also did a little review of them which is available at http://www.head-fi.org/products/burson-audio-supreme-sound-opamp-v5i/reviews/16822


----------



## Makiah S

Glad to see this thread is still kicking! 
  
 Happy to say my PB2 is still performing well,


----------



## Lohb

mshenay said:


> Glad to see this thread is still kicking!
> 
> Happy to say my PB2 is still performing well,


 

 Kicking the dust more like it...., but as long as my PB2 doesn't kick the dust I'm more than happy with it.


----------



## Lohb

Anyone no longer using their LME49990s let me know...


----------



## Makiah S

lohb said:


> Kicking the dust more like it...., but as long as my PB2 doesn't kick the dust I'm more than happy with it.


 
 Yea I know it's dieing, really hoping iBasso  does an upgrade for the PB2,


----------



## Lohb

mshenay said:


> Yea I know it's dieing, really hoping iBasso  does an upgrade for the PB2,


 
 http://www.head-fi.org/t/829878/ibasso-pb3-mockingbird-portable-balanced-headphone-amplifier


----------



## Lohb

Anyone find the LME49990 a step up from AD797 ?
 I'm using the BUF634P WB in front of AD797 to fill out the body of the presentation.
  
 It has been tricky trying to find the right opamp that will work with my Fostex T50 woodies and hybrid IEMs.
 AD797 great with planars, but too bright with hybrids.
 OPA604 really filled out the hybrid IEM making it musical/rich/full with BUF634P WB but it sounded skewed and rolled off with planars, almost wonky.
  
 Did not like either v5i or Sparkos strangely....the quest continues.


----------



## Lohb

Really liking the LME49990 with planars and wondering how MUSES 8820 compares in PB2 ?
 I just read the MUSES 8820 is like a budget materials version of MUSESO2, and may pick it up to get a feel for it, before going for a MUSES02.
  
 Any PB2 opamp roller input appreciated !


----------



## snellemin

Using the muses 02 with the WB634 and I like it with the 400I in balance mode.


----------



## Lohb

So if anyone has a dying battery, it is fairly easy to remove. I started to remove it about 4 times before, but then stopped for fear of ripping traces off below.
 it actually is just held in with double-sided tape and is easy to get out. My battery got swollen on previous charge and lid would not close, so this time I went full in 100% to get it out..

 So now I'm deciding to get a new battery from iBasso or fill that former battery space with quality caps.
  
 Thanks a million to @zilch0md *for his very kind gift of 1 set of Muses02*. I'm loving the PB2 even more now.


----------



## Lohb

snellemin said:


> Using the muses 02 with the WB634 and I like it with the 400I in balance mode.


 

 Planars better with high current/lower battery life *BUF634P* *WB* IMO. Normal 634 may be a current bottleneck.
 EDIT :
 Aha, i see from your review you are using same buffers as me already.
  
 Try running it off battery power energizer LPS (zilch0md's photo)

  
 or a 16v LPS mains unit such as...
 http://www.ebay.co.uk/itm/112007457911?var=410948176767&ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649
  
 ...vs internal battery or stock power block.


----------



## snellemin

lohb said:


> So if anyone has a dying battery, it is fairly easy to remove. I started to remove it about 4 times before, but then stopped for fear of ripping traces off below.
> it actually is just held in with double-sided tape and is easy to get out. My battery got swollen on previous charge and lid would not close, so this time I went full in 100% to get it out..
> 
> So now I'm deciding to get a new battery from iBasso or fill that former battery space with quality caps.
> ...


 
 Installed two 1800uf 16V caps in place of the stock 1200uf cap.  Worth the effort for basshead use.


----------



## Lohb

snellemin said:


> Installed two 1800uf 16V caps in place of the stock 1200uf cap.  Worth the effort for basshead use.


 
 Nice, and the battery still in there too. I wonder what you are running as buffers now ?
 I just fired off an email to iBasso to get a quote on a fresh battery cost today. I'd only use the internal battery with IEMs OTG myself....
 Edit : Already bookmarked some Panasonic caps at your rating unless there would be a better brand to go for (?)
 Think I'll give the fake/ancient dried out D-stock stuff from China a miss....


----------



## snellemin

lohb said:


> Nice, and the battery still in there too. I wonder what you are running as buffers now ?
> I just fired off an email to iBasso to get a quote on a fresh battery cost today. I'd only use the internal battery with IEMs OTG myself....
> Edit : Already bookmarked some Panasonic caps at your rating unless there would be a better brand to go for (?)
> Think I'll give the fake/ancient dried out D-stock stuff from China a miss....


 
 I'm running the 634WB buffers still.  You could try to source your own 3s1p  lipo or li-ion battery in a smaller format to fit inside the case.  At least that is what I would do if I were only to use the internal battery sparingly.  The batteries available today output more power vs when the Ibasso PB2 first came out.  So less voltage drop under load and no bigger caps needed. 
 The PB2 only has that one single electrolytic capacitor.  So the Panasonic cap will do fine.
  
 Here is the back of the Ibasso PB2.


----------



## Lohb

$20 for the PB2 battery + shipping - same capacity.
  
 Good to know it is still available.
  
 Edit : The PB2 board layout is much more complex than the surface layout indicates after seeing the underside !


----------



## snellemin

lohb said:


> $20 for the PB2 battery + shipping - same capacity.
> 
> Good to know it is still available.
> 
> Edit : The PB2 board layout is much more complex than the surface layout indicates after seeing the underside !


 
 Good to know about the battery.  
  
 The board is indeed more complex. The original cap is not through-hole mounted, but surface mounted.


----------



## Lohb

I ordered 4 of the caps, try them in the battery area first, and if it gets too bass dominant/bloomy - roll back to 2 or 1.
 Luckily I know a speaker designer locally who also recaps those old monster 70s/80s amps.


----------



## vapman

How is this holding up vs. the competition on balanced amps?
  
 I am looking for a balanced amp only for my headphones. I have a DAC capable of outputting either digital or analog balanced signal. Either form of digital, XLR or TRS 1/4 is easiest for me...


----------



## Lohb

vapman said:


> How is this holding up vs. the competition on balanced amps?
> 
> I am looking for a balanced amp only for my headphones. I have a DAC capable of outputting either digital or analog balanced signal. Either form of digital, XLR or TRS 1/4 is easiest for me...


 

 For the price used, it holds up excellently.
 Plus you have the endless opamp/buffer rolling as your cans/IEMs change, you can re-dial things back to your sweet-spot sound preference.
  
 EDIT : You'll be after Muses02 and caps upgrade for your basshead preferences.
 If on a budget, get the mass market version of 02
  
 http://www.ebay.co.uk/itm/MUSES8820-JRC-Bipolar-Input-Dual-Operational-Amplifier-1pc-DIP-8-Package-/252270396084?hash=item3abc7cc2b4:g:amQAAOSw-vlVkqiF
  
  
  
 I just picked these up to upgrade the surface mount cap
  
 http://www.ebay.co.uk/itm/332084815470?_trksid=p2057872.m2749.l2649&var=541120633179&ssPageName=STRK%3AMEBIDX%3AIT
 but being in USA, you can pick up pairs from mouser.
  
 New battery is also $20 plus shipping (2100mAh) as if you are picking up used the original battery will be thrashed no doubt.
  
 Look into Energizer LPS solution in the thread....


 Also toroidal LPS set 16V
 http://www.ebay.co.uk/itm/112007457911?var=410948176767&ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649


----------



## vapman

lohb said:


> For the price used, it holds up excellently.
> Plus you have the endless opamp/buffer rolling as your cans/IEMs change, you can re-dial things back to your sweet-spot sound preference.




I kinda dont really wanna even buy a balanced amp but it seems like a necessity more or less now. At least with building custom stuff. Was thinking about diy a balanced amp but if i could get this used for a decent price that might be cool...


----------



## Lohb

vapman said:


> I kinda dont really wanna even buy a balanced amp but it seems like a necessity more or less now. At least with building custom stuff. Was thinking about diy a balanced amp but if i could get this used for a decent price that might be cool...


 

 Look into this and buy 2 - potential to run dual mono.
 I think the circuit board and BOM is about $50 per amp if you can solder.
  
 http://www.head-fi.org/t/833106/new-diy-altoids-tin-amp-the-class-a-wintergreen-handwarmer-by-xrk971


----------



## vapman

lohb said:


> Look into this and buy 2 - potential to run dual mono.
> I think the circuit board and BOM is about $50 per amp if you can solder.
> 
> http://www.head-fi.org/t/833106/new-diy-altoids-tin-amp-the-class-a-wintergreen-handwarmer-by-xrk971


 
 Whoaaaa, i had been following that but somehow missed it would do balanced!
 i guess that's what i need 
 fill it up with OSCONs for that maximum bass.


----------



## Lohb

vapman said:


> Whoaaaa, i had been following that but somehow missed it would do balanced!
> i guess that's what i need
> fill it up with OSCONs for that maximum bass.


 

 Buying 2 means you could run one per channel I'm guessing, into a balanced output. Best to ask the designer in the thread.


----------



## Reima

Just joined the PB2 club having scored a mint condition PB2 from the BST. So far I am liking what I hear, my source is a DIYImod. It currently has OPA604 and BUF634U installed.


----------



## Lohb

reima said:


> Just joined the PB2 club having scored a mint condition PB2 from the BST. So far I am liking what I hear, my source is a DIYImod. It currently has OPA604 and BUF634U installed.


 

 Yes, OPA604 is quite a tubey character signature - good for hot treble gear if you are sensitive to that. I notice with volume increases before that it fills out the lows/mids rather than large dB increases. Kind of the polar end to LME49990/ Muses01 and the new boutique chips (Burson v5i + Sparkos 3601/2) that were rolled in to the PB2 in last 6 months on this thread.


----------



## Reima

lohb said:


> Yes, OPA604 is quite a tubey character signature - good for hot treble gear if you are sensitive to that. I notice with volume increases before that it fills out the lows/mids rather than large dB increases. Kind of the polar end to LME49990/ Muses01 and the new boutique chips (Burson v5i + Sparkos 3601/2) that were rolled in to the PB2 in last 6 months on this thread.


 
 I am planning to get the Sparkos 3602 as some point, right now I am investing in wood cups for my headphones. I also got a Hiflight Topkit so today I am going to try the LT1010 buffers with a pair of unknown opamps from the kit, the designation starts with AD but the rest of it is covered with red paint.


----------



## zilch0md

reima said:


> I am planning to get the Sparkos 3602 as some point, right now I am investing in wood cups for my headphones. I also got a Hiflight Topkit so today I am going to try the LT1010 buffers with a pair of unknown opamps from the kit, the designation starts with AD but the rest of it is covered with red paint.


 
  
 Ask Hiflight to identify the "red paint" op-amps.


----------



## vapman

Dude is selling kits to head fiers and hiding the part #'s? Kinda lame...?


