# Twisted Pear Audio Opus DAC



## Nebby

The Twistd Pear Opus DAC board is "..based around the Wolfson WM8740 DAC chip. It offers I2S input, stereo balanced output, hardware control of DAC options via jumpers, as well as a header for optional software control. The DAC board can also be configured to allow the WM8740 to operate in dual-mono mode (see datasheet for more information)."

 Source: Opus - A Balanced DAC


 With headphones the Opus is very detailed, and IMO more detailed than Aaron's Oritek modded Zhaolu. On the other hand the Zhaolu seemed to have a much wider soundstage.

 After switching the Apache to preamp and listening to Aaron's Av123 Mini Strata's powered by a Pass Aleph 30, I am inclined to believe that the DAC excels much more at imaging with speakers than with headphones.


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## cotdt

i was just there. amazing DAC! it sounds very similar to my Zapfiltered Zhaolu, otherwise I would definately build one. And it's cheap!


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## threEchelon

Fierce Freak said that his Opus didn't have as much bass as his Zapfiltered Zhaolu. Did you guys find that to be the case?

 Also, how warm is the Opus?

 Thanks.


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## fierce_freak

The Opus is an incredible DAC. I think a Zapfilter installed in the Opus will take it to a level I don't see leaving for a good time. Also, the difference in bass levels wasn't night and day. The Zhaolu just seemed a little more present there (subtle difference), but I don't doubt that adding the zap wouldn't bring it on par or better.

 I would call the Opus pretty neutral, really. It's not exactly warm, but it's certainly not cold, either.


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## cotdt

Quote:


  Originally Posted by *threEchelon* /img/forum/go_quote.gif 
_Fierce Freak said that his Opus didn't have as much bass as his Zapfiltered Zhaolu. Did you guys find that to be the case?_

 

Yes, based on my memory (and not direct comparison), it seems to be true. It could be the tiny power supply in the OPUS DAC relative to the one in the Zhaolu. You can use the Zhaolu's big beefy power supply with the OPUS, but I don't think anyone has tried it yet.

  Quote:


 Also, how warm is the Opus? 
 

It was pretty neutral, but can be warm when it needs to be. It is pretty much in line with other high end DACs, and yes I do consider this a high-end DAC because I prefer it over the usual $1000-$1500 class of commerical DACs that I've heard so far. I've also heard much more expensive DACs but it's definately a matter of preference.

 Edit: Ah I see fierce-freak just posted a reply as I was typing this up. Seems like we agree


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## threEchelon

Hmm. I would really like to build an Opus and a B22, but I'm afraid they'll be too neutral together. I would prefer a backend with warmth and a little extra bass (All my headphones are bass light, including the pair of vintage RS-1's I'll be receiving soon. 
	

	
	
		
		

		
		
	


	




). Any suggestions?


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## cotdt

Quote:


  Originally Posted by *threEchelon* /img/forum/go_quote.gif 
_Hmm. I would really like to build an Opus and a B22, but I'm afraid they'll be too neutral together. I would prefer a backend with warmth and a little extra bass (All my headphones are bass light, including the pair of vintage RS-1's I'll be receiving soon. 
	

	
	
		
		

		
		
	


	




). Any suggestions?_

 

the M^3 in your sig is already on the warm side for an amp, the Beta22 is even warmer, and if you want warmer still there are certain tube amps that have a nice, fat tone. But if you're using the X-Fi as your source then the OPUS is definately warmer. I say go for it! The OPUS is cheap!


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## Nebby

Quote:


  Originally Posted by *cotdt* /img/forum/go_quote.gif 
_Yes, based on my memory (and not direct comparison), it seems to be true. It could be the tiny power supply in the OPUS DAC relative to the one in the Zhaolu. You can use the Zhaolu's big beefy power supply with the OPUS, but I don't think anyone has tried it yet._

 

I'm planning on using AMB's sigma22 to upgrade the power supply and see where that takes the Opus dac. 

 As it right now, it's simply amazing when used with speakers! I can't believe the soundstage I am hearing out of Aaron's speakers. I wish cotdt brought his Zhaolu over to do some comparisons.


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## cotdt

That's a great idea, Nebby! The Sigma22 might even get rid of that high frequency noise, who knows. I'm deaf so I couldn't hear it anyway, lol.


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## johnsonad

This is being run through my speaker rig right now and the imaging is 3D. I've never heard anything like it and now have to build one of these. IMHO, my Oritek 2.5 and a Zap Filtered Sony NS9100ES sound great with headphones but the Opus will be my new primary speaker DAC.


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## threEchelon

Quote:


  Originally Posted by *cotdt* /img/forum/go_quote.gif 
_the M^3 in your sig is already on the warm side for an amp, the Beta22 is even warmer, and if you want warmer still there are certain tube amps that have a nice, fat tone. But if you're using the X-Fi as your source then the OPUS is definately warmer. I say go for it! The OPUS is cheap!_

 

I'm using the Behringer DEQ2496 as a source, but they don't sound _that_ much different.

 Okay, okay. You might've convinced me. 
	

	
	
		
		

		
		
	


	




 What about the bass, though? The bass on the M^3 isn't very impressive (probably, the source's fault too) and I want something not necessarily with more "oomph" but at least with more volume and texture.


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## swt61

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_The Opus is an incredible DAC. I think a Zapfilter installed in the Opus will take it to a level I don't see leaving for a good time. Also, the difference in bass levels wasn't night and day. The Zhaolu just seemed a little more present there (subtle difference), but I don't doubt that adding the zap wouldn't bring it on par or better.

 I would call the Opus pretty neutral, really. It's not exactly warm, but it's certainly not cold, either._

 

We'll put this to the test soon. fierce_freak has been gracious enough to agree to build one for me. It will be dual differential and have the Zapfilter MKII discrete output. Twisted Pear is out of stock of the Opus kit and DAC boards at the moment. It seems they expect to have some ready for orders by the end of August. That's my luck of coarse, but it will be worth the wait.

  Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I'm planning on using AMB's sigma22 to upgrade the power supply and see where that takes the Opus dac._

 

Please let us know how this works out. If you finish it before the parts for mine arrive, and it has a favorable outcome, I can have Jim add one to mine.


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## philodox

Are you building yours with the OPUS PSU or something else? Might be cool to use one of AMB's power supplies, the o22 or o11.


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## Nebby

I think the sigma22 is more appropriate for the opus since it has dual rails, and the opus dac boards require separate rails for the analog and digital stages. What exactly does a zapfilter do? I keep hearing about it and I'm curious to hear how it affects the sound.

 Cotdt, I left my opus dac at Johnsonad's place, so it would be great if you two could somehow meet up and do a comparison between your zhaolu and the opus dac. I'm really interested in seeing if the zhaolu also has the 3-d imaging that the opus has with the speakers.

 Personally after listening to the Opus thru the 650's, dt770s, and d5000's all balanced, I don't believe it needs any more bass. Particularly when switching between the 650's and the d5000's, it strikes me as having a neutral enough signature that it doesn't overemphasize the sound after the headphone's coloration. Perhaps Johnsonad will post his impressions since he has a larger variety of headphones than I do.

 By the way, I'm not joking about the speaker part even if I probably sound a little overzealous right now.....the detail, soundstage, and 3d-ness of the sound with speakers is unbelievable with the opus when compared to the Ori Zhaolu, Meridian 805, and Sony 9100ES. Has anyone else tried hooking up their Opus to speakers?


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## philodox

The Zapfilter is just a high quality analog output stage.


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## Nebby

Quote:


  Originally Posted by *philodox* /img/forum/go_quote.gif 
_The Zapfilter is just a high quality analog output stage. 
	

	
	
		
		

		
			



_

 

Ah I see. That ought to be interesting 
	

	
	
		
		

		
		
	


	




 I've done a little reading and searching on head-fi, and from what I've read it seems like it's rather on the bassy side. If so, I definitely won't be using that for my opus, since listening to it through the Apache, the D5000's have gobs and gobs of bass already. I think adding any more would be too much for my ears


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## philodox

I wouldn't say it is bassy personally... the bass is definately there, but has good definition.


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## Nebby

I must say....you've piqued my interest, philodox. I found the Opus stock to have plenty of detail esp compared to the Oritek zhaolu, so it makes me wonder how it would sound zapfiltered.


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## philodox

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I must say....you've piqued my interest, philodox. I found the Opus stock to have plenty of detail esp compared to the Oritek zhaolu, so it makes me wonder how it would sound zapfiltered._

 

I'd wait until after swt61 has his built. They are going to try it out with and without the zapfilter to decide.


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## Nebby

That's what I meant by "wonder" 
	

	
	
		
		

		
		
	


	




 I am definitely going ahead with the sigma upgrade, just need to find out the resistor values I need to get 7.5...though I might just go for 9v since those values are already provided on Ti's page.


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## swt61

Quote:


  Originally Posted by *philodox* /img/forum/go_quote.gif 
_Are you building yours with the OPUS PSU or something else? Might be cool to use one of AMB's power supplies, the o22 or o11._

 

fierce_freak thought the stock power supply was adequate, but I am interested in an upgraded power supply. Better to do it all at once than send it back again.

  Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I think the sigma22 is more appropriate for the opus since it has dual rails, and the opus dac boards require separate rails for the analog and digital stages. What exactly does a zapfilter do? I keep hearing about it and I'm curious to hear how it affects the sound._

 

What's the cost of building a Sigma22? Do you need to buy the board and the parts seperately, or do they have a kit?

 The Zapfilter definitely has strong bass, but it's not at all overexagerated. It's tight, well controlled, accurate bass. It's just the ticket for the K340 I own, but doesn't overwhelm my 600Ω DT990 either. The way it transforms the Zhaolu is amazing, so it's worth a try in the Opus. If it doesn't yield substantial gains I'll have it installed in my Parasound DAC instead.


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## n_maher

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_What's the cost of building a Sigma22? Do you need to buy the board and the parts seperately, or do they have a kit?_

 

I'd budget around $125 for it if you need an enclosure. Kit's can be found here.


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## FallenAngel

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_The Zapfilter definitely has strong bass, but it's not at all overexagerated. It's tight, well controlled, accurate bass. It's just the ticket for the K340 I own, but doesn't overwhelm my 600Ω DT990 either. The way it transforms the Zhaolu is amazing, so it's worth a try in the Opus. If it doesn't yield substantial gains I'll have it installed in my Parasound DAC instead._

 

Just looked at the schematics of the ZapFilter 2, it looks quite a bit like PPL's diamond buffers as per the PPAv2 and the ones used for the Millet Hybrid. Definitely should be a great output stage.


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## swt61

Well it's decided, fierce_freak PM'd me and we're going with the σ22 power supply just to play it safe. He was also gracious enough to offer me his Opus parts so that I don't have to wait a month. His will be dormant until he gets a new amp anyway, but the offer was very nice, and greatly appreciated. So I'll be an Opus owner before long.


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## looser101

I don't believe you can use the sigma22 with the opus dac as intended. I've read that it's dedicated to provide + and - rails (tracking) and not two positive rails. The opus needs two positive rails, one for analog supply and one for digital supply. So you would need two sigma11. A dual (individual) secondary winding transformer would be good, two individual transformers may be even better. Somebody correct me if I am wrong.


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## swt61

Hmmm, I need to figure this out, as the parts order goes in soon. I don't doubt you though Renato. So do you think two σ11's will be a nice upgrade from the stock power supply? Is that all that would be needed?


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## looser101

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Hmmm, I need to figure this out, as the parts order goes in soon. I don't doubt you though Renato. So do you think two σ11's will be a nice upgrade from the stock power supply? Is that all that would be needed?_

 

You have PM.


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## swt61

Thanks Renato!


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## Nebby

Well the schematic for the sigma 22 board is here:
http://www.amb.org/audio/sigma22/s22_sch_small.png

 I'm still a relative beginner when it comes to DIY, but to me it looks like it should be fine. I see the two secondaries being connected to the rectifier diodes which smooth it into two seperate dc rails with + and - in each rail, then all the power supply fun....and then two terminal blocks per rail. I know that's a rather rudimentary interpretation.....so excuse my lack of technical knowledge 
	

	
	
		
		

		
		
	


	




 But am I wrong in thinking the sigma22 appropriate for the Opus dac?


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## looser101

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Well the schematic for the sigma 22 board is here:
http://www.amb.org/audio/sigma22/s22_sch_small.png

 I'm still a relative beginner when it comes to DIY, but to me it looks like it should be fine. I see the two secondaries being connected to the rectifier diodes which smooth it into two seperate dc rails with + and - in each rail, then all the power supply fun....and then two terminal blocks per rail. I know that's a rather rudimentary interpretation.....so excuse my lack of technical knowledge 
	

	
	
		
		

		
		
	


	




 But am I wrong in thinking the sigma22 appropriate for the Opus dac?_

 

Well, almost. The output opamp for the negative rail tracks the voltage of the positive rail to generate the negative rail. I've read somewhere - the headwize thread? - that it can not be used for dual positive rails.

 Not sure there would be an improvement from the twisted pear supply. The dac board has regulators for digital and analog supplies onboard. Most psu noise would be from the onboard regs as long as a reasonably quiet psu is used to power the dac IMO. Obviously the sigma psu's are much quieter, I'm just not convinced they would be an improvement. But if you want to try then use 2 sigma11's (or 1 for the analog supply only) with separate transformers and let us know.

 Renato


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## Nebby

I did notice that the dac boards have regulators on board for both digital and analog supplies onboard, I am still curious though. My plan was to build the sigma22 and try it to see if theres a difference, and if there wasn't I would just change a few parts out to use for my future beta22. After reading some more I think I understand how it works a bit better now. I still have so much to learn


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## looser101

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I did notice that the dac boards have regulators on board for both digital and analog supplies onboard, I am still curious though. My plan was to build the sigma22 and try it to see if theres a difference, and if there wasn't I would just change a few parts out to use for my future beta22. After reading some more I think I understand how it works a bit better now. I still have so much to learn 
	

	
	
		
		

		
		
	


	


_

 

Not all is lost. Get the sigma22 for your future project and use the positive rail to power the analog supply of the dac and see if it makes a difference. If it does then you may want to upgrade to the sigma11's down the road. Just make sure the sigma22 is configured to supply 6-7volts for the dac (calculations are on the AMB website) to keep the onboard LDO regulator(s) from dissipating too much heat.

 Renato


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## swt61

It's like a whole other language that I don't speak. 
	

	
	
		
		

		
		
	


	




 Thank goodness you guys do! 

 Datos and dovetails I know!


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## Nebby

No worries, I'm picking up a sigma11 or two for my squeezeboxes, so not all is lost either way


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## Nebby

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_It's like a whole other language that I don't speak. 
	

	
	
		
		

		
		
	


	




 Thank goodness you guys do! 

 Datos and dovetails I know! 
	

	
	
		
		

		
		
	


	


_

 

I'm learning that language slowly yet surely too!


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## looser101

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_No worries, I'm picking up a sigma11 or two for my squeezeboxes, so not all is lost either way 
	

	
	
		
		

		
		
	


	


_

 

Nate (n_maher) built some for squeezboxes. If i remember correctly there was a change to the configuration for 5Volts. I think it's in the sigma22 thread on headwize.

 ~R~


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## johnsonad

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_It's like a whole other language that I don't speak. 
	

	
	
		
		

		
		
	


	




 Thank goodness you guys do! 

 Datos and dovetails I know! 
	

	
	
		
		

		
		
	


	


_

 

Steve I feel ya! Ben had been helping me and I really have no idea what I am doing with this stuff. The Opus sounds trully amazing balanced through a speaker rig. I really don't care for it with headphones much but I can't wait to build one for the speakers! Thankfully he left it with me for a couple of weeks to play with. 

 I emailed Jeff at GlassJar and Ti about the Sigma 22 board. I'll probably use the Twisted Pear power supply to start until you guys perfect the Sigma 11 build and use a shielded transformer and a copper housing for now. 

 BTW, who else sells shielded transformers other than Avrel? Excuse me as I am a NOOB when it comes to this 
	

	
	
		
		

		
		
	


	




 I have a strong desire to build this and fast


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## johnsonad

This is from Ti in response to the Sigma 11 boards being used for the Opus DAC.

 " You can configure the sigma11s to output 7.5VDC by using the 9V configuration, except use BAX55C7V5 zener diodes for D5."


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## Nebby

Quote:


  Originally Posted by *philodox* /img/forum/go_quote.gif 
_The Zapfilter is just a high quality analog output stage. 
	

	
	
		
		

		
		
	


	


_

 

I just noticed Twisted Pear has a line driver that would fit the bill as a line driver: http://www.twistedpearaudio.com/txd/txd.aspx I wonder how it would compare vs the zapfilter


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## n_maher

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Nate (n_maher) built some for squeezboxes. If i remember correctly there was a change to the configuration for 5Volts. I think it's in the sigma22 thread on headwize.

 ~R~_

 

Yup, I've built 3 or 4 now. There is 5V specific information on amb's site now too.


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## Nebby

Master of the Squeezebox Sigma you are, Nate


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## n_maher

Ha! I'm sure it won't stay that way for long.

 And I had quite the interesting visit with Brian from Twisted Pear yesterday. All I can say is keep your eyes on these guys. They've got some really cool stuff planned in the near future.


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## greyhorse

Just because there's been more than one voltage said to be optimal for the Opus power supply, let me quote directly from the Opus documentation.

 "The Opus is designed to utilize separate analog and digital power supplies from 6.5V to 15V. They do not need to be regulated, but a good dual regulated supply like the LCPS is recommended. There are two on-board voltage regulators to provide power to the DAC. If you use the LCPS adjust both output voltages to *7.5* for good results. This will provide more than enough voltage drop for the on-board LDO VREGs while not making them dissipate more power than required."

 Just a note about pre-regulators, which is what you guys are planning on using the Sigma 11 for. These things need not be so elaborate to get the DAC to operate well. Depending on what sound you're looking for, an even simpler regulator could give you better results. A less regulated supply using a simple pass transistor without any feedback could give you looser, fuller bass and more overall warmth. I tend to like these more for pre-regulator use, but that's just me.

 On that note, I do like the circuit topology of the Sigma series regulators, which feature very good stability into various loads. But man, for the current that the Opus or two Opuses are going to be drawing, TOTALLY overkill
	

	
	
		
		

		
		
	


	




 But heck, going overkill is one of the advantages of DIY. Have fun guys.


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## fierce_freak

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_They've got some really cool stuff planned in the near future. 
	

	
	
		
		

		
		
	


	


_

 

Can you hint at all in what direction they're going? More amps, more steppers, more DACs?


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## swt61

Yeah, that was just evil to drop that hint and run!


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## fierce_freak

Yeah, seriously. My first thought was transport, but that's probably just because that's been on my mind lately.

 If not what, how about a likely time-frame. Near-future is rather relative O_o

 Ah well, that's the nature of the beast, I s'pose...


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## n_maher

Run? I'm not going anywhere. Brian didn't go into great detail about what they were up to but did hint at a few things. About as specific as I could get would be to answer fierce's questions with yes, yes, and yes. 
	

	
	
		
		

		
			








 Brian said Russ is cranking out things faster than he can deal with them at this point.


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## swt61

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_My first thought was transport,_

 

Get out of my brain! It's dangerous in there!

 I was hoping the exact same thing.

  Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_Run? I'm not going anywhere. Brian didn't go into great detail about what they were up to but did hint at a few things. About as specific as I could get would be to answer fierce's questions with yes, yes, and yes. 
	

	
	
		
		

		
		
	


	







 Brian said Russ is cranking out things faster than he can deal with them at this point._

 

Now that is interesting!
 Thanks for the hints Nate.


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## n_maher

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Yeah, seriously. My first thought was transport, but that's probably just because that's been on my mind lately._

 

I think I mighta heard something about that, but in all honesty I'm not 100% sure about that. We talked about both modding transports and also standalone units so I could be getting those two conversations mixed up.

  Quote:


 If not what, how about a likely time-frame. Near-future is rather relative O_o 
 

Some are seriously close and those I'm sure most are already aware of. The next round of Opus DACs are due in shortly, the next gen remote controlled stepper. A whole host of module add ons for the DAC's to allow various inputs, etc.


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## BradJudy

This looks like an interesting project to try. At first glance, it looks like it's designed for balanced output only with an add-on board to convert to single-ended. Is that right? Are those who have built one running it balanced or single-ended?


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## Nebby

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_Ha! I'm sure it won't stay that way for long.

 And I had quite the interesting visit with Brian from Twisted Pear yesterday. All I can say is keep your eyes on these guys. They've got some really cool stuff planned in the near future. 
	

	
	
		
		

		
		
	


	


_

 

Wow you're lucky to be able to visit them, they certainly have a lot of cool stuff coming out. I've seen them drop hints and showing off some of there prototyping stuff over in their diyaudio threads. I really do like what I've seen so far 
	

	
	
		
		

		
		
	


	




 greyhorse: I am completely aware that it's overkill.....but I'm somewhat of a fan of overkill when building DIY stuff 
	

	
	
		
		

		
		
	


	




 I noticed their TXD modules, and I'm thinking of using two of those as line drivers for the opus dac's output. A twisted pear substitute for the zapfilter, I'm hoping. I'm thinking of possibly going for even more overkill and using sigma's to power those boards too 
	

	
	
		
		

		
		
	


	




 BradJudy: It is indeed designed for balanced output, with an add-on board to convert to single ended.


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## n_maher

Quote:


  Originally Posted by *BradJudy* /img/forum/go_quote.gif 
_This looks like an interesting project to try. At first glance, it looks like it's designed for balanced output only with an add-on board to convert to single-ended. Is that right? Are those who have built one running it balanced or single-ended?_

 

If you could live with a little less output power you can use the DAC single-ended without a problem. A balanced source, by definition, just puts out an in-phase (L+/R+) and out-of-phase (L-/R-) signals. Either one could be used as a single ended signal. Just look at the CIAudio VDA-2, that's exactly what its output is doing. So the single ended output board is just designed so that you get the full output power of the DAC, which I'm guessing could easily be lived without.


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## Nebby

I've always seen recommendations to use a transformer when converting a balanced output to single ended. I always thought that you could simply use one of the in phase signals for SE, but never saw it recommended. I guess it's less than optimal?

 edit: Ah, just different paths to an end....


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## BrianDonegan

Don't want to be seen as plugging products or anything, but just want to answer some questions...

 The idea with the pre-reg supply is just to provide a really clean DC for and to lessen the voltage drop of the SMT the on board regs. Sigma 11 should work fine. It's all about ripple reduction there. The current draw is so tiny that you would be hard pressed to create a power supply that runs dry. You can't use a split-rail supply (Sigma 22).

 The Ballsie also adds an optional LP filter from the Wolfson datasheet. It actually allows you to use the filter and keep balanced outs, in addition to the SE outs. As said previously, it basically eliminates the 6dB drop of using one side of the balanced outputs. It also gives you an output buffer by it's nature. Transformers would work very well for the conversion as well (we contemplated a transformer board, but thought it would be easy to perf board it or use an existing product).

 We basically make stuff that we want for ourselves, so that's our general direction


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## n_maher

Great to see you here Brian and thanks again for the tour around Pear HQ.


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## BrianDonegan

My secretary says "Hi."


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## colonelkernel8

Haha, cant wait until the Opus is in stock again, will you be selling sets that include the Ballsie? Will operating two Opus units in dual-differential improve the sound on the Ballsie?


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## BradJudy

Thanks for the notes. I've run balanced outputs to single-ended as mentioned here before, but wanted to be sure there wasn't anything unusual going on with this DAC. I'll be pretty tempted to try this out when the kits are shipping again.


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## Nebby

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Don't want to be seen as plugging products or anything, but just want to answer some questions...

 The idea with the pre-reg supply is just to provide a really clean DC for and to lessen the voltage drop of the SMT the on board regs. Sigma 11 should work fine. It's all about ripple reduction there. The current draw is so tiny that you would be hard pressed to create a power supply that runs dry. You can't use a split-rail supply (Sigma 22).

 The Ballsie also adds an optional LP filter from the Wolfson datasheet. It actually allows you to use the filter and keep balanced outs, in addition to the SE outs. As said previously, it basically eliminates the 6dB drop of using one side of the balanced outputs. It also gives you an output buffer by it's nature. Transformers would work very well for the conversion as well (we contemplated a transformer board, but thought it would be easy to perf board it or use an existing product).

 We basically make stuff that we want for ourselves, so that's our general direction 
	

	
	
		
		

		
		
	


	


_

 

Glad to see you here Brian! I was thinking of using the TXD as a buffer, but it looks like the Ballsie will do just fine 
	

	
	
		
		

		
		
	


	




 I like how a lot of the stuff I'd like to make matches the stuff you folks have been making


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## johnsonad

Welcome Brian and thanks for putting out an outstanding product!


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## Daveze

What's it take to make one with both USB and S/PDIF input, am I right in guessing thats what the multi-plexer will facilitate?

 Cheers,
 Josh D


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## Russ White

Quote:


  Originally Posted by *Daveze* /img/forum/go_quote.gif 
_What's it take to make one with both USB and S/PDIF input, am I right in guessing thats what the multi-plexer will facilitate?_

 

That is correct 
	

	
	
		
		

		
			





 This is on the list of incubator projects. Pretty well designed we just need to build and test.

 Cheers!
 Russ


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## Russ White

Just to drop some more solid hints...

 Here are some other thing in the incubator at Twisted Pear. 
	

	
	
		
		

		
		
	


	




 1) Uber Controller (basically will control everything we sell that needs a controller) with Display, IR control, and analog rotary encoder control.

 2) POGO, a SE/BAL programmable gain amplifier/attenuator.

 3) "yet to named" discrete fully 200W differential power amplifier. This amp could be run class A or class A/B still very much in the design stage.

 4) A discrete balanced(fully differential) headphone amp.

 5) A discrete fully differential driver capable of up to 80vpp(maybe more) swing to facilitate projects 3 and 4.

 Also we are redesigning the "Joshua Tree" and "Darwin" projects to make them integrate better with "uber controller" 

 I can't make any promises when these will be done, but they are being developed. That is assuming Brian does not run out of patience with me for dropping all these on him. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ White (the trouble maker)


----------



## threEchelon

Hmm... now I have a reason to procrastinate.


----------



## fierce_freak

Russ, Brian, glad to see you around and getting the attention your designs deserve. Thanks for the strong hints


----------



## luvdunhill

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Also we are redesigning the "Joshua Tree" and "Darwin" projects to make them integrate better with "uber controller"_

 

sweet! Any ETA on the Joshua Tree kits?


----------



## swt61

Wow! You guys are busy!


----------



## Nebby

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Just to drop some more solid hints...

 Here are some other thing in the incubator at Twisted Pear. 
	

	
	
		
		

		
		
	


	




 1) Uber Controller (basically will control everything we sell that needs a controller) with Display, IR control, and analog rotary encoder control._

 

I've been waiting for this one since you posted pictures in the JT thread 
	

	
	
		
		

		
		
	


	




  Quote:


 3) "yet to named" discrete fully 200W differential power amplifier. This amp could be run class A or class A/B still very much in the design stage. 
 

Ouch....and I've just started to build up on a txo-2 that I planned to make into a txo-4, maybe I'll just make it a txo-2 for now 
	

	
	
		
		

		
		
	


	




  Quote:


 Also we are redesigning the "Joshua Tree" and "Darwin" projects to make them integrate better with "uber controller" 
 

I'm glad I waited to pick those up 
	

	
	
		
		

		
		
	


	




  Quote:


 I can't make any promises when these will be done, but they are being developed. That is assuming Brian does not run out of patience with me for dropping all these on him. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ White (the trouble maker) 
 

Thanks for dropping the big hints Russ; they're much appreciated and lets me plan my approach


----------



## n_maher

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Wow! You guys are busy!_

 

Seeeeeeeeeee, I told you!


----------



## pabbi1

Any updates on when the Opus will be available again for order? I'm feeling 'soon', but just thought I'd ask...


----------



## swt61

I don't have an answer Al, but I think I may be just days away from hearing my dual differential Zapfiltered "Epic Opus". I've got a PS Audio Lambda transport sitting here waiting for the initial test drive, and I'm quite curious to hear the combo.


----------



## BrianDonegan

I just received the WM8804 receivers and WM8740 DAC chips from Wolfson (rail of each). I now have everything, and will start building this week. I need a couple weeks to build up enough stock for what I think the response will be (scared actually). Lets call it Sept 3rd for now.


----------



## Jambo

That WM8804 is pretty sweet, saw the results of one on an AP2700 recently.


----------



## holland

Sweet...Definitely stock up, cause I'm ordering for sure.


----------



## Rise To The Top

My Opus isnt going to be build till mid November, but will have a matching Carbon fibre case to go next to my CKK3! Gonna look nice!


----------



## luvdunhill

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_I don't have an answer Al, but I think I may be just days away from hearing my dual differential Zapfiltered "Epic Opus". I've got a PS Audio Lambda transport sitting here waiting for the initial test drive, and I'm quite curious to hear the combo._

 

cool! I'm interested in hearing about all the updates you've done to your system! Hopefully I'll be able to find your post when you get around to writing something up


----------



## dwk

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_ I need a couple weeks to build up enough stock for what I think the response will be (scared actually). Lets call it Sept 3rd for now._

 

Gadzooks! I've been following this over on diyaudio, where my take was that there is a lot of interest but not an overwhelming number that are sitting around hitting 'refresh' on the Opus page waiting for the order link to finally show up. After reading this thread, though, I'm a bit concerned about getting shut out of this run. You guys look to have a winner on your hands.

 Sept 3 would be bad, though - Labor Day, and I'll be out of e-touch. Wait until the 5th


----------



## Nebby

I'm planning on building another dual differential opus dac for my bookshelf rig, and then for fun I think I'm going to see how small I can make an opus dac


----------



## swt61

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_cool! I'm interested in hearing about all the updates you've done to your system! Hopefully I'll be able to find your post when you get around to writing something up 
	

	
	
		
		

		
		
	


	


_

 

Well Jim told me he's shipping it tomorrow, so you won't have long to wait. I'll PM you a link to my post once I've had a chance to listen a bit.


----------



## Nebby

I'm also looking forward to your impressions


----------



## swt61

I think I'll post impressions in this thread then, or at least link to it in here.


----------



## swt61

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Just quick impressions for now...more details later.

 With headphones they are very detailed, and IMO more detailed than Aaron's Oritek modded Zhaolu. On the other hand the Zhaolu seemed to have a much wider soundstage.

 After switching the Apache to preamp and listening to Aaron's Av123 Mini Strata's powered by a Pass Aleph 30, I am inclined to believe that the DAC excelss much more at imaging with speakers than with headphones._

 

I just went back to the beggining of this thread, and your post grabbed my attention. I was surprised that the Aleph 30 could adequately power the Mini Stratas. With the ribbon drivers I assumed they'd be very power hungry.


----------



## pabbi1

Just sitting on the Opus site, pounding refresh...


----------



## philodox

Can't wait to hear about your 'Epic Opus' Steve.


----------



## Nebby

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_I just went back to the beggining of this thread, and your post grabbed my attention. I was surprised that the Aleph 30 could adequately power the Mini Stratas. With the ribbon drivers I assumed they'd be very power hungry._

 

I have no doubt that they would improve with more power, but what I heard from his current setup was no slouch. I never felt like the speakers were constrained. Of course, I don't have too much speaker experience to reference to, so my opinions are extremely skewed when it comes to speakers.

 I'm curious how the opus does with and without the zapfilter


----------



## swt61

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I'm curious how the opus does with and without the zapfilter 
	

	
	
		
		

		
		
	


	


_

 

Well fierce_freak was gracious enough to offer up his Opus boards so I wouldn't have to wait for them to be available again. So his impressions will be without benifit of direct comparison. He says he does have some impressions, and I gather they're favorable, but he won't give them until I hear the DAC myself. That's cool, so I can hear it without any preconceived ideas. Once I give some impressions I'm sure Jim will chime in with his ideas of the Opus vs. Zapped Opus. I'm curious about the soundstage myself. 
 I believe the "Epic Opus" uses a different transformer too. We talked about it anyway as per Renato's advice.


----------



## luvdunhill

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_Just sitting on the Opus site, pounding refresh..._

 






 is this for your office setup, or are you going to hang it off your Eastsound?


----------



## johnsonad

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_I just went back to the beggining of this thread, and your post grabbed my attention. I was surprised that the Aleph 30 could adequately power the Mini Stratas. With the ribbon drivers I assumed they'd be very power hungry._

 

Steve, I was very surprised too with the Aleph. When speaking with the makers of the speakers, they felt that 30 watts should drive them just fine as they sell the speakers with a 39 watt tube amp. For the moment, I am quite happy with the sound but am looking to upgrade to a larger balanced Pass Labs amp in the future. The Aleph 30 sounds quite good with the Strata's but I only have a 30 year old amp to compare it too right now 
	

	
	
		
		

		
		
	


	




 The difference between sources was truly impressive and the forward presenting soundstage (almost holographic) with the Opus DAC is what sold me on it. I'm looking forward to your impressions and please let us know your opinion through your speaker rig too.

 Aaron


----------



## Nebby

I wish I could hook up the the monoblocks I'm building to your speakers Aaron, I'm very curious to hear how they compare. Alas it looks like they're going to end up too heavy to ship economically, with the transformer alone weighing in at 10lbs 
	

	
	
		
		

		
		
	


	




 I am also curious how having the ballsie with filter enabled will sound compared with the zapfiltered opus and stock opus.


----------



## pabbi1

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_





 is this for your office setup, or are you going to hang it off your Eastsound?_

 


 No, it will have a dedicated transport, like this:

 The designers have mentioned I can run the Ballsie and the OPUS both from the dual PSU (using the 15v toroid)... and using the + rail to power the DAC. Anyone else have experience with this idea? The constraint is space, and I have enough for two toroids and one psu board, but not two - anyone else being this aggressive?


----------



## swt61

Quote:


  Originally Posted by *johnsonad* /img/forum/go_quote.gif 
_they felt that 30 watts should drive them just fine as they sell the speakers with a 39 watt tube amp._

 

Yeah I noticed that they marketed it with the rebadged Onix tube amp. I assumed that was because they don't carry a more powerfull amp. It's nice to know that the Strata is that efficient. I've been very interested in them for quite awhile before availability. How's the low end? I have two Rocket UFW-10's so it won't be an issue for me, just curious.

  Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_No, it will have a dedicated transport, like this:_

 

I'm still considering that transport too. I purchased a PS Audio Lambda, that's built like a tank, but I think I may still pull the trigger on one of those. I'm waiting to hear more of Nate's impressions.


----------



## error401

Looks like they just got pre orders up and running. Just ordered mine


----------



## pabbi1

Yep, ordered the Ballsie & Opus - but, they are out of the trafo... anyone know the RIGHT replacement for: 

 Avel Lindberg Transformer (115V+115V prim. / 15V+15V 25VA sec.)

 is it this, or close enough?

http://www.partsexpress.com/pe/showd...number=122-605


----------



## luvdunhill

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_Yep, ordered the Ballsie & Opus - but, they are out of the trafo... anyone know the RIGHT replacement for: 

 Avel Lindberg Transformer (115V+115V prim. / 15V+15V 25VA sec.)

 is it this, or close enough?

http://www.partsexpress.com/pe/showd...number=122-605_

 

so, I've noticed this as well... there is no such thing as a 25VA toroid in the standard Avel Lindberg line. The 30 VA one will work and give you a bit more headroom. In fact, I may be placing an order with Avel directly for three 30 VA 15+15 and would be willing to pick one up for you and send it back with your transistors. Maybe we'll get a discount for four, who knows. Just send me an e-mail / PM.

 Here's the entire Y23 Avel line here:

http://www.avellindberg.com/transfor...ange_specs.htm


----------



## error401

DigiKey carries the Amveco 70063 (TE70063-ND), a 15V+15V 25VA unit for $21.13 USD if you often order from them.


----------



## BrianDonegan

The Avel number is Y236053. They only have 3 in stock (usually order 50). They have a ship date of "End of October" but have the 15VA version in stock (which is what we were originally going to carry). I'll probably get those instead, still plenty of extra power for an application that draws less then 500mA.


----------



## Nebby

I've picked up a full opus setup, including an usb board. I was going to pick up 4 more TPM modules to upgrade my TXO, but I have a few questions about that first


----------



## error401

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_The Avel number is Y236053. They only have 3 in stock (usually order 50). They have a ship date of "End of October" but have the 15VA version in stock (which is what we were originally going to carry). I'll probably get those instead, still plenty of extra power for an application that draws less then 500mA._

 

I don't know what price you're getting from Avel, but the volume discount on the Amveco that DigiKey sells is pretty hefty. At an order of 50ct, they're $15 each, for the 25VA unit. It seems this is approximately inline with what you're listing them for on your site, so possibly an alternative if the smaller Avel isn't going to allow you to cut the price?


----------



## johnsonad

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Yeah I noticed that they marketed it with the rebadged Onix tube amp. I assumed that was because they don't carry a more powerfull amp. It's nice to know that the Strata is that efficient. I've been very interested in them for quite awhile before availability. How's the low end? I have two Rocket UFW-10's so it won't be an issue for me, just curious._

 


 The low end is tight and goes well beyond any bass I would ever need. As you know they have 300 watt internally powered subs built in. I really need to get an SPL meter to tune them in but with work for the next month, I barely have time to turn them on. PM Sleestack, he has a set too and can give you another opinion on them. It was through his system that inspired me to get mine. I can't speak for their efficiency with a sold knowledge but to me and Nebby, they sounded pretty damm good with the Aleph driving.


----------



## MrMajestic2

Did anyone build the Opus with an SPDIF input switch? Im considering doing this, but Im not sure if just using a rotary switch is good enough,


----------



## swt61

Mine has coaxial and toslink inputs, but in the interest of purity we decided to forgo a switch. I just won't pass both signals through simultaneously.


----------



## DigiPete

Hi guys,

 New to this thread. Looking at the schematic of the OPUS,
 it looks like the Wolfson Dac has output coupling caps (to filter
 the DC)... Is this standard for a voltage output Dac? 

 Does not seem optimal for sound quality to have electrolytic caps in the signal path ...

 Any thoughts?

 Pete


----------



## Cauhtemoc

Quote:


  Originally Posted by *DigiPete* 
_Hi guys,

 New to this thread. Looking at the schematic of the OPUS,
 it looks like the Wolfson Dac has output coupling caps (to filter
 the DC)... Is this standard for a voltage output Dac? 

 Does not seem optimal for sound quality to have electrolytic caps in the signal path ...

 Any thoughts?

 Pete_

 

Voltage out DACs normally have a DC offset of 2.5V. The common practise is to use an opamp to sum the two outputs, this will make the output single ended and automatically remove the DC offset. If you want balanced outputs the easiest is to use capacitors.


----------



## awpagan

Quote:


  Originally Posted by *DigiPete* /img/forum/go_quote.gif 
_Hi guys,

 New to this thread. Looking at the schematic of the OPUS,
 it looks like the Wolfson Dac has output coupling caps (to filter
 the DC)... Is this standard for a voltage output Dac? 

 Does not seem optimal for sound quality to have electrolytic caps in the signal path ...

 Any thoughts?

 Pete_

 

Or use the zapfilter or the discrete filter buffer stage on the DIYaudio CD63/67 mods thread.
 The opus does look interesting though...

 allan


----------



## bearmann

Greetings,
 I'm very interested in this DAC. But wondering if/how "Ballsie" will decrease the sound-quality?! I've read a comment at the diyaudio-thread, that the only advantage of the OPUS is his balanced out ... so if you'll use the Ballsie it's quite unspectacular/worthless. What do you think? - Is the Opus still interesting if you'll use unbalanced out?

 Best regards,
 bearmann


----------



## ezkcdude

Quote:


  Originally Posted by *bearmann* /img/forum/go_quote.gif 
_Greetings,
 I'm very interested in this DAC. But wondering if/how "Ballsie" will decrease the sound-quality?! I've read a comment at the diyaudio-thread, that the only advantage of the OPUS is his balanced out ... so if you'll use the Ballsie it's quite unspectacular/worthless. What do you think? - Is the Opus still interesting if you'll use unbalanced out?

 Best regards,
 bearmann_

 

If that's what is being said, I don't agree. Whether a DAC is balanced or not is only one part of the equation. If a mediocre DAC could be made great just by making it balanced, wouldn't they all be that way? Sure, a DAC may be generally improved by adding a balanced output, but it also depends on how it is implemented. Simply because a DAC is balanced does not make it great. And vice-versa, of course. You must understand the entire DAC topology, and not just focus on one aspect like balanced or unbalanced. If the Opus is a good DAC (and I can't make that judgement not having heard it), then it is *not just because* it is balanced. It is the overall design. Making the balanced-to-single-ended conversion should not make an otherwise great DAC poor or mediocre (maybe just a teenie weenie less great). IMHO, YMMV.


----------



## ezkcdude

double post, sorry.


----------



## tomb

Quote:


  Originally Posted by *ezkcdude* /img/forum/go_quote.gif 
_If that's what is being said, I don't agree. Whether a DAC is balanced or not is only one part of the equation. If a mediocre DAC could be made great just by making it balanced, wouldn't they all be that way? Sure, a DAC may be generally improved by adding a balanced output, but it also depends on how it is implemented. Simply because a DAC is balanced does not make it great. And vice-versa, of course. You must understand the entire DAC topology, and not just focus on one aspect like balanced or unbalanced. If the Opus is a good DAC (and I can't make that judgement not having heard it), then it is *not just because* it is balanced. It is the overall design. Making the balanced-to-single-ended conversion should not make an otherwise great DAC poor or mediocre (maybe just a teenie weenie less great). IMHO, YMMV._

 

I agree in priciple with what you've said - but I was wondering the same thing as Bearmann. If you study the Ballsie, you'll see that the Wolfson DAC's quad outputs are funneled through two sets of opamps in series - two LM4562's and an LME4974. Using a USB input card is even further extending things - they employ a second PCM2707 DAC and state that the USB card for the OPUS can be used as a "single-ended, mid-level, standalone DAC" by itself. So, if you're wanting a USB-input, stereo source DAC similar to an Alien - only "high end," you'd have to add three opamps and another DAC into the signal path of the OPUS. 

 There may not be anything bad with any of that, but it seems we're taught to avoid opamps in order to be king of the hill these days, and the PCM 2707 seems to really confuse things.

 So, not trying to cause trouble, but I think Bearmann's question was a good one, perhaps.


----------



## FallenAngel

Quote:


  Originally Posted by *tomb* /img/forum/go_quote.gif 
_I agree in priciple with what you've said - but I was wondering the same thing as Bearmann. If you study the Ballsie, you'll see that the Wolfson DAC's quad outputs are funneled through two sets of opamps in series - two LM4562's and an LME4974. Using a USB input card is even further extending things - they employ a second PCM2707 DAC and state that the USB card for the OPUS can be used as a "single-ended, mid-level, standalone DAC" by itself. So, if you're wanting a USB-input, stereo source DAC similar to an Alien - only "high end," you'd have to add three opamps and another DAC into the signal path of the OPUS. 

 There may not be anything bad with any of that, but it seems we're taught to avoid opamps in order to be king of the hill these days, and the PCM 2707 seems to really confuse things.

 So, not trying to cause trouble, but I think Bearmann's question was a good one, perhaps._

 

I thought that the USB input is handled by the PCM2707 and then I2S is sent to the WM8740 DAC. The "standalone DAC" is referring to using the DAC inside the PCM2707 and getting line level analog output from there, this would not be a "preferred intended" use of the Opus, in fact, it bypasses it. Under normal circumstances, that PCM2707 is just a USB receiver, nothing more.

 As for the Ballsie, I have no idea how it's done 
	

	
	
		
		

		
			





 or why it's done that way. But then again, it's not surprising since I don't know balanced to single ended conversion architecture.


----------



## tomb

Quote:


  Originally Posted by *FallenAngel* /img/forum/go_quote.gif 
_I thought that the USB input is handled by the PCM2707 and then I2S is sent to the WM8740 DAC. The "standalone DAC" is referring to using the DAC inside the PCM2707 and getting line level analog output from there, this would not be a "preferred intended" use of the Opus, in fact, it bypasses it. Under normal circumstances, that PCM2707 is just a USB receiver, nothing more.

 As for the Ballsie, I have no idea how it's done 
	

	
	
		
		

		
		
	


	




 or why it's done that way. But then again, it's not surprising since I don't know balanced to single ended conversion architecture._

 

I only referenced the PCM2707 stand alone because they imply "mid-level". Maybe that would have some effect on degrading the USB processing since it is in the path (lower level subroutines)? Again, it may just not be optimum to take an OPUS and turn it into a single ended, but that's the reason I thought it was a good question. I added the USB question because that's how I'd like to use it.

 I hardly know any of the architecture, period.


----------



## Pars

Quote:


  Originally Posted by *error401* /img/forum/go_quote.gif 
_DigiKey carries the Amveco 70063 (TE70063-ND), a 15V+15V 25VA unit for $21.13 USD if you often order from them._

 

That's the PCB mount transformer... the standard toroid (non-PCB mount) is the TE62063-ND at $24.98 each. http://dkc3.digikey.com/PDF/T073/P2145.pdf


----------



## bearmann

Greetings,
 at first to state this clear: I've no idea about the whole dac-architecture in detail. My knowledge ends somewhere between the fact, that you need a receiver for the spdif-stream through usb and an (integrated) I/V-stage at the DAC-chip itself.
 I've probably the same problem as tomb...
 All my rig is single ended and the Opus DAC seems to be a really nice and reasonable priced diy-dac. BUT is it still worth the ~$300 (dac, usb, ballsie, psu) if you will use it "only" single ended?!
 I know that wether a ballsie nor a zapfilter will decrease the soundquality of the Opus in that way, that'll be on AlienDAC level ...
 And I know that the PCM2707 is only used to transform the spdif-stream through usb to I²S and in that fact it's not acting like a PCM2707-based DAC (like AlienDAC and so on) ...
 I simply don't have the technical background to judge if it's intelligent to build a balanced DAC (with all the effort) and use it then just single ended?! This question stays ... or is it redundant?!

 best regards,
 bearmann


----------



## ezkcdude

Balanced-to-single-ended conversion *can* be performed with a single op amp per channel. Just take a look at my ezDAC design! That's how I did it. Like you guys, I too am somewhat scared by the prospect of several op amps in a row. Seems like bad things can happen. However, there are plenty of real-world designs out there using several op amps per channel, and at the same time, loved by audiophiles. These folks may also point out that using a single op amp, as in my design, also has its pitfalls. Indeed, even using a single resistor for I/V (again as I have) may be the simplest and seemingly most "pure" design, but it has flaws as well. There is no perfect design. For example, you may increase dynamic range at the expense of linearity. Or you may increase noise at the expense of frequency response. These are totally random examples, and may not actually be the case, but hopefully, you see my point.


----------



## BrianDonegan

Couple small points:

 You can use the Opus single-ended without the Ballsie, by just using the +OUT and GND from each channel. It will be -6dB (half of a balanced signal), but no op-amps, if that's what you are after. You just need a bit more gain afterwards.

 The Ballsie uses one op-amp for Bal->SE conversion (LM4562). The quad-opamp (dual 4562) is used as a low-pass filter. The caps for the filter are through-hole and shipped un-mounted, so the filtering is optional. You can feed the Ballsie a balanced signal, and take balanced out after the filter, without using the Bal-SE converter, or use both. You can also feed the Ballsie from a dual-mono balanced setup. 

 If you do not need the Ballsie for SE, why did we make it? Options. Balanced or SE Output Buffer, optional Output LP filter (500kHz). 

 As for the PCM2707, we called it "mid-range" because the WM8740 is a better DAC, so it's relative. We were both suprised at how good it is though. I use a USB board as my PC headphone amp now at work. Bus powered makes it simple (not ideal, but simple). Sounds fantastic compared to the sound card in my work machine, which is not hard to do. 

 It's all about options for us, and not dictating how the modules will be used.


----------



## MASantos

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Couple small points:

 You can use the Opus single-ended without the Ballsie, by just using the +OUT and GND from each channel. It will be -6dB (half of a balanced signal), but no op-amps, if that's what you are after. You just need a bit more gain afterwards.

 The Ballsie uses one op-amp for Bal->SE conversion (LM4562). The quad-opamp (dual 4562) is used as a low-pass filter. The caps for the filter are through-hole and shipped un-mounted, so the filtering is optional. You can feed the Ballsie a balanced signal, and take balanced out after the filter, without using the Bal-SE converter, or use both. You can also feed the Ballsie from a dual-mono balanced setup. 

 If you do not need the Ballsie for SE, why did we make it? Options. Balanced or SE Output Buffer, optional Output LP filter (500kHz). 

 As for the PCM2707, we called it "mid-range" because the WM8740 is a better DAC, so it's relative. We were both suprised at how good it is though. I use a USB board as my PC headphone amp now at work. Bus powered makes it simple (not ideal, but simple). Sounds fantastic compared to the sound card in my work machine, which is not hard to do. 

 It's all about options for us, and not dictating how the modules will be used._

 

I didn't know that you could get SE without the ballsie, but then I haven't studied the shematic that well yet. This certainly is good news since it removes complexity(read price).


----------



## Cauhtemoc

Quote:


  Originally Posted by *BrianDonegan* 
_It will be -6dB (half of a balanced signal), but no op-amps, if that's what you are after. You just need a bit more gain afterwards._

 

Using only one output will decrease the signal by 3 dB, not 6 dB. The main thing however is that it will also decrease the dynamic headroom and signal to noise ratio by 3 dB.


----------



## Jambo

3dB in power, 6dB in voltage - voltage really being the more appropriate.


----------



## n_maher

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_I didn't know that you could get SE without the ballsie, but then I haven't studied the shematic that well yet. This certainly is good news since it removes complexity(read price)._

 

As far as I know you can always use a balanced source single ended provided that you're willing to live with the lower output levels. As Brian said, that's really just a function of how much gain you need/have downstream. Me, using my balanced DAC single-ended hasn't presented an issue at all and I'd forgo using the ballasie unless you really need the maximum output level from the DAC.


----------



## Jambo

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_As far as I know you can always use a balanced source single ended provided that you're willing to live with the lower output levels._

 

That and the common mode rejection of noise.


----------



## BrianDonegan

Quote:


 I'd forgo using the ballasie unless you really need the maximum output level from the DAC. 
 

Or an output buffer (SE or balanced) and/or want to LP filter.


----------



## Russ White

Hello, sorry I missed this conversation so far. Some points if I may. 
	

	
	
		
		

		
			





 1) The Opus works wonderfully single ended even without the Ballsie module as others have pointed out.

 2) The Ballsie is a bit more than a BAL/SE converter. The output of the DAC is not conducive to driving very current hungry loads, it has a minimum load of 1K. In those cases where the load is < 1K the Ballsie acts a buffer (both balanced and SE). Notice that the Ballsie has balanced AND SE outputs at the same time. I have been listening to the DAC with Ballsie in place for a couple weeks now. I truly like it better in the mix especially with single ended power amps like the "MyREF". 

 3) The Ballsie is an implementation of Wolfson's own recommended filter circuit that has been tweaked just a tad. In this respect it can be viewed as a stand in for something like a zap-filter. The opamps we are using are incredibly low distortion and low noise, and work very well for the role. The design was blessed by the Wolfson engineers I submitted it to. Call it peer review. 
	

	
	
		
		

		
		
	


	




 4) The USB module was really intended to simply be another I2S source for the Opus stack, in which case it sounds incredibly good. But, Brian and I have found that also despite being bus powered, it actually sounds very good on its own (much better than I expected) using its internal DAC and analog outputs.

 5) I have a lot of tricks up my sleeve, The Opus stack is by no means complete yet 
	

	
	
		
		

		
		
	


	




 , look for some very very cool things coming soon... I would say more but Brian will shoot me. One thing I will mention is our ASRC module(possibly more than one ASRC module).

 You can look at the Opus stack as an expandable project. You can start out as basic as you please, and add to it as you like. Start with just the REC/DAC and later add USB, Ballsie, ASRC, etc. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## MASantos

ASRC?


----------



## Russ White

ASRC = Asynchronous Reclocker. It can up-sample 44.1 to 192,96,48khz whatever, or even down-sample. Because it can host the master clock, it can provide a nice clean clock solution. How much better it is than the other clock sources remains to be seen. But at least it will be an option. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## swt61

Thanks for the clarifications Brian and Russ. I'll be using the balanced outputs 99% of the time, and my Opus build has a Zapfilter discrete output stage, but you did make things clearer for me. 

 Can't wait to hear your Joshua Tree on my ϐ22 build.


----------



## _atari_

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Hello, sorry I missed this conversation so far. Some points if I may. 
	

	
	
		
		

		
		
	


	




 1) The Opus works wonderfully single ended even without the Ballsie module as others have pointed out.

 2) The Ballsie is a bit more than a BAL/SE converter. The output of the DAC is not conducive to driving very current hungry loads, it has a minimum load of 1K. In those cases where the load is < 1K the Ballsie acts a buffer (both balanced and SE). Notice that the Ballsie has balanced AND SE outputs at the same time. I have been listening to the DAC with Ballsie in place for a couple weeks now. I truly like it better in the mix especially with single ended power amps like the "MyREF". 

 3) The Ballsie is an implementation of Wolfson's own recommended filter circuit that has been tweaked just a tad. In this respect it can be viewed as a stand in for something like a zap-filter. The opamps we are using are incredibly low distortion and low noise, and work very well for the role. The design was blessed by the Wolfson engineers I submitted it to. Call it peer review. 
	

	
	
		
		

		
		
	


	




 4) The USB module was really intended to simply be another I2S source for the Opus stack, in which case it sounds incredibly good. But, Brian and I have found that also despite being bus powered, it actually sounds very good on its own (much better than I expected) using its internal DAC and analog outputs.

 5) I have a lot of tricks up my sleeve, The Opus stack is by no means complete yet 
	

	
	
		
		

		
		
	


	




 , look for some very very cool things coming soon... I would say more but Brian will shoot me. One thing I will mention is our ASRC module(possibly more than one ASRC module).

 You can look at the Opus stack as an expandable project. You can start out as basic as you please, and add to it as you like. Start with just the REC/DAC and later add USB, Ballsie, ASRC, etc. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ_

 

ASRC? whicked! looking really forward!!!!
 You do awesome stuff!


----------



## bearmann

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Hello, sorry I missed this conversation so far. Some points if I may. 
	

	
	
		
		

		
		
	


	




 1) The Opus works wonderfully single ended even without the Ballsie module as others have pointed out.

 2) The Ballsie is a bit more than a BAL/SE converter. The output of the DAC is not conducive to driving very current hungry loads, it has a minimum load of 1K. In those cases where the load is < 1K the Ballsie acts a buffer (both balanced and SE). Notice that the Ballsie has balanced AND SE outputs at the same time. I have been listening to the DAC with Ballsie in place for a couple weeks now. I truly like it better in the mix especially with single ended power amps like the "MyREF". 

 3) The Ballsie is an implementation of Wolfson's own recommended filter circuit that has been tweaked just a tad. In this respect it can be viewed as a stand in for something like a zap-filter. The opamps we are using are incredibly low distortion and low noise, and work very well for the role. The design was blessed by the Wolfson engineers I submitted it to. Call it peer review. 
	

	
	
		
		

		
		
	


	




 4) The USB module was really intended to simply be another I2S source for the Opus stack, in which case it sounds incredibly good. But, Brian and I have found that also despite being bus powered, it actually sounds very good on its own (much better than I expected) using its internal DAC and analog outputs.

 5) I have a lot of tricks up my sleeve, The Opus stack is by no means complete yet 
	

	
	
		
		

		
		
	


	




 , look for some very very cool things coming soon... I would say more but Brian will shoot me. One thing I will mention is our ASRC module(possibly more than one ASRC module).

 You can look at the Opus stack as an expandable project. You can start out as basic as you please, and add to it as you like. Start with just the REC/DAC and later add USB, Ballsie, ASRC, etc. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ_

 

Greetings,
 and thanks a lot for your statement, russ! Now the Opus is on the top of my own list ... which you could call "My first DAC". Well, perhaps an AlienDAC at first - as a "warm up". 
	

	
	
		
		

		
		
	


	




 best regards,
 bearmann


----------



## luvdunhill

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_look for some very very cool things coming soon..._

 

like more Joshua Tree boards?


----------



## luvdunhill

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_look for some very very cool things coming soon..._

 

like more Joshua Tree boards? 
	

	
	
		
		

		
		
	


	




 edit: nevermind, just checked your website....


----------



## sleepy dan

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_
 2) The Ballsie is a bit more than a BAL/SE converter......I truly like it better in the mix especially with single ended power amps like the "MyREF". 
_

 

Could you expand? Thanks.


----------



## Russ White

Expanding:

 First, let me describe two setups for loudspeakers.

 I2S(USB, SB, CDP, DVD, etc..) -> Opus -> Power Amp (TXO) 1K impedance.
 I2S(USB, SB, CDP, DVD, etc..) -> Opus -> Ballsie -> Power Amp (TXO) 1K impedance.

 There is no preamp currently in the mix. I have firmware written to control the volume direct from the Opus. The voltage gain of the power amps is low(about 10X) so I can run the DACs without much attenuation (usually around 18db) Both setups above work well, but as I said earlier the current drive of the DAC chip itself is not exactly beefy. The TXO power amp as I have it configured uses fully symmetric current feedback and the source sees a load of around 1K. This is right at the DAC's minimum. While it sounded fine, I was anxious to try it with the Ballsie in place. Well lets just say it is staying... 
	

	
	
		
		

		
		
	


	




 The music is just more alive and dynamic, there is more punch. Also, with the filter caps in place on the ballsie, the presentation of the DAC become a bit warmer, sweeter, while still leaving the excellent dynamics of the DAC. I can't decide if I like it better with or without the filter caps, but I am glad it is easy to use it either way.

 Here is the other side benefit, the SE output of the ballsie is the same level as the differential output. This worked out great for me as I have a very good subwoofer amp with only SE inputs, and before I was simply feeding it half the differential signal directly from that DAC, the problem with that being that then the DAC was asymmetrically loaded. While that does no serious harm, it is not optimal, especially when you are using it balanced too, the balanced output is then not quite quite as balanced if you follow.