----------



## zilch0md

vapman said:


> Dude is selling kits to head fiers and hiding the part #'s? Kinda lame...?




Ron (HiFlight) only color codes the op-amps in his kits to help avoid the mixing of pairs. They are all very smartly soldered and represent a nice collection of community favorites. It would take a lot of shopping to come up with all the pieces separately and already soldered to DIP8 PCBs. For those of us who don't solder, his kits are a great way to get started with rolling op-amps. He's also a really nice guy to deal with.


----------



## Reima

vapman said:


> Dude is selling kits to head fiers and hiding the part #'s? Kinda lame...?


 
 I don't see it that way, the opamp is so small that when he put a blob of paint on it for color coding it obscured the markings on the opamp. I got the kit second hand but I am pretty sure the original owner knew what he was getting from HiFlight.


----------



## Makiah S

reima said:


> I don't see it that way, the opamp is so small that when he put a blob of paint on it for color coding it obscured the markings on the opamp. I got the kit second hand but I am pretty sure the original owner knew what he was getting from HiFlight.


 
 I can see how that would be frustrating, 
  
 Still though, I've been content with Dummy BUffers an LME 49990s in mine since I got them, I source out of my HM901 line out and it'll drive my HE 4 nicely!!!


----------



## snellemin

Used a 65W laptop PSU with an old 3A step down dc converter to see if there would be any improvement over the stock PSU.  I max out the volume on some bass heavy music and the step down converter was complaining.  Added a 2200uf cap and things got better.  So I'm going to get me a better step down converter and enjoy massive power on the cheap.


----------



## zilch0md

That's cool.  You're shooting for a 16V maximum, right?


----------



## snellemin

zilch0md said:


> That's cool.  You're shooting for a 16V maximum, right?


 
 Yup 16V.  Drops to 15.7V under bass hits.


----------



## Makiah S (May 5, 2017)

welp my PB2 is dead, I had an issue with a lot of noise on the Right Channel, any time I'd change the voulme I'd get some static. But my unit has always done that, I'd pop her open, remove and re seat everything, then it would be 100% silent for about a month... tonight I was listening, normal volume, lme 49990s dummy buffers with no issues.

Battery went dead, so I plugged it in, used the same charger and everything, and it was silent... couldn't hear the music while I charged it... couldn't hear anything but it was quite. Cut if off again, opened it up removed and reseated everything, including the little cable for the battery and now  I get a LOT of loud Popping and noise when I plug anything into to it

plugged in and it's completely silent

any tips or suggestions? I tried different opAmps and still had an issue with the noise, Trying different buffers now

I swapped out the buffers and I can smell heat, as soon as I turn it on...

running back into my LME 49990s and Dummy Buffers everything smells normal, like metal

but what do you guys suggest I start with? As far as getting it repaired. It kinda went from 100% to zero in like a second


----------



## zilch0md

^ I have no recommendations, unfortunately, but I feel for you!  How sad!  Makes me want to buy another one as a backup, but I'll give you a chance to find one, first.  

You could write iBasso and ask them if they are equipped to do repairs, for a fee, out of warranty.

Sigh...


----------



## Makiah S

zilch0md said:


> ^ I have no recommendations, unfortunately, but I feel for you!  How sad!  Makes me want to buy another one as a backup, but I'll give you a chance to find one, first.
> 
> You could write iBasso and ask them if they are equipped to do repairs, for a fee, out of warranty.
> 
> Sigh...



well it was pretty sudden, and I don't see any black char or anything physical dmg'd on the board. I'm tempted to start with replacing the Battery, but I've emailed Paul the iBasso guy here. As their website was pretty useless

The big problem I have now is what to replace it with? I don't really use to many of BIG balanced Headphones on the go, mostly my Audio Technica ES 10 now a days, or my Nhoord Red V1, I'm happy with HM 901 as a source, but amp wise since I don't need the power any more, what would work?

I guess this is kinda good, I bought the PB2 back in the day to drive my HE 4 any where. But it NEVER leaves my house... EVER, so really all of my other full sized Headphones are 4pin Terminated, and are all low impedance high sensitivity. So, what SE compares to the PB2 with LME 49990 and Dummy Buffers, while the Balanced output had... better everything, I'm hoping there's a SE portable amp that is well better


----------



## snellemin

Got me another set of 634U buffers and used 100 ohms resistors for the wide bandwidth mode.  To my ears this sounds better then stacking the 634P WB buffers on top of the 634U's.


----------



## zilch0md

snellemin said:


> Got me another set of 634U buffers and used 100 ohms resistors for the wide bandwidth mode.  To my ears this sounds better then stacking the 634P WB buffers on top of the 634U's.



Awesome!  Oliver Twist asks, "Please sir, may I have some more current with my voltage sir?"


----------



## Makiah S

zilch0md said:


> Awesome!  Oliver Twist asks, "Please sir, may I have some more current with my voltage sir?"



mmmmmm that looks good man. Also, I decided on a HeadAmp Pico power to replace my iBasso PB2. I may honestly repair it here soon and start to tinker with it as I get deeper into my Electrical Engineering Tech program, but I don't intended to ever have to deal with the... sadness that over took me q.q I had my PB2 for like 4 years, and in a second it died... and rendered my Hifiman HM 901 completely useless! [I gutted out it's amp last year, to try and get more battery life plus I really only like it for the UI and DAC lineOut] 

So here's to hoping I'm back here soon, tinkering as you guys do


----------



## HiFlight

vapman said:


> Dude is selling kits to head fiers and hiding the part #'s? Kinda lame...?


I color-code the opamps to prevent incorrect installation and for the owner to be able to tell them apart, as after soldering, it is often impossible to read the numbers on the opamp.   I have had to replace too many opamps due to incorrect installation by the owner of the Topkit to send the opamps "uncoded".   
Also, not every Topkit is the same for the same device as they are custom build based on the purchasers sonic preferences and the type of headphones used.   I am alway happy to tell the purchaser exactly what opamps are included and what color they are.   The colored end always indicates the number one pin end.  I make no effort to conceal what devices I use although some manufacturers do, including such reputable builders as iBasso and RSA (Ray Samuels)


----------



## HiFlight (May 6, 2017)

Mshenay said:


> welp my PB2 is dead, I had an issue with a lot of noise on the Right Channel, any time I'd change the voulme I'd get some static. But my unit has always done that, I'd pop her open, remove and re seat everything, then it would be 100% silent for about a month... tonight I was listening, normal volume, lme 49990s dummy buffers with no issues.
> 
> Battery went dead, so I plugged it in, used the same charger and everything, and it was silent... couldn't hear the music while I charged it... couldn't hear anything but it was quite. Cut if off again, opened it up removed and reseated everything, including the little cable for the battery and now  I get a LOT of loud Popping and noise when I plug anything into to it
> 
> ...



Couple of comments/suggestions:
The scratch sound when rotating the volume knob is usually the result of some offset voltage.  All opamps have the offset voltages listed in their datasheets from minimum to maximums  In other words, you might be using 4 LME49990 opamps and each will have a slightly different offset voltage.  Always try to select opamps with offset voltages specified in microvolts rather than minivolts.  Offset voltage is NOT a good thing. 

The crackling/popping sound you hear is typical of a shorted opamp. This can be due to a number of reasons, such as incorrect installation, excessive supply voltage, simple failure for no good reason or fake asian opamps to name a few. 

Some opamps are relatively unstable for use in audio circuits and can initial ultrasonic oscillation.  This can often be identified by touching each opamp or buffer.  None should be hot to the touch.   Needless to say, make sure you are using single-channel opamps in a single-channel device and vice-versa!   Again the datasheet can be your best friend if you are uncertain which opamps are which.

For starters, I would suggest installing a set of OEM opamps that were included in the device when new, making sure that they are installed correctly.  If you have a decent multimeter, check the supply voltage at the V+ pin socket and see if there is the proper voltage being supplied by the battery (or PS)

Generally speaking, the circuitboard component are pretty robust and it will be opamps that are the most prone to failure.  Always start with the simple things and work up from there!

Good luck!


----------



## zilch0md

^ Great advice Ron!  I wish I had your knowledge, your soldering skills and your patience.  

Mike


----------



## Makiah S (May 6, 2017)

HiFlight said:


> Couple of comments/suggestions:
> The scratch sound when rotating the volume knob is usually the result of some offset voltage.  All opamps have the offset voltages listed in their datasheets from minimum to maximums  In other words, you might be using 4 LME49990 opamps and each will have a slightly different offset voltage.  Always try to select opamps with offset voltages specified in microvolts rather than minivolts.  Offset voltage is NOT a good thing.
> 
> The crackling/popping sound you hear is typical of a shorted opamp. This can be due to a number of reasons, such as incorrect installation, excessive supply voltage, simple failure for no good reason or fake asian opamps to name a few.
> ...



Wow thanks! Well I had your TopFlight Kit LME 49990s, and I've had them in the amp for years. I did try switching into another set of completely different OEM OpAmps and Buffers, but I got the same noise. An the Cracking has been replaced by VERY LOUD pops, it sounds to my ears like a short, there's to much of something

Let me just start by asking, are you still selling the TopKits? I purchased mine used, and it may benefit me to purchase an entirely new set from you, I may also look into purchasing a Power Supply Cable and new battery from iBasso as well, before I ship it off

I've been using some random lapTop Charger I found online for... well about 4 years now. I got it back when I first purchased my Pb2, as my seller didn't have/include the OEM verison. An again it's been working fine for a long time now, and it's strange that even with a completely different set of opAmps it's the same... completely lack of sound 

If you have some time though, I'd love to run through some more tests to try and get this amp back up and running my self


----------



## Makiah S (May 6, 2017)

Actually I just noticed this but my 3.5mm Output jack has some black scortching on it


----------



## Makiah S (May 6, 2017)

Oh it does indeed make noise, it's super quiet though I got some music to play out of the balanced OutPut
the balanced out put does NOT make that CRAZY loud Popping, AND I got music to play out of the Balanced OutPut

I use the Lowest Gain setting, as I don't need a lot of power... I guess I could go to High Gain and get it auidble but that might just distort things 

still my reading was .7 that was with the black contact on the metal pin that pokes out of the charging socket


----------



## Makiah S

I get a reading of .7 when I put my Black Contact onto the little power pin that sticks out of the charging port

if I reverse the OpAmps it drops to .23 but at .23 I get an audile drop out or big nasty popping/buzzing where there should be bass


----------



## Makiah S

also If I plug the Charger into the unit and try to play music, I can't hear anything. 