 Also, I like to run the DAC in mono mode (dual differential) where both differential outputs are in parallel. The Ballsie allows for this and provides series resistance so that the parallel outputs are evenly loaded and do not drive each other. Dual differential mode is definitely the way to go for absolute optimal performance from the WM8740.

 I hope that helps.

 Cheers!
 Russ


----------



## soloz2

I think I'm going to get to hear one soon! Fierce and I are planning to get together for a little listening session


----------



## sleepy dan

Thanks Russ.

 mmmm .... multi-dac modules ..... drool


----------



## swt61

Quote:


  Originally Posted by *soloz2* /img/forum/go_quote.gif 
_I think I'm going to get to hear one soon! Fierce and I are planning to get together for a little listening session_

 

Doh! You'll get to hear my DAC before me. Remember that one has a Zapfilter installed, but Jim has heard it without the ZF as well. I'm dying to hear about it!


----------



## soloz2

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Doh! You'll get to hear my DAC before me. Remember that one has a Zapfilter installed, but Jim has heard it without the ZF as well. I'm dying to hear about it!_

 

If I'm lucky I'll get to hear spacemanspliff's Beresford too 
	

	
	
		
		

		
		
	


	




 and I have my modded Zhaolu 1.3 andmy Bereford MKIII


----------



## luvdunhill

^^bump^^

 any impressions?


----------



## swt61

I think they were getting together this weekend.


----------



## soloz2

I've gotta get ahold of Jim, I was hoping to meet tomorrow, but I haven't heard from him.


----------



## ast

Any impression of the Opus with headphones ?


----------



## Clutz

And I'm curious if anyone has used this DAC without the Ballsie with a headphone amp. They say that the benefit of using it is that it isn't a very good current source (i.e. amps < 1K impedance) - but my Beta22 (almost done) and Dynalo have 50K impedances, so, it seems like it would be unnecessary.
 Brad


----------



## OverlordXenu

I wish I could DIY. I want an OPUS so much...

 Also, what's the difference between using one DAC module, or running it in a dual-mono configuration?


----------



## Jambo

Better SNR because of the higher output levels and, one would imagine, better seperation between the channels...


----------



## MrMajestic2

Did anyone have problems with the PS for the DAC? Im running both the digital section of the DAC and the SPDIF receiver on out2 on the LCDPS and R4 on the PS is turning very hot and smells burned. When running it unloaded its fine and pumping out 7.5V on both channels.


----------



## MrMajestic2

Hmm, it seems like when the Ballsie with PS is plugged in to the same toroid it gets overloaded. I took them out and its now up and running. Sound fantastic by the way 
	

	
	
		
		

		
			





 Apparently my 15VA 2x15V toroid is not strong enough for all modules.


----------



## BrianDonegan

If I understand what you correctly, you have a single 15VA transformer powering both supplies... this is the problem.

 The DAC's LCPS (LCDPS) cannot use a center tapped transformer, because the center tap will become the + rail of first supply, and the - rail of the second supply (two distinct supplies on the board). When you connect them to the DAC, the grounds from each supply meet, and you are basically shorting + and -.

 The Ballsie's Dual Supply (now LCBPS) does the opposite. The two center secondaries of your dual secondary transformer are joined to form a virtual center tap, and the center (Ground) rail of the supply.

 Therefore, when you attach your transformer to both supplies, the Ballsie's power supply is turning your transformer into a center tapped transformer, and that causes a problem on the DAC supply. In the end, you need separate transformers.

 The alternative, is use the single transformer to power the Ballsie supply, then use a single set of its secondaries to power both sides of the DAC supply - this will prevent the center tap shorting situation.


----------



## MrMajestic2

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_If I understand what you correctly, you have a single 15VA transformer powering both supplies... this is the problem.

 The DAC's LCPS (LCDPS) cannot use a center tapped transformer, because the center tap will become the + rail of first supply, and the - rail of the second supply (two distinct supplies on the board). When you connect them to the DAC, the grounds from each supply meet, and you are basically shorting + and -.

 The Ballsie's Dual Supply (now LCBPS) does the opposite. The two center secondaries of your dual secondary transformer are joined to form a virtual center tap, and the center (Ground) rail of the supply.

 Therefore, when you attach your transformer to both supplies, the Ballsie's power supply is turning your transformer into a center tapped transformer, and that causes a problem on the DAC supply. In the end, you need separate transformers.

 The alternative, is use the single transformer to power the Ballsie supply, then use a single set of its secondaries to power both sides of the DAC supply - this will prevent the center tap shorting situation._

 

Aha, I see. Didnt realise that this would happen. So the solution for this is to run both secondaries to the Ballsie PS, and then run a single secondary from the Ballsie supply to the DAC supply? But all four power inlets on the DAC supply must be populated I guess, so Ill just jumper between them, right? Hmm, maybe I will run dual transformers anyway, even though the umbilical will be huge 
	

	
	
		
		

		
		
	


	




 Anyway, thanks for the swift reply and thanks for a great sounding DAC. Now I just need the upsampler module


----------



## MrMajestic2

Ok, decided to go with dual transformers. Dual umbilicals actually looks pretty cool 
	

	
	
		
		

		
		
	


	




 The DAC sounds fantastic with the Ballsie up and and running. Now I just need a bigger case to house all the modules. The Galaxy GX243 is getting kind of cramped.


----------



## swt61

Sounds pretty nice. How is the soundstage?


----------



## MrMajestic2

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Sounds pretty nice. How is the soundstage?_

 

Little early to give a review, but to my ears its very wide and detailed. Im not set up to A/B with and without Ballsie yet, but I will be later when my B22 is built 
	

	
	
		
		

		
		
	


	




 Im listening though a pimped out Pimeta at the moment since my Millet Max is undergoing some modifications. Im betting that it will sound even better with another amp.


----------



## luvdunhill

^^ synchronized bump (or not... must wait 30 seconds between posts?) ^^

 any more impressions?

 Also, can any of the twisted pear goodies be configured to operate in non-oversampling mode?


----------



## Clutz

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_^^ synchronized bump (or not... must wait 30 seconds between posts?) ^^

 any more impressions?

 Also, can any of the twisted pear goodies be configured to operate in non-oversampling mode?_

 

No, because the DAC chip that they have used has both the oversampling filter and the DAC itself integrated into a single chip solution. In order to make use of a non-oversampling DAC, you need to use a DAC chip that doesn't have a digital filter integrated. To the best of my knowledge, all current DAC chips have the digital filters integrated, except maybe the AD1853?

 Brad


----------



## fordgtlover

MrMajestic2

 Do you have pics?


----------



## MrMajestic2

Quote:


  Originally Posted by *fordgtlover* /img/forum/go_quote.gif 
_MrMajestic2

 Do you have pics?_

 

Here it is, in a very temporary case. Its even complete with blutac and cardboard panel express backpanel 
	

	
	
		
		

		
			





 I just ordered a much bigger case for it so I can have space for upgrades.


----------



## fordgtlover

Thanks heaps This is very helpful.


----------



## BrianDonegan

Here's a few pics of the one I just built for the Burning Amp festival (www.burningamp.com).
















 More pics of the build here: http://www.twistedpearaudio.com/user...y/_burning_dac

 It is a dual mono dac with both USB and S/PDIF inputs (switched with a hand etched relay board), two ballsies (one with filters, one without, for comparisons) and the first build of the ASRC module (Metronome).


----------



## pageman99

D@mn, that's nice!


----------



## MrMajestic2

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Here's a few pics of the one I just built for the Burning Amp festival (www.burningamp.com).

 It is a dual mono dac with both USB and S/PDIF inputs (switched with a hand etched relay board), two ballsies (one with filters, one without, for comparisons) and the first build of the ASRC module (Metronome)._

 

Thats beautiful Brian. Does the Ballsie to anything for the balanced output as well, besides passing it thru the filter? Also, can you give any specs on the ASRC module, Im dying to know more


----------



## BrianDonegan

It provides a current buffer for the balanced outs. Not really needed in controlled circumstances, when you know what's going to be connected to it. Also, the filtered Ballsie provides the 500kHz 6dB filter to both balanced and SE signals. Another reason to tap both balanced and SE from the ballsie (when used) would be for both to have the same output level, and also because it is easier.

 Another note on wiring. I was doing some tests on the workbench last night, and found it's not too hard to get the I2S clock lines to induce noise in both power and analog signal lines. It's best to stack the I2S components, or keep them somewhat isolated, and keep clock lines as short as possible. In the pics above, I kept all the digital stuff to the left, analog on the right. If I had that one to do over again, I would have done two digital stacks and left more space between them and the Ballsies. It worked out fine this time, but will be more careful after last night's tests. Also, as always, best to make power wiring as straight and short as possible.


----------



## n_maher

Brian wins the prize for both having the sexiest DAC I've seen in a long time and using it with the cheapest digital cable! 
	

	
	
		
		

		
		
	


	




 Very, very nice.


----------



## thrice

Very nice indeed...what case is that?


----------



## BrianDonegan

Thanks! Cheap wiring too. Mostly SPC (Newark) 24gauge stranded PVC wire I got on closeout. XLR wire is retwisted (to 3) cat5, and the rca coax is the center of a triple-shielded car audio cable I had laying around.

 It's a Par-Metal 12x12x3 case with custom front and rear panels, and knob (all machined by my brother - that's why all the closeups of the switch and such in the photo library - part of our discussions).


----------



## MASantos

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Thanks! Cheap wiring too. Mostly SPC (Newark) 24gauge stranded PVC wire I got on closeout. XLR wire is retwisted (to 3) cat5, and the rca coax is the center of a triple-shielded car audio cable I had laying around.

 It's a Par-Metal 12x12x3 case with custom front and rear panels, and knob (all machined by my brother - that's why all the closeups of the switch and such in the photo library - part of our discussions)._

 

Nicest Opus I've seen so far! The front panel is awesome, very clean. 

 Are you considering selling front panels?


----------



## Cauhtemoc

Quote:


  Originally Posted by *Clutz* 
_No, because the DAC chip that they have used has both the oversampling filter and the DAC itself integrated into a single chip solution. In order to make use of a non-oversampling DAC, you need to use a DAC chip that doesn't have a digital filter integrated. To the best of my knowledge, all current DAC chips have the digital filters integrated, except maybe the AD1853?

 Brad_

 

Sigma delta DACs are by nature oversampling, it is the very principle on how they operate. AD1853 is a sigma delta DAC.

 Some examples of non-oversampling DACs are AD1862, AD1865, TDA1541, TDA1543 and PCM56, PCM63.


----------



## BrianDonegan

Quote:


 Some examples of non-oversampling DACs are AD1862, AD1865, TDA1541, TDA1543 and PCM56, PCM63. 
 

none of which are still available. Coincidence?


----------



## MASantos

Despite some current family affairs which take almost all my time from DIY, 

 I'm still studying all the options about the OPUS. I will be using the USB input.

 Then I thought about the option of using the USB input module by itself and saving both the $ and the space of the extra module, PS an transformer, which is quite important as I will be sharing a place with other people soon and won't have much private space to have a big rig.

 I will be using the DAC with a CK2III and what I am thinking is how much better will the extra $ and space sound when paired with the CK2.

 I know all the yadayada about only subjectivity of sound and only me being able to judge if it is worth it. I am looking for your experiences and opinions. 

 Also, if anyone compared both, how does the USB module form Twisted compare with the Alien DAC?

 If using the SUB module alone I could put it in the same enclosure as the Amp thus saving more space and $


----------



## holland

The DAC you built, Brian, is very pretty. Props to your brother for the panels.

 I think the USB module is similar to the Alien DAC in that it will be 16-bit still.

 How about an FPGA for USB?


----------



## J.D.N

*Newbie questions alert*

 Is it possible to build the twisted DAC with just USB and optical input? 

 What kind of experience level is needed for the kit?


----------



## holland

It's case work and wiring and very little soldering. There's some soldering in the power boards, but it's through hole and very easy. You need to do some drilling for the standoffs and wiring to connect the boards together and drill the panels for the connectors, etc.


----------



## swt61

Gorgeous work Brian! That is one beautiful DAC!


----------



## pabbi1

Well, reality check time - here is my scenario:

 1) I am using the SP8416 S/PDIF receiver with the OPUS DAC. 
 2) Using the ddigital PS (one side) to power both - 10.5v, using only + / G 

 Pics:
PSU connection
Recsiver to DAC
Input to Receiver

 Is this all kosher?


----------



## Russ White

Things look fine except I don't see any wire from the supply to VA on the DAC board.

 Cheers!
 Russ


----------



## pabbi1

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Things look fine except I don't see any wire from the supply to VA on the DAC board.

 Cheers!
 Russ_

 

True - so is that just a jumpered wire from + as well, or ????


----------



## pabbi1

OK, jumpered the VA, but I only hear what seems to be transport noise - no music signal - anyone ever experience this, and know (or can guess) what might be the culprit?

 So close (I hope)...


----------



## BrianDonegan

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_OK, jumpered the VA, but I only hear what seems to be transport noise - no music signal - anyone ever experience this, and know (or can guess) what might be the culprit?

 So close (I hope)..._

 

Some things to check in order...

 1) Check jumpers. Your DAC jumpers look okay, but can't see your receiver jumpers.

 2) Check input wiring. Are you getting a lock light (LED)? Is R1 in place on your receiver board? I remember something about you having balanced S/PDIF and SE S/PDIF (might be wrong). Looks like you are using a SE input in these pics, so you want either R1 (jumper) in place or add a jumper between GND and IN- in the terminal block (easier).

 3) Possibly missing clock. Double check continuity between the DAC and Receiver I2S. This is easily done by checking for continuity from the screw-clamp heads for each I2S line.


----------



## pabbi1

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Some things to check in order...

 1) Check jumpers. Your DAC jumpers look okay, but can't see your receiver jumpers.

 2) Check input wiring. Are you getting a lock light (LED)? Is R1 in place on your receiver board? I remember something about you having balanced S/PDIF and SE S/PDIF (might be wrong). Looks like you are using a SE input in these pics, so you want either R1 (jumper) in place or add a jumper between GND and IN- in the terminal block (easier).

 3) Possibly missing clock. Double check continuity between the DAC and Receiver I2S. This is easily done by checking for continuity from the screw-clamp heads for each I2S line._

 

Yes, using coax input.

 No R1, and jumpers set. OK, I am not getting a lock light...

 Each I2S line has continuity...

 Pics of the receiver board:

Receiver shot
Another...
One last shot


----------



## BrianDonegan

Try setting the PDR jumper to 

 What is your S/PDIF source?


----------



## pabbi1

A Sony DVD player...


----------



## BrianDonegan

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_A Sony DVD player..._

 

Make sure it is configured for PCM out (usually done through on-screen menus).


----------



## pabbi1

Yes, verified PCM digital output - I get the same with my Eastfield E5 digital out, that I know we have used at meets, and has no configuration...

 The PDR jumper is jumpered to the left two pins - and a jumper from G -> input-, which I guess is redundant.

 The sound I get is like a soft whirling projector... 

 Would current pics help?


----------



## MASantos

For those using a zapfilter with the opus, so you simply remove the output caps and connec the output of the dac to the zapfilter? 

 can someone elaborate on this?


----------



## BrianDonegan

So, I figured out recently that a few of the Ballsie modules shipped with mislabeled filter caps (the option ones). That is, C1-C8 are supposed to be 1200pF, C9-C12 are 22pF. The values supplied were reversed.

 The effects if installed this way are messed up phase and roll-off of high frequencies (22pF instead of 1200pF in the HP filter). I have already emailed anyone who might have one like this, but thought I would post here as well in the email I have is not monitored (PayPal email). I am sending out replacements if you have one and need them.


----------



## pabbi1

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_Would current pics help?_

 

One
Two
Three
Four
Five
Six
Seven


----------



## BrianDonegan

All seems to look good in your pictures. I would try changing PDR to high (currently low). 

 How is it wired to your Millet? Have you tried checking it's outputs directly while not connected to anything else? 

 A simple way to do this is to use a cheap pair of headphones; attach an alligator clip from GND to the headphones ground ring, then touch the plug tip to each of the dac's outputs, one at a time.


----------



## swt61

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_For those using a zapfilter with the opus, so you simply remove the output caps and connec the output of the dac to the zapfilter? 

 can someone elaborate on this?_

 

As far as I know my Opus is the only one with a Zapfilter currently. I have not heard it yet, and it's still with the builder (fierce_freak). I would PM him, he's a very easy guy to talk to.


----------



## pabbi1

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_All seems to look good in your pictures. I would try changing PDR to high (currently low). 

 How is it wired to your Millet? Have you tried checking it's outputs directly while not connected to anything else? 

 A simple way to do this is to use a cheap pair of headphones; attach an alligator clip from GND to the headphones ground ring, then touch the plug tip to each of the dac's outputs, one at a time._

 

More concerned that I never get a lock light on the receiver, but I will try the PDR setting.


----------



## Russ White

Pabbi,

 One of first thing you should do is isolate the receiver (nothing connected to it except power). Make it the only thing connected to a power supply. Apply your SPDIF signal, and see if you get a good lock.

 Then we can move on from there.

 Brian is working on a diagram to show where to check the voltages (he will be posting it soon). If the REC is not locking on its own its time to check your LDO output voltages and be sure you are not dealing with a dead LDO.

 Cheers!
 Russ


----------



## pabbi1

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Pabbi,

 One of first thing you should do is isolate the receiver (nothing connected to it except power). Make it the only thing connected to a power supply. Apply your SPDIF signal, and see if you get a good lock.

 Then we can move on from there._

 

Done - no lock... voltage in is +, and 10.61v...


----------



## BrianDonegan

On the bottom of the board, measure the voltage across the pins of each of the three OSCON capacitors (blue).


----------



## MASantos

can't wait for my parts to arrive!!! opus module plus all 3 input boards with some sort of switching arrangement. this will connect directly to a single ended CK2III. I choose not to use the ballsie to save some $ as well as not increasing the case even more. All together in a custom made zebrawood enclosure with ebony knobs. inputs will also feature RCA's and possibly an IMOD input(with nice film caps inside the case).


----------



## swt61

That sounds fantastic!


----------



## pabbi1

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_On the bottom of the board, measure the voltage across the pins of each of the three OSCON capacitors (blue)._

 

C15 - 4.97v
 C14 - 3.26v
 C16 - 3.27v


----------



## srobertson

Ballsie question:

 I'm just about ready to place the final touches on my parts list for a PIMETA which will be cased up right along-side the Opus. I'd love to have an output for my loudspeaker amp as well. My loudspeakers are decent, but I care only about the sound quality in my cans; if adding the amplifier output will discernibly reduce the sound quality of my headphones, I'll skip it and live with inconvenience.

 Which of these sounds like the best solution for preserving quality of signal to headphones?

 * Output of headphone amp runs in parallel to headphones and loudspeaker amp (AudioSource Amp 100/A, with attenuators so it doesn't get crazy loud)
 * Single-ended Ballsie output run in parallel to PIMETA and 100/A inputs
 * Single-ended Ballsie to PIMETA, GND and balanced + Ballsie to 100/A
 * The reverse of the above

 Note that both amps tie the two input grounds together as expected.

 Side note: the Ballsie uses NP0 ceramics for its through-hole caps. Is it worth considering finding e.g. polystyrene equivalents?

 Thanks in advance!


----------



## luvdunhill

wait, a PIMETA as a speaker amp?


----------



## srobertson

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_wait, a PIMETA as a speaker amp? 
	

	
	
		
		

		
		
	


	


_

 

Well, I was just going to run 220VAC across it to give the amp the kick it needs to drive loudspeakers. I know what you're thinking - "wait, isn't that cheating?" - and yes, it is cheating. But don't worry, I switched the all the capacitors for BlackGates, which should compensate for the extra power draw. (I was also going to use a higher-power reverse-bias "crowbar" diode, but we all know how much things like diodes and fuses can mess up that clean stream of power. I'm just soldering the power in to my apartment's three-phase in the breaker cabinet to bypass all those noisy circuit breakers.)

 The PIMETA is exclusively for my HD650s (or whatever else comes along); the AudioSource Amp 100/A (which I abbreviated as 100/A above) will be driving my speakers. Sorry for any ambiguity.


----------



## Daveze

Quote:


  Originally Posted by *srobertson* /img/forum/go_quote.gif 
_Well, I was just going to run 220VAC across it to give the amp the kick it needs to drive loudspeakers. I know what you're thinking - "wait, isn't that cheating?" - and yes, it is cheating. But don't worry, I switched the all the capacitors for BlackGates, which should compensate for the extra power draw. (I was also going to use a higher-power reverse-bias "crowbar" diode, but we all know how much things like diodes and fuses can mess up that clean stream of power. I'm just soldering the power in to my apartment's three-phase in the breaker cabinet to bypass all those noisy circuit breakers.)_

 

Make sure you distribute the shots of the amp in action...I'm thinking plenty of pretty lights.


----------



## soloz2

you should put something better than a PIMETA in there, especially for HD650's


----------



## BrianDonegan

Quote:


 C15 - 4.97v
 C14 - 3.26v
 C16 - 3.27v 
 

Might be easiest to send the receiver back for testing/replacement.


----------



## pabbi1

Ok, as I take it that didn't look right? I'll get it back out tonight... to send the DAC as well, since I'm waiting on the receiver anyway?


----------



## BrianDonegan

Well, the voltages look right, so it's either a) some nitty gritty problem or b) something silly that I am not seeing in the pics.


----------



## OverlordXenu

Damn, I want one of these. 
	

	
	
		
		

		
			





 Edit: Brian, I must say, that is the most AMAZING things I've seen in audio...The casework is extraordinary. If I could get a DAC that looked like that, I think I may have to bite the bullet and do that.

 Ah, if only I could DIMyself...


----------



## jellybones

Has anyone posted any impressions?


----------



## fierce_freak

There were some impressions in the Meet Impressions forum (look for displaced Canadians in Western New York).


----------



## MASantos

Got my opus kit and receiver pcbs today in the mail. Now I need to wait for the transformer to arrive and I'll be ready to fire it up!!!


 Brian do you solder the SMD chips yourself or do you have it made somewhere else, the soldering is pretty impressive! Packaging was awesome!!! Thumbs up one more time!!


----------



## el_matt0

hey guys im sure someone can easily answer this. i wasnt quite able to piece together everything i would need through the twisted pear site. im hoping to build an opus dac that will have 1 pair of balanced xlr outputs, and 1 or 2 pairs of RCA outputs. i would like a coaxial as well as a toslink input. at this point i plan to run it as a dual mono dac assuming that is no more difficult than setting up one in stereo. i know for a toslink input i need the s/pdif module as well as the toslink module. do i need an ADDITIONAL s/pdif module alone to run a coaxial input as well, or can 2 inputs be run into one s/pdif? id also need to grab a ballsie and bipolar PSU for it in order to have RCA outputs right? my only other questions are, 1 trafo and 1 lcdps is sufficient for an entire opus group of modules right? also, what is the metronome crystal listed at $75. is that the clock (in which case i assume its obviously necessary right)? or is it an optional upgrade (if so what does it do 
	

	
	
		
		

		
		
	


	




!) hopefully someone can answer these so i can start thinking about ordering up!


----------



## MASantos

Quote:


  Originally Posted by *el_matt0* /img/forum/go_quote.gif 
_hey guys im sure someone can easily answer this. i wasnt quite able to piece together everything i would need through the twisted pear site. im hoping to build an opus dac that will have 1 pair of balanced xlr outputs, and 1 or 2 pairs of RCA outputs. i would like a coaxial as well as a toslink input. at this point i plan to run it as a dual mono dac assuming that is no more difficult than setting up one in stereo. i know for a toslink input i need the s/pdif module as well as the toslink module. do i need an ADDITIONAL s/pdif module alone to run a coaxial input as well, or can 2 inputs be run into one s/pdif? id also need to grab a ballsie and bipolar PSU for it in order to have RCA outputs right? my only other questions are, 1 trafo and 1 lcdps is sufficient for an entire opus group of modules right? also, what is the metronome crystal listed at $75. is that the clock (in which case i assume its obviously necessary right)? or is it an optional upgrade (if so what does it do 
	

	
	
		
		

		
		
	


	




!) hopefully someone can answer these so i can start thinking about ordering up! 
	

	
	
		
		

		
		
	


	


_

 

here is my take on your questions, but take it with a grain of salt as I'm not completely sure of some of them:

 YOu don't need the ballsie to use the DAC single ended. Just connect one of the positive outputs to signal to one of the negatives to ground. It won't have as much gain as when using a ballsie, but you might get away with it. 

 The metronome is not needed to build the opus. It is an external clock that improves upon the internal clock of the DAC. I won't expend much here as I don't know much about the subject but itis said to improve SQ. I sure that if you search the web about assincronous clocks for DAC you'll find very usefull info. 

 AFAIK, you can feed the optical and coaxial through one spdif module, that's should be a problem and it wouldn't make much sense to need another one just to make it work right?

 The great thing about the OPUS is the modularrity and opportunity of expansion. 

 I just got myself one opus board with the 3 input boards, but when I have some more funds available, I'll get the metronome, another dac module to run in dual mono with dual PS and probably some sort of selector between both imputs. That could save you some money now and still give you upgrade option in the future.

 Good luck with your build!


----------



## el_matt0

thanks, do you know if dual power supplies are needed or even recommended for running dual mono or can you get away with one?


----------



## Nebby

You can indeed run two dac boards from a single power supply no problem. Done it myself and it's what I'm using for my headphone setup.

 I've recently picked up a head unit with digital out, and I'm building up an opus to use with it 
	

	
	
		
		

		
		
	


	




 Just need to pick up a relay so I can do the remote power on.


----------



## OverlordXenu

So I'm getting one. 
	

	
	
		
		

		
		
	


	




 Brain, for the love of aesthetics, sell those front panels! (Preferably in black and silver. 
	

	
	
		
		

		
		
	


	




 )


----------



## BrianDonegan

Quote:


 Brian do you solder the SMD chips yourself or do you have it made somewhere else, the soldering is pretty impressive! Packaging was awesome!!! Thumbs up one more time!! 
 

Thanks! I do it myself with solder paste and a reflow oven, not using an iron.

  Quote:


 YOu don't need the ballsie to use the DAC single ended. Just connect one of the positive outputs to signal to one of the negatives to ground. It won't have as much gain as when using a ballsie, but you might get away with it. 
 

This is almost right. You want to use +OUT and GND, leave -OUT disconnected. The reason to not use -OUT, is that many devices will join the GND of left and right channels, which would cause a short on the DAC if you were using -OUT. GND are shared already. If you are sure GND would not be shared, then +OUT and -OUT is okay.

  Quote:


 Brain, for the love of aesthetics, sell those front panels! (Preferably in black and silver. ) 
 

First, it's Brian, not brain (common mistake 
	

	
	
		
		

		
		
	


	




). The only problem with making the front and rear panels for the Par-Metal cases is coming up with a design that works for most people. I this case (pun intended), a single center control worked. We could come up with 2 or 3 standard layouts, but doing one-offs is expensive.


----------



## el_matt0

@ brian, i dont know if its been asked in this forum or elsewhere yet. but how did you come up with the twisted pear "logo" on your dac? was it done by hand by your brother? if it was done via computer, is there any chance u have the imagine in some sort of format others might be able to incorporate into a front panel express panel? tied into that question of course is, if it IS possible for you to share the pear symbol, would you MIND? again, i know im not the first to say it, but absolutely beautiful work on that dac man, i can only hope to have one that looks half as nice as that beauty!


----------



## BrianDonegan

Geez, thanks!

 The logo... interesting story... well, to me.

 Back in the day, when Russ and I first hooked up and decided to do this, we were trying to think up a name. Being engineer types, this was not pretty. After a lot of back and forth, we came up with Twisted Pair Audio. 
 Next, we needed a logo. If you thought the naming was bad... yikes.

 So, I was driving around with my wife, who is an artist, and who loves me despite my complete lack of artistic ability. I tell her we are trying to think up a logo design, and ask her what she sees when she thinks of "twisted pair?" She says, "the fruit. Why not just use a twisted pear?" 

 Bing, that's fantastic, all we need to do is change the name to "Twisted Pear." But, how do I draw a twisted pear? We finally get home, and as we come in the door, and with one arm holding groceries, she scribbles the logo on a piece of paper with a Sharpy marker (picture rolling eyes... "like that").

 Scanned it in, and there's the logo. And our name that generally makes no sense. Perfect for us. 
	

	
	
		
		

		
		
	


	




 Now, I do have the logo as jpeg, psd, etc. Not sure if we want to release it in the wild. Have to think on that. The one on the front panel of the DAC is not actually etched into the metal. My brother used a laser etcher (really made for plastics and such). There is a special ink they apply to the aluminum, then hit it with the laser. Anything not hit washes off with water. If we made these panels, they would be etched, if we put a logo on them at all. The cool thing about that machine, for our rushed build schedule, is that it reads just about any format, so we didn't need to redraw the logo in solid works, just plug in the jpeg.