The last time it worked, when I plugged the charger in and tried to listen it was all staticy and garbage [that was on the SE output]


----------



## Makiah S

mhm, going back to the SE output, if I plug into, IMMEDIATLEY there's a LOUD popping but ONLY the the SE output, the hiRose balanced out doesn't have this issue. I also use the 3.5mm input 

I'll upload a picture of that little jack, as it's really black looking


----------



## Makiah S

in Conclusion


So I've done some more testing, and what I've found is that the Balanced Output on my unit will produce sound, but it's REALLY REALLY quiet on the lowest gain setting, how ever if I try to use the SE output I get a NASTY LOUD popping sound in my headphones

and this is the same regardless of what opAmps I'm using. Balanced out has no ugly nasty noise, but it's SUPER DUPER quite... 

So something is clearly wrong with my unit, and it's not the opAmps as no matter which opAmp/Buffer combo I try that SE out jack makes an UGLY nasty Popping, and the balanced output is SUPER duper quite 

I sent that in eMail form to Paul@ibasso and the service desk people. I tried a few of my OpAmps and it's always the same. LOUD Pop on the 6.5mm REALLY quite music on the Balanced out


----------



## Makiah S

The first set of opAmps that get's loud enough to actually listen to, but that's on Low Gain and with the Pot ALL the way up 






The Noisy Popping 3.5mm out, what I see is that it's either Pitch Black, like it's burned or it's bare metal. The other 3.5mm jack has a more even all gray kind of color, it's not this mix of SILVER and BLACK, 






the not noisy 3.5mm in, again it's all one color


----------



## Lohb (May 16, 2017)

_*Finally found this thread via google, all my followed threads got wiped. *_

So here is a DAFT add-on that I strapped to my PB2 to un-tether from sources at the DAC end.....

You can search out in google-land for :-

" TROND 3.5mm Bluetooth V4.2 Audio Receiver Adapter"




It is a dirt cheap bluetooth apt-X DAC receiver and it goes amazingly well with PB2.  No glare/sibilanczzzzzz.
You'll need a device that can transmit bluetooth apt-X grade audio OUT at bare minimum. To me, it is near CD red book grade sounding.

I can output from Macbook air via Audirvana + and my phone also luckily outputs apt-X... (there is a higher grade apt-X LL level it has with even tighter latency specs.)

Give it a whirl for fun ! _This thing should not sound like it does via PB2 for the price it is._ Redbook 44k sampling level limit though...It seems to transmit around 352kbps from my original 16/44 FLAC files (if a secondary Bluetooth Explorer OSX app stream analyser is correct.) I think you'd only want to use 16/44 source files with this combo stack.

Now I can keep my PB2/apt-X DAC and phone* in separate pockets vs dealing with the dreaded brick stack *!

I tried asking them some techy questions, but never realised it was a bigger company. Rep never had a clue at my questions/upgrade suggestions..Digging through the internal chip white paper, there may be a slight filter active on sound-stage expansion.

This combo sounds better to me/more musically involving than a few $600-$800 level DAC/amp all-in-ones.
Someone on the PB2 thread spend $20, hook this thing up, and let me know if I need my ears checked/waxed


----------



## Makiah S

Lohb said:


> _*Finally found this thread via google, all my followed threads got wiped. *_
> 
> So here is a DAFT add-on that I strapped to my PB2 to un-tether from sources at the DAC end.....
> 
> ...



welp, when/if I get my PB2 repair'd I might look into this!


----------



## zilch0md

Lohb said:


> _*Finally found this thread via google, all my followed threads got wiped. *_
> 
> So here is a DAFT add-on that I strapped to my PB2 to un-tether from sources at the DAC end.....
> 
> ...



Hi Lohb,

It doesn't seem to have a Line Out, so you're "double amping," right?   And it doesn't have its own DAC, so you are actually using the DAC of your BT transmitting source, right?

I'm not sure about either of these points.  Please clarify.

Thanks!

Mike


----------



## Lohb (May 19, 2017)

zilch0md said:


> Hi Lohb,
> 
> It doesn't seem to have a Line Out, so you're "double amping," right?   And it doesn't have its own DAC, so you are actually using the DAC of your BT transmitting source, right?
> 
> ...


Double-amping yes, it is a cheap/fun $20 hack....may need to dial a bit on 2 volume fronts (source/amp).
It never occurred to me that the DAC on my Macbook Air would be imparting its character into the SQ. I thought that was done all on the internal chip-side of the decode from digital apt-X to analogue. Anyway, I found it great for the price as its my 2nd exp of bluetooth and the first dongle I bought about 2 years ago was hissy, compressed and flat-sounding and would cut in and out.

Edit : Actually, I remember having to de-select HRT microStreamer and select TROND BT as preferred output device in Audirvana + before any sound came out.

Next, with HRT microStreamer physically removed from the system, I doubt it would then be re-routing through the internal Cirrus DAC before going on to the TROND units CSRA64215 chip to be decoded.




Once paired with OSX bluetooth switched on,  'Active Audio Device' also changes from built-in to.....




It is closer in sound to the $100+ region 'segmented current' HRT dongles (natural/richer/dynamic) than other dongle-sized Sabre stuff (cooler/neutral/transparent) on its own, without PB2.

Coupled with PB2, its a decent fuller/rich and involving extra sound unit that has its place, if you need your source physically separate for convenience - along with your main better wired DAC in the hardware collection.


----------



## zilch0md

For $20, it's a no-brainer, if it solves a problem, even slightly.  Good find.  And very interesting.


----------



## Paul - iBasso

Mshenay said:


> mhm, going back to the SE output, if I plug into, IMMEDIATLEY there's a LOUD popping but ONLY the the SE output, the hiRose balanced out doesn't have this issue. I also use the 3.5mm input
> 
> I'll upload a picture of that little jack, as it's really black looking


If you have issues with all the op amps you try then most likely there is something wrong with the PB2. I would suggest contacting us for an RMA number to have the PB2 serviced.


----------



## zilch0md

That's great to learn that service is still available for the PB2, from iBasso.


----------



## Makiah S

Paul - iBasso said:


> If you have issues with all the op amps you try then most likely there is something wrong with the PB2. I would suggest contacting us for an RMA number to have the PB2 serviced.


Already did that Paul, actually your the one that issued the RMA after an email, but thank you for the response...


----------



## snellemin

Installed some Wima caps on spare 8 pin sockets.  Plugged them in with the Muses02 for that extra Umami in sound.  Sounds nicer after a few hours of burn in.  I think I'm done with this amp for a while.


----------



## Lohb

Do you have an overhead photo of the WIMA inserts and could you explain the effect they have on SQ ?


----------



## snellemin

Lohb said:


> Do you have an overhead photo of the WIMA inserts and could you explain the effect they have on SQ ?



I don't have an overhead shot.  I already closed up the unit.  But's it's basically just soldering the cap between the positive and negative poles of where the Opamp plugs into.  Been using these caps since installing Burson's opamps in my desktop amps.  I'm also using it in my Fiio E12A and Fiio DIY E12.   
It basically cleans up the power signal.  And you can actually hear the difference.  After a few hours of playing music, you will hear a nice "cleaner" signal.  It's worth the effort.


----------



## privilege15

Does anyone know where is it still possible to find and buy iBasso PB2?

Not much interested in any other amplifier on the market nowadays.


----------



## snellemin

My PB2 went into distortion for no apparent reason while listening at low volume.  Thought it was my player at first, but omitted that quickly. Swapped in a different set of buffers and opamps and same thing.  Gonna take the board out and see if I can troubleshoot it.


----------



## privilege15 (Jun 23, 2017)

I thought of sharing this info here as this is my favorite thread and basically all my portable setup is build around PB2 

Recently I tried this new red toy - *Burson Audio Cable+ Pro* with integrated discrete OpAmp inside. I'm yet to do a lot more auditioning but even now the results are very promising in either of the two worlds:

portable use (just like in the picture below)...but my wild guess is the results may vary depending on the opamp combination inside and jumper settings. I'm yet to play with it more.
for use with full size audio system by connecting a portable source to an amplifier and, my, this baby rocks through home stereo






There is Burson V5 discrete OpAmp inside the cable, hence one needs to ensure external power fed into it.

I used other than my Energizer battery to power the cable due to Energizer shortcomings and me being unable to properly power up two devices (PB2 and the cable) from the same battery at the same time. So I had to snatch my wife's USB power bank making everything an independent transportable audio pack which I've been using for years.


----------



## Makiah S

@Paul - iBasso 

Hey it's been over a month since you guys received my PB2? What's the status of it


----------



## Makiah S (Jul 10, 2017)

Welp sadly, I heard back from iBasso today and apparently



> We are unable to repair the PB2. I am sorry about this. It seems that the PCB traces were damaged and someone modified it.



so :/ I really can't argue with them at this point. I did purchase mine used around 3 years ago in January of 2014, for a $250 amp I guess I can't complain that it only lasted 3 years

Non the less, I have two adapters if any one would like to purchase them. I've got a single 4pin XLR to hiRose 6pin in addition to a dual 4pin XLR to Hirose 6pin! Back when I had my W1000X and my LA D2k I used to run them both off the balanced output of my PB2, made them sing effortlessly. I have no idea what the build on the single Cable is but, the Dual 4pin XLR to HiRose is some form of OCC Copper, braid pair and clear coated

Shoot me a PM if you'd like them! I don't think I'll be purchasing another PB2, the Pico Power I got has been working wonderfully for my SE needs, and I don't intend to drive my HE 4 balanced on the go any time soon. Plus I got a nice trade for a GeekOut v2+, still I'd like to keep the cables in the PB2 family is it were, so I'm really only looking to get like $35 a piece for them or $60 for both

An I guess, it goes without saying when I get the amp back it'll be up for grabs, though I'm not sure what a defective PB2 is worth! Maybe one of you brave souls would like a stab at rebuilding it lol,


----------



## Reima (Jul 28, 2017)

I recently got the opportunity to try out the Burson V5i opamps in my Ibasso PB2. I popped out the LME49720HA dual opamps (my favorites in the PB2) and installed the Bursons. These opamps impressed me right from the get go.
The first thing that I noticed was the bass or should I say sub bass. I am hearing more bass (not bloated) with these opamp than I have heard with any other opamp, if there is no bass in the music you will not hear any but if it is present boy will you hear it!. The separation is better than with the LME49720HA, providing a nice 3 dimensional soundstage. There are also more details coming through in the music.
My source is a DIY imod Ipod 5G. I mostly listen with my modded FostexT50RP headphones I listened to mostly classic rock, some Jazz and Diana Krall.
I would not hesitate to recommend the Burson V5i for use in the Ibasso PB2.


----------



## alphanumerix1 (Aug 6, 2017)

Answered.


----------



## Lohb

The good old PB2 thread...how I miss thee.

PB2 still going strong. No urge to buy new. 
I think with the right opamp and buffer it would still give the Vorzuge line a run for its money.


----------



## casper3127

Hi Folks,

should anyone be interested in a mint PB2 with box, accessories, charger (EU-220V), opamps, etc. can shoot me a PM. Not really using mine so it's a pity having it stored (with silica gel bags) not receiving the use it deserves.

I'm based in Spain.


Cheers.


----------



## kingdixon

Hey guys,

I have some questions,

I haven't used my pb2 for more than a year, i had it kept in its box, while the top cap is unscrewed.

Now i took it out, tried to screw the top cap but couldn't get it to fit, it seems that the battery had some swelling and grew abit in size ..

Did it occur to anyone ?

Also, i didnt try to charge it or use it ? The battery is covered in blue plastic, what kind of battery should i get to replace it, anybody can send me a link to replacement battery ?

I sent ibasso about 3 days ago but got no answer still, so i thought of asking here ..

Thanks !!


----------



## Reima

Last week was a big holiday in China, you should get a reply from them this week. If you don't hear from them you can always contact  paul@ibasso.com he is pretty active on the forum.


----------



## snellemin

kingdixon said:


> Hey guys,
> 
> I have some questions,
> 
> ...



I have a PB2 that I recently gotten and it too was a bit swollen.  Cell number 3 is dead, so I bought a hobby grade Lipo that should be here tomorrow.  I will see how it fits.  The capacity is about half but the C rate is way higher.  So it should be a pretty stable voltage going in during my bass sessions.


----------



## Lohb

Does anyone know the exact battery spec. if you were ordering online to get a new one  ?


----------



## kingdixon

Lohb said:


> Does anyone know the exact battery spec. if you were ordering online to get a new one  ?



Well, 

Ibasso replied back to me "The battery is a custom battery pack.  The cost is 25USD, shipping is 5USD via airmail."

Honestly, i only used it like may be 3 weeks, then it was collecting dust until swollen.

I sent them back asking if there is an alternative ready made battery that can be used and what is the specs ?

once i get a reply i will post it here ..


----------



## snellemin

Got to fit 3 Tatu 380mah Lipo in the ibasso.  I moved the capacitor and laid one pack on top.  6 batteries for 8 bucks shipped.


----------



## Makiah S

Might be re joining this thread again soon


----------



## zilch0md

Mshenay said:


> Might be re joining this thread again soon



Hi!

Did you sell your PB2, then buy another?


----------



## Makiah S

zilch0md said:


> Hi!
> 
> Did you sell your PB2, then buy another?



MY pb2 failed, the board traces are friend... I paid to ship it to iBasso where they told me they could not fix it, but I could get a trade in credit if I purchase another product. They are also asking I pay to have my unit shipped back to me, @Paul - iBasso that's really disappointing, I can understand paying to ship to you but you should at least cover the return shipping cost, but you've chosen not to. Doing so you've isolated me from this brand, as I have not enjoyed dealing with you guys at all. It's been nothing but bad news and additional costs. After purchasing a second unit second hand It'll probably be my last purchase from them, 

Either way, I'll hopefully have everything for the PB2 by Early December. I'm excited to get this back!


----------



## zilch0md

@Mshenay 
Having been told it couldn't be repaired, I would have made the same decision. I wouldn't have paid anything to have it returned. They can throw it in the trash just as easily as you can. 

Meanwhile, it's good to hear you have a replacement on the way, but I'm surprised you have to wait until December for delivery.  You don't have to explain it if my asking only adds misery to your experience.  

Best wishes!

Mike


----------



## Makiah S

zilch0md said:


> @Mshenay
> Having been told it couldn't be repaired, I would have made the same decision. I wouldn't have paid anything to have it returned. They can throw it in the trash just as easily as you can.
> 
> Meanwhile, it's good to hear you have a replacement on the way, but I'm surprised you have to wait until December for delivery.  You don't have to explain it if my asking only adds misery to your experience.
> ...


Oh it doesn't add misery, I'm more irate at not having the defective unit as a practice board! I'm trying to work on my de-soldering and I'd love to take my PB2 apart honestly... I don't have really any defective electronics to work on. An at the very least it would be nice for my now dead PB2 to bring something good into my life! An if tearing it apart gives me a chance to learn, then I think I'll have honored it's years of service well! [Though that does sound corny doesn't it?]


----------



## zilch0md

^ More noble than corny.


----------



## snellemin (Oct 23, 2017)

The cheapo 4 dollar battery setup is working out nicely and the Burson seems to be broken in completely.  Time to build the wima cap adapters again.


----------



## Lohb

Has anyone received the iBasso PB2 replacemant battery by airmail ?
When I inquired from south-east Asia, the PB2 unit had to be shipped to them to get a new battery due inbound postal restrictions on 'naked' batteries vs installed in amps which is allowed.

Is that the case in USA ? Are there any restrictions on receiving a new battery in 'ol US ?


----------



## snellemin

The pb2 has been out of production for a while.  So I seriously dought the batteries they sell as replacement are fresh stock.


----------



## zilch0md

Can anyone recommend an off-the-shelf replacement battery?   All I know is that it's a 3s LiPo, which means it has 3 cells in series and will put out 3 x 4.2V (12.6V) when fully charged or 3 x 3.0V (9.0V) when fully discharged (ready for recharging).   Getting the right physical dimensions and the right connector type would be the hard part when searching for LiPo batteries online.


----------



## snellemin

zilch0md said:


> Can anyone recommend an off-the-shelf replacement battery?   All I know is that it's a 3s LiPo, which means it has 3 cells in series and will put out 3 x 4.2V (12.6V) when fully charged or 3 x 3.0V (9.0V) when fully discharged (ready for recharging).   Getting the right physical dimensions and the right connector type would be the hard part when searching for LiPo batteries online.


I searched and didn't find one in any low C rate.  For the stock battery to have 700 mah, the C-rate must be like 10 and below.  Which also translate to ripple current under load.  That is why I had an improvement in my previous PB2 when I swapped stock cap to a dual cap setup.  With me swapping out to the smaller capacity higher c-rate, noticed a cleaner sound output and loud levels.  I have no need to swap out the stock cap.


----------



## zilch0md (Oct 25, 2017)

snellemin said:


> I searched and didn't find one in any low C rate.  For the stock battery to have 700 mah, the C-rate must be like 10 and below.  Which also translate to ripple current under load.  That is why I had an improvement in my previous PB2 when I swapped stock cap to a dual cap setup.  With me swapping out to the smaller capacity higher c-rate, noticed a cleaner sound output and loud levels.  I have no need to swap out the stock cap.



Thanks for this info.  I've used RC LiPo batteries with ridiculously excessive continuous current ratings for the loads in question - a Meier Corda Stepdance portable headphone amp (15VDC max) and a TBI Audio MG3 Millenia power amp (24VDC max).  In both cases, I wrote the designers (Jan Meier and Jan Plummer (coincidentally having the same first name), and they both conveyed that unless a "dust bunny" or some other impurity encourages an "air arc" to short two traces on a PCB, it's highly unlikely that a LiPo battery which can deliver 350 Amps continuous without overheating is going to damage their respective products. 

YMMV - proceed at your own risk - but I routinely use these high-amperage RC LiPo batteries and haven't had a problem (yet) with those two amps.


----------



## plutonim

Hi everyone,
a few weeks ago I swap my Centrance mini M8 to a set of ibasso pb2 + db2. I liked the possibility of replacing the op-amp, the 32V output swing and the DIY design. No battery was inside, so I tested PB2 with an external 16V power supply.

First of all, I measured the supply voltage to the op-amp - it was +/- 8V, which fully corresponds to the input voltage of 16V. Accordingly the maximum output amplitude voltage swing can not be greater than 16V (+/- 8V), and this is correctly only for rail-to-rail op-amp. But how do they state the output amplitude swing of the 32V if even on one wire of the balanced output the maximum amplitude peak can be + 8V, and on the other output, in the opposite phase, minimum -8V. Therfore the amplitude of 16V on the balance output is obtained.

I began to understand the power circuit in order to increase the voltage. Making modification of the FiiO X7 amplifier I realized that the higher power supply of the op-amp, the better sound at the output.

For a long time I could not find the microcchips names with erased labels, but when I make a reverse engineering of the PB2 PCB, the idea of power supply inmplementation became clear. The PB2 power supply is taken from an external source or internal battery, and the middle point is created by the microchip divider. Thus we obtain from a unipolar input voltage a bipolar supply of the op-amp. Since the characteristics of this chip allow to feed it with voltage up to 40V, I tried to connect an external power source 24V from the photo printer. !But before connecting it is necessary to change the input capacitor to a higher voltage, I replaced it to 2200u35V! The sound quality increased significantly. The resolution and depth became amazing.


Spoiler: PB2 sch








After that, I decided to raise the voltage as much as possible. For this, I bought two LiPo 4S 14.8V 1000mA 70C batteries and connected them in series. It turned out about 30V at the input of the amplifier and the power supply of the op-amp became +/- 15V. Just in case, I changed all the tantalum capacitors in the power supply rails, since the marking is flawed and it's not clear what maximum voltage they can withstand, replaced it to 220u16V. 



Spoiler: Tantal






And on this input voltage has burned a 2.2 Ohm resistor that limits the starting current when the power is turned on. Therefore, it must be replaced by a more powerful or greater resistance. It can not be short-circuited, since when the power is turned on, a strong current surge occurs when the capacitor is charged and the power switch contacts are burned.

Now the amplitude output swing of the amplifier can reach 30V. And the sound of the amplifier became unbeatable. All the same, the power supply of an op-amp for good sound should be not less than +/- 12V.



Spoiler: LiPo PB2



 





Now I am working on DB2 modification and it became sounds much better.

PS Sorry for my "Google translated" English


----------



## zilch0md

plutonim said:


> Hi everyone,
> a few weeks ago I swap my Centrance mini M8 to a set of ibasso pb2 + db2. I liked the possibility of replacing the op-amp, the 32V output swing and the DIY design. No battery was inside, so I tested PB2 with an external 16V power supply.
> 
> First of all, I measured the supply voltage to the op-amp - it was +/- 8V, which fully corresponds to the input voltage of 16V. Accordingly the maximum output amplitude voltage swing can not be greater than 16V (+/- 8V), and this is correctly only for rail-to-rail op-amp. But how do they state the output amplitude swing of the 32V if even on one wire of the balanced output the maximum amplitude peak can be + 8V, and on the other output, in the opposite phase, minimum -8V. Therfore the amplitude of 16V on the balance output is obtained.
> ...



Wow!  I very much enjoyed reading your story of modifying the PB2 for MORE POWER!  

It's obvious that you have some excellent skills. I'm envious.  

I had once concluded that no matter how high the voltage applied to the external DC input jack, the op-amps only see the voltage coming out of the PB2's internal power supply.   Do you agree?

If so, you must be bypassing the charger to increase the supply voltage seen at the op-amps.  Your schematic is very smartly drawn, but I'm not smart enough to interpret it.  