 On that topic, I just had a quick conversation about panels with my brother, as it is something we have talked about for a long time. Current thinking goes like this. We could make panels like those on my dac (3/8" aluminum plate, cut and tapped to mount in the Par-Metal cases. The rear panels would have a standard spot for the power inlet and fuse. The rest of the panel would have a grid maybe 8x2. In any of the grid intersections we could cut and tap holes for a standard Neutrik connector (XLR m/f, RCA, USB, etc, all the same hole). Front panel would be similar, but maybe a 1x5 grid, and we would need to decide on a set of hole/recess sizes, and probably a few knobs. So, to buy you would select the locations of your ins/outs on the rear, and/or the locations and knob types for the front, and we turn it around in a week or so. I could resell the Par-Metal cases too to make it a one stop shop thing. Not sure how popular it would be, and the real question will be shipping. Nothing insurmountable though. Another problem, aluminum like most metals is not so cheap anymore, and costs by weight, so we would have to look at costs before it could be priced.


----------



## el_matt0

well, speaking for myself at least, i know i would definitely be interested. im sure shipping and everything wouldnt end up coming out to TOO much, and im sure you guys could even make profit for all your hard work without the prices being set to ridiculously high. I think for the quality of DAC being put together here, and the quality of case you are producing, people would not object to paying a decent amount of money for them. just a question about your opus, so it has 2 pairs of XLR outputs and two pairs of RCA outputs? i think personally id be happy with one pair of xlr outs and probably 2 pairs of RCA (its possible to run 2 sets of RCA out (4 total) from a single ballsie right? anyway, is this a serious idea you guys are considering, producing some more of these panels/cases i mean? because at the moment im beginning to seriosuly put together plans for building myself an opus, if you could have these up and going at ALL in the near future i would definitely jump right on that immediately!! 
	

	
	
		
		

		
			





 let me know, im VERY keen to hear back about this


----------



## MASantos

Brian, even though your idea sounds interesting, I'm not sure about the acceptance. The OPUS is extremely versatile regarding input modules, outputs, external clocks, the ballsie, etc

 Not everyone uses the same combination of modules and making a panel that would please everyone might be difficult. I personnaly like to design my own panels as this is part of the whole DIY thing. I am considering starting to build my own cases from scratch including the anodising process, so other people might find this service your proposing usefull. 

 Just my 0.02 €

 Manuel


----------



## penger

Hrm... why not? I would be interested in something like this. One stop shop sounds like an awesome idea.


----------



## BrianDonegan

Quote:


 Not everyone uses the same combination of modules and making a panel that would please everyone might be difficult. 
 

This is why we don't have them currently. If we can figure out a half-decent way to let people customize them to their needs, then we have something. Ironically, the rear panel is easier than the front panel.


----------



## penger

I guess the complexity of the back panel will end up dictating what ends up being on the front panel?


----------



## Nebby

After listening to the opus in my car, I must say it works really well 
	

	
	
		
		

		
		
	


	




 Now I just need a volume control and some sort of line driver to up the voltage. I think it'll be a bit fun trying to get the ballsie power supply given a 12v and ground supply


----------



## BrianDonegan

Quote:


 I guess the complexity of the back panel will end up dictating what ends up being on the front panel? 
 

I think the whole thing will hinge on us finishing the Uber controller. Then you can have an LCD and two rotary encoders on the front panel (maybe premounted), and control any/all of our stuff, so the rear panel changes with the guts you select.


----------



## Marzie

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_I think the whole thing will hinge on us finishing the Uber controller. Then you can have an LCD and two rotary encoders on the front panel (maybe premounted), and control any/all of our stuff, so the rear panel changes with the guts you select._

 


 Speaking of the controller, any date in mind (or even month?)


----------



## naamanf

For those that have built their Opus with a Ballsie what voltages did you use for it?

 Also any preferences on deemphasis and roll-offs?


----------



## regal

There was talk at DIYaudio about a PCM1794 version with a fully discrete I/V. I think this sort of DAC is much needed for DIYers. Has anyone got any news on this?


----------



## SoapSeller

there are news on the front page in twistedpearaudio.com


----------



## regal

Quote:


  Originally Posted by *SoapSeller* /img/forum/go_quote.gif 
_there are news on the front page in twistedpearaudio.com 
	

	
	
		
		

		
		
	


	


_

 

OK we all need to email him that we want the active I/V (Jocko or D1 style).
 There's plenty of passive I/V PCM1794 projects out there.


----------



## Cata1yst

*patiently waits for my turn at the Opus.....*

 these things sell like hot cakes, i swear i think ill need to make it my homepage and keep an eye on it before you all take it away from me


----------



## BrianDonegan

We will definitely have an active I/V stage, and are considering a few designs. The passive I/V I mentioned is an optional on-board set of R's and C's, and will be through hole parts that can be installed by the end user (I might install them and you could simply clip them off if not used). If you use the passive I/V, you will also need a buffer, such as a ballsie.

 With the active I/V, you would simply omit those parts and go direct to the I/V board. Our current favorite (no pun intended) is based on the THS4131 symmetric fully differential op-amp.


----------



## OverlordXenu

What's are the differences between the WM8740 and the WM8741?

 The one I have coming has a WM8740, what does this mean for me?

 :|


----------



## BrianDonegan

Basically:

 Better SNR
 Better THD
 DSD support (SACD)
 More expensive


----------



## Cata1yst

Is there a big difference between the Active IV versus a Passive IV?


----------



## BrianDonegan

In our testing, not much that we can hear. It will come down to personal preference.


----------



## BrianDonegan

Early look at the discrete active i/v stage...

diyAudio Forums - Discrete Super Symmetric(I think) Opamp for I/V Etc...


----------



## Cata1yst

Alright so it basically means we have to get a ballise or a buffer to go single ended now? or am i missing something?


----------



## koike

Yeah to go single ended you have to get the opus DAC + the ballsie. but what i want to know is what the usb receiver does?
 is it a USB input? or is it another DAC all togetheR? anyone tell me how much they cost to? twisted pear didnt reply my mails.


----------



## FallenAngel

Cata1yst: You can just use "half" of the OPUS to get a single-ended signal, you don't *need* to use the Ballsie, but it does allow you to get rid of the output caps (as I've heard, not positive) and it's a much stronger signal as opposed to using half of the OPUS.

 koike: The USB receiver uses the PCM2707 which outputs I2S to the OPUS DAC for DAC duties, but since the PCM2707 has its own DAC, the board also lets you take analog output straight from it.

 The prices are all on the site.


----------



## koike

so when will brian stock the dacs?
 hahaha i would like 1 for my bijou and b22


----------



## regal

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_With the active I/V, you would simply omit those parts and go direct to the I/V board. Our current favorite (no pun intended) is based on the THS4131 symmetric fully differential op-amp._

 


 So does this mean the discrete I/V idea is out of the picture now ?


----------



## BrianDonegan

We are making some minor layout changes to the DAC boards and should have them back in stock by the end of January (hopefully before that).

 We are actually working on a fully discrete balance I/V, which you can see the current state of here: diyAudio Forums - Discrete Super Symmetric(I think) Opamp for I/V Etc...


----------



## Cata1yst

Quote:


  Originally Posted by *FallenAngel* /img/forum/go_quote.gif 
_Cata1yst: You can just use "half" of the OPUS to get a single-ended signal, you don't *need* to use the Ballsie, but it does allow you to get rid of the output caps (as I've heard, not positive) and it's a much stronger signal as opposed to using half of the OPUS.

 The prices are all on the site._

 

Alright, for some reason his Active/Passive I.V post confused the living daylight out of me...i thought i would have to use a ballise after the changes

 thanks for clearing it up FallenAngel


----------



## BrianDonegan

Sorry, to confuse. The I/V isn't needed for the Opus, only the COD, because it is a current output DAC.

 I have about 20 COD modules that I will be putting up on the site in the next week or so.


----------



## fierce_freak

I'll have to keep an eye out for that.


----------



## swt61

Well I got back from a 6 week out of town job today, and my Opus DAC was waiting for me, along with my new β22.

 This Opus has a Zapfilter MkII discrete output installed, and the sound is phenominal.

 No real impressions until I've had a few days to spend with it, but I have a big, stupid grin on my face that won't go away. 
	

	
	
		
		

		
		
	


	















 The Opus and the β22 were built by fierce_freak, and I can't begin to tell you how professional his work is.


----------



## OverlordXenu

What's on the front panel, an on button and source selector?


----------



## swt61

Quote:


  Originally Posted by *OverlordXenu* /img/forum/go_quote.gif 
_What's on the front panel, an on button and source selector?_

 

If you're looking at the Black units on the top shelf that's the β22 and σ22 power supply. 
 The Opus is the Silver unit two shelves down, and it has a power switch located in the center of the faceplate, and two LEDs on either side (left power, right signal).
 It does have coaxial and Toslink inputs, but no source selector switch (I didn't want the noise from a switch), so whichever input is active is the one processed.


----------



## koike

im quite confused.
 what do i need?
 i know i need an opus, a ballsie and a usb receiver.
 whats the I/V and COD?


----------



## Jambo

I think you could do with some new clothes as well... 
	

	
	
		
		

		
			





 With the three modules you mention you will be pretty well set, although you'll need a power supply of some kind...


----------



## fierce_freak

the I/V and the COD is a completely different set of modules, a different DAC. The Opus uses the WM8740 DAC chip from Wolfson which is a voltage out DAC, and the COD (current output DAC) is based around the PCM1794 by Burr Brown. Current output DACs need a current to voltage (I/V) conversion at their output.

 If you want to use the Opus, the Opus, Ballsie, and USB receiver is a great choice, and all you need (plus the power supplies).


----------



## Cata1yst

So what are the benefits of a COD module? and is it an addon unit? or is it just an alternative to the current DAC board?

 Cata1yst


----------



## Jambo

For a while, all DACs were current output and you needed an external current to voltage stage. 

 Then IC manufacturers put the I/V stage on the silicon, but apparently (I haven't tried a comparison) didn't make a good job of it so many purists prefer the original method.

 The WM8740 doesn't use this kind of architecture though as someone has already pointed out.


----------



## MASantos

Quote:


  Originally Posted by *koike* /img/forum/go_quote.gif 
_im quite confused.
 what do i need?
 i know i need an opus, a ballsie and a usb receiver.
 whats the I/V and COD?_

 

 Quote:


  Originally Posted by *Cata1yst* /img/forum/go_quote.gif 
_So what are the benefits of a COD module? and is it an addon unit? or is it just an alternative to the current DAC board?

 Cata1yst_

 

Guys, most of this information is spread around in the different threads both here and over at DIYaudio.com as well on twistedpearaudio.com

 Read every thread thoroughly. I've learned that this is one of the best ways to start a project. you'll read about all sorts of difficulties other people have gone through, read about different configurations and options and get a much better overall idea about the project. THis will save you from asking tons of questions and will prepare you much better to the project!


----------



## Nebby

Has anyone done comparisons of a ballsie'd opus vs zapfiltered opus?


----------



## swt61

I doubt enough people have the Opus yet to do a comparison like that.

 Pabbi1 has an Opus integrated into a Millet hybrid, and if I remember right it has a ballsie. We'll both be at the Dallas meet Jan. 26th, so we may be able to accomodate you then.


----------



## pabbi1

In the end I chose to NOT use the Ballsie as I think I have enough SE gain for those rare times I won't be using my unit balanced. And, since it is my office rig, I didn't think the flexibility would ever really be needed.


----------



## swt61

I was wrong on two counts, I see the amp it's housed in is a MilletMax.
 Can't wait to hear it Al.


----------



## naamanf

I was tempted to order a Zap filter for my Opus. I am using the Ballsie now and it sounds very good. A step up from the other DACs I have used so far. I would try out the Zap filter but the cost of shipping is silly.


----------



## Cata1yst

The ballise is only 100$ shipped...the Zap is 200$ +shipping last time i checked....

 eh, get the ballise and mod it a little bit


----------



## naamanf

Speaking of moding I am thinking about replacing the output caps on the Opus with some BG NX-HiQs. What do you guys think?


----------



## pabbi1

Quote:


  Originally Posted by *Cata1yst* /img/forum/go_quote.gif 
_The ballise is only 100$ shipped...the Zap is 200$ +shipping last time i checked....

 eh, get the ballise and mod it a little bit 
	

	
	
		
		

		
		
	


	


_

 

Yeah, but he is shipping into an APO in Iraq...


----------



## pabbi1

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_Speaking of moding I am thinking about replacing the output caps on the Opus with some BG NX-HiQs. What do you guys think?_

 

Except for the stinking 'bloom', not a bad idea - it just takes so long to break them in, though I do think the BG are better than the Oscons... but, you still have the smd Panasonics to deal with... not sure if the overall hassle is worth it, but you have the lead.


----------



## naamanf

Actually shipping USPS is the same as shipping to New York/NJ. 

 The Zap filter shipping was like 30 euros which just seems a bit silly for something that is maybe half a pound.


----------



## naamanf

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_Except for the stinking 'bloom', not a bad idea - it just takes so long to break them in, though I do think the BG are better than the Oscons... but, you still have the smd Panasonics to deal with... not sure if the overall hassle is worth it, but you have the lead._

 

I just happen to have 8 22uF NXs sitting here. Not like I have any other use for them. Just means I would have to order some more to keep the stock up 
	

	
	
		
		

		
			





 The Panasonics can stay. It's the Oscons that are being used as the coupling caps for +/-.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Basically:

 Better SNR
 Better THD
 DSD support (SACD)
 More expensive_

 


 Would I be able to hot wire the I2S signal out of my SACD player and run it to the OPUS DAC for SACD?


----------



## Nebby

With the chip used in the current opus dac, it is not capable of decoding SACD. The next iteration of the opus dac is supposed to be able to decode DSD which is SACD.


----------



## Nebby

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_I was tempted to order a Zap filter for my Opus. I am using the Ballsie now and it sounds very good. A step up from the other DACs I have used so far. I would try out the Zap filter but the cost of shipping is silly._

 

Good to hear that the opus sounds good with a ballsie, I'm currently working on implementing the ballsie in my opus dac stack in my car and hope to get it up and running soon. Personally I'm leaning towards picking up a zapfilter, I'm sure I could find a use for it even if I don't like how it sounds compared to the ballsie. 
	

	
	
		
		

		
		
	


	




 On a separate note I hooked up the metronome into my opus dac stack yesterday and instead of hearing more detail it seemed as if the details were muddied a bit. I'm thinking I set it up incorrectly or something, as this seems to go against what I've read about reclocking/resampling in general.


----------



## naamanf

Just saw that PartsConnexion has zapfilters. They are $215 compared to $260 direct. And cheaper shipping to boot. I might just have to give one a try.

 I plan on putting the BlackGates in today


----------



## naamanf

And the BGs are in! One thing I noticed (at least think I noticed) was improved bass right off the bat. As for the rest, time will tell.


----------



## rodentmacbeastie

Hello Jim,

 I have a couple of questions regarding the build of the Opus DAC... First, did you sort out the cap mess up from Twisted Pear? I am interested in how it would fair against the ZAPfilter? In one meet it was said that the Ballsie and the ZAP were close. If this is the case, how does the properly assembled Ballsie compare? Would a Ballsie be necessary if I were to run the DAC output directly to an Aikido line stage/head-amp?

 Also, the next generation Opus has the Wolson DAC chip to support DSD. Would I not be able to jumper the I2S and clock signals in my Oppo and have the Opus do the D/A with no spdif conversion?

 I am getting excited about starting to build my new system and will be mostly DIY. I want to use Twisted Pear's upcoming contoller interface to operate the DAC, attenuator and I2S switching board. This would be built into a chassis with the Aikido preamp/phone amp. Another seperate chassis for power supplies for the DAC and Aikido. The preamp/DAC would have SE, coax digital, I2S, and USB inputs. SE outputs and headphone jack. This should allow me to make the DAC the centre of the system hooked up to an Oppo transport (either spdif or I2S), my computer through I2S output, SE sources with a high quality amp to drive the cans and speakers.

 Unless my cash flow improves it will likely start as a SE rig and may stay that way if it sounds as good as I think it will! However, I am thinking big with a Balanced set-up. If you have any ideas I would love to hear them. Thanks for your time.

 David


----------



## luvdunhill

Brian:

 would you mind sharing the part number for the screw terminals that you send with your projects? They have a philips screw and seem a bit more rugged than the ones I usually buy.

 Thanks!


----------



## BrianDonegan

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_Brian:

 would you mind sharing the part number for the screw terminals that you send with your projects? They have a philips screw and seem a bit more rugged than the ones I usually buy.

 Thanks!_

 

Phoenix Contact numbers 1935161 and 1935174. In the US, available from Mouser and Digikey.


----------



## swt61

Just wanted to report that I'm more than a little impressed with my dual differential Zapfiltered Opus. Fantastic dynamics and sounstage. The bass is outstanding as well. Huge $ - performance factor here! 

 A full review to come in the near future.


----------



## johnsonad

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Just wanted to report that I'm more than a little impressed with my dual differential Zapfiltered Opus. Fantastic dynamics and sounstage. The bass is outstanding as well. Huge $ - performance factor here! 

 A full review to come in the near future._

 

Glad to hear it Steve! Hopefully I'll get mine finished soon


----------



## swt61

Quote:


  Originally Posted by *johnsonad* /img/forum/go_quote.gif 
_Glad to hear it Steve! Hopefully I'll get mine finished soon 
	

	
	
		
		

		
		
	


	


_


----------



## Reynaldo

I made up my mind to build one of these dacs, right now I am only interested in one coax input and unbalanced outputs, maybe in the future I will add the USB input but my motherboard came with a coax digital out, and I already spend money in a 20 ft canares digital cable, so If I have it right all I need to order is the combo with the opus DAC module, S/PDIF receiver module and LCDPS kit. The above with the Avel Lindberg Transformer (115V+115V prim. / 15V+15V 15VA sec.) make a working DAC, right? Ready to order, hope they become available soon.


----------



## glt

Yes, that's all you need. I bought the same kit and later added the Metronome ASRC. Some pictures here: Picasa Web Albums - glt - OpusDac


----------



## Reynaldo

Thanks for the answer, nice looking wood bases, did you make those yourself? Any reason why you are using 7.5 secondaries? What does the metronome do?


----------



## glt

7.5V recommended by the manufacturer. Every board has a local regulator so the value I think is not too important. It just need to be a couple of volts above 5V. One leg of the PS goes to the analog side of the DAC board, the other leg powers the digital side of the DAC board, the receiver board, the toslink module and the metronome. Metronome is a reclocker board. You can find more info in the diyaudio board. The wood feets I made, the wood base is a cutting board only used to take the pictures


----------



## glt

Oh, not 7.5v secondaries, 7.5 is the output DC voltage of the PSU. The secondaries of the transformer are 15V


----------



## bhobba

Hi All

 This is my first post here. I have been following this thread with interest.

  Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_Speaking of moding I am thinking about replacing the output caps on the Opus with some BG NX-HiQs. What do you guys think?_

 

I have decided on a modded Azur 740C that uses the same DAC in dual differential mode. When speaking to the guys that will be doing the mods they mentioned it had blocking capacitors they will be replacing with BG's because they think it sounds better than most film capacitors. One thing I can't understand is why you even need them. The suggested circuit for dual differential mode is DC coupled - providing the offset is the same it will sum to zero in the output stage.

 Am I missing something?

 Thanks
 Bill


----------



## bhobba

The suggested circuit for dual differential mode is DC coupled - providing the offset is the same it will sum to zero in the output stage.
 l[/QUOTE]

 Sorry - forgot to mention of course you will need them for the balanced output - but single ended has me scratching my head.

 Thanks
 Bill


----------



## Jambo

You are correct - dual differential mode should require no caps in the signal path, as long as an opamp with low DC offset is used. Any idea what is used in the 740C opamp wise? We should probably keep a bit more on topic though...


----------



## BrianDonegan

Quote:


 Sorry - forgot to mention of course you will need them for the balanced output - but single ended has me scratching my head. 
 

Since our output stage is optional (not needed at all for balanced operation), we have blocking caps for the DAC's balanced outputs. If you use our Ballsie for single ended output, you can safely bypass the output caps. I think this has already been covered in the thread, but there are a few of them now so it may have been somewhere else.


----------



## bhobba

Quote:


  Originally Posted by *Jambo* /img/forum/go_quote.gif 
_You are correct - dual differential mode should require no caps in the signal path, as long as an opamp with low DC offset is used. Any idea what is used in the 740C opamp wise? We should probably keep a bit more on topic though..._

 

OPA2604. The moders replace it with an LM4562. I have no idea why they don't scrap the coupling caps. Maybe it is part of the filter.

 Thanks
 Bill


----------



## Nebby

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Just wanted to report that I'm more than a little impressed with my dual differential Zapfiltered Opus. Fantastic dynamics and sounstage. The bass is outstanding as well. Huge $ - performance factor here! 

 A full review to come in the near future._

 

Good to hear the zapfiltered opus is doing well 
	

	
	
		
		

		
		
	


	




 Looking forward to your full review!


----------



## Jambo

Probably because they then couldn't tell you that they're putting blackgates in! Sounds like you should attempt the mod yourself to me...


  Quote:


  Originally Posted by *bhobba* /img/forum/go_quote.gif 
_OPA2604. The moders replace it with an LM4562. I have no idea why they don't scrap the coupling caps. Maybe it is part of the filter.

 Thanks
 Bill_


----------



## naamanf

Well I can tell you what sounds better than Blackgates. No Blackgates. Pulled them out and installed jumpers. Really seemed to make a huge difference. I am always a bit skeptical of what I hear when changing things around but it really does sound a lot better. Seemed to make the largest difference on the top end and transparency. Very worthy upgrade (downgrade?). 

 Here it is:





 Still waiting on a certain Uber controller to finish it up and make it pretty.


----------



## BradJudy

very nice naamanf - I'm thinking of doing something similar, but SE only. Did you get those transformers from Twisted Pear too, or elsewhere?


----------



## naamanf

Those are the trafos that Twisted Pears sells.


----------



## SoapSeller

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_If you use our Ballsie for single ended output, you can safely bypass the output caps._

 


 When using the Ballsie for balanced output, this is safe too, right?


----------



## naamanf

I still think you need them unless your amp can do the dc filtering.


----------



## BrianDonegan

Quote:


 When using the Ballsie for balanced output, this is safe too, right? 
 

No. the DC offset will still be present on the balanced outputs of the Ballsie. As naamanf mentioned, some equipment can deal with the 2.5V offset, but definitely not all.


----------



## 04BluMach

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_Well I can tell you what sounds better than Blackgates. No Blackgates. Pulled them out and installed jumpers. Really seemed to make a huge difference. I am always a bit skeptical of what I hear when changing things around but it really does sound a lot better. Seemed to make the largest difference on the top end and transparency. Very worthy upgrade (downgrade?). 

 Here it is:






 Still waiting on a certain Uber controller to finish it up and make it pretty._

 

SWEET build....
	

	
	
		
		

		
		
	


	




 No high Frequency hash or listening fatigue experienced with the removal of the BG's from the output? What level, if any, dc on your outputs with the BG's removed?


----------



## pinkfloyd4ever

umm I'm an electrical dumbass but why would someone want to take an awesome balanced dac, add a S.E. converter and then try to use that for a balanced setup? Why not just skip the ballsie in the first place?


----------



## naamanf

Quote:


  Originally Posted by *04BluMach* /img/forum/go_quote.gif 
_SWEET build....
	

	
	
		
		

		
		
	


	




 No high Frequency hash or listening fatigue experienced with the removal of the BG's from the output? What level, if any, dc on your outputs with the BG's removed?_

 

There might be just a tad but I much prefer the sound now with them gone than with them there. The problem is I am going to need a output with no DC eventually. I think I might give the Zap filter a try.


 The DC offset is 2.5V.

  Quote:


  Originally Posted by *pinkfloyd4ever* /img/forum/go_quote.gif 
_umm I'm an electrical dumbass but why would someone want to take an awesome balanced dac, add a S.E. converter and then try to use that for a balanced setup? Why not just skip the ballsie in the first place?_

 

The ballsie has separate SE and balanced outputs.


----------



## hershann

Brian,

 any idea when the next batch of Opus will be available?

 her shann


----------



## BrianDonegan

We should be ordering the new boards in the next day or two. It will take a few weeks for them to arrive, then I need to start building. Probably the beginning of February. I'll post ship dates on our site once I know more detail.


----------



## SoapSeller

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_No. the DC offset will still be present on the balanced outputs of the Ballsie. As naamanf mentioned, some equipment can deal with the 2.5V offset, but definitely not all._

 

Thanks for the answers.

 My in-build-b22 will kill my headphones with such offset 
	

	
	
		
		

		
		
	


	





 Probably I'll try to change the caps, and maybe the zapfilter later.


----------



## BrianDonegan

The ZapFilter has caps in the path too (I think). It's either going to be a discrete circuit, op-amp or caps to get rid of the offset, take your pick. You could use a TXD module to do it as well.

 [EDIT] Nope, it doesn't. Just looked. Well, not ELs anyway.


----------



## koike

hi brian,
 im wondering if its possible to reserve a set since everything goes so fast?
 i have been emailing you but to no avail.


----------



## Epicurean

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_The ZapFilter has caps in the path too (I think). It's either going to be a discrete circuit, op-amp or caps to get rid of the offset, take your pick. You could use a TXD module to do it as well.

 [EDIT] Nope, it doesn't. Just looked. Well, not ELs anyway._

 

AFAIK the Zapfilter mkII doesn't have caps anywhere in the signal path but uses an opamp for a dc-servo.


----------



## BrianDonegan

Quote:


 AFAIK the Zapfilter mkII doesn't have caps anywhere in the signal path but uses an opamp for a dc-servo. 
 

It has three 470pF caps (silver mica), one for stability, to as filters, similar to the Ballsie. Nothing wrong with that. Can't make a filter without them.


----------



## Cauhtemoc

Quote:


  Originally Posted by *BrianDonegan* 
_It has three 470pF caps (silver mica), one for stability, to as filters, similar to the Ballsie. Nothing wrong with that. Can't make a filter without them._

 

Actually, all three as used for filters. The first capacitor is part of a differential filter set at 127 kHz, the second and third capacitor are two single filters set at 84 kHz.


----------



## BrianDonegan

Quote:


 im wondering if its possible to reserve a set since everything goes so fast? 
 

Once we know when the boards will be arriving and we have a solid ship date (including time for me to build), we will open up pre-orders. We are again doubling the number of boards in the order, so they should last longer this time. We are also going to be ready to order more before we run out.


----------



## regal

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_The ZapFilter has caps in the path too (I think). It's either going to be a discrete circuit, op-amp or caps to get rid of the offset, take your pick. You could use a TXD module to do it as well.

 [EDIT] Nope, it doesn't. Just looked. Well, not ELs anyway._

 

or a Sowter transformer


----------



## BrianDonegan

Quote:


 but uses an opamp for a dc-servo. 
 

No servo. Those are matched transistors in an 8-pin package.


----------



## rodentmacbeastie

Brian, any news on the Uber controller, I2S hub, and SACD capability?


----------



## hershann

Brian & Russ,

 have read through the threads here as well as in DiyAudio (although I must say a lot of the jargon just does not register), have a few questions:

 1) Opus DAC - I understand it is a balanced out but can be used SE with halved output just by using the the +R / +L and GND. And it is a capacitor coupled output because of the DC generated by the DAC - correct so far?

 2) I see a lot of design that require the use of an opamp / discrete components after the DAC chip to supply enough juice for the next stage - the lack of the opamp in this design means that the internal amplification of the DAC is good enough to drive the next stage? (what preamp input impedance is it optimised for?). I guess the current is halved for the SE vs balanced or is it only the voltage swing that is halved?

 3) The Ballsie - I think it it meant to convert the balanced output to SE while preserving the balanced output power / voltage. Although it can be configured to be an optional low pass filter for the balanced output (advantage of bypassing the capacitor too). How much difference does it make to the balanced output?

 4) Is the Ballsie a current buffer too for both the SE and balanced set-up? How much more capable is it compared to the DAC output alone? Does it matter if the next stage has got high impedance anyway?

 5) What's the advantage / disadvantage of a class A discrete analog output stage if used for the opus dac (replacing the ballsie) if driving a high impedance preamp (e.g. 10k ohm) i.e. not being used as a headphone amp?

 Sorry if that has been answered before, but I did try to look through the thread.

 thanks

 her shann


----------



## BrianDonegan

Quote:


  Originally Posted by *hershann* /img/forum/go_quote.gif 
_1) Opus DAC - I understand it is a balanced out but can be used SE with halved output just by using the the +R / +L and GND. And it is a capacitor coupled output because of the DC generated by the DAC - correct so far?_

 

Correct so far.

  Quote:


 2) I see a lot of design that require the use of an opamp / discrete components after the DAC chip to supply enough juice for the next stage - the lack of the opamp in this design means that the internal amplification of the DAC is good enough to drive the next stage? (what preamp input impedance is it optimised for?). I guess the current is halved for the SE vs balanced or is it only the voltage swing that is halved? 
 

Yes. The WM8740 can feed a minimum impedance of 1K (absolute minimum), but 10K or higher is ideal. Current is halved as well as voltage.

  Quote:


 3) The Ballsie - I think it it meant to convert the balanced output to SE while preserving the balanced output power / voltage. Although it can be configured to be an optional low pass filter for the balanced output (advantage of bypassing the capacitor too). How much difference does it make to the balanced output? 
 

Correct. In my back to back testing, I haven't noticed much difference, but I'm also driving a 100K load. Incidently, the next gen of the Ballsie will come with the filter caps preinstalled, but switch to Panasonic PPS film. We are also switching to ultra low noise Susumu 0.1% thin film resistors on all the boards (there's no problem now, but it can't hurt). 

 Also, the Ballsie gives you the ability to drive balanced and se stages at the same time. For example, a balanced speaker amp and an se sub amp. 

 Note that the DAC's DC offset is only nulled for the se outputs, NOT the balanced outputs as you alluded to.

  Quote:


 4) Is the Ballsie a current buffer too for both the SE and balanced set-up? How much more capable is it compared to the DAC output alone? Does it matter if the next stage has got high impedance anyway? 
 

The opamps in the Ballsie can drive loads down to 600ohm, which is significantly better then the DAC direct, but if you are driving a 10K+ stage, it won't matter much.

  Quote:


 5) What's the advantage / disadvantage of a class A discrete analog output stage if used for the opus dac (replacing the ballsie) if driving a high impedance preamp (e.g. 10k ohm) i.e. not being used as a headphone amp? 
 

I have not done so, so can't comment. It would be pretty subjective, and I try to shy away from things (audio bliss is in the ear of the beholder). I'm sure there are others who can give you the answer you are looking for here.


----------



## BrianDonegan

Quote:


 Brian, any news on the Uber controller, I2S hub, and SACD capability? 
 

I do have news as a matter of fact. And it involves a bit of a chage of plan, but I think in a good way.

 First, the I2S hub. Our original plan was to use a pair of quad 4:1 mux chips and an isolator to create a 4:1 I2S mux. The concern we have is running a lot of I2S cables around creates a lot of noise and a really good chance of interference etc. Keeping I2S lines as short as possible seems to be the way to go. We have thus simplified the mux plan to be a 2:1 mux (two inputs, one output), using a 4PDT relay, and an onboard trigger, like the one I etched for my Opus demo dac, but better. Here is a preliminary pic (we are calling it OTTO):





 It is very basic, but works very well. You give it 5V and GND. Connecting 3-5V to the TR pin triggers the relay. This can be done by wiring a switch between the 5V and TR pins, or by sending it a signal from a microcontroller (like the Uber).
 It can also be used for other things, like a 2:1 balanced source selector (two of them for stereo), or any other signal you might want to switch.
 So, what if you have more inputs? Well, we are planning a new receiver board based on the WM8805, which will allow up to eight S/PDIF inouts and provide the excellent de-jitter for each. This will allow you to attach multiple coax, torx and/or usb (usb receiver w/s/pdif out) inputs. Source selection will be controllable via the Uber or a new simple controller (see below).

 SACD capability:
 The new Opus uses the WM8741 (ordering boards in the next couple days) has a DSD header for SACD support. You can get more information on DSD from the WM8741 datasheet. In order to use it, you will need an SACD player from which you can tap the unencrypted DSD signal (HDMI header will not work I think), and a WC (clock) either from the player or from an external master clock. Here is a preview of the new Opus board layout:





 Finally Uber:
 We are still working on the code for the Uber, and it is pretty slow going with all the other projects we have going. LCD, Rotary Encoder support, Remote control are all working quite well. We are still experimenting with different type of non-volatile memory (FRAM at the moment) and different digipots for things like LDC contrast control. That said, there are some new developments. 
 Our Kook pre/head amp was very popular, and very easy to build. The new Pogo will take it's place, but with the Uber is a bigger, more expensive venture. We had the idea of replacing it by creating a couple bew circuits we are calling simple controllers, which has a single task. The one for the Kook replacement will use the same pot-control methodology (uC ADC monitors voltage from a pot and in turn controls volume appropriately), and control the Pogo (PGA2320 volume chip), the Joshua Tree (stepped attenuator) and probably even the Opus volume using the DAC's digital volume control. Another simple controller will control S/PDIF input selection of the new WM8805 board via simple ground switching (like a rotary switch).
 None of the simple controllers will have displays, memory, etc, which is what makes them simple.

 Sorry for the long post. I'll be updating the information on our site with all of this in the next couple of days.


----------



## rodentmacbeastie

Brian,

 So, if I understand this correctly, I need to rip the spinner and front end out of a Sony SACD player(SCD-E595) up to the DAC chip or a DVD like an Oppo and jump wires before the DSD gets converted to PCM and the clock? Sony should be easier as it sends that DSD data to the DAC intact, right? I am eagerly awaiting the start of my build. The Opus is the center. I want to take advantage of the I2S switch(2 sources is all I need) and the Uber controller. The hope is that the Uber will be as you say and work as I need, I am excited to see. I will be building the case for the media server/SACD transport/Opus/tube pre/head amp and I plan on mounting the motherboard and the SACD below and above the Opus to keep the I2S leads as short as possible. All component compartments will be lined with copper to keep their noise to themselves. The leads should be 2-4" in length, is this OK? Should I shield them? Also, it looks like the DAC's volume control cannot be used with pure DSD only converted to PCM? If this is the case, I will need a balanced attenuator as well.

 Again, I am really looking forward to start this build! The thought of a one box, easily upgradeable media server that has a top quality DAC that is easily expandable, fed to a balanced tube amp to drive my cans and later, some amps and speakers and a TV in another room makes me happy!

 Thanks again Brian.

 David


----------



## CSO

I've searched and tried to find this information. Is the driver for the Opus USB input module contained within XP and Vista? Do I need to download a separate driver? Are there any settings within the OS? Is there a thread that discusses this somewhere? Thanks.


----------



## pabbi1

Regarding SACD, having the current generation OPUS, I get no recognition of SACD hybrids that play on all my other redbook players - is this a jumper, or are hybrid layers currently unrecognizable? Will this change with the new design?


----------



## glt

If you play the SACD layer, there is no digital output due to copyright restrictions. If you play the PCM layer, then the player or transport will output the PCM data through spdif or toslink. Not a function of the OPUS.

 Re: USB Driver: the OS will automatically recognize the PCM2707 (the USB receiver of the OPUS USB board) as a sound device.


----------



## digora

Hello

 What do you use after your OPUS module ? 

 Filter or not ? 

 Do you have remove the output capacitor is you have a balanced stage after the opus ? 

 Thx


----------



## rodentmacbeastie

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_Regarding SACD, having the current generation OPUS, I get no recognition of SACD hybrids that play on all my other redbook players - is this a jumper, or are hybrid layers currently unrecognizable? Will this change with the new design?_

 


 First, your Wolfson DAC does not do SACD. Second, your SACD transport has to be tapped before the DAC and after the DSD decoder. The new design should decode the SACD layer, not just Redbook. You will have to do this mod to. your SACD player first though.


----------



## glt

Quote:


  Originally Posted by *digora* /img/forum/go_quote.gif 
_Hello

 What do you use after your OPUS module ? 

 Filter or not ? 

 Do you have remove the output capacitor is you have a balanced stage after the opus ? 

 Thx_

 

Gathering the info from previous discussions, I've come to the conclusion that: If you removed the caps in the OPUS, then you will have a 2.5 V DC offset. This DC offset is removed in the SE output of the Balsie but not in the balanced output of the Balsie. If you want to remove this DC bias in the balanced mode, you will need to use the TXD modules.


----------



## BrianDonegan

Quote:


 Gathering the info from previous discussions, I've come to the conclusion that: If you removed the caps in the OPUS, then you will have a 2.5 V DC offset. This DC offset is removed in the SE output of the Balsie but not in the balanced output of the Balsie. If you want to remove this DC bias in the balanced mode, you will need to use the TXD modules. 
 

Correct, except that the TXD is just one way to do it (that happens to be ours).


----------



## hershann

This is a duplicate of the post at DIYaudio.

 Currently am waiting for the next batch of modules to be available - just a few questions:

 1) How can we tell if the next stage (e.g. preamp) can accept common mode DC? 
 e.g I am going to build the Pumpkin Preamp as discussed in the Passlab section - can you tell from the schematic if it can accept the DC?

 2) There was a lot of discussion about the poor audio implementation on the USB - I'm using a Macbook with built in optical (no external sound card) - is the Toslink->spDIF->I2S superior or the USB->I2S superior in this case?

 3) Ok really simple question here - bear with me - can I use a simple xlr to rca converter that ties the -R or -L to GND (e.g. the Neutrik Neutrik NA2FPMF) on the xlr balanced out to use as SE? - edit - there was a previous post that mentioned that -out to gnd will short the DAC -

 Any builders with more listening comments on the reclocking unit?

 thanks

 her shann


----------



## wquiles

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_The new Opus uses the WM8741 (ordering boards in the next couple days) 

 (snip)

 Sorry for the long post. I'll be updating the information on our site with all of this in the next couple of days._

 

Looking forward to the new boards 
	

	
	
		
		

		
		
	


	




 Thanks Brian!


----------



## CSO

Well, since the Opus Dac boards are out of stock, I decided to get an Opus USB receiver module and mess around with it a bit. The Opus USB receiver board uses the TI PCM2707 chip which not only provides S/PDIF output or I^2S output, but it also has analog L/R outputs. Russ has very nicely put a four terminal header on the board to connect to headphones, etc. The single Opus USB receiver board can be used as a low-mid quality dac on its own, which is nice for an office computer based stereo. It is totally powered from the USB 5V bus and installs in Vista without any extra drivers (XP too I believe). Although described "low-mid" fi, the analog outs from the Opus USB module sound good in my office.

 A caveat to the PCM 2707 chip is that the function select (FSEL) seems to allow for analog audio output only in the S/PDIF mode, so you can only get analog out from the Opus USB board when it is jumpered to S/PDIF. It took me a while to figure this out.

 I am curious to know if anyone has used the serial programming interface (SPI) on this chip for anything. Russ has given us a header for this as well.


----------



## BrianDonegan

Quote:


 A caveat to the PCM 2707 chip is that the function select (FSEL) seems to allow for analog audio output only in the S/PDIF mode, so you can only get analog out from the Opus USB board when it is jumpered to S/PDIF. It took me a while to figure this out. 
 

The new version of these board have a DIN pin next to the digital output header. If you pumper DOUT to DIN, you can use the analog outs in I2S mode as well.


----------



## CSO

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_The new version of these board has a DIN pin next to the digital output header. If you jumper DOUT to DIN, you can use the analog outs in I2S mode as well._

 

Cool. I wondered what the DIN was for. Now I know. Nice design. Thank you.


----------



## SoapSeller

Small question, for the Opus output caps, 6.3V rating is enough?


----------



## naamanf

Yes. I tried it with 6.3V 47uf BGs with no problem.


----------



## SoapSeller

Thanks.

 I'll report back after I'll change the caps(going to try BG as you did...).


----------



## rodentmacbeastie

Brian,

 Just out of interest, why didn't you use the DSD1794A in your COD instead of the PCM1974A? I like the idea of a current output DAC but I will be using your DSD support on the Opus. The DSD and PCM DAC chips are both 28 pins but I don't think they are interchangeable.


----------



## Russ White

I designed the COD around the PCM1794A because our sources are all PCM for now. 
	

	
	
		
		

		
			





 We will try out DSD with the WM8741(which is cool because it does both PCM and DSD very easily in hardware mode) and perhaps I will try the DSD TI parts at some point. The biggest obstacle to most people using DSD parts is just getting to unencrypted DSD. So demand is not very great.

 Cheers!
 Russ


----------



## Nebby

Just need to find a player that has somewhat accessible unencrypted DSD signal points


----------



## rodentmacbeastie

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Just need to find a player that has somewhat accessible unencrypted DSD signal points 
	

	
	
		
		

		
		
	


	


_

 



 That is the ticket. I will test this out with the Opus when I can get a DAC and a doner player.


----------



## BrianDonegan

Quote:


 I will test this out with the Opus when I can get a DAC and a doner player. 
 

...and when we can get WM8741s! We have been working with two Wolfson distributors, and even Wolfson directly. We can't even get a date as to when we can get them. Expecting a reply from our Wolfson rep soon...


----------



## Nebby

I've found out that the Oppo 981 has I2S headers that are wide open, so I think I will pick up one of those and hook up a spdif board to that and call it good enough 
	

	
	
		
		

		
		
	


	




 Though I need to read up and find out if it's possible to output both a coax and toslink spdif out at the same time, so I might be able to do some comparison listening


----------



## MASantos

Hey Brian, is the otto promo only valid if you buy the receiver modules outside the combo?


----------



## Nebby

Also, do we need to add the otto in cart for the promo, or will it automagically be put into our shipping box? 
	

	
	
		
		

		
		
	


	




 Btw, great new pictures!


----------



## BrianDonegan

Quote:


 Hey Brian, is the otto promo only valid if you buy the receiver modules outside the combo? 
 

Combos count. I will make it more clear on the page.

  Quote:


 Also, do we need to add the otto in cart for the promo, or will it automagically be put into our shipping box? 
 

I will add it. If you accidentally buy it, I will refund the cost.


----------



## MrMajestic2

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I've found out that the Oppo 981 has I2S headers that are wide open, so I think I will pick up one of those and hook up a spdif board to that and call it good enough 
	

	
	
		
		

		
			





 Though I need to read up and find out if it's possible to output both a coax and toslink spdif out at the same time, so I might be able to do some comparison listening 
	

	
	
		
		

		
		
	


	


_

 

Im also picking up the Oppo for this purpose. It seems almost too good to be true


----------



## MASantos

Great! 

 I'll be ordering the otto and metronome soon, probably next month,so that I have the ultimate OPUS DAC! Only the uber controller left!


----------



## rodentmacbeastie

Brian,

 Will the OTTO be able to switch the DSD I will tap from my player?


----------



## Nebby

I noticed on the opus page otto it said "for example, it can easily be used as a mono 2:1 or 1:2 switch for balanced analog signals, a stereo 2:1 or 1: switch for single-ended signals" Anyone know why can the otto only be used for mono in a balanced configuration? 

 With four switching contacts, that should allow for both +/- signals of left and right be switched. Is there something wrong with sharing a ground between left and right in a balanced configuration?


----------



## MrMajestic2

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I noticed on the opus page otto it said "for example, it can easily be used as a mono 2:1 or 1:2 switch for balanced analog signals, a stereo 2:1 or 1: switch for single-ended signals" Anyone know why can the otto only be used for mono in a balanced configuration? 

 With four switching contacts, that should allow for both +/- signals of left and right be switched. Is there something wrong with sharing a ground between left and right in a balanced configuration?_

 

Are you sure it says mono? I was under the impression that it will work in stereo, its got enough switching contacts like you say. Twisted Pears Opus page is down at the moment so I cant verify.


----------



## Nebby

That was a direct quote from the page, I'm thinking it's just a typo, but I had to ask before buying. Btw, was anyone else having issues with removing or changing quantities of parts in cart?


----------



## akione

Hi Nebby,

 Yes, I emailed Brian about that the other day and he said there was a bug in the scripting that he needed to fix.


----------



## MrMajestic2

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_That was a direct quote from the page, I'm thinking it's just a typo, but I had to ask before buying. Btw, was anyone else having issues with removing or changing quantities of parts in cart?_

 

Yeah, I see now that you are correct. In my head, the OTTO would work in balanced stereo, but maybe Im missing something.


----------



## Nebby

Wow, the usb board is already out of stock....that went quick


----------



## CSO

Hello,

 Can someone help me with a few details regarding the power supplies for the Opus DAC. This is a duplicate post (not sure if the DIYAudio board is very active).

 How much current do the LCDPS and LCBPS need from their respective transformer(s)? What is the current rating of the LM317 and LM337 supplied with the kits?

 What DC voltages should each power supply be adjusted to?

 Thanks.


----------



## naamanf

Quote:


  Originally Posted by *CSO* /img/forum/go_quote.gif 
_Hello,

 Can someone help me with a few details regarding the power supplies for the Opus DAC. This is a duplicate post (not sure if the DIYAudio board is very active).

 How much current do the LCDPS and LCBPS need from their respective transformer(s)? What is the current rating of the LM317 and LM337 supplied with the kits?

 What DC voltages should each power supply be adjusted to?

 Thanks._

 

TP sells the 15VA transformer to go with the power supplies. Remember you will need a transformer for each power supply. Not sure on the current rating of the regulators but I would guess they are 1A-1.5A

 The LCDPS is set to 7.5V on both sides and the LCBPS is 15V+/-


----------



## Brewmaster

How hard would it be for somebody with little electronics experience to put together one of these?

 I've never done a DIY project, but I have a basic understanding of what electronic components do, can use a multi meter, and have done some simple soldering.

 It looks like the soldering on the power supply would be the only tricky part, but seeing as it's all thorugh hole I can't imaging it would be that bad for somebody who had done even basic soldering before.


----------



## naamanf

It's pretty easy to put together. A soldering iron and multimeter would be the only tools you need beside those for the case work. Building the power supplies is very easy and all the parts are labeled for you. Pretty much connecting the dots. If you have any questions there are plenty of people here that could answer them.


----------



## Brewmaster

Just one quick question. If running with the Ballsie module, I would need both the Bipolar supply module, and the Low current dual power supply?

 I'm also assuming I would need a seperate transformer for each power supply.


----------



## naamanf

Yes to both.


----------



## johnsonad

Well, I am finally about ready to put this project together. A question to the group though, I am considering using the Metronome for jitter reduction only. If I match it to the input bit rate (44.1kHz or whatever) then that should be taken out of the picture and I can benefit from the jitter reduction from the oscillator chip right? Pro's or con's on this? Experiences so far? Also, Brian or anyone else, the tranny listed on the site will work fine with the bipolar supply module for the Ballsie right?


----------



## Russ White

Quote:


  Originally Posted by *johnsonad* /img/forum/go_quote.gif 
_Well, I am finally about ready to put this project together. A question to the group though, I am considering using the Metronome for jitter reduction only. If I match it to the input bit rate (44.1kHz or whatever) then that should be taken out of the picture and I can benefit from the jitter reduction from the oscillator chip right? Pro's or con's on this? Experiences so far? Also, Brian or anyone else, the tranny listed on the site will work fine with the bipolar supply module for the Ballsie right?_

 

Hi,

 You can do something close to that, but the XO we provide will not do 44.1, only 48khz. Still, I think you would be pleased with the results none the less.

 To do 44.1 you would need another XO. I would not bother. The WM8804 has extremely low jitter, if you want just 44.1 I would just use that.

 The trafo is perfect for the LCBPS feeding a ballsie.

 Hope that helps.

 Cheers!
 Russ


----------



## johnsonad

Thanks Russ


----------



## Lifthanger

This whole project is very interesting, but without the USB module its almost useless to me. 
	

	
	
		
		

		
		
	


	




 Is there an ETA on new USB boards?


----------



## Russ White

USB boards will be ordered this week. We should have them back in stock in the next couple weeks.

 Cheers!
 Russ


----------



## Lifthanger

thanks alot


----------



## scottj

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_USB boards will be ordered this week. We should have them back in stock in the next couple weeks._

 

Awesome! Just as I was finally ready to order, the USB boards were gone. You guys are great!

 -Scott


----------



## Lifthanger

I really love to DIY - will there be kits for the dac modules or the ballsie as well?
 If not I'll just order PCBs and have the added fun of sourcing components 
	

	
	
		
		

		
		
	


	




.

 While listening to my CKKIII everything is fun though!


----------



## Russ White

Hi,

 We get asked about kits a lot.

 We simply don't have time to do both modules and kits for everything in the digital lineup. Kits are incredibly time consuming, and prone to user issues. 
	

	
	
		
		

		
		
	


	




 For the Ballsie sourcing parts should not be very hard though.

 We are happy to sell bare boards, and if you really need some hard to find part to stuff the board feel free to ask us.

 Cheers!
 Russ


----------



## Lifthanger

ok thanks 
	

	
	
		
		

		
		
	


	




. With support of other DIYers this shouldn't be to hard for me.


----------



## MrMajestic2

Are there any issues in going dual differential using a version 1.0 and a 2.0 board together?


----------



## munchkin

hi,

 I've been using the opus dac through usb for a few days now. I was only using it on my main computer, which is running Vista, and it's been running fine. Today I tried plugging in the usb into 2 windows xp computers, but all i get is static and heavy interference with the music. Anyone have this problem?


----------



## MrMajestic2

Quote:


  Originally Posted by *MrMajestic2* /img/forum/go_quote.gif 
_Are there any issues in going dual differential using a version 1.0 and a 2.0 board together?_

 

Got a reply in the TP forum. Yes, its no problem running the different version together 
	

	
	
		
		

		
		
	


	




 Got another question to the people who built a differential Opus already: Is it worth going differential?


----------



## BrianDonegan

The only potential issue (if you want to call it that), is that the output caps may be different. The early first generation Opus modules used OSCONs (22uF), and later switched to SilmikII's. Second generation are SilmikIIs.


----------



## MrMajestic2

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_The only potential issue (if you want to call it that), is that the output caps may be different. The early first generation Opus modules used OSCONs (22uF), and later switched to SilmikII's. Second generation are SilmikIIs._

 

My board does not have Oscons, so Im safe 
	

	
	
		
		

		
		
	


	




 i just have to figure out if its worth it to go differential. Otherwise it might be fun to get a COD and switching between them using an OTTO board.


----------



## luvdunhill

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Phoenix Contact numbers 1935161 and 1935174. In the US, available from Mouser and Digikey._

 

Brian:

 This is JT related, but I figured it would be okay to post here. I added a switch + resistor to my JT that I am using to level-match two sets of headphones. Kinda nifty. I figure "volume presets" will be something that might be in the uber-controller, but adding a tactile switch and a re-programmed PIC might be able to do this same thing perhaps? I was even thinking about adding another pot and a switch between the two... which brings me to my next question:

 Do you think you could share the Alpha pot part number, as I have panels cut to account for the locking pin and need to order another 5k pot 
	

	
	
		
		

		
			





 Also, I'm supposing that it's hard to find a place to supply less than 100' of that 10-pin ribbon cable... I cannot find less at Mouser at least.

 edit:

 ooh, I'm assuming this cable should work:

Flat Ribbon Cable Gray 28 AWG IDC 10 Conductor 25 ft. - eBay (item 200197678096 end time Mar-05-08 08:26:10 PST)

 Thanks!


----------



## MrMajestic2

Quote:


  Originally Posted by *MrMajestic2* /img/forum/go_quote.gif 
_My board does not have Oscons, so Im safe 
	

	
	
		
		

		
		
	


	




 i just have to figure out if its worth it to go differential. Otherwise it might be fun to get a COD and switching between them using an OTTO board._

 

Doh, I dont know what I was smoking last night 
	

	
	
		
		

		
		
	


	




 My board does in fact have Oscons.


----------



## BrianDonegan

Quote:


 Do you think you could share the Alpha pot part number, as I have panels cut to account for the locking pin and need to order another 5k pot Also, I'm supposing that it's hard to find a place to supply less than 100' of that 10-pin ribbon cable. 
 

That wire is fine. The Pot is from Mouser: 313-2441-5K


  Quote:


 Doh, I dont know what I was smoking last night My board does in fact have Oscons. 
 

If you end up needing them, I can send extra Elnas.


----------



## hershann

Brian,

 received the Opus kit today. I must say this is the most professional packaging of a kit I've ever seen. The packing is so good that I am hesistating whether to set up the kit to trial as I know I'll need to repack them in 3 months time for my big shift back home.

 thanks for the beautiful kit

 her shann


----------



## Nebby

Quote:


  Originally Posted by *hershann* /img/forum/go_quote.gif 
_Brian,

 received the Opus kit today. I must say this is the most professional packaging of a kit I've ever seen. The packing is so good that I am hesistating whether to set up the kit to trial as I know I'll need to repack them in 3 months time for my big shift back home.

 thanks for the beautiful kit

 her shann_

 

I agree, between the packing and the amazingly well labeled parts TPA's kits are the best I've had so far. Although I haven't exactly had experience with all that many DIY kit providers


----------



## hershann

Brian, Russ,

 Don't want to assume anything - I gather that the tristate dip switch is read from left to right: 1 0 + corresponding to 1 0 open?

 her shann


----------



## Russ White

Yes, very close. 
	

	
	
		
		

		
		
	


	




 Its "-" minus = low (0) or GND
 "+" plus = high (1) or VDD
 "O" = open.

 Cheers!
 Russ


----------



## hershann

Russ,

 lucky I don't presume anything. Tried to google tristate switches but didn't get anywhere.

 Ok - another question popped up regarding the metronome - to enable ASRC, I will remove the Disable Jumper and configure switches as per recommended in the manual. Connect all wires except the SCK (PCM in) from the WM8804. Connect all wires (PCM out) to WM8740.
 Leave the automute jumper on - it will automute if there is anything wrong with the signal.

 Correct?

 thanks

 her shann


----------



## Alcaudon

I should have never entered this thread, know nothing about DAC's, but......... now i want one! 
	

	
	
		
		

		
		
	


	




 how long will it take until they are available again???? 

 I'm planning to add one to my Millet Max, is it too much for a DAC noob??? was thinking of an Alien, but.....


----------



## Nebby

Quote:


  Originally Posted by *Alcaudon* /img/forum/go_quote.gif 
_I should have never entered this thread, know nothing about DAC's, but......... now i want one! 
	

	
	
		
		

		
		
	


	




 how long will it take until they are available again???? 

 I'm planning to add one to my Millet Max, is it too much for a DAC noob??? was thinking of an Alien, but..... 
	

	
	
		
		

		
		
	


	


_

 

With the boards pre-assembled all you really need to worry about is building the power supply boards and wiring


----------



## Alcaudon

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_With the boards pre-assembled all you really need to worry about is building the power supply boards and wiring 
	

	
	
		
		

		
		
	


	


_

 

....and as I can see there's a kit even for the power supply 
	

	
	
		
		

		
		
	


	




 now I just need to read more about this DAC (or DAC's in general) and wait untill they are available.

 Thanks!!!!


----------



## Nebby

Quote:


  Originally Posted by *Alcaudon* /img/forum/go_quote.gif 
_....and as I can see there's a kit even for the power supply 
	

	
	
		
		

		
		
	


	




 now I just need to read more about this DAC (or DAC's in general) and wait untill they are available.

 Thanks!!!!_

 

Ah, but there's a distinction between kit and pre-assembled; kit means you get the parts and board, while pre-assembled means it totally put together (though I think with the latest batch they're shipping the boards out without the terminal blocks on for more customizability)

 I've been playing with the modules for a while now, and the opus sounds really good. Only problem these days is getting the boards, since it seems demand for the boards has gone up quite a bit; I wonder how many hits Twisted Pear gets nowadays.


----------



## swt61

Yeah, I hope the increased traffic is a good thing for them. I really want to see these guys succeed in every way. Their offerings are great, and their attitudes are even better.


----------



## earfanatic

Can someone tell me what (exactly) is L1 and L2 in the Ballsie PSU modul?


----------



## Nebby

Quote:


  Originally Posted by *earfanatic* /img/forum/go_quote.gif 
_Can someone tell me what (exactly) is L1 and L2 in the Ballsie PSU modul?_

 

Where's the L1 and L2? I tried looking on the layout at the site: http://www.twistedpearaudio.com/imag...bps_layout.jpg and didn't see either on there.


----------



## MrMajestic2

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Where's the L1 and L2? I tried looking on the layout at the site: http://www.twistedpearaudio.com/imag...bps_layout.jpg and didn't see either on there._

 

Check the kit picture, its there. On the layout it says U1/U2. They are chokes and are pictured between the IC1 and C1,C2 parts in an unmarked plastic container. Surface mount with two copper coils each.


----------



## Nebby

I should've taken a look at the schematic, it's definitely there. I blame it on still waking up


----------



## earfanatic

I know they are chokes. 
	

	
	
		
		

		
		
	


	




 I'd like to know the value or ordering number. I want to rebuild that PSU for a DAC.


----------



## akione

Quote:


  Originally Posted by *earfanatic* /img/forum/go_quote.gif 
_I know they are chokes. 
	

	
	
		
		

		
		
	


	




 I'd like to know the value or ordering number. I want to rebuild that PSU for a DAC._

 

I believe they are TDK ACM7060-701-2PL-TL (DigiKey 445-2215-1-ND), apparently they are the only ones that will fit on the board. 

 I think the psu board might come with them pre-soldered. 

 You could always ask them.


----------



## kugino

have people received their orders from the last shipment? ordered on feb. 3 but my metronome is nowhere is sight...hmmm....


----------



## akione

Quote:


  Originally Posted by *kugino* /img/forum/go_quote.gif 
_have people received their orders from the last shipment? ordered on feb. 3 but my metronome is nowhere is sight...hmmm...._

 

You might have just missed out. They sold out of several modules before Brian had sent out the first lot !


----------



## Nebby

You can always shoot them and email and find out. I think they were surprised at how quickly the pre-orders went


----------



## johnsonad

I received my Metronome module last week.


----------



## BrianDonegan

Quote:


  Originally Posted by *earfanatic* /img/forum/go_quote.gif 
_Can someone tell me what (exactly) is L1 and L2 in the Ballsie PSU modul?_

 

 Quote:


 I believe they are TDK ACM7060-701-2PL-TL (DigiKey 445-2215-1-ND), apparently they are the only ones that will fit on the board.