When reading the datasheets for many different op-amps, I've noticed that they sometimes include charts that show supply voltage vs. THD + N and, quite often, the lowest (best) THD+N is achieved at a supply voltage that is a little bit below the maximum allowable supply voltage for a given op-amp.   I recall seeing charts where something like +/- 15V produces lower THD+N for an op-amp that can handle up to +/- 18V, for example.  

It is possible, however, that the difference in THD+N is so negligible, that any improvement in dynamics or bass control that comes with higher output power to the headphones, will outweigh any _audible_ increase in THD+N.

I would very much appreciate your thoughts on this and please tell us what headphones you are using - that are responding so positively to an increase in power.

Also, are you happy with the DB2 Boomerang DAC?   I bought it and returned it along time ago, finding it to be too warm for my tastes.

Thanks!

Mike


----------



## plutonim (Oct 27, 2017)

zilch0md said:


> I had once concluded that no matter how high the voltage applied to the external DC input jack, the op-amps only see the voltage coming out of the PB2's internal power supply. Do you agree?


No, it is not correct. The more input voltage on the DC input jack, the more voltage on the op-amp. The input voltage divided by 2 like in this scheme  with virtual ground  https://tangentsoft.net/elec/vgrounds.html (look at the VFB OPAMP-BASED VIRTUAL GROUND DRIVER).
Thus , the power supply voltage on the op-amps equal the input voltage divided by 2 (Vopa=+/-Vin/2)   I started to test increasing voltage by using  laptop  power supply 19V (+/-9.5V op-amp) and there is no any problem with electronic components, but the sound improvement was audible. Only the input big capacitor was replaced for more voltage.



zilch0md said:


> I would very much appreciate your thoughts on this and please tell us what headphones you are using - that are responding so positively to an increase in power.


My excellent headphone is XBA-Z5, and I don't need to increase the power, but it is necessary to increase the op-amp supply voltage, because, how you said - to increase THD+N.
And I found that charge controller can support 4S batteries, and I want to set up four elements 3.7V 450mAh inside the PB2


Spoiler: battery



https://ru.aliexpress.com/item/3pcs...y-For-Flash-lighting-DIY-PAD/32697834391.html


Later I'll tell you how it would be.



zilch0md said:


> Also, are you happy with the DB2 Boomerang DAC? I bought it and returned it along time ago, finding it to be too warm for my tastes.


It WAS very warm and turbid untill I replaced WM8740 DACs to WM8741. The sound became exciting , so lively and transparent.


Spoiler: DB2 WM8741







And now the WM8741 are supported 192/24 and DSD64, therefore I want to change later USB interface to that module



Spoiler: Amanero



https://ru.aliexpress.com/item/Pisw...anero-USB-IIS-Support-DSD512/32818234640.html


 
Denis


----------



## zilch0md

plutonim said:


> Hi everyone,
> a few weeks ago I swap my Centrance mini M8 to a set of ibasso pb2 + db2. I liked the possibility of replacing the op-amp, the 32V output swing and the DIY design. No battery was inside, so I tested PB2 with an external 16V power supply.
> 
> First of all, I measured the supply voltage to the op-amp - it was +/- 8V, which fully corresponds to the input voltage of 16V. Accordingly the maximum output amplitude voltage swing can not be greater than 16V (+/- 8V), and this is correctly only for rail-to-rail op-amp. But how do they state the output amplitude swing of the 32V if even on one wire of the balanced output the maximum amplitude peak can be + 8V, and on the other output, in the opposite phase, minimum -8V. Therfore the amplitude of 16V on the balance output is obtained.
> ...



Amazing!  You are taking the DB2/PB2 duo to a performance level never seen before.  Congratulations on your planning and successful execution.

I had never attempted to measure the supply voltage at the op-amps themselves, when I (incorrectly) concluded that increasing the input voltage at the jack had no audible impact.  Apparently, I had made a false assumption that the battery charging circuit was limiting the supply voltage to the of-amps. I was afraid to increase  the input voltage at the jack by much.

Your DB2 mod is VERY appealing.  I'm really nvious of your skills, again!

Mike


----------



## snellemin

plutonim said:


> Hi everyone,
> a few weeks ago I swap my Centrance mini M8 to a set of ibasso pb2 + db2. I liked the possibility of replacing the op-amp, the 32V output swing and the DIY design. No battery was inside, so I tested PB2 with an external 16V power supply.
> 
> First of all, I measured the supply voltage to the op-amp - it was +/- 8V, which fully corresponds to the input voltage of 16V. Accordingly the maximum output amplitude voltage swing can not be greater than 16V (+/- 8V), and this is correctly only for rail-to-rail op-amp. But how do they state the output amplitude swing of the 32V if even on one wire of the balanced output the maximum amplitude peak can be + 8V, and on the other output, in the opposite phase, minimum -8V. Therfore the amplitude of 16V on the balance output is obtained.
> ...



Pretty cool mods there man.  I'm interested in the 4S lipo mod and the charging within in the stock unit.


----------



## zilch0md

I could never have soldered those WM8741 pins so neatly.


----------



## plutonim (Oct 28, 2017)

zilch0md said:


> I could never have soldered those WM8741 pins so neatly.


Microscope and sodering station, it's my job 
I'am listening MUSES02 and dummy buffers on the PB2 output. It's enough power for my Z5 and the sound very lively.
Also I have Sparkoslabs SS3601 and they sounds much better but they are unstable. I'll check and fix it later when I have some time.



snellemin said:


> I'm interested in the 4S lipo mod and the charging within in the stock unit.


I bought four batteries now and when I get them I'll make mod and tell you what to do, but you must have some soldering skills.


----------



## snellemin

Soldered some caps on spare dip sockets to be used with the Bursons. Sounds nicer with the 8 buffers.  That 4s Lipo mod would be nice as the next step up.


----------



## zilch0md

I love seeing this stuff!


----------



## plutonim

zilch0md said:


> I love seeing this stuff!


sparkos very nice with dummy buffers, I'm waiting MUSES03 to set it in the output


----------



## snellemin

plutonim said:


> sparkos very nice with dummy buffers, I'm waiting MUSES03 to set it in the output



What capacitor value did you swap out the stock one from?  Have you found a source for the Muses03?


----------



## plutonim

snellemin said:


> What capacitor value did you swap out the stock one from?


2200uF35V what I found, when I'll get batteries I will set another one, smaller.



snellemin said:


> Have you found a source for the Muses03?


https://www.ebay.com/itm/MUSES03-si...445BM-AD797ANZ-LME49710HA-SS3601/272904804226
don't know about authenticity, but the photos looks OK.


----------



## snellemin

plutonim said:


> 2200uF35V what I found, when I'll get batteries I will set another one, smaller.
> 
> 
> https://www.ebay.com/itm/MUSES03-si...445BM-AD797ANZ-LME49710HA-SS3601/272904804226
> don't know about authenticity, but the photos looks OK.



So you are not running the PB2 in balanced mode yet?

Thanks for the Ebay link.


----------



## plutonim

snellemin said:


> So you are not running the PB2 in balanced mode yet?


Balanced input from DB2 (today forgot it at my work) and not balanced output to the headphones cause I need to solder balanced adapter to Z5.


----------



## snellemin

plutonim said:


> 2200uF35V what I found, when I'll get batteries I will set another one, smaller.



I had replaced my stock capacitor with two before.  

BTW, I just measured my voltage across the opamp and measured 11.10 ~11.08V.  I'm running balanced mode though.


----------



## plutonim

snellemin said:


> measured 11.10 ~11.08V.


I have 32V input from two 4S LiPo connected serial, therefore I need 35V capacitor and I have 32V across opamp.
If you connect AC power supply you can measure ~16V across opamp.


----------



## snellemin

These two amps sound mighty similar now.  The RSA has the upper hand in power though.


----------



## snellemin

plutonim said:


> I have 32V input from two 4S LiPo connected serial, therefore I need 35V capacitor and I have 32V across opamp.
> If you connect AC power supply you can measure ~16V across opamp.



I'm hoping the higher voltage will make the Ibasso on the same level as the RSA in both power and THD.  At low volumes they are equal, but at high volumes and deep bass sessions the PB2 craps outs on battery power.  The signal distorts, until I plug the power supply back in.


----------



## kingdixon

Guys,

Any one find a nice replacement battery ??

The customer service is very bad and they take very long time to reply, if they did ..

The last thing i reached with them is that they sell the battery for 25$ + 5$ shipping to egypt ..

They didnt reply to my questions if swollen battery is normal, the device is out of warranty but it has only been used for less than 3 weeks and has been collecting dust since, what if i bought their battery and this happens again, i dont know if this is normal or not but it never occured to me with any other device,

Honestly, i would rather buy a replacement battery from somewhere else if available and not deal with them again..

I have seen people using other batteries here on the forum but i need verification it works on stock, as iam not into mods or changing capacitors ..

Thanks


----------



## snellemin

kingdixon said:


> Guys,
> 
> Any one find a nice replacement battery ??
> 
> ...



It sounds like you fully charged your battery when you last used it.  You should always deplete your lipo batteries halfway, when storing it for long term.  

There are no plug and play batteries available.  You will need to build you own pack, which was the cheapest route for me.


----------



## kingdixon

snellemin said:


> It sounds like you fully charged your battery when you last used it.  You should always deplete your lipo batteries halfway, when storing it for long term.
> 
> There are no plug and play batteries available.  You will need to build you own pack, which was the cheapest route for me.



Well, i might have done that .. but i had no idea.

Ok, can you give a link for the batteries that i can use to build that pack, and is it safe to use it on stock components ?


----------



## snellemin

kingdixon said:


> Well, i might have done that .. but i had no idea.
> 
> Ok, can you give a link for the batteries that i can use to build that pack, and is it safe to use it on stock components ?



I bought my Tattu batteries from Amazon. https://www.amazon.com/gp/product/B01N74S3LO/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1.  

I cut of the connectors and soldered them in series and used the old Ibasso battery cable harness for plug and play purposes and cell balancing.


----------



## snellemin

Pushing my little amp to the limit.  I increased the input voltage to 17V and nearly maxed out the volume.  Saw a peak of 7W near the end of the video.  Using a regular laptop power supply.


----------



## zilch0md

plutonim said:


> sparkos very nice with dummy buffers, I'm waiting MUSES03 to set it in the output



I've yet to find any buffer that sounds as good as dummy buffers with the Sparkos SS3601.  With balanced output, there's plenty of power for most headphones.  Adding buffers only colors the sound and/or "blurs" the resolution - especially in the low-energy signals down near the noise floor - which contribute so much to sound stage and imaging.  