 I think the psu board might come with them pre-soldered. 
 

That is the correct part number. The bare boards do not currently come with them, but since it's a specific part without available substitutions, that could change.


----------



## parrymike

I'm about to order an OPUS kit but I was wondering what people's views were on where best to spend the money.

 My options are:

 Dual OPUS
 Single OPUS + Metronome

 I'll be using a Squeezebox as my source, a BrianGT 3875 gainclone for amplification all feeding some DIY ScanSpeak speakers. As my amp is unbalanced I was going to use the DAC output directly and accept the 6dB loss in signal.

 So what do you think will make the biggest difference? Dual differential or ASRC????

 Cheers,
 Mike


----------



## Russ White

Hi Mike,

 Having spent a lot of time with both setups, naturally 
	

	
	
		
		

		
		
	


	




 ,my personal advice would be to go with the stereo mode single opus + metronome. That will be your most bang for the buck. Later you can always add a second opus.

 Cheers!
 Russ


----------



## parrymike

Thanks for the quick response. I'm afraid I just couldn't resist and ended up ordering a dual DAC and Metronome. Ho hum.

 Happy Birthday to me


----------



## KoKoKrunch

I'm considering Zhaolu D3, single Opus DAC + metronome, and Beresford TC-7510, any comparisons between them? Really racking my brain with all these choices...


----------



## cook

Sorry for dumb question but... How do DACs with USB and S/PDIF inputs play with new things like Blu-Ray ? Will I be limited to music on my computer, CDP and low res outputs from HDTV/Blu Ray devices ?

 Also if I get Ballsie and one DAC, both with own power supplies - now many transformers will I need ? As I read somewhere DAC needs about 7.5V so Avel Lindberg Transformer (115V+115V prim. / 15V+15V 25VA sec.) is for Ballsie only ?

 thanks


----------



## akione

Quote:


  Originally Posted by *KoKoKrunch* /img/forum/go_quote.gif 
_I'm considering Zhaolu D3, single Opus DAC + metronome, and Beresford TC-7510, any comparisons between them? Really racking my brain with all these choices..._

 

In my opinion, the Opus should be well ahead of the others. 

 That's why I'm building one


----------



## akione

Quote:


  Originally Posted by *cook* /img/forum/go_quote.gif 
_Sorry for dumb question but... How do DACs with USB and S/PDIF inputs play with new things like Blu-Ray ? Will I be limited to music on my computer, CDP and low res outputs from HDTV/Blu Ray devices ?

 Also if I get Ballsie and one DAC, both with own power supplies - now many transformers will I need ? As I read somewhere DAC needs about 7.5V so Avel Lindberg Transformer (115V+115V prim. / 15V+15V 25VA sec.) is for Ballsie only ?

 thanks_

 

Not sure about this. At the moment it's pcm only, later they hope to support unencrypted dsd. It might be possible then. 

 Maybe others can help with this. I'm no expert on High def. 

 The boards for the Opus all need 7.5v the Ballsie needs +15 - 0 - -15, so 2 transformers. One LCBPS for Ballsie and one LCDPS for the dac boards. You can use the same transformer type for both.


----------



## Nebby

Quote:


  Originally Posted by *cook* /img/forum/go_quote.gif 
_Sorry for dumb question but... How do DACs with USB and S/PDIF inputs play with new things like Blu-Ray ? Will I be limited to music on my computer, CDP and low res outputs from HDTV/Blu Ray devices ?

 Also if I get Ballsie and one DAC, both with own power supplies - now many transformers will I need ? As I read somewhere DAC needs about 7.5V so Avel Lindberg Transformer (115V+115V prim. / 15V+15V 25VA sec.) is for Ballsie only ?

 thanks_

 

This has been discussed quite a few times over in the diyaudio thread, and consensus was that the licensing costs for HDMI made it cost prohibitive 
	

	
	
		
		

		
			





 edit: To be more exact, the only way to get hi-def digital output (aside from modding) is through HDMI or brand-specific connectors (denon-link is one example), and there is no way to get the data from the HDMI connection without licensing it.


----------



## tf1216

Hey folks,

 I could use some help choosing modules if someone has the time and patience to deal with me ( :

 I am wishing to build the best Opus Dac with USB input I can. I attached the modules I believe are required for such a build in List 1. I would also like to have the ability to have other digital inputs in the future. I attached List 2 for the other modules I believe I would need.

 Anyone have personal experience they would like to share about populating the boards themselves? I would love to do the soldering and testing myself.

 List 1:

 The Opus Dac Module
 The USB Receiver Module
 Ballsie Module
 The Bipolar Supply Module (for Ballsie) 
 The LCDPS 
 The Metronome ASRC Module 

 List 2:

 The S/PDIF Receiver Module
 The OTTO 2:1 Switching Module 
 The TOSLINK Optical Input Module


----------



## strangedaze39

I was reading about this DAC and it sounds like an amazing bang for the buck. I currently own a Oritek V4, is the OPUS something I should be looking into or does the Oritek sound better, anyone know ? How about has anyone put a S22 PSU or Zapfilter 2 on the OPUS with huge success ? 

 Or will it not make much of a difference I do currently rather enjoy my Oritek v4.


----------



## akione

Quote:


  Originally Posted by *tf1216* /img/forum/go_quote.gif 
_Hey folks,

 I could use some help choosing modules if someone has the time and patience to deal with me ( :

 I am wishing to build the best Opus Dac with USB input I can. I attached the modules I believe are required for such a build in List 1. I would also like to have the ability to have other digital inputs in the future. I attached List 2 for the other modules I believe I would need.

 Anyone have personal experience they would like to share about populating the boards themselves? I would love to do the soldering and testing myself.

 List 1:

 The Opus Dac Module
 The USB Receiver Module
 Ballsie Module
 The Bipolar Supply Module (for Ballsie) 
 The LCDPS 
 The Metronome ASRC Module 

 List 2:

 The S/PDIF Receiver Module
 The OTTO 2:1 Switching Module 
 The TOSLINK Optical Input Module_

 

Hi,

 Your list is fine. The only thing to bear in mind is that the toslink and spdif cannot be used at the same time, as the toslink feeds into the spdif board. If you need both, you'll have to add some additional switching for them.

 There's only the power supplies and Otto that require building and maybe toslink too, everthing else come as ready built modules. 

 Have Fun


----------



## tf1216

Thank you for your answer akione.

 I have to guess that the S/PDIF module comes with a digital cable input, correct? Is the OTTO used for those people who want both USB input and coax input?

 Any idea how much the parts cost? I would love to populate the boards myself.


----------



## akione

Quote:


  Originally Posted by *strangedaze39* /img/forum/go_quote.gif 
_I was reading about this DAC and it sounds like an amazing bang for the buck. I currently own a Oritek V4, is the OPUS something I should be looking into or does the Oritek sound better, anyone know ? How about has anyone put a S22 PSU or Zapfilter 2 on the OPUS with huge success ? 

 Or will it not make much of a difference I do currently rather enjoy my Oritek v4._

 

I think someone tried a Zapfilter in the early days, but I don't know what the final verdict was. 

 The Sigma22 isn't suitable for the Opus and would be massive overkill if it were. 

 The Ballsie output stage is the Opus' equivalent to the Zapfilter, as it includes an optional filter stage.

 Whether it's better than your Oritek is a personal thing.


----------



## akione

Quote:


  Originally Posted by *tf1216* /img/forum/go_quote.gif 
_Thank you for your answer akione.

 I have to guess that the S/PDIF module comes with a digital cable input, correct? Is the OTTO used for those people who want both USB input and coax input?

 Any idea how much the parts cost? I would love to populate the boards myself._

 

Yes, the spdif and usb inputs are selected through the otto. The spdif board has spdif in and spdif out on it.

 You would be better checking out the Twisted Pear web site for all the details. There are also manuals for most of the boards, too.

 The boards use smd parts mainly, so are only available as modules, AFAIK.


----------



## BrianDonegan

I am thinking about offering kits for the modules for those who are feeling adventurous. Most of the SMD parts are easy, apart from the MSOP chips. If I do a kit, I may pre-mount the chips, not sure. Maybe interested folks can chime in on what they would want.

 Also, for the Ballsie, I am not premounting the filter caps as well, and am using high-grade PPS film (0805 smd) for the 1.2nF and silver mica (0805 smd) for the 22pF. Just easier this way.


----------



## tf1216

Brian, would the minimum buy for the parts cost me as much as the assembled modules themselves?


----------



## BrianDonegan

Not as much as the assembled modules, no. A kit (board and all parts) would be less as well.


----------



## ruZZ.il

I'd be more interested in a kit, even if similarly priced. Naturally, I'd make my way to an OPUS faster if it were, and hopefully will be, priced more modestly than assembled units. I'd personally prefer an unsoldered chip too, but I believe the option would be useful to many. I hope to se this idea implemented! and I look forward to building soon


----------



## tf1216

Do you guys prefer we order through your website or by e-mail because there is a wait?


----------



## BrianDonegan

Through thew web site. Not sure what you mean by a wait.


----------



## tf1216

Sorry, I thought some of the boards for the Opus DAC were on backorder.


----------



## BrianDonegan

Ah. Boards arrived today. I will be building for the next week or two before shipping. So, yes, there is a wait.


----------



## tf1216

Last question, for those who want to populate the boards themselves, where do they get unique parts like heatsink, USB connector, etc.?

 Thank you for replying Brian.


----------



## BrianDonegan

Mouser and DigiKey carry everything except the WM8804 chip.


----------



## tf1216

Sweet, I am in! I may purchase the boards tonight or wait for a kit to become available That would be awesome!

 A while back in this thread you showed a completed Opus of yours with some nice printing on it. Are cases available through your website? Any suggestions for a case?


----------



## Nebby

Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_I think someone tried a Zapfilter in the early days, but I don't know what the final verdict was. 

 The Sigma22 isn't suitable for the Opus and would be massive overkill if it were. 

 The Ballsie output stage is the Opus' equivalent to the Zapfilter, as it includes an optional filter stage.

 Whether it's better than your Oritek is a personal thing. 
	

	
	
		
		

		
			



_

 

I'm currently in the process of building my sigma11/sigma22 powered opus. Overkill was exactly what I was shooting for 
	

	
	
		
		

		
		
	


	




  Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_I am thinking about offering kits for the modules for those who are feeling adventurous. Most of the SMD parts are easy, apart from the MSOP chips. If I do a kit, I may pre-mount the chips, not sure. Maybe interested folks can chime in on what they would want.

 Also, for the Ballsie, I am not premounting the filter caps as well, and am using high-grade PPS film (0805 smd) for the 1.2nF and silver mica (0805 smd) for the 22pF. Just easier this way._

 

How much would the kits cost? I'd definitely be up for them as long as the MSOP chips are pre-mounted. That fine of a pitch scares me


----------



## BrianDonegan

Quote:


 How much would the kits cost? 
 

Dunno. Need to figure that out.


----------



## naamanf

New website you say? Same URL? I am currently getting a 404.


----------



## swt61

Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_I think someone tried a Zapfilter in the early days, but I don't know what the final verdict was._

 

The final verdict was great!


----------



## Nebby

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_New website you say? Same URL? I am currently getting a 404._

 

Site seems to work fine for me.


----------



## akione

Quote:


 I'm currently in the process of building my sigma11/sigma22 powered opus. Overkill was exactly what I was shooting for 
 

 I await your conclusions with great excitement. 
	

	
	
		
		

		
		
	


	





 ( how will it help when the boards have their own regs on ? 
	

	
	
		
		

		
		
	


	




 )


----------



## Nebby

Who said anything about help? I did say I was shooting for overkill did I not? 
	

	
	
		
		

		
		
	


	




 I have a tendency to want to upgrade parts for the sake of upgrading parts; so this time I just wanted to go to the point of overkill to sidestep the whole process. I know that there is very likely little to no chance I will hear any difference, but the simple fact in knowing that my power supply is much more than enough gives me a warm fuzzy. Having multiple terminal ports on board the sigma also makes wiring a bit easier and neater without having a terminal strip in the middle.


----------



## akione

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Who said anything about help? I did say I was shooting for overkill did I not? 
	

	
	
		
		

		
		
	


	




 I have a tendency to want to upgrade parts for the sake of upgrading parts; so this time I just wanted to go to the point of overkill to sidestep the whole process. I know that there is very likely little to no chance I will hear any difference, but the simple fact in knowing that my power supply is much more than enough gives me a warm fuzzy. Having multiple terminal ports on board the sigma also makes wiring a bit easier and neater without having a terminal strip in the middle._

 

They'll run a bit warmer, too, so you can save on heating


----------



## FallenAngel

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Who said anything about help? I did say I was shooting for overkill did I not? 
	

	
	
		
		

		
		
	


	




 I have a tendency to want to upgrade parts for the sake of upgrading parts; so this time I just wanted to go to the point of overkill to sidestep the whole process. I know that there is very likely little to no chance I will hear any difference, but the simple fact in knowing that my power supply is much more than enough gives me a warm fuzzy. Having multiple terminal ports on board the sigma also makes wiring a bit easier and neater without having a terminal strip in the middle._

 

Why bother with upgrading the PSU, the "stock" supply is pretty nice, first thing to do is get rid of those absolutely horrible Elna Silmic II output caps and some good quality film caps in there. 
	

	
	
		
		

		
		
	


	




*NOTE* The phrase "absolutely horrible" is used in comparison to high quality film caps, they're pretty nice normally, but seriously would not be my choice for signal path.

 Oh and I'm so building this thing in a few weeks (or months), but yeah ASAP


----------



## Nebby

Actually, the boards I have originally came with Panasonic FM's and those have been replaced with Blackgates already 
	

	
	
		
		

		
		
	


	




 Film caps? Aren't most of those pretty massive for the capacity?

 edit: just checked prices; film caps sure are as expensive as I remember them to be


----------



## FallenAngel

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Actually, the boards I have originally came with Panasonic FM's and those have been replaced with Blackgates already 
	

	
	
		
		

		
		
	


	




 Film caps? Aren't most of those pretty massive for the capacity?

 edit: just checked prices; film caps sure are as expensive as I remember them to be 
	

	
	
		
		

		
		
	


	


_

 

Oh, it's only for the output. Sure, BlackGates are pretty nice as PSU caps, but for PSU I usually like to stick to Panasonic FM, or maximum Silmic II, it's the output that's important. For those I would recommend something else. According to the WM8740 datasheet you might not need 22uF on the output and if my memory serves me correnctly, you would take a MUCH lower value. With a 50K input impedance amp, take a 1uF film cap. Now we're talking about reasonably priced 
	

	
	
		
		

		
		
	


	




 How about Sonicap Gen 1 1.0uf/200V at only $5.80 
	

	
	
		
		

		
		
	


	




 If you want something fancier (although not as highly recognized, but I really like them), consider our sponsor - PartsConneXion, they offer the "old style" Mundorf MCap ZN 0.82uF/250V for only $7.74! I used these caps in my SOHA and AlienDACs, they're really nice.


----------



## Nebby

We'll see. I already put in the blackgates and I haven't listened to them yet. At the moment building my case has more of a priority, and planning the wiring, and the shielding, and the anondizing....plenty of fun to be had before I start worrying about upgrading to film caps


----------



## Russ White

One other option (well the best option) is to not use output caps at all. 
	

	
	
		
		

		
		
	


	




 This is possible two ways. 

 1) You can use the Ballsie with just SE output. SE output has no common mode DC.

 2) You can use our new "IVY" (it also does BAL to SE conversion) board with 1K input and 1K FB resistors. IVY uses THS41xx SuSy amplifiers which have a pin which sets the common mode output voltage to GND. So there will be no DC at either the balanced or SE outputs.

 My advice is that the very best output cap, is the one you don't use. 
	

	
	
		
		

		
		
	


	




 In my experience though, if you must use a high value cap, the Simlic II actually work very well. We critically tested different types before settling on them. Nelson Pass also seems to like them as he mentioned them in another thread on DIYAudio.

 Cheers!
 Russ


----------



## Nebby

You bring up a good point with the IVY, Russ. The reason I still have caps is because I plan on using balanced output and the ballsie only blocks DC on the SE outputs. That all changes with the IVY out now. Hmmm....

 Perhaps I should just throw an IVY, Ballsie, and zapfilter all in a wood box, switch them with my darwin switch and have a fun time comparing.


----------



## akione

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_You bring up a good point with the IVY, Russ. The reason I still have caps is because I plan on using balanced output and the ballsie only blocks DC on the SE outputs. That all changes with the IVY out now. Hmmm....

 Perhaps I should just throw an IVY, Ballsie, and zapfilter all in a wood box, switch them with my darwin switch and have a fun time comparing. 
	

	
	
		
		

		
		
	


	


_

 

Yeah, I have the same problem, Nebby. 

 You just get it all planned out and they bring out another board that changes everything.


----------



## jgonino

Does anyone want to build me one of these? Looking for USB and Digital coax inputs, and two sets of output RCA's (this whole thing would be single ended).


----------



## Nebby

Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_Yeah, I have the same problem, Nebby. 

 You just get it all planned out and they bring out another board that changes everything. 
	

	
	
		
		

		
		
	


	


_

 

Well I just picked up the IVY along with the USB input board that I just missed out on last batch. It's a good thing I have a mock up of my case made out of scrap wood to test with, because I foresee a lot of swapping around for testing in my near future


----------



## glt

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_One other option (well the best option) is to not use output caps at all. 
	

	
	
		
		

		
		
	


	




 This is possible two ways. 

 1) You can use the Ballsie with just SE output. SE output has no common mode DC.

 2) You can use our new "IVY" (it also does BAL to SE conversion) board with 1K input and 1K FB resistors. IVY uses THS41xx SuSy amplifiers which have a pin which sets the common mode output voltage to GND. So there will be no DC at either the balanced or SE outputs.

 My advice is that the very best output cap, is the one you don't use. 
	

	
	
		
		

		
		
	


	




 In my experience though, if you must use a high value cap, the Simlic II actually work very well. We critically tested different types before settling on them. Nelson Pass also seems to like them as he mentioned them in another thread on DIYAudio.

 Cheers!
 Russ_

 

Hi Russ,

 There is absolutely no degradation to OPUS due to the "lower" 1K input impedance? What advantage would I get if I use the TXD with the instrumentation amp in front with 100K input impedance? I also want to eliminate the capacitors for balanced operation.


----------



## Russ White

I also had the same concern until I tried it. The Opus handles a 1K load with no issues at all. I have been running it that way quite a bit directly into a TXO power amp. That particular power amp has a TXD in it with no instrumentation amp front end. 
	

	
	
		
		

		
		
	


	




 So I can very confidently say it will sound very very good. 
	

	
	
		
		

		
		
	


	




 That said, the TXD with the instrumentation amp front end will also work very well, but you won't have the SE conversion you would get with the IVY. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## Russ White

One other note, nothing says you have to use 1K 2.21K would also work just fine.


----------



## fierce_freak

If using with a dual differential setup (Opus), should we add load balancing resistors to the input of the IVY?


----------



## hershann

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_One other option (well the best option) is to not use output caps at all. 
	

	
	
		
		

		
		
	


	




 This is possible two ways. 

 1) You can use the Ballsie with just SE output. SE output has no common mode DC.

 2) You can use our new "IVY" (it also does BAL to SE conversion) board with 1K input and 1K FB resistors. IVY uses THS41xx SuSy amplifiers which have a pin which sets the common mode output voltage to GND. So there will be no DC at either the balanced or SE outputs.

 My advice is that the very best output cap, is the one you don't use. 
	

	
	
		
		

		
		
	


	




 In my experience though, if you must use a high value cap, the Simlic II actually work very well. We critically tested different types before settling on them. Nelson Pass also seems to like them as he mentioned them in another thread on DIYAudio.

 Cheers!
 Russ_

 


 Russ,

 Have just assembled my Opus DAC - Toslink module to WM8804 to Metronome to 2 x WM8740 - currently using SE output from the DAC. Working nicely in a temp chassis.

 Using it to feed a SOHA / JISBOS (tube with discrete CCS) acting as a preamp.

 What advantage does the IVY confer in this kind of setup? I do not want to introduce another set of opamps into the chain unless there are definite audible benefits. (Not to mention that with another transformer, 1 power board and 1 IVY board - my chassis has to grow a lot more)

 What advantage if using balanced out (bypassing the caps and replacing it with resistors and opamps I guess) as I planned to do in the near future?

 Assuming all driving high impedance loads of >10k.

 Sorry lots of newbie questions!

 her shann


----------



## Brewmaster

Just to confirm.

 The tristate dip switch has the label + O -
 I'm guessing + is 1
 O is open
 - is 0.

 Is that correct?


 Thanks.


----------



## Nebby

Correct!


----------



## Brewmaster

This is my first DIY endeavour of any kind. What a great feeling powering things up and seeing the right voltages, and then seeing the lights on the 8804 receiver module turn green when plugging in my optical cable.

 I can't wait to get my second transformer and get everything mounted together to listen to this sucker.


----------



## Nebby

Quote:


  Originally Posted by *Brewmaster* /img/forum/go_quote.gif 
_This is my first DIY endeavour of any kind. What a great feeling powering things up and seeing the right voltages, and then seeing the lights on the 8804 receiver module turn green when plugging in my optical cable.

 I can't wait to get my second transformer and get everything mounted together to listen to this sucker._

 

Glad your first DIY experience went smoothly! Mine involved a lot of blue smoke and scorch marks.


----------



## jgonino

Quote:


  Originally Posted by *jgonino* /img/forum/go_quote.gif 
_Does anyone want to build me one of these? Looking for USB and Digital coax inputs, and two sets of output RCA's (this whole thing would be single ended)._

 

Please? At Least one of you must be able to do this? I have a thread posted in the FS forums. Please PM me, I am willing to offer $ for labor.


----------



## akione

Hi jgonino, 
	

	
	
		
		

		
			





 You might have to be patient for a while. 

 This is very new to everyone at the moment and very few have their own systems complete and up and running.

 Also, like me, some of us are on the other side of the pond, so it's a long way to send stuff.


----------



## akione

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_If using with a dual differential setup (Opus), should we add load balancing resistors to the input of the IVY?_

 

I was wondering about this, too. 
	

	
	
		
		

		
		
	


	




 For a while I considered making a little board that fastened into the terminals on the Dac outputs, with the resistors on.

 At the moment I'm sticking with Ballsie on the end of the Dac, but I'm willing to change, if IVY turns out to be better. 
	

	
	
		
		

		
		
	


	





 Ballsie & Ivy .......... whatever next


----------



## Nebby

I have a rather large backlog of projects that I am doing and plan on doing, so I literally have no time for anything else. Not to mention I'm rather terrible when it comes to casing stuff up 
	

	
	
		
		

		
		
	


	




 Btw, what harm is there if I don't use load balancing resistors with the IVY?


----------



## akione

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I have a rather large backlog of projects that I am doing and plan on doing, so I literally have no time for anything else. Not to mention I'm rather terrible when it comes to casing stuff up 
	

	
	
		
		

		
		
	


	


_

 

Me too. I love the electronics, but I really hate the casework .......... 
	

	
	
		
		

		
		
	


	




 Nebby, My problem was that I intended to put a balanced JT in the chain, and I was concerned about going through the JTs, before It had been balanced. It might have been Ok, but it just looked like there might be problems.

 Others, seem to have just paralleled up th outputs.


----------



## jgonino

No pressure, I just really miss my old DAC, and want a new one ASAP. I am also interested in the one the Jambo is making. It looks very promising.


----------



## naamanf

Why not try your hand at DIY? This is one of the easier projects to do and would be a good start.


----------



## Clutz

Question: What do I connect from the Opus DAC module to the Balsie for single ended output - I'm a little confused and the manual isn't helping me.

 Thanks!
 Brad


----------



## Russ White

Just wire the ballanced outputs to the balanced inputs of the Ballsie. The terminals are marked input and output. The you just take SE, and GND out of each side of the Ballsie. I hope that helps.


----------



## Clutz

I've got a question that I've posted on the TwistedPearAudio forums, but I'll ask here cause we get more traffic. On the Low Current Bipolar Power Supply - what is IC1 and IC2 supposed to be?


----------



## glt

lm317 and lm337 positive and negative variable voltage regulators


----------



## Clutz

I know they are LM317 and LM337, but is IC1 LM317 and IC2 LM337, or is it the opposite?


----------



## error401

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_I know they are LM317 and LM337, but is IC1 LM317 and IC2 LM337, or is it the opposite?_

 

The schematic has the LM337 as IC2.


----------



## Clutz

Can you point me to the schematic? The only one I can find doesn't list the parts value for each part.

 Thanks,
 Brad


----------



## error401

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_Can you point me to the schematic? The only one I can find doesn't list the parts value for each part.

 Thanks,
 Brad_

 

You're right, the part values aren't included. You can infer the positive and negative regulators from the polarity of the protection diodes. You can see that the bottom rail in the schematic must be negative w.r.t the ADJ pin to make sure the protection diode is always reverse biased. ADJ connects to ground, so the output must be negative wrt ground. If it were forward biased, it would break the operation of the regulator by screwing with the ADJ pin reference voltage drop. You'll see that the top diode is oriented in the opposite direction, and must be positive w.r.t ADJ
	

	
	
		
		

		
		
	


	




.


----------



## Clutz

Hey error401: Do you have any idea why I would be getting +22V between + and G, and 0V between GND and -V? Additionally R3 and R4 are getting super hot? I've got S1 and S2 each wired up to a single secondary, all my caps are correctly oriented, as are my bridges and diodes. The only thing that is left are the LM317 and LM337, so I wonder if they are fried.

 Brad


----------



## luvdunhill

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_That wire is fine. The Pot is from Mouser: 313-2441-5K_

 

I noticed on the silk that the values is marked 5k-20k. Does the 20k option assume that you're using a different resistor combination, and if not then what effect does using a higher pot have on the volume control?


----------



## error401

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_Hey error401: Do you have any idea why I would be getting +22V between + and G, and 0V between GND and -V? Additionally R3 and R4 are getting super hot? I've got S1 and S2 each wired up to a single secondary, all my caps are correctly oriented, as are my bridges and diodes. The only thing that is left are the LM317 and LM337, so I wonder if they are fried.

 Brad_

 

If you have D4 in backwards and VR2 at a low setting, you're basically shorting the V- output to ground which would explain the symptoms you describe. This probably isn't good for VR2 either. If that's not it, IC2 is probably fried and shorting some pins. Either way, without an external load, all DC short circuit current must pass through VR2. If you turn it up to its 5K maximum it should be safe to power the circuit while you diagnose the problem.

 Turn VR2 to the max and measure the voltage between ADJ and OUT. It should be 1.25V. If it's 0.7V, D4 is in backwards. If it's 0V, either D4, R6 (unlikely) or IC2 is shorted. You do seem to have a short somewhere in the negative regulator though, and my bet is D4 
	

	
	
		
		

		
			





.

 Is there a problem with the positive regulator? 22V seems a reasonable output to me.


----------



## Clutz

D4 is correctly oriented. I've double and triple checked the orientation of everything and its all good. So I am totally confused.

 I just tried replacing the LM337 and that didn't help- and it's the negative side that has the problem. Perhaps I should go and replace the LM317 too.


----------



## Clutz

Okay, this is strange. I replaced the LM337 and LM317 and now I'm getting -15V on the - side, and it is responding to the pot to adjust it's voltage, but only +5V on the positive side, but adjusting the trimmer only changes the voltage from +5.2V to +5.8V. Odd odd odd


----------



## Clutz

So I'm not sure what is wrong with the Bipolar power supply. I am coming to the conclusion that it was just cursed and that I will either have to replace both regulators on it (instead of doing them one at a time), or just start over from scratch because the traces are starting to look a little delicate now.

 but instead of using the balsie I decided to wire up the DAC and just use the DACS outputs directly into my Mini^3 that I have at home right now, just to test out the rest of the DAC and see if it was working.

 BUT I DON'T HAVE THE RIGHT USB CABLE AT HOME.

 It was fate that I wasn't going to get this to work this weekend - that is all that I can say.


----------



## Nebby

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_So I'm not sure what is wrong with the Bipolar power supply. I am coming to the conclusion that it was just cursed and that I will either have to replace both regulators on it (instead of doing them one at a time), or just start over from scratch because the traces are starting to look a little delicate now.

 but instead of using the balsie I decided to wire up the DAC and just use the DACS outputs directly into my Mini^3 that I have at home right now, just to test out the rest of the DAC and see if it was working.

 BUT I DON'T HAVE THE RIGHT USB CABLE AT HOME.

 It was fate that I wasn't going to get this to work this weekend - that is all that I can say._

 

Wow that sucks, hope you have better luck next weekend


----------



## naamanf

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_So I'm not sure what is wrong with the Bipolar power supply._

 

Try and post some pictures.


----------



## Clutz

I posted pictures earlier over at TwistedPearAudio. There must be a failure of one of the components because I've gone over each and every part 4 times to make sure it's in the correct place and correctly oriented and to ensure that there isn't a solder bridge. :|


----------



## Clutz

I've replaced the diodes, checked the caps and I can't find any problem with any of them. I'm officially frustrated, so I think I'm just going to order another bipolar supply and hope it gets here this week.


----------



## Nebby

For what it's worth, I'm having a bit of fun with my opus too. First, I put it together as SPDIF -> Metro -> Opus -> Ballsie, and it worked fine. I then proceeded to add in the second board to make it dual-mono, and now I'm getting nothing. 

 I've only done a bit of troubleshooting, but so far the checking the I2S lines at the opus input terminal blocks show voltage relative to ground, but nothing is showing on the output of the opus boards. I'm going to go double check my jumpers next and then go from there.

 edit: I feel like an idiot. For future reference, wiring dout to ground will result in a serious lack of music.


----------



## akione

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_For what it's worth, I'm having a bit of fun with my opus too. First, I put it together as SPDIF -> Metro -> Opus -> Ballsie, and it worked fine. I then proceeded to add in the second board to make it dual-mono, and now I'm getting nothing. 

 I've only done a bit of troubleshooting, but so far the checking the I2S lines at the opus input terminal blocks show voltage relative to ground, but nothing is showing on the output of the opus boards. I'm going to go double check my jumpers next and then go from there.

 edit: I feel like an idiot. For future reference, wiring dout to ground will result in a serious lack of music._

 

Oops! 
	

	
	
		
		

		
		
	


	




 I hope you've got it sorted, now. 

 Do you notice much difference going dual mono ?


----------



## Nebby

Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_Oops! 
	

	
	
		
		

		
		
	


	




 I hope you've got it sorted, now. 

 Do you notice much difference going dual mono ?_

 

It's all sorted out now, sounds very good; seems to have more detail particularly in the lows than my Denon receiver. But it's difficult to do a proper comparison as the level from the DAC is 5db higher than from my receiver.

 Honestly, I can't tell if it was placebo or not, but I think I heard a slight difference. It certainly wasn't "night and day" and I wouldn't expect it to be, of course. Either way I like the piece of mind that it's "maxed out" as it were.


----------



## johnsonad

hahaha, "maxed out", come on Ben, you are going to tinker with it forever 
	

	
	
		
		

		
		
	


	




 It's going on a year already! (not that I'm not in the same boat 
	

	
	
		
		

		
		
	


	




)


----------



## Nebby

Actually no, I'm going to finish it up relatively soon. I have a few other projects I have planned, and the casing of the opus and TXO is a project in and of itself 
	

	
	
		
		

		
		
	


	




 I'm not sure on the zapfilter now, the opus sounds rather good with the ballsie already, and I have an IVY coming soon. On the other hand I could use the zapfilter for something else


----------



## Clutz

I think the IVY is cool, but the Wolfson DAC already has an opamp based I/V in it - I'll wait until they have a discrete I/V before I try the COD. 

 I wish I could find the D1 I/V schematic again. It was on my old computer, but it died.


----------



## MrMajestic2

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_I think the IVY is cool, but the Wolfson DAC already has an opamp based I/V in it - I'll wait until they have a discrete I/V before I try the COD. 

 I wish I could find the D1 I/V schematic again. It was on my old computer, but it died._

 

diyAudio Forums - Anyone built a Pass D1 I/V for a TI1794 or TI1794 DAC?

 Maybe thats the one?


----------



## Clutz

You should be MrMajestic1 not MrMajestic2, because the 2 simply doesn't capture your Majesty the way a 1 does! 

 Thanks buddy, you ROCK!


----------



## MrMajestic2

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_You should be MrMajestic1 not MrMajestic2, because the 2 simply doesn't capture your Majesty the way a 1 does! 

 Thanks buddy, you ROCK!_

 

You´re welcome


----------



## error401

Quote:


  Originally Posted by *Clutz* /img/forum/go_quote.gif 
_I think the IVY is cool, but the Wolfson DAC already has an opamp based I/V in it._

 

I don't think that's true. Modern sigma-delta DACs can be I-out or V-out by nature. Of course, the datasheet isn't specific, but I suspect the internal DAC is voltage out, not a current-out DAC with an onboard I/V.


----------



## Clutz

Well, I didn't know that. 
	

	
	
		
		

		
		
	


	




 Thanks error401! You're a fountain of information. 
	

	
	
		
		

		
		
	


	




 Next problem- I have high cholesterol and my dad had a 6 way bypass 7 years ago (and believe it or not, they wanted to do 8). Can you reduce my cholesterol and prevent me from requiring massively invasive heart surgery 30 years down the line?


----------



## Nebby

Did some critical listening with the opus in my friend's Klipsch reference setup today. First thing that came to mind was the fact that the highs are definitely much harsher and brassy with the Blackgates in. I wonder if this is the much-rumored blackgate burn-in requirement? Anyone have any advice on burning in blackgates? I was thinking of simply playing some pink noise or a sine wave into the opus and leaving the output detached.

 Also playing with the metronome bypassed and non-bypassed seemed to show a large reduction in bass when the metronome was active. Granted the rest of the audio spectrum sounded more refined but the large amount of bass lost did not seem worth it. I am going to have to put in my OTTO to allow direct comparisons.

 Speaking of the OTTO, looking at the omron datasheet for the relay I should be able to hook the OTTO directly to my 7.5v power supply right?

 edit: After some more listening, it seems that the bass reduction was just a fluke, I didn't hear any lack of bass on my listening test yesterday.


----------



## BrianDonegan

Quote:


 Hey error401: Do you have any idea why I would be getting +22V between + and G, and 0V between GND and -V? Additionally R3 and R4 are getting super hot? I've got S1 and S2 each wired up to a single secondary, all my caps are correctly oriented, as are my bridges and diodes. The only thing that is left are the LM317 and LM337, so I wonder if they are fried. 
 

Does this mean they are sharing a secondary? If so, that would be bad. If not, what are the AC voltages at S1 and S2?

  Quote:


 Speaking of the OTTO, looking at the omron datasheet for the relay I should be able to hook the OTTO directly to my 7.5v power supply right? 
 

Yes, the OTTO will be just fine at 7.5V. Coincidence?


----------



## tf1216

Any word whether kits will be offered for the Opus?


----------



## Russ White

Nebby, I am a bit puzzled by your comment regarding the metronome. Adding the metronome into the mix should have no negative impact on bass levels at all, the only thing you might notice would be a change in distortion levels and DNR, all of which should be improved not degraded. I am not questioning your result (I don't have enough data), but if I were you I would look into some other cause beside the metronome. The metronome does not attenuate or enhance any particular frequency range, it does not even work in that domain. I can say this with a high degree of confidence, and I think others will agree.

 Every user I have talked who has used the metronome actually prefers it in every way. This is because it reduces (jitter induced) distortion and provides an ultra clean clock to the DAC.

 Cheers!
 Russ


----------



## Nebby

Russ, I absolutely agree with you that it should not have any impact on the bass levels, so I am also puzzled as to what I've been hearing. I'm going to check out the metronome settings when I get a chance.


  Quote:


 Yes, the OTTO will be just fine at 7.5V. Coincidence? 
 

No way! 
	

	
	
		
		

		
		
	


	




 Hey, give me a break, I like to be safe than sorry especially when dealing with electrical equipment 
	

	
	
		
		

		
		
	


	




 Thanks for taking the time to respond nonetheless, it's much appreciated.


----------



## Russ White

Hi Nebby,

 Some people actually hear jitter as "fat bass". Here is a short explanation of jitter induced noise:

 The noise that jitter induces is not easily described: it is not a harmonic
 distortion but is a noise near the tone of the music that varies with the music:
 it is a noise that surrounds each frequency present in the audio signal and is
 proportional to it. Jitter noise is therefore subtle and will not be heard in the
 silence between audio programs. Experienced listeners will perceive it as a
 lack of clarity in the sound field or as a faint noise that accompanies the
 otherwise well defined quieter elements of the audio program.

 So it is possible the fat bass you are hearing without the metronome is actually jitter induced noise. As it almost sounds much like a harmonic in many cases, especially at low freq.

 That said, there are many more plausible explanations. As the receiver is also low jitter, so you should not have enough jitter to make any trouble at all.

 Cheers!
 Russ


----------



## _atari_

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_Russ, I absolutely agree with you that it should not have any impact on the bass levels, so I am also puzzled as to what I've been hearing. I'm going to check out the metronome settings when I get a chance.



 No way! 
	

	
	
		
		

		
		
	


	




 Hey, give me a break, I like to be safe than sorry especially when dealing with electrical equipment 
	

	
	
		
		

		
		
	


	




 Thanks for taking the time to respond nonetheless, it's much appreciated._

 

Just as an uneducated guess: Is it possible that some kind of power supply problem could be involved here? Something like inserting noise in some other circuit, driving some voltage regulator to the upper end of its upper end? reducing capacitor capacitance (sharing capacitors between more components) by some wiring effects?

 For me it sounds a bi like that.


----------



## BrianDonegan

Quote:


 No way! Hey, give me a break, I like to be safe than sorry especially when dealing with electrical equipment Thanks for taking the time to respond nonetheless, it's much appreciated. 
 

Didn't mean it like that. I have actually been meaning to update the page to state this, as it is not immediately obvious.


----------



## sleepy dan

Jitter can be noise, or it can be a correlated tone. The relationship to the "fundamental" will determine what type of distortion it produces. Low frequency jitter will typically make the sound fat.


----------



## Nebby

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Didn't mean it like that. I have actually been meaning to update the page to state this, as it is not immediately obvious._

 

Sorry for that outburst, it was 2 in the morning when I typed that 
	

	
	
		
		

		
			





 I'm now looking forward to that Sabre based dac board, it sure looks quite interesting!


----------



## naamanf

So I finally got around to putting the Zapfilter in the Opus. For those that have a Zapfilter have you noticed any "burn-in" changes? As for right now I much prefer the Ballsie. The top end is very harsh actually to the point of giving me a headache. To be fair I think I will leave it in and give it a couple days. But if it doesn't change after that it's coming out.


----------



## swt61

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_So I finally got around to putting the Zapfilter in the Opus. For those that have a Zapfilter have you noticed any "burn-in" changes? As for right now I much prefer the Ballsie. The top end is very harsh actually to the point of giving me a headache. To be fair I think I will leave it in and give it a couple days. But if it doesn't change after that it's coming out._

 

I definitely remember looser101 saying that mine had a burn in period, but I though it was low, as in a few hours.

 Now I'm very curious about the Ballsie.


----------



## fierce_freak

The Zapfilter does have an initial burn in. It can be pretty harsh the first few hours, but I'd say within 10 hours that should be gone.


----------



## luvdunhill

Quote:


  Originally Posted by *swt61* /img/forum/go_quote.gif 
_Now I'm very curious about the Ballsie._

 

man, I need to get your gear out the door quick! Talk about scope creep ... geez


----------



## Nebby

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_man, I need to get your gear out the door quick! Talk about scope creep ... geez 
	

	
	
		
		

		
		
	


	


_

 

Same could be said for me, and I have the DAC in hand! I'm thinking of picking up an aftermarket XO for the metronome


----------



## philodox

Yeah, the zapfilter sounds like crap for the first bit. Can't say I noticed much difference after running it a couple days though.


----------



## jantze

Hi,
 I'd like to build a Opus DAC to feed my Corda Opera. 
 Does anyone know where to order a case just like the one Corda Opera uses?


----------



## MrMajestic2

Quote:


  Originally Posted by *jantze* /img/forum/go_quote.gif 
_Hi,
 I'd like to build a Opus DAC to feed my Corda Opera. 
 Does anyone know where to order a case just like the one Corda Opera uses?_

 

I doubt that you can buy that case anywhere. Im pretty sure its custom made for Meier Audio.


----------



## Lifthanger

Hi,
 I intend to go the hardcore DIY route.I've ordered the PCBs (awesome shipping time, by the way!) and want to use the WM8741. Do I need to change any of the components, or is the schematic the same?

 thanks 
	

	
	
		
		

		
		
	


	




 edit: I almost forgot: I want to compare USB powered and standalone powered operation. Is there a recommended PSU?
 I'm looking into the tread, but am still undecided.


----------



## BrianDonegan

The WM8741 is a drop in replacement. No other changes are needed. You just need to find an 8741.

 Edit for edit: Our USB module only supports USB-powered operation.


----------



## Lifthanger

wow, you were quicker than my 2 minute edit of the first post.
 thanks 
	

	
	
		
		

		
		
	


	




.

 I'm very patient, so if the wolfson is not available, I'll just use the USB DAC.
 That way I'll be able to better appreciate the opus in the end.


----------



## swt61

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_man, I need to get your gear out the door quick! Talk about scope creep ... geez 
	

	
	
		
		

		
		
	


	


_

 













 I like my Zapfilter just fine, but I'd like to hear a Ballsie as well. No plans to change though.


----------



## manaox2

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_ I'm now looking forward to that Sabre based dac board, it sure looks quite interesting!_

 

Sorry to get this a little off topic, but I am interested in the ESS Sabre8 based DAC coming out too. 

 I am planning a new balanced rig using the OPUS DAC which I would have prepared first. I am now going to build the Millett first while I follow project Buffalo.


----------



## sleepy dan

Quote:


  Originally Posted by *Lifthanger* /img/forum/go_quote.gif 
_Hi,
 I intend to go the hardcore DIY route.I've ordered the PCBs (awesome shipping time, by the way!) and want to use the WM8741. Do I need to change any of the components, or is the schematic the same?

 thanks 
	

	
	
		
		

		
		
	


	



_

 

The digital part of the WM8741 needs 3.3V, so make sure you use a suitable reg.


----------



## Nebby

More listening with the opus seems to indicate the "missing bass" statement I made earlier was just a fluke. My apologies for being a sensationalist. 
	

	
	
		
		

		
			





 Moreover, the the metronome sounds like it brings out even more detail than without it. Only issue at the moment is that the highs are still on the bright side, not sure if it's the blackgates needing the much rumored "extremely long burn-in" requirement or just the nature of how his system presents extreme detail (my friend's Klipsch speakers have titanium horn tweeters, so they present the highs very much in-your-face). I'd be listening to my own setup, but my 2ch setup is in pieces, quite literally. Speakers, crossovers, mdf, the works!

 As a side note, I picked up some silmicII's to upgrade my oscons of my other opus, but apparently I pulled the wrong part number, because they're the 35v versions! It was a tight fit, but I managed to get them to mostly fit on the board


----------



## Russ White

Nebby,

 I very much admire the talented bassist. You may, as I do, appreciate Rob Wasserman's "Duets" album. Incredible bassist and an excellent recording.

 I use that CD as a benchmark for accurate bass. If it sounds "right" then all is well.

 Cheers!
 Russ


----------



## pabbi1

x2 on the 'Buffalo Sabre'...

 Well, I am listening to 'Who's Next' and Entwhistle's bass sounds very 'right' -missing bass it is not.


----------



## Nebby

Thanks for the recommendations, I'll be sure to check them out! I'm definitely looking forward to the Buffalo IVY combo, I think that'll be quite interesting


----------



## Jambo

Quote:


  Originally Posted by *sleepy dan* /img/forum/go_quote.gif 
_The digital part of the WM8741 needs 3.3V, so make sure you use a suitable reg._

 

Also the pin which is MODE8X on the 8740 becomes the digital filter selection pin on the WM8741 IIRC.


----------



## BrianDonegan

Yup. Labeled on the board that way...

http://www.twistedpearaudio.com/imag...pus_layout.jpg


----------



## Lifthanger

I guess the caps before the analog out of the USB board are to get out the DC.
 Which value do you use?
 thanks


----------



## BrianDonegan

220uF. I just switched to these:

Digi-Key - 604-1056-ND (Elna America - RFS-25V221MI5#)

 SilmikII 220uf


----------



## TimJo

I have a couple of questions about the interface between the Metronome module and the DAC module. 

 Looking at the schematics, the Twisted Pear manuals, and the specs for the chips, it looks like the 'OPUS system' is set up for being run at 128fs, based on your crystal selection. Right?

 The WM8740 spec shows the system clock input (SCLK) to be at pin 5. The OPUS schematic shows pin 5 (MCLK) is connected to PCM_IN.1, yet the Metronome schematic shows the crystal is connected to the PCMOUT.2 terminal on that board. Likewise, the audio data bit clock on the Metronome board (BCKO - pin 25) is connected to PCMOUT.1, but the bit clock input on the OPUS module (BCLK - pin 3) is connected to the PCM_IN.2 terminal. It seems like terminal 1 & 2 on the PCM interface are inverted going between the two modules, or am I missing something?

 Related to this, I noticed that under the "OUTPUT PORT OPERATION" in the SRC4192 spec, it states that "In Master mode, BCKO operates at a fixed rate of 64fs for all data formats except TDM." If the schematics are correct, and the modules are wired pin for pin via the PCM terminals, then this implies the system clock on the WM8740 is being fed a 64fs clock, not a 128fs clock. What am I missing here?

 I'm suddenly feeling very confused...


----------



## Russ White

I am not sure what driving your confusion but I will do my best to help. Different data sheets use different names for the same signal. On my boards I try to stick with the name for a signal that the chip used in its data sheet. 

 For example. SCK(system clock) is the same as (master clock). 

 SCK is also sometime as Serial Clock which is the same as bit clock. 

 The word clock is sometime called a frame clock or lrck(left right clock). Fs is sample frequency. It is the frequency of LRCK.

 Ok so that said the metronome can operate at lot of clock frequencies (data, word, bit clocks). 64fs,128fs,256 etc. The master clock output is fixed (in normal master mode using on board XO). Its the other frequencies that change. In I2S mode bitclock will always be 64fs.

 so in relation to the DAC 64,128,256fs all relate to the master clock frequency copared to the sample rate.

 If the output sample rate out of the metronome is 96khz the DAc will be operating at 256fs master clock.

 If the sample rate out of the metronome is 48khz it will be 512fs.

 if the sample rate is 192khz then it will be 128fs.

 The PCBs are designed so that appropriate PCM pins on the terminal blocks line up when stacked.

 the receiver has an additional PCM pin to the right of GND which is the PCM in PIN since it can act as a transceiver. 

 Hope that helps.

 Cheers!
 Russ


----------



## Russ White

One other note, on the schematics there are two pins, the logical pin, and the physical pin. The physical pin number is the smaller number. They are not always the same.

 Cheers!
 Russ


----------



## TimJo

I follow your first post, which helps solidify my understanding of how this is set up, and it all makes sense. 

 It is actually the second post that cleared up my confusion. I now see that on the OPUS schematic, PCM_IN.1 is really located on pin 2 of the terminal block, and PCM_IN.2 is on pin 1. So, the system clock on the DAC really is connected to the crystal on the Metronome. I feel better now.

 Thanks for the quick reply. I really look forward to building the OPUS.


----------



## luvdunhill

I just got the Otto installed as an XLR input switcher. Works great! I need to setup a input switcher for the Opus and was wondering if there is any reason the exact same circuit with a G6K-2P-DC5 instead wouldn't get the job done. I looked at the schematic for the Darwin, but I'm not sure what the 100k resistors are for ...


----------



## naamanf

The 100k resistors are to prevent noise when switching sources and provide a high input impedance for the source not selected. (I asked the same question
	

	
	
		
		

		
		
	


	




 )


----------



## Mazuki

I was thinking about buying the USB receivers to interface with a SAA7220+TDA1541A. I'm just not sure about the I2S output of the USB receiver. If it outputs in 24-bit I2S, will the SAA7220 still recognise the signal? Can I set the PCM2707 to output 16/44.1khz?


----------



## luvdunhill

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_The 100k resistors are to prevent noise when switching sources and provide a high input impedance for the source not selected. (I asked the same question
	

	
	
		
		

		
			





 )_

 

ah, so what method what you guys recommend going with when dealing with a simple digital input selector? It seems there are problems with just tying both to the SPDIF receiver input, which is the problem I'm trying to fix


----------



## naamanf

I don't see any reason why that Omron relay you used wouldn't work. How do you plan on switching it? I made (well sort of copied) a circuit for switching a relay with a momentary switch that also displays what state it is in with a LED. Uses the 5v from a JT


----------



## luvdunhill

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_I don't see any reason why that Omron relay you used wouldn't work. How do you plan on switching it? I made (well sort of copied) a circuit for switching a relay with a momentary switch that also displays what state it is in with a LED. Uses the 5v from a JT 
	

	
	
		
		

		
		
	


	


_

 

yup, this is what I plan on doing exactly 
	

	
	
		
		

		
		
	


	




 i'll let you know tonite if it works. So, you say use the Otto circuit exactly with the smaller relay? sounds reasonable.


----------



## naamanf

Yup. If you want the schematic for the one I did shoot me a PM.


----------



## swt61

Cool!
 naamanf this is my Opus and Beta22 that luvdunhill is adding the switching to.

 We talked about putting the momentary switch at the end of a cable, so that I could switch from my office chair a few feet away. I thought I might make a little wood housing for the button that I could mount to the desk or wall. If that works out it will be pretty slick, so thanks for the help!


----------



## luvdunhill

argh.. looks like I need a relay with 0.3" spacing between the two rows, like a PDIP format. Would the G5V or G6A series from Omron be good choices, in lieu of the G6K?


----------



## BrianDonegan

Try a G6H. Fits perf board, works great (small, low current). Most mfg have an equiv.


----------



## Nebby

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_So I finally got around to putting the Zapfilter in the Opus. For those that have a Zapfilter have you noticed any "burn-in" changes? As for right now I much prefer the Ballsie. The top end is very harsh actually to the point of giving me a headache. To be fair I think I will leave it in and give it a couple days. But if it doesn't change after that it's coming out._

 

So has the zapfilter smoothed out any?


----------



## denden88

Could one of you guys give me a few measurements from the USB board? I'd like to order the dac and the prepunched enclosure at the same time.

 Thanks very much!


----------



## akione

Well, I get:

 A=75mm, B=5mm, C=42mm, E=10mm

 D=14mm or 18mm depending on which spacers are used.


 Note: all approx as my boards are all fitted and not easy to measure


----------



## jh4db536

It came today...
 it was fun to build the DPS
 how do i setup the LCDPS? what do i set the pot trimmers to? where do i measure?


----------



## denden88

That will do great, thanks akione


----------



## naamanf

Quote:


  Originally Posted by *jh4db536* /img/forum/go_quote.gif 
_It came today...
 it was fun to build the DPS
 how do i setup the LCDPS? what do i set the pot trimmers to? where do i measure?
_

 

Set it for 7.5vdc on each side. Measure from the output header.


----------



## jh4db536

It works!! first time and it fired right up. this is awesome 
	

	
	
		
		

		
		
	


	



 i'm not one for aesthetics, but this thing sounds really nice during the mock up. time to invest in the ASRC and a case.


----------



## shinew

where do you guys find nice enclosures(not fancy & expensive, but sturdy & relatively easy to mods & drill holes...)?


----------



## glt

I like server class power supplies form the junk pile at work 
Picasa Web Albums - glt - OpusDac


----------



## jh4db536

My impressions of the Opus compared to the DAC1. I'm running this as fully balanced source to my Apache.

 The first thing i noticed on the Opus was the mids. It's very forward, highly energetic, they pop out and grab you which sounds really nice with my HD650. The Opus has about 10-15% more bass, but it's a bit loose and it doesn't extend as low. A lot of the details that i had with the DAC1 are not present with the Opus especially in the lower frequencies. I can no longer get a sense of the recording environment. Drums (especially large, kick) don't sound real anymore. The decay on cymbals and drums is way too short. Impact is strong, but not realistic. Highs can be very bright when the recording asks for it, but overall the Opus is maybe just a smidgen dark of neutral. In short, this doesn't have perfect tonality to me. Perceived soundstage is not as wide as the DAC1, but it's deeper and maybe a little better at layering.

 The DAC1 is mellow, while the opus is more aggressive. I don't how else to put this, but i think the Opus emphasizes ranges of frequencies. It's like [Loudness] [Bassboost/enhancer] and then a mid highs boost - like 3 peaks/plateaus. The DAC1 is very coherent and flat across the board IMO.

 Overall the Opus sounds "fun". The DAC1 is just serious business/definitely a studio tool and has proven that once again. Not everyone appreciates the sound of the DAC1 so im not really implying that one is "better".

 I ordered a ASRC so hopefully thatll bring the Opus to higher level for round#2.

 I was hoping this could replace my DAC1, but i dont think the Opus can dethrone it. The DAC1 has too many features within one box, by the time you add another LCBPS + transformer, add more modules ballsie, ASRC, SPDIF receiver, toslink, usb etc...even the Opus can be quite an expensive adventure. For sure this thing destroys other DACs that ive played with ie EMU, Alien, Edirol EX1, and the DAC707. The fact that you can have this level of performance and a balanced source (USB balanced kit + transformer) for under $250 is the selling point.


----------



## glt

Have you tried removing the DC blocking caps? (if your amp can handle the DC)


----------



## BrianDonegan

Quote:


 I was hoping this could replace my DAC1, but i dont think the Opus can dethrone it. The DAC1 has too many features within one box, by the time you add another LCBPS + transformer, add more modules ballsie, ASRC, SPDIF receiver, toslink, usb etc...even the Opus can be quite an expensive adventure. For sure this thing destroys other DACs that ive played with ie EMU, Alien, Edirol EX1, and the DAC707. The fact that you can have this level of performance and a balanced source (USB balanced kit + transformer) for under $250 is the selling point. 
 

If you really want to compare apples to apples, you would need to add the Metronome and Ballsie, as the DAC1 up-samples the USB's 16/44.1 to a higher rate which is more friendly to the DAC's filters (try 96kHz) and it also has output buffers which can make a big difference, depending on your equipment.

 Also, a complete Opus (dual DACs, USB, spdif, toslink, ballsie, two power supplies, two trafos, metronome, and otto switch) comes to $579, which is less then half the cost of the DAC1.

 I look forward to your round 2 review with the Metro.


----------



## error401

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_If you really want to compare apples to apples, you would need to add the Metronome and Ballsie, as the DAC1 up-samples the USB's 16/44.1 to a higher rate which is more friendly to the DAC's filters (try 96kHz) and it also has output buffers which can make a big difference, depending on your equipment._

 

I believe the DAC1 actually has a 24/96KHz USB interface Brian.


----------



## shinew

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_I look forward to your round 2 review with the Metro._

 

x2


----------



## BrianDonegan

Quote:


 I believe the DAC1 actually has a 24/96KHz USB interface Brian. 
 

You are correct! I guess it is just as likely then that our USB module is the weak link in the comparison.


----------



## jh4db536

I have a DAC1 non USB (toslink) if that makes a difference. The price of a non USB DAC1 is significantly lower than the newer.

 I look forward to the ASRC too 
	

	
	
		
		

		
		
	


	




 What setting is optimal? 24bit/96? mode 0,1,2?

 How much would the Ballsie help? It's not like im driving headphones straight out of either DAC (although i have that choice with the DAC1). I'm comparing both DACs (as a source) through an RSA Apache which should be more than a competent amp.

 the flow is:

 Laptop (foobar2k,asio4all, ALL Original EAC ripped flac, set@24 bit) => Opus (balanced) => Apache(balanced) => HD650 (balanced)
 Laptop (Asio set@16bit) Edirol EX1 Toslink Out => DAC1 => Apache => HD650


----------



## shinew

Quote:


  Originally Posted by *error401* /img/forum/go_quote.gif 
_I believe the DAC1 actually has a 24/96KHz USB interface Brian._

 

So does the DAC1 upsample or not when played through USB?


----------



## jantze

Quote:


  Originally Posted by *shinew* /img/forum/go_quote.gif 
_where do you guys find nice enclosures(not fancy & expensive, but sturdy & relatively easy to mods & drill holes...)?_

 

I'm going to build TPA DAC soon and I did try to figure out what casing to choose, but I think we have different budget. 

 These were the sites/manufacturers that I found:
Par-Metal Products
modu
Hi-Fi 2000 contenitori per l'elettronica, case modding HTPC, Galaxy, rack, DIYaudio, computer cases, knobs,milled Handles, milled fronts, hi-end,
Products
thlaudio web site pages
ATI Research Company Limited
High quality aluminum enclosures designed for maximum flexibility in form and function
DIY Enclosures LLC. - Welcome
Enclosures
Audiokit Home Page
Hammond Mfg. - Small Electronic Enclosure Index

 I think that so far this is my favorite: ATI Research Company Limited


----------



## shinew

Quote:


  Originally Posted by *jantze* /img/forum/go_quote.gif 
_I'm going to build TPA DAC soon and I did try to figure out what casing to choose, but I think we have different budget. 

 These were the sites/manufacturers that I found:
Par-Metal Products
modu
Hi-Fi 2000 contenitori per l'elettronica, case modding HTPC, Galaxy, rack, DIYaudio, computer cases, knobs,milled Handles, milled fronts, hi-end,
Products
thlaudio web site pages
ATI Research Company Limited
High quality aluminum enclosures designed for maximum flexibility in form and function
DIY Enclosures LLC. - Welcome
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 I think that so far this is my favorite: ATI Research Company Limited_

 

Cool! thanks for the links. ATI-738U looks nice, the 737U doesn't look bad either ATI Research Company Limited
 It'll be great if I can fit the DAC in this(maybe use an external power supply) -> Hammond Mfg. - Extruded Aluminum (Metal End Panels) - 1455 Series Enclosures , but I doubt it...

 So does TPA also offer the non-assembled version(complete parts only) of the OPUS?