I'm very interested in what you hear with the MUSES 03.  I've tried the MUSES 02 at the input-voltage gain stage and as buffers - I don't care for them, at all - at least not with my gear and my tastes.  They are particularly "colorful."  I might like the MUSES 01, but I've never heard them.

https://www.head-fi.org/threads/iba...-op-amps-page-16.528149/page-91#post-12667507


----------



## Makiah S

Speaking of, can any one point me in the direction of some Dummy Buffers for sale? iBasso kept mine with my defective unit -.- and I'm not paying $25 to have them ship it back JUST so I can get my dummy buffers


----------



## snellemin

Got to replace the cap with two 25V Panasonics.  Reterminated the output with silver plated foil wires.


----------



## plutonim (Dec 4, 2017)

zilch0md said:


> I love seeing this stuff!





snellemin said:


> So you are not running the PB2 in balanced mode yet?





Spoiler: It is genuine!



 




My new setup - Amanero USB to I2S converter for DB2, Hidizs AP60 mark II as digital source and 4S LiPo inside PB2 (+/-8V opamp supply)


Spoiler









MUSES03 sometimes more interesting than Sparkos. And now I'm waiting for Burson V5i...


----------



## snellemin

plutonim said:


> Spoiler: It is genuine!
> 
> 
> 
> ...



That is a nice looking battery pack inside the PB2.  I'm liking my V5i's a lot.  I'm running four double stacked buffers, with two Dual V5i's.


----------



## plutonim

snellemin said:


> That is a nice looking battery pack inside the PB2.


----------



## zilch0md

plutonim said:


>



Those are 3.7V nominal, per cell, so the four of them are giving you 4.2V x 4 = 16.8V for the first couple of minutes of play, but then it will rapidly come down below the 16V max. iBasso specifies, so no problem there, really.  

The best part is that for the majority of your discharge cycle, you will have 3.7V x 4 = 14.8V, which in my experience with external supplies, would be audibly better than the 12.6V (nominal) that we get with the original 3-cell battery.

Well done!  

Watch out to avoid deep discharging any one cell below 3.0V.  I doubt the charge circuit in the PB2 is intelligent and those individual batteries probably don't have any built-in protection.  Over time, one cell can end up getting "out of sync" with the other cells, in terms of voltage at both the top and bottom of a cycle.  This is less likely to happen if you avoid deep cycling the pack.  (Probably stuff a guy with your DIY skills already knows...)

Mike


----------



## snellemin

I had some time again to mess around with cable upgrades inside the PB2 and I think I found a happy medium.  Mixed copper with silver over the just the sliver alone.  Got my deep sub bass back, along with the benefits the silver brought to the table.


----------



## Makiah S

wooooooooooooooooooooooooooooooow

I got another PB2, and this time the OpAmps are in correctly! No dummy buffers how ever as I'm going to be using this EXCLUSIVELY for my hard to drive open backs, like my HE 4, Pre Fazor LCD 2 and my AKG K240 Sextett, so far with the Sextett... WOOOOW It's SOOOOOOOOOOOOOOO Much quieter than my last one was. Granted I've got a Schiit Etir, new Power Cables for everything and an upgraded Power Conditioner, but WOW this thing is SUPER quiet. I am using the energizer battery pack as well. If I'm taking my big Heavy OLD fragile planars out the house than I'll have no issues carrying around... the Battery for my Amp [which is a bit bigger than the amp itself] 

All in all wooooooooooow, just WOW Super impressed with this bad boi! An I paid about the same this time as I did the first time I got it! I got lucky and found one on eBay, but just wow! It's ALMOST as good as my NFB10ES2 with Phase Reversal... ALMOST and it's portable ;3 have to say it's wonderful to be back in the Club again! 



 

Sadly only stock internals for now, aside from the entirely separate battery


----------



## zilch0md

^ Happy post!   

Puts a smile on my face!   

Thanks!

Mike


----------



## Makiah S

zilch0md said:


> ^ Happy post!
> 
> Puts a smile on my face!
> 
> ...



Me too! I was worried I wouldn't like the sound with the High Current buffers over the Dummy, but I think the improvements of the battery kinda negate what ever losses the non Dummy Buffers introduce. Plus my portable set up is super specialized! The Head Amp Pico Power [isn't nearly as powerful as I wanted it to be] does a great job with my dynamics, and the PB2 handles my Planars and the AKG K240 Sextett! Plus I have some nice hiRose 6pin to dual 4pin XLR adapters I can use again!


----------



## zilch0md

^ You are literally "good to go" with just about any headphone, now.


----------



## snellemin

I got the DB2  not long ago and didn't like what I heard.  Sounded dull and I had to turn up the volume on the PB2 to hear details.  So I swapped out the opamps in the DAC using two Muses 8832.  What a difference it has made.  Subbass is cleaner, mids and highs are all there at lower volumes.  Still waiting on the Hirose connectors and mogami quad cable to come in, for me to the built the balance cables to connect the PB2 and DB2. 
I also have a pair of  WM8741 on order to stick into the DB2.  Got inspired doing that, seeing that it can be done  @plutonim


----------



## zilch0md

^ Dude!  (I'm envying your skills again!)


----------



## snellemin

Sooooo, I didn't want to mess with the DB2 yet, and I opted to swap out the dac inside my D7 Sidewinder instead.  The "new" WM8741 does sound different vs the 8740 it replaced.  Nicer topend and more "analog" overall.  You would think both dacs would sound the same, with the 8741 just having more features.  But that is not what my ears tell me.  Anyways, sooner or later I'll be changing out the ones in the DB2.


----------



## plutonim

snellemin said:


> I had some time again to mess around with cable upgrades inside the PB2 and I think I found a happy medium.  Mixed copper with silver over the just the sliver alone.  Got my deep sub bass back, along with the benefits the silver brought to the table.





zilch0md said:


> ^ Dude!  (I'm envying your skills again!)



Check this out


----------



## snellemin (Jan 23, 2018)

plutonim said:


> Check this out




Wow man.  That is a serious setup.  I had thought about doing that with two Burson classics and no batteries.  You went way beyond my idea. 

I really like the Burson V6 classics in the PB2.  I should have my other setup of WM8741 in today, so tomorrow the upgrade in the DB2 should happen.


----------



## Makiah S

Huh you know I have no battery in my unit... I might be able to fit in a set of those bad bois... I actually have the PLAY on loan with a set of both their red Vivids and the orange Classics, I'm a little scared to try them lol as then I'll need to get them

@plutonim what are those little bendy things your using?


----------



## snellemin

Mshenay said:


> Huh you know I have no battery in my unit... I might be able to fit in a set of those bad bois... I actually have the PLAY on loan with a set of both their red Vivids and the orange Classics, I'm a little scared to try them lol as then I'll need to get them
> 
> @plutonim what are those little bendy things your using?




Those bendy thingies are just short extensions.  Easy to make if you have some time.  I've made some before in my other projects.  Even added a Wima cap in some.


----------



## Makiah S

What did you find adding the wima what I imagine is a bypass cap, into the mix? 

Also my soldering skills are a bit lacking, I'm curious though would you care to make a set for me?


----------



## snellemin

Mshenay said:


> What did you find adding the wima what I imagine is a bypass cap, into the mix?
> 
> Also my soldering skills are a bit lacking, I'm curious though would you care to make a set for me?



Adding the cap made a nice difference in the sound to me.  I'm a basshead, so the sub levels were a bit lacking at loud sound levels.  Adding the cap made it come back out in the V4 Burson.  Tried it with the V5, V5i and V6 classic with good results.  "Warning"....at first it will sound like crap, until a few hours have gone through the cap.  After that enjoy the clean sound.

I can make a set of extensions for you, whenever I make some more.  I've lost mine in the Houston flood and I'm still rebuilding my house.  Slow slow process when you are on a budget. So anyways,  I will have to make new extensions for my future equipment and make some extras.


----------



## plutonim (Jan 23, 2018)

snellemin said:


> tomorrow the upgrade in the DB2 should happen


Don't rush, pal. In DB2 the digital supply of the WM8740 is +5V, but the 8741 digital power supply must not exceed 3.3V.
You need to change voltage on the LTC3440 buck/boost converter (LTNP marking) by replacing one resistor.
I'll tell you tomorrow where is it and what its value.

PS  But I know it when soldered WM8741 and listen it. The sound became exciting, but the chips was very hot. Although they survived and worked nearly one hour until I checked it.

PSS I like the power boost DAC sound and I had set +4V of digital supply (maximum 4,5V by datasheet) It sounds very crystal and open.


----------



## plutonim

@snellemin, 



 

In DB2 the R1 is 1000kOhm and R2 is 330kOhm. Therefore Vout=1.22*(1+R1/R2)=4.9V
We need Vout=4V (max). If R1=750kOhm then Vout=3.99V
You can replace R1 to 750kOhm or make a parallel connection with R1 another resistor R*=3000kOhm (look at the picture).


----------



## snellemin

Swapped in the new dacs and nothing.  Unit turns on, but no sound.  Bummer.


----------



## plutonim

snellemin said:


> Swapped in the new dacs and nothing.  Unit turns on, but no sound.  Bummer.


How you are connecting DB2 to the source? USB or coaxial(optical)?
Check the voltage on the DACs (AVDD and DVDD). 
And be sure to unsolder pin 22 on both DACs and conected it to the pin 23.


----------



## snellemin

My unit is dead.  Should not have the technician desolder dacs for me.  He overheated the board it seems. Next one I'll do myself again.


----------



## Paul Graham

Someone help lol....
I am making an interconnect.
4 Pole XLR ( Female ) to Hirose 6 Pole ( Male )  So I can connect any of my cans with a male 4 pole XLR to my PB2.
I'm stuck as I can't find a diagram that explains this. 
ie The Hirose has 2 hots 2 colds and 2 grounds, Where the XLR has Left and Right Hots and 2 grounds. So where do the 2 Colds from the Hirose solder to?


----------



## plutonim (Mar 26, 2018)

Paul Graham said:


> he Hirose has 2 hots 2 colds and 2 grounds


For the headphone connection you don't need grounds )




R+ Signal and L+ Signal means Rch+ and Lch+
R- Ground and L- Ground means Rch- and Lch-


----------



## Paul Graham

Thanks


----------



## zilch0md

snellemin said:


> My unit is dead.  Should not have the technician desolder dacs for me.  He overheated the board it seems. Next one I'll do myself again.



Bummer


----------



## Makiah S

plutonim said:


> For the headphone connection you don't need grounds )
> 
> 
> 
> ...



Whoa that's priceless! Stolen and uploaded!!! Here's to hoping Head Fi outlive the connector and the amp

anyways getting ready to do a nice little review featuring a variety of balanced amps including my LME 49990 rolled iBasso PB2 with High Current Buffers and a old school energizer Battery Pack, that said at the moment I'm listening with my LCD 2 and I started on an RS Intruder DAC/Amp... and frankly I noticed with my LCD 2 the bass was kinda... soft and weak -.- so needing a point of reference I ran the same track but with my PB2 Stack and viola! Bass has RETURNED well the depth, power, texture and SLAM has returned! YAY no more whiny, soft wimpy bass shame I still haven't found an all in one Amp/Dac that does the LCD 2 justice


----------



## Paul Graham

I shall have to share some pics when I get a chance to find them but I managed to do this. Now have a Pair of HE400's I can drive balanced with the PB2


----------



## Paul Graham

Mshenay said:


> Whoa that's priceless! Stolen and uploaded!!! Here's to hoping Head Fi outlive the connector and the amp
> 
> anyways getting ready to do a nice little review featuring a variety of balanced amps including my LME 49990 rolled iBasso PB2 with High Current Buffers and a old school energizer Battery Pack, that said at the moment I'm listening with my LCD 2 and I started on an RS Intruder DAC/Amp... and frankly I noticed with my LCD 2 the bass was kinda... soft and weak -.- so needing a point of reference I ran the same track but with my PB2 Stack and viola! Bass has RETURNED well the depth, power, texture and SLAM has returned! YAY no more whiny, soft wimpy bass shame I still haven't found an all in one Amp/Dac that does the LCD 2 justice


Long time dude. Hope all is well! PS are you on facebook. PM me and I'll tell you more.


----------



## DBaldock9

I've just purchased a PB2 from another Head-Fi'er, and am looking forward to receiving it - and doing some modifications.
.
One thing I've found, is that this panel mount 2.5mm TRRS jack fits in a hole that's basically the same size as the Hirose jack.
The 2.5mm TRRS jack goes in a 5/16" (7.9375mm) hole, and the Hirose HR10A-7R-6S(73) jack has an M8x0.5 nut (8mm diameter).
https://vetco.net/products/2-5mm-4-conductor-jack-panel-mount-plastic
.


----------



## snellemin

DBaldock9 said:


> I've just purchased a PB2 from another Head-Fi'er, and am looking forward to receiving it - and doing some modifications.
> .
> One thing I've found, is that this panel mount 2.5mm TRRS jack fits in a hole that's basically the same size as the Hirose jack.
> The 2.5mm TRRS jack goes in a 5/16" (7.9375mm) hole, and the Hirose HR10A-7R-6S(73) jack has an M8x0.5 nut (8mm diameter).
> ...



I personally would leave the hirose connector alone.  Those have way more contact area vs the 2.5mm you are trying to put in.  The 2.5mm is ok for IEM, but not for stuff that require more power.  You'll have more fun playing with Opamps, buffers and capacitors.  I did replace the wires from the board into the front Hirose connector for "Tuning" it to my liking.


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## DBaldock9

Currently, the only (non-Bluetooth) headphones I've got, are:
01.) Beyerdynamic DT-831 - Headphone, 250Ω, 96dB/mW, 5Hz-32KHz, Sealed back, 1x Dynamic, Tethered cable
02.) KEF Space One (w/ANC) - Headphone, 32Ω, 89-93dB/mW, 20Hz-20KHz, Sealed back, 1x Dynamic, Removable cable

So, I'm mainly using a 2.5mm TRRS connection for the Balanced cables on my Earbuds & Earphones.


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## DBaldock9

Ended up removing the 4-Pin XLR-F from the adapter cable that came with my used amp, and soldered on a high quality Eidolic 2.5mm TRRS Jack.
Works great (but not as compact as having the 2.5mm Jack mounted _in_ the amp) for connecting my Balanced Earbud and Earphone cables.
*NOTE:* While the Eidolic jack is good and secure on the 2.5mm TRRS plugs, it is not the style with a back-shell - so you have to protect and strain-relief the solder connections with heat-shrink.
.


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## snellemin

PB2 powering the Audeze El 8 to deafening levels.  Basshead levels can also be achieved and get the earpads vibrating.


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## DBaldock9

If you want to replace the Torx head screws that hold the PB2 case together, they're size: M2 x 10
My PB2 has the silver case, so I've identified stainless steel knurled thumbscrews, Phillips, and Allen socket screws from Amazon.
.
Knurled Thumbscrews - https://www.amazon.com/Knurled-Screws-Stainless-Steel-Pieces/dp/B01N8WLWOH
.
Phillips Screws - https://www.amazon.com/Stainless-Steel-Phillips-Round-Screws/dp/B012TD8XQI
.
Allen Socket Screws - https://www.amazon.com/uxcell-M2x10mm-Socket-Knurled-Screws/dp/B017ART2JK


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## DBaldock9

Does anyone know whether a 15V / 1.2A low noise power supply would be adequate for the PB2, in place of the stock 16V supply?  Thanks!


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## andylesch

[QUOTE = "DBaldock9, post: 14752155, member: 451728"] Кто-нибудь знает, подойдет ли источник питания 15V / 1.2A с низким уровнем шума для PB2 вместо стандартного источника питания 16V? Спасибо! [/ QUOTE]
Yes


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## snellemin

DBaldock9 said:


> Does anyone know whether a 15V / 1.2A low noise power supply would be adequate for the PB2, in place of the stock 16V supply?  Thanks!



Yes it will work.  But you won't get the max voltage swing, when driving hungry Headphones.  Or when you feel the need to go nuts with the volume.


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## DBaldock9

andylesch said:


> DBaldock9 said:
> 
> 
> > Кто-нибудь знает, подойдет ли источник питания 15V / 1.2A с низким уровнем шума для PB2 вместо стандартного источника питания 16V? Спасибо!
> ...





snellemin said:


> Yes it will work.  But you won't get the max voltage swing, when driving hungry Headphones.  Or when you feel the need to go nuts with the volume.




Then the 15V supply should work just fine for me.
I hardly ever use headphones, and none of mine are wired for Balanced input, so they're usually connected to my iFi Micro iDSD.
The PB2 Balanced output is used to drive my various earphones and earbuds.


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## Lohb (Mar 13, 2019)

Long time no see all in my old fav thread....
I have a set of used custom wood Fostex T50s in rainforest wood already wired for balanced PB2 F/S soon...they were my prototype 001 set when I was planning to get rolling with my own woodie headphone small biz before. You need to add your own earpads.
These were original photos of them when they were made---> https://postimg.cc/gallery/1vq2jdhyo/

Anyone interested, let me know by PM.
Back to all things PB2


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## zilch0md

Hi Lohb.  It's nice to hear from you.  Best wishes!

Mike


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## Lohb

zilch0md said:


> Hi Lohb.  It's nice to hear from you.  Best wishes!
> 
> Mike


 Yep,you too. Was looking at PB3....terrible I know to consider it over PB2, but easier plug for earphones.


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## DBaldock9

I've got several sets of LME49710HA 1-Channel Op-Amps, mounted on "2x 1-Channel TO-99 to DIP-8 2-Channel" adapters - but they're too wide to fit side-by-side, on the 2-Channel sockets in the PB2.
So, I've mounted 4x of the LME49710HA onto "1-Channel TO-99 to DIP-8 1-Channel" adapters, and they do fit on the 1-Channel sockets.
They sound good in the PB2.
.


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## Lohb

Guys any decent _discrete_ opamp discoveries in 2019 you are using with PB2 ? 

I'm looking at replacing stock opamps in an ES9038Q2M Dac/amp that does about 1.5 watts per channel...bit of a wildcard portable audio unit from aliX.


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## DBaldock9

Lohb said:


> Guys any decent _discrete_ opamp discoveries in 2019 you are using with PB2 ?
> 
> I'm looking at replacing stock opamps in an ES9038Q2M Dac/amp that does about 1.5 watts per channel...bit of a wildcard portable audio unit from aliX.



I placed several layers of Kapton tape over the gain jumpers, and on the underside of the cover, so that the Sparkos SS3602 Dual Discrete Op-Amps can be used in the PB2, with the top installed.


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## Lohb (Apr 18, 2019)

OK, I owned the Sparkos and the Burson V5i with PB2 at one point, but strangely found the simple and cheaper LME49990 'better' than both even though the Sparkos did remove another layer of veil...V5i found a bit try-hard the way it presented stuff.

Had found a few discrete opamp sellers on Aliexpress but a lot of the electronics on there are half-baked.
'Hi IC' seller was one seller that had quite a few Chinese designed discrete opamps now in 2019...
among others... AliX Chi-Fi discrete opamps 2019

Edit : Decided on Hi IC's SX52B as as a low risk/price discrete opamp with some kind of positive buyer feedback.


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## Lohb (Jun 12, 2019)

Quick mention to PB2 opamp rollers..not sure any you tried OPA1622...pretty amazing little chip for the price..it is the high current version of OPA1612 and 1612 was the replacement for LME49990 as far as I read.
If you liked LME49990, then give this little chip a try ! Am using 2 in series in a small barebones ES9038Q2M DAC/amp (not Khadas in signature below)...transparency,layering,dynamics,micro-detail,common mode noise suppression..it's all in there.
_Specifically designed for driving headphones._


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## DBaldock9

Lohb said:


> Quick mention to PB2 opamp rollers..not sure any you tried OPA1622...pretty amazing little chip for the price..it is the high current version of OPA1612 and 1612 was the replacement for LME49990 as far as I read.
> If you liked LME49990, then give this little chip a try ! Am using 2 in series in a small ES9038Q2M DAC/amp...transparency,layering,dynamics,micro-detail,common mode noise suppression..it's all in there. Specifically designed for driving headphones.



With such a high current output capability (~145mA), are you using them in your PB2 with the pass-through headers in the Buffer sockets?
I wish there was a single channel version of the OPA1622, which could be used in the buffer locations.
Since there isn't, I guess adapters could be built, to plug one of dual channel op-amp into two side-by-side sockets.


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## Lohb (Jun 12, 2019)

DBaldock9 said:


> With such a high current output capability (~145mA), are you using them in your PB2 with the pass-through headers in the Buffer sockets?
> I wish there was a single channel version of the OPA1622, which could be used in the buffer locations.
> Since there isn't, I guess adapters could be built, to plug one of dual channel op-amp into two side-by-side sockets.


No longer have PB2, just a pretty great rolling chip heads-up.
OPA1611 is single, but 1/3 current output of 1622.


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## DBaldock9

Lohb said:


> No longer have PB2, just a pretty great rolling chip heads-up.
> OPA1611 is single, but 1/3 current output.



There is the LME49600, with ~250mA of output current, which is only available in a TO-263-5 surface mount package.
I did a quick search, but haven't found a TO-263-5 to DIP-8 adapter - to make it easy to use in the PB2, and other amps with DIP-8 sockets.


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## Lohb (Jun 12, 2019)

Right. Google images maybe churn something up....

OPA1622 coming quite close to the new gen. THXAAA stuff on the 2 measurement fronts below.
Seems to be a chip that steps into discrete chip performance territory.


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## plutonim

DBaldock9 said:


> I did a quick search, but haven't found a TO-263-5 to DIP-8 adapter - to make it easy to use in the PB2, and other amps with DIP-8 sockets.


https://www.ebay.com/itm/1PCS-LME49600TS-LME49600-ON-DIP-ADPTER-REPLACE-BUF634/322879211538


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## Lohb

So the LME49600 is just a buffer like Buf634p in the provided PB2 chips, and not an opamp, and it would go behind the opamps in the PB2 Dip-8 board ?


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## DBaldock9

Lohb said:


> So the LME49600 is just a buffer like Buf634p in the provided PB2 chips, and not an opamp, and it would go behind the opamps in the PB2 Dip-8 board ?



Well, it's a very high current op-amp, which could drive hard-to-drive loads - and could probably be used in either the op-amp or buffer sockets.
But, due to the offset of that LME49600 adapter, it may be hard to install as an op-amp, since there's not much space between the back of the op-amp sockets and the jumpers / battery.


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## HiFlight

DBaldock9 said:


> There is the LME49600, with ~250mA of output current, which is only available in a TO-263-5 surface mount package.
> I did a quick search, but haven't found a TO-263-5 to DIP-8 adapter - to make it easy to use in the PB2, and other amps with DIP-8 sockets.


When I was still producing the PB2 Topkits, I developed a custom LME49600 plug and play buffer module which I felt was a significant improvement over the stock buffers.  I finally stopped making them after shipping a number of sets as they were very labor-intensive to build.


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## DBaldock9

Since all of my current Balanced loads are Earbuds and Earphones, rather than any hard to drive Headphones - I've gone ahead and replaced the 6-pin Hirose Balanced Output connector with a 2.5mm TRRS jack (that fits into the same hole).
.


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## Lohb (Jun 16, 2019)

HiFlight said:


> When I was still producing the PB2 Topkits, I developed a custom LME49600 plug and play buffer module which I felt was a significant improvement over the stock buffers.  I finally stopped making them after shipping a number of sets as they were very labor-intensive to build.



Would you rank LME49600's sound characteristics close to mid-tier discrete chips ..and any downsides to it you found ?


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## Lohb

Wish iBasso would bring out an improved PB2 for the chip rolling fanatics, the PB3 is discontinued but still avail. from a few online retailers...so it just did not do well obviously.


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## HiFlight

Lohb said:


> Would you rank LME49600's sound characteristics close to mid-tier discrete chips ..and any downsides to it you found ?


Based solely on SQ, the LME49600 is right up there with the best, however I believe production has ceased and it is increasingly difficult to find existing stock.  As there are no adapters available to convert this case style to DIP8, using it in the PB2 will be strictly a DIY endeavor.


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## HiFlight

Lohb said:


> Wish iBasso would bring out an improved PB2 for the chip rolling fanatics, the PB3 is discontinued but still avail. from a few online retailers...so it just did not do well obviously.


While the PB3 is an excellent sounding amp, it is not a candidate for opamp rolling due to the case dimensions ...it is simply too thin.


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## HiFlight

DBaldock9 said:


> Since all of my current Balanced loads are Earbuds and Earphones, rather than any hard to drive Headphones - I've gone ahead and replaced the 6-pin Hirose Balanced Output connector with a 2.5mm TRRS jack (that fits into the same hole).
> .


Great idea and well implemented!


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## DBaldock9

HiFlight said:


> Great idea and well implemented!



Thanks!
I used 18 gauge solid copper wire, so it was a bit tricky getting them routed to the correct lugs.
Looking back through this thread, you'll see where the pin-out for the original Hirose 6-pin connector is shown.
So, that allowed me to determine which circuit board pads are which signals.
I used Kapton tape over the two pads (#1 & #4), for Right & Left channel GND, since the earphones only need the (L+), (L-), (R+), & (R-) signals.
Since it's deeper than the Hirose jack, the back edge of the 2.5mm jack did require some filing, so that it would clear the circuit board.


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## Lohb

Anyone know if BUF634P WB were produced specially for PB2, no luck digging them up so far..


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## DBaldock9

Lohb said:


> Anyone know if BUF634P WB were produced specially for PB2, no luck digging them up so far..



Looks like someone on eBay has the "P" model - https://www.ebay.com/itm/1pcs-BUF634P-250mA-HIGH-SPEED-BUFFER-BUF634-DIP-8-pin-/202519434139


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## Lohb

ADA4627 = great little chips...like an LME49990 with that transparency/separation/microdetail ...but more natural tonality and fuller 'body' to the presentation.
$38 on bay from Taiwan.... 
eBay item number: 283459781418
Never heard of them before, but were already in an amp I just grabbed as an upgrade option over stock OPA134.


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## Rizonsik

plutonim said:


> How you are connecting DB2 to the source? USB or coaxial(optical)?
> Check the voltage on the DACs (AVDD and DVDD).
> And be sure to unsolder pin 22 on both DACs and conected it to the pin 23.


Hello! I want modding my db2... Please, tell me where is this pin 22 and 23 or post screenshot modification. And where you soldering usb to I2S too. Thank you!


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## plutonim

Rizonsik said:


> Hello! I want modding my db2... Please, tell me where is this pin 22 and 23 or post screenshot modification. And where you soldering usb to I2S too. Thank you!


----------



## Rizonsik

plutonim said:


>


With Both chip i guess? Maybe I'll leave it as it is  Love warm sound :3 And darkest too! Have you tried role db2 opamp? With blue it sounds wider and YAMY :3 Whats opamp in your db2? Thank you for the fast replay!


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## Lohb

I have the Energizer battery and LPS dongles for PB2 below if anyone is interested...has 12-Volt for sure and maybe 15-volt LPS is around.
https://www.head-fi.org/threads/ene...pella-or-beresford-dacs-or-ibasso-pb2.915680/


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## plutonim

Rizonsik said:


> With Both chip i guess?


Yes, of course 


Rizonsik said:


> Whats opamp in your db2?


ADA4897-1, but the muses8832 was very nice too


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## Rizonsik

plutonim said:


> ADA4897-1, but the muses8832 was very nice too


OK. I try ADA4897-1 becase price is very nice! Thanks!


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## Lohb

Rizonsik said:


> OK. I try ADA4897-1 becase price is very nice! Thanks!



I found my fav. mass market opamp to be ADA4627B over LME49990 which it took top position from.


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## Rizonsik

Can anyone come across... At me, why that if to connect with dyummy buffer, LME49990 from a network crack. With normal buffer all works fine. I dont have battery to test with it.


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## Rizonsik

Can anyone know where I can buy the original LME49990? I think I have noname opamp...


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## Lohb

Rizonsik said:


> Can anyone know where I can buy the original LME49990? I think I have noname opamp...



There was a seller in Taiwan on ebay.com that offered various grades of solder with that chip..his ones were real.
OPA1622 is supposed to be the nearest replacement for LME49990. Cheaper.


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## Rizonsik

I listened to lme49990, I really like them! If only it hadn't been for that crack... With the blue Buffer, the crackling is not audible. But, I'd like to listen with a dummy buffer! Can who knows, how much cost original lme49990?


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## Rizonsik (Dec 10, 2019)

Lohb said:


> There was a seller in Taiwan on ebay.com that offered various grades of solder with that chip..his ones were real.
> OPA1622 is supposed to be the nearest replacement for LME49990. Cheaper.


I found Taiwan seller. Thanks!


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## DBaldock9

Found a post in this thread, from 2017, that listed the contact email at iBasso for ordering a replacement PB-2 battery. 
. 
I contacted them, and the current price is USD$25 + $10 Shipping/Handling. 
. 
So, now I've got one on order.


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## Rizonsik

When I wanted to put 4 batteries (14.8v) in, something went wrong. And now pb2 does not work on batteries  I Think add more batteries, up to 6 (22.2v) and use as an external source


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## paulybatz

Just pulled my P4 out after a long while...think the battery is shot. Haven’t tried the PB2 yet

have these been upgraded much
Saw there was a PB3???


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## DBaldock9

DBaldock9 said:


> Found a post in this thread, from 2017, that listed the contact email at iBasso for ordering a replacement PB-2 battery.
> .
> I contacted them, and the current price is USD$25 + $10 Shipping/Handling.
> .
> So, now I've got one on order.



The replacement battery arrived today. 
It's definitely flatter, and not swelled up in the middle, like the original battery - although the heat shrink / plastic that's wrapped around it, does seem to make it a little bit longer. 
I'm trying to get the wires routed low around the end, so they don't get pinched when the top is installed.


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## paulybatz

Hmmm. How much was it??


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## DBaldock9

paulybatz said:


> Hmmm. How much was it??



In my quoted post, I list the price of the battety. 
USD$25 + $10 Shipping/Handling


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## paulybatz

Oh...lol. I see it now. 
I think that’s a bit pricey for the battery


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## DBaldock9

It is more expensive than standard 3.7V Li-Ion batteries - but it is a proprietary size / voltage.
The DC supply is 16V, so the battery is probably something like 12 - 14V.


----------



## XanderL

I have recently acquired an Opus#1 and would like to use it with the PB2. The balanced output on the Opus#1 is a 2.5mm TRRS with no ground. How do I hook this up to the PB2 balanced input, would I just leave the ground disconnected?


----------



## DBaldock9

XanderL said:


> I have recently acquired an Opus#1 and would like to use it with the PB2. The balanced output on the Opus#1 is a 2.5mm TRRS with no ground. How do I hook this up to the PB2 balanced input, would I just leave the ground disconnected?



You may be able to gain access to GND from your Opus #1, by connecting the shield of your Balanced cable to the sleeve of the 3.5mm TRS jack.
Just don't connect anything to the Tip & Ring.
It will depend on whether the DAP detects plugs inserted into the jacks, and changes modes.

Your cable will need to be assembled like this:
.

Hirose 6-Pin Plug​Pin 1​Right GND​3.5mm TRS Plug​Sleeve​Hirose 6-Pin Plug​Pin 2​R+​2.5mm TRRS Plug​Ring 1​Hirose 6-Pin Plug​Pin 3​R-​2.5mm TRRS Plug​Tip​Hirose 6-Pin Plug​Pin 4​Left GND​3.5mm TRS Plug​Sleeve​Hirose 6-Pin Plug​Pin 5​L+​2.5mm TRRS Plug​Ring 2​Hirose 6-Pin Plug​Pin 6​L-​2.5mm TRRS Plug​Sleeve​


----------



## XanderL

Thanks. I will give it a try. Isn't that similar to how A&K build their balanced to XLR cable? If I can't use the ground, because of mode switching, would it still work without the ground?


----------



## DBaldock9

XanderL said:


> Thanks. I will give it a try. Isn't that similar to how A&K build their balanced to XLR cable? If I can't use the ground, because of mode switching, would it still work without the ground?



It should work, but there may be issues with noise pick-up, without a grounded shield in the cable.


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## paulybatz

Y’all are making my brain hurt


----------