----------



## akione

Quote:


  Originally Posted by *shinew* /img/forum/go_quote.gif 
_So does TPA also offer the non-assembled version(complete parts only) of the OPUS?_

 

The only self-build units are the power supplies. 
 Most of the units use surface mount parts and come pre-assembled. 
 There are some odd bits and pieces to do, like screw terminal and some caps, but not much. 
 Essentially you just select which modules you need for your project and connect them together


----------



## BrianDonegan

Quote:


 It'll be great if I can fit the DAC in this(maybe use an external power supply) -> Hammond Mfg. - Extruded Aluminum (Metal End Panels) - 1455 Series Enclosures , but I doubt it... 
 

I am about to build one in a 1455 case. I will take pictures...


  Quote:


 So does TPA also offer the non-assembled version(complete parts only) of the OPUS? 
 

While we do not officially offer a kit, if you really want to build one yourself, send me email as we can work something out.


----------



## Nebby

Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_The only self-build units are the power supplies. 
 Most of the units use surface mount parts and come pre-assembled. 
 There are some odd bits and pieces to do, like screw terminal and some caps, but not much. 
 Essentially you just select which modules you need for your project and connect them together 
	

	
	
		
		

		
		
	


	


_

 

It's a rather expensive electronic lego set


----------



## BrianDonegan

Quote:


 I am about to build one in a 1455 case. I will take pictures... 
 

Ok, here is my initial layout for a Hammond 6x8x2" 1455 case.










 Power will run up the side to the transformer, then across the front to the PS. The PS in these pictures is a bipolar supply, as it's what I had on hand and am only testing layouts. It will be a dual supply.

 The board stacks will fit once I switch standoffs. I will be using .25" m/f on the very bottom, then .375" m/f in between each layer. I will remove the terminal blocks and direct wire the power and I2S lines. 

 The first board stack will be an S/PDIF receiver, USB receiver and OTTO switch. The second board stack will be a metronome and two opus in dual-mono, which will feed the XLR connectors directly.

 For control, I am thinking of whiping up a small board with a PIC16F690 (from JT leftovers) with a rotary encoder (with push button) and a little 4-character Avego display.

 When off, push button will power up. Push button and turn to select S/PDIF/ USB, Power Off (release to select). Just turning will control volume of the DACs. Display will show "USB", "SPDF", ""OFF", or attenuation dB (0 to -128, then "MUTE").

 I have two of these cases. The second case will house a head amp. For now I will use an s/e diamante and a ballsie, both fed from a LCBPS in case #2. Later I will change to a balanced head amp.


----------



## shinew

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Ok, here is my initial layout for a Hammond 6x8x2" 1455 case.











 Power will run up the side to the transformer, then across the front to the PS. The PS in these pictures is a bipolar supply, as it's what I had on hand and am only testing layouts. It will be a dual supply.

 The board stacks will fit once I switch standoffs. I will be using .25" m/f on the very bottom, then .375" m/f in between each layer. I will remove the terminal blocks and direct wire the power and I2S lines. 

 The first board stack will be an S/PDIF receiver, USB receiver and OTTO switch. The second board stack will be a metronome and two opus in dual-mono, which will feed the XLR connectors directly.

 For control, I am thinking of whiping up a small board with a PIC16F690 (from JT leftovers) with a rotary encoder (with push button) and a little 4-character Avego display.

 When off, push button will power up. Push button and turn to select S/PDIF/ USB, Power Off (release to select). Just turning will control volume of the DACs. Display will show "USB", "SPDF", ""OFF", or attenuation dB (0 to -128, then "MUTE").

 I have two of these cases. The second case will house a head amp. For now I will use an s/e diamante and a ballsie, both fed from a LCBPS in case #2. Later I will change to a balanced head amp._

 

That's awesome! how difficult is it to drill holes on the 1455 case? I've never modded a alluminum case before. The only tools I have are these, are they up for the job?
 B&D 5.0amp VSR Drill - Black & Decker Power Tools
 Denali 136-bit drill kit - Amazon.com: Denali 136-Piece Titanium Contractor's Drill And Drive Bit Accessory Set: Home Improvement


----------



## BrianDonegan

Generally speaking, work working tools work very well on aluminum.


----------



## Clutz

I'm having some difficulty with the tri-state switches. Looking at the switch it isn't obvious to me which direction is 1 and which is 0 - assuming that the middle state is open. Can someone help me? I'm trying to finish this up so I can case it today.


----------



## jh4db536

left is 0, open is middle, right is 1


----------



## Clutz

IT IS ALIVE! 

 IT'S ALIVE! IT'S ALIVE!

 Thanks Brian, Russ and jh4db536!


----------



## shinew

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Generally speaking, work working tools work very well on aluminum._

 

what does it mean


----------



## Clutz

Quote:


  Originally Posted by *shinew* /img/forum/go_quote.gif 
_what does it mean 
	

	
	
		
		

		
		
	


	


_

 

I think it's a typo. I think he meant "Generally speaking, *wood* working tools work very well on aluminum."


----------



## Clutz

I don't have my other USB DAC here for a direct comparison, but I can do a comparison from memory- and I did use my previous DAC on Friday, so that's reasonable recent. This DAC has better highs than my other USB DAC (which is a non-oversampling DAC based on the TDA1541A, which a much simpler power supply setup) - it makes this sound more precise. There is also a difference in the sound of cymbals and high-hats. I would also say that this DAC is a bit more revealing. That said, it cost 2x more to build, has two dedicated power supplies, and the TDA1541A being an NONOS design should have rolled off treble.

 I havent finished the case work for this yet. I'm a bit disappointed I didn't go with a SPDIF input in this DAC - but maybe when the Sabre DAC becomes available I'll get an SPDIF input for this and use it with my home stereo and use the USB input with the Sabre DAC. Who knows.

 Great work though guys, it sounds great.


----------



## fordgtlover

Quote:


  Originally Posted by *shinew* /img/forum/go_quote.gif 
_That's awesome! how difficult is it to drill holes on the 1455 case? I've never modded a alluminum case before. The only tools I have are these, are they up for the job?
 B&D 5.0amp VSR Drill - Black & Decker Power Tools
 Denali 136-bit drill kit - Amazon.com: Denali 136-Piece Titanium Contractor's Drill And Drive Bit Accessory Set: Home Improvement_

 

I find that a stepped drill bit works the best for everything but the smallest holes in aluminium. That is, anything over about 6mm. 

 I typically use a center punch to mark the spot then drill a 4mm pilot hole and work my way up with the stepped drill bit - nice neat holes with cordless drill.


----------



## BrianDonegan

Quote:


 I think it's a typo. I think he meant "Generally speaking, wood working tools work very well on aluminum." 
 

You cracked my code! Yes, I meant wood working tools.


----------



## Clutz

I still need to case this thing up. I've got a Par Metals case ready for it - in fact it already has the IEC in it as well as holes for the RCA jacks and the USB plug -- but I'm having a hard time figuring out how I want to arrange the boards. I may have to re-do some of the wiring with more flexible, lower gauge wire in order to get the board layout nice and neat. That said, I don't really have a lot of motivation to do that right now - cause I'm enjoying listening to it.


----------



## BrianDonegan

Quote:


 but I'm having a hard time figuring out how I want to arrange the boards 
 

Stack them if you can. They were designed for that, and will give you the shortest I2S signal path (less noise).


----------



## Clutz

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Stack them if you can. They were designed for that, and will give you the shortest I2S signal path (less noise)._

 

Yes, stacking them- what an intriguing idea. I'll stack the USB module, the metronome and the Opus DAC itself in one tower and the two power supplies in another tower. If only the bolt for the transformers was long enough. 
	

	
	
		
		

		
		
	


	




 Guess I'll have to go to the store to buy a longer one. 
	

	
	
		
		

		
		
	


	




 Another question: Is there a drilling guide available? I know I can just remove all the legs from one of the boards and make one of my own, but that requires disassembly versus just printing.


----------



## Clutz

Question for the other opus builders using the Balsie to go single ended: Did you find that jumpering the output capacitors on the DAC board made a big difference to the sound quality? I know it's basically a free improvement in sound quality, but jumpering them means separating the boards and bringing out the soldering iron again. It won't happen tonight by any means.


----------



## akione

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Ok, here is my initial layout for a Hammond 6x8x2" 1455 case.










 Power will run up the side to the transformer, then across the front to the PS. The PS in these pictures is a bipolar supply, as it's what I had on hand and am only testing layouts. It will be a dual supply.

 The board stacks will fit once I switch standoffs. I will be using .25" m/f on the very bottom, then .375" m/f in between each layer. I will remove the terminal blocks and direct wire the power and I2S lines. 

 The first board stack will be an S/PDIF receiver, USB receiver and OTTO switch. The second board stack will be a metronome and two opus in dual-mono, which will feed the XLR connectors directly.

 For control, I am thinking of whiping up a small board with a PIC16F690 (from JT leftovers) with a rotary encoder (with push button) and a little 4-character Avego display.

 When off, push button will power up. Push button and turn to select S/PDIF/ USB, Power Off (release to select). Just turning will control volume of the DACs. Display will show "USB", "SPDF", ""OFF", or attenuation dB (0 to -128, then "MUTE").

 I have two of these cases. The second case will house a head amp. For now I will use an s/e diamante and a ballsie, both fed from a LCBPS in case #2. Later I will change to a balanced head amp._

 

Very Interesting, Brian. 

 Using your DACs in dual mono, are you just going to use the outputs from one side of each DAC direct to the XLRs?

 Or are you doing load-balancing in some way first - or just not bothering and linking them together, anyway?


----------



## Clutz

Are you using a single transformer for both power supplies? Or are you just not using a balsie for the output?


----------



## BrianDonegan

Quote:


 Using your DACs in dual mono, are you just going to use the outputs from one side of each DAC direct to the XLRs?

 Or are you doing load-balancing in some way first - or just not bothering and linking them together, anyway? 
 

 Quote:


 Are you using a single transformer for both power supplies? Or are you just not using a balsie for the output? 
 

There is only one supply, as there is no Ballsie. My plan is to, if I use a Ballsie, to do so in the next case. I haven't decided on how to do the load balancing yet... smds or radial resistors from the pads to the XLRs. 

 Yesterday was "initial layout" day. Today is "stew on it and change everything" day 
	

	
	
		
		

		
			





.


----------



## error401

Quote:


  Originally Posted by *shinew* /img/forum/go_quote.gif 
_So does the DAC1 upsample or not when played through USB?_

 

I don't own and haven't used one, but from both their website and anecdotal evidence, I believe it is true 24/96 over USB.

 It seems like they're using one of TI's USB streaming processors with some custom firmware.


----------



## Clutz

Has anyone using the BALSIE output stage in single ended mode found a difference in bypassing C5-C8 on the DAC board? I never plan on using this for balanced operation (at least not for a very long time). I am thinking about doing this tomorrow morning before I take it in to work with me, where I have another DAC which needs a similar operation. Perhas I should just take the soldering iron into work and do it on the bench.


----------



## jh4db536

Got the Metro installed. (beware the orientation of the dip switches on the left and right side of the board!) Settings = 24bit, 256fs, 96khz

 Initial Impressions:

 The Metro board changes the Opus a LOT. The BurrBrown chip has SIGNIFICANT influence on the new overall signature.'

 Soundstage was the biggest improvement. Overall, it is better than the DAC1 IMO. It's still not as wide, but it's WAY deeper, layered, super accurate in position, reveals the details of the environment, and 3d real. The stage is flat and perfectly spaced with a test track i use (i have never had this before in a headphone setup).

 The low end detail is now there, the bass is very tight and controlled. The Opus has a LOT more bass quantity than the DAC1 in the first place, now it is up to par with control.

 "you can't change something without destroying what it was"

 The aggressive forwardness and electrifying midend that i really liked with the non-metro'd Opus is Gone. Replaced with the laidback and dark nature of the BurrBrown chip. The Opus has gone down half a notch in brightness. I think it used to synergize better with the HD650 and im very sad it's gone.

 Highs might have veil (non Metro'd Opus was very good about this) and cymbals are weaksauce sometimes. Ugh. Were the gains worth the compromise? Maybe i should listen to it with my HD600 instead.

 Another note..the LCDPS runs Much warmer on the side where the Metro is leeching power. Is this thing a powerhog? It's not extremely hot to touch (can hold my finger on it). Bigger heatsink?

 That's what i have for now. Maybe i'll have more to add later this week.


----------



## Nebby

Make it switchable and have both available on tap! 
	

	
	
		
		

		
		
	


	




 I currently have the Metro wired to an OTTO for switching, but I'm having issues with noise (guessing it's due to the I2S wiring) so I'm working on a setup that will allow for shorter I2S runs.


----------



## TimJo

Instead of using an OTTO for switching the Metro 'on and off' can't you just use the Bypass Mode (pin 9 on the SRC4192) to toggle between modes?

 Also, in general, how big an issue is noise when passing the PCM data between boards? I noticed Brian mentioned that he was going to remove the terminal blocks and direct wire the stacks on the one he is putting together right now.


----------



## BrianDonegan

Quote:


 Also, in general, how big an issue is noise when passing the PCM data between boards? I noticed Brian mentioned that he was going to remove the terminal blocks and direct wire the stacks on the one he is putting together right now. 
 

Noise can be easily avoided on the I2S lines by keeping the them short and away from the power supply lines. This is perfectly possible with the terminal blocks. The way the boards are designed, the I2S pads line up vertically, so you could place a receiver on top of a DAC board and run wires straight through the pads to connect the boards.

 I leave the terminal blocks off of the modules now for two main reasons. First, it's less work for me 
	

	
	
		
		

		
		
	


	




. Second, it allows more flexibility, such as direct wiring, or backward mounting*, because once added, the TBs are hard to desolder and remove.

 By backward mounting, I mean mounting with the wire access to the inside rather than the outside, which can be helpful sometimes.

 I am leaving the terminal blocks off on mine because I want to use .375" standoffs, and the tbs woudl be too tall.


----------



## luvdunhill

hey guys, where can I find the documentation for the older CS SPDIF receiver boards?


----------



## BrianDonegan

Manual 1.0 link on the Opus page: http://www.twistedpearaudio.com/docs...804_manual.pdf

 [EDIT]

 Oops. Try here: http://www.twistedpearaudio.com/docs...dif_manual.pdf

 [/edit]


----------



## miky

Did anyone have problems with LCBPS for Ballsie? R1, R2, R5, R6 on the LCBPS becomes very hot and OUT DC drop to 0.6v. When running it unloaded it’s fine and gives 15 and -15 volt. Loaded on one side only (15-GND or -15-GND) its fine too. I’m use the single transformer to power the Ballsie supply (Avel Lindberg Y236053).


----------



## jh4db536

Can someone explain Ballsie & IVY? They are both output stages? Is the IVY a ballsie without the single ended converter? Which is better for just a fully balanced system? Any feedback w/ and w/o ballsie or IVY?


----------



## Clutz

Quote:


  Originally Posted by *jh4db536* /img/forum/go_quote.gif 
_Can someone explain Ballsie & IVY? They are both output stages? Is the IVY a ballsie without the single ended converter? Which is better for just a fully balanced system? Any feedback w/ and w/o ballsie or IVY?_

 

BALSIE is a balanced to single ended convert + buffered output. It is to be used with the OPUS DAC, which outputs voltage instead of current. If you are using the OPUS DAC, you can skip the BALSIE stage if you are using a preamplifier or headphone amplifier with a high input impedance.

 The IVY is a current to voltage converter + output buffer. It is to be used with the COD DAC which outputs its analog signal by varying current as opposed to voltage (like the OPUS). With the COD DAC you can use the BALSIE by using a simple resistor based I/V (which is easily installable directly on the COD DAC board) and then use the BALSIE for output buffering, or you can use the IVY and let it's opamps do the I/V conversion for you. It has been recommended that if you are going to use the COD DAC, that you will get better performance with the IVY's active I/V stage than a passive I/V stage - although you may prefer a passive I/V stage- some people do.

 What you use is decide to use is based on what DAC you use, and what other choices you make.


 Brad


----------



## akione

Quote:


  Originally Posted by *jh4db536* /img/forum/go_quote.gif 
_Can someone explain Ballsie & IVY? They are both output stages? Is the IVY a ballsie without the single ended converter? 
 Which is better for just a fully balanced system? Any feedback w/ and w/o ballsie or IVY?_

 

Another difference is that the Ballsie has load-balancing resistors on the inputs. 
 These are needed if you are building a dual mono configuration. It also has provision for filter caps.

 Although they were designed for different purposes, there is some similarity and both can be configured 
 to do the same thing in some cases, but they are not always interchangeable. 
 What comes after is equally important, as each handles its loading differently.


----------



## miky

Quote:


  Originally Posted by *miky* /img/forum/go_quote.gif 
_Did anyone have problems with LCBPS for Ballsie? R1, R2, R5, R6 on the LCBPS becomes very hot and OUT DC drop to 0.6v. When running it unloaded it’s fine and gives 15 and -15 volt. Loaded on one side only (15-GND or -15-GND) its fine too. I’m use the single transformer to power the Ballsie supply (Avel Lindberg Y236053)._

 

Help, please … Russ, Brian, someone?


----------



## naamanf

Are you only using the transformer for LCBPS?


----------



## Lifthanger

which regulators do you use for VRD and VRA on the opus board?

 thanks


----------



## BrianDonegan

Quote:


  Originally Posted by *miky* /img/forum/go_quote.gif 
_Help, please … Russ, Brian, someone?_

 


 I need to know a little more. How do you have the transformer attached to the power supply (wire order). Also, as naamanf asked, are you sharing the transformer with anything else?

  Quote:


 which regulators do you use for VRD and VRA on the opus board? 
 

National Semiconductor LP2985 5V


----------



## miky

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_How do you have the transformer attached to the power supply (wire order)._

 

Primaries series connected - gry+vio (230v), secondaries independent - blk, red, org, yel.
  Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Also, as naamanf asked, are you sharing the transformer with anything else?_

 

No, I don't.

 It's R1, R2, *R3*, *R4* and not *R5*,*R6*


----------



## Lifthanger

Thanks for your answer brian! 
	

	
	
		
		

		
		
	


	




 could you also tell me which inductors L1 and L2 are used for the lcdps?

 My experience with schematics is still rather low :/.


----------



## BrianDonegan

It sounds like it may be a short on the Ballsie. Can you test resistance between the V+ GND and V- terminals (with nothing connected).


----------



## miky

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_It sounds like it may be a short on the Ballsie. Can you test resistance between the V+ GND and V- terminals (with nothing connected)._

 

It's 410K ohm between the V+ and GND, 426K ohm between the V- and GND and 340K ohm between the V+ and V- terminals.


----------



## Lifthanger

in the meantime I found out, that the resistors behind the inductors are 10R 3W types. but I'm still clueless about the inductivity of the used inductors in the PSU.
 Do these values depend on the filter caps used? In the picture 470µF panasonics are used, while in the schematic 220µF are in place..


----------



## naamanf

Quote:


  Originally Posted by *miky* /img/forum/go_quote.gif 
_It's 410K ohm between the V+ and GND, 426K ohm between the V- and GND and 340K ohm between the V+ and V- terminals._

 

Those seem really high. Mine reads 2.8K on both sides. How long are you leaving the probes on for? Takes about 10 sec or so to get a stable reading. 

 If you can post some picture of the top and bottom it might help figure out what is wrong.


----------



## miky

Hi naamanf
 Thanks for your replay. I'm leaving the probes on for about 30 sec. It what it takes to get a reading.
 You need picture of LCBPS, Ballsie o both of them?


----------



## naamanf

Just the LCBPS. Top and Bottom.


----------



## Lifthanger

The inductors used in lcdps and lcbps are:
 ACM7060-701-2PL — TDK
 Looking for l1 helped much..
 I'll also use 470µF caps on the PSU like shown on the picture.

 My final question is:
 Where is the value for the output coupling caps coming from?

 I intend to use the opus with a CKK3 which should have an input impedance of 50k. Calculating the needed output cap yields about 1µF. 
 Is 22µF needed for stability reasons or is it just a number to be on the safe side?
 I could get some very nice MKPs with 4.7µF-8.2µF at a fair price.

 thanks again!


----------



## Gautama

^Mm, tell me how you like that combo onec you get it up and running.


----------



## Russ White

Quote:


  Originally Posted by *Lifthanger* /img/forum/go_quote.gif 
_My final question is:
 Where is the value for the output coupling caps coming from?

 I intend to use the opus with a CKK3 which should have an input impedance of 50k. Calculating the needed output cap yields about 1µF. 
 Is 22µF needed for stability reasons or is it just a number to be on the safe side?
 I could get some very nice MKPs with 4.7µF-8.2µF at a fair price.

 thanks again!_

 

You can indeed lower the value if you want, The 22uf value is there to get low phase shift and distortion at low an mid frequencies. The lower the value, the more phase shift/distortion you will get.

 You can change the value if you like without worry.

 Cheers!
 Riss


----------



## BrianDonegan

Quote:


 Hi naamanf
 Thanks for your replay. I'm leaving the probes on for about 30 sec. It what it takes to get a reading.
 You need picture of LCBPS, Ballsie o both of them? 
 

Both, wired up would be best.


----------



## Lifthanger

thanks 
	

	
	
		
		

		
			





 should be up and running in 2 weeks, I'll report back with my results.


----------



## miky

Quote:


  Originally Posted by *naamanf* /img/forum/go_quote.gif 
_If you can post some picture of the top and bottom it might help figure out what is wrong._

 






















 And something else.
 When I disconnect a V+ wire on Ballsie, I still have:
 V- 15v
 V+ 14.3v
 Between V- and V+ 0.6v
 The same, when I disconnect a V+ wire (V- 14.3v, V+ 15v, V- + V+ 0.6v)


----------



## Clutz

Quote:


  Originally Posted by *miky* /img/forum/go_quote.gif 
_And something else.
 When I disconnect a V+ wire on Ballsie, I still have:
 V- 15v
 V+ 14.3v
 Between V- and V+ 0.6v
 The same, when I disconnect a V+ wire (V- 14.3v, V+ 15v, V- + V+ 0.6v)_

 

First of all, you probably want to dial the bipolar power supplies output to +/-7.5V instead of +/-15V. Second, if you are measuring -.6V between V- and V+, it makes me think that both V+ is outputting +14.3V and V- is outputting +15V. 15-14.3=0.7, which is very close to the 0.6v you measured. When you measure the voltage here, you want to put the red terminal on + and the negative terminal on gnd. When you measure the negative voltage you want to put the red probe on -V and the black probe on GND.


----------



## BrianDonegan

Russ wins today's Eagle Eye prize. 

 Ballsie IC1 is on backwards, my fault. New unit on the way.

 For Ballsie, +-15VDC is good.


----------



## Clutz

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Russ wins today's Eagle Eye prize. 

 Ballsie IC1 is on backwards, my fault. New unit on the way.

 For Ballsie, +-15VDC is good._

 

Is +/-15 better than +/-7.5? I have it running at +/-7.5.


----------



## BrianDonegan

Quote:


 Is +/-15 better than +/-7.5? I have it running at +/-7.5. 
 

Yes, you will get better performance from the op amps. We recommend the dual supply be set for 7.5V (DAC and Accessory power).


----------



## Clutz

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Yes, you will get better performance from the op amps. We recommend the dual supply be set for 7.5V (DAC and Accessory power)._

 

Oops! I will have to change that on Monday.


----------



## fierce_freak

You'll notice a nice change, too


----------



## miky

Ok, here are the details of some measurements I’ve made




*-0.6v, 2.834K ohm*



*0.657v 2.842K ohm*



*1.268v,* *524.2 ohm*



*14.35v, 364.6K ohm*



*15v, 2.846K ohm*



*0.65v, 337.8K ohm*



*-15v, 2.836K ohm* 



*-14.36, 341.6K ohm*



*0.635v, 338.6K ohm*

 Why I have 14v/-14v when wire is disconnected?


----------



## Nebby

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Russ wins today's Eagle Eye prize. 

 Ballsie IC1 is on backwards, my fault. New unit on the way.

 For Ballsie, +-15VDC is good._

 

Just wanted to quote this for you milky


----------



## miky

I would like to have +-15VDC. But I have +-0.6VDC (see above).


----------



## BrianDonegan

One of the op amps on the Ballsie is installed backwards. It will cause all sorts of problems. I am sending you a new one.

 When the supply is not connected to the Ballsie, all is well, no?


----------



## miky

When the LCBPS is not connected to the Ballsie, I have +/- 15VDC.
  Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_One of the op amps on the Ballsie is installed backwards._

 






 You mean this one?


----------



## regal

This looks ideal for the Opus anyone tried it yet:


----------



## Russ White

Quote:


  Originally Posted by *miky* /img/forum/go_quote.gif 
_When the LCBPS is not connected to the Ballsie, I have +/- 15VDC.






 You mean this one?_

 

Yes, thats the one.


----------



## BrianDonegan

Quote:


  Originally Posted by *regal* /img/forum/go_quote.gif 
_This looks ideal for the Opus anyone tried it yet:





_

 

I have some sub-mini 6021 dual triode tubes I could try that with I suppose...

 I don't usually "do tubes" though so could use help with some values.


----------



## jh4db536

I want to add more about the OPUS+METRO (amp=Apache) beyond the initial excitement phase and given a couple weeks of burn in. I haven't changed any of the settings.

 The Opus DAC's distinctive signature to me is a full bodied sound, ton's of detail, aggressive, and is dark + bright at the same time (powerful light coming out of blackness). It reminds me of the Ultrasone signature in this regard, but as a source.

 The Opus is perfect for the HD650 (i found it to be completely unbearable with the K701). I think 580/600 flaws are being revealed, because i can finally detect the 650's superiority. I don't think i could listen to 650's any other way now. I would totally recommend this to anyone with a hd650 looking for a more energetic sound.

 The Metro changes the sound signature significantly (for better or worst YMMV). The aggressiveness of the Opus has ridded All of the 650's mellowness (like an exciter dsp). I have never heard Senns this way, but it's really cool. The Opus Completely cuts through the veil and gives the 650's the highest amount of detail that i have heard so far. They seem to excel at almost everything now (bass could be a tighter). Separation and layers are distinct and i feel i can easily dissect the music. The proportion of depth to width is a lot more correct than the DAC1. I mentioned earlier it performed good in a soundstage spacing test track...headphones always seem to do poorly.

 I am convinced that i should enclose this thing 
	

	
	
		
		

		
		
	


	




 When is an OPUS 3.0 with the WM8741 going to be released?


----------



## Jambo

Quote:


  Originally Posted by *jh4db536* /img/forum/go_quote.gif 
_When is an OPUS 3.0 with the WM8741 going to be released?_

 

Probably when Wolfson start selling that chip to someone other than Pioneer and Linn!


----------



## BrianDonegan

The WM8741 will work on the 2.0 board (designed for it). So, yes, whenever they start selling the chips.


----------



## luvdunhill

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Manual 1.0 link on the Opus page: http://www.twistedpearaudio.com/docs...804_manual.pdf

 [EDIT]

 Oops. Try here: http://www.twistedpearaudio.com/docs...dif_manual.pdf

 [/edit]_

 

Brian:

 Can I also get a link to the schematic? Sorry, I cannot find it anywhere on your website, and no hits using google...


----------



## BrianDonegan

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_Brian:

 Can I also get a link to the schematic? Sorry, I cannot find it anywhere on your website, and no hits using google..._

 

Twisted Pear Audio News


----------



## luvdunhill

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Twisted Pear Audio News_

 

ah a bit too late 
	

	
	
		
		

		
		
	


	




 I just followed the datasheet, and removed a 5 or so resistors and 2 caps, added a resistor and....... AES3!


----------



## Lifthanger

my opus is done 
	

	
	
		
		

		
		
	


	




 some questions though:

 I'm using it unbalanced with the ballsie and have just jumpered the opuses output coupling caps.

 DC offset is zero after the ballsie. But the two opamps get rather hot (60C, +15V/-15V). Is this fine, or do I have to use the coupling caps on the opus?

 And: the metronome: The schematic lacks all part values. Could you help me find them out?

 Thanks.

 My rig is now : USB -> Opus -> Ballsie -> CKK3 -> HD595

 How does it sound?

 Compared to my previous rig with just onboard sound into the CKK3, details have gone up quite a bit. Music is still lively which was introduced with the CKK3 in the first place. I really like it and find it to be a great rig for the money. Unfortunately I have never heard another rig. It's hard to judge without a reference. I'm happy though 
	

	
	
		
		

		
		
	


	




 and will report back after installing the metronome.

 What would you say is the weakest link in the rig? 

 And another question: How do you make a reference collection? Is it just personal taste, or is there a trick involved?


----------



## Russ White

Quote:


  Originally Posted by *Lifthanger* /img/forum/go_quote.gif 
_my opus is done 
	

	
	
		
		

		
		
	


	




 some questions though:
 DC offset is zero after the ballsie. But the two opamps get rather hot (60C, +15V/-15V). Is this fine, or do I have to use the coupling caps on the opus?

 And: the metronome: The schematic lacks all part values. Could you help me find them out?
_

 

Those opamps are always warm at 15V rails. Perfectly normal. They have a pretty high idle current.

 As for the metronome schematic I will make sure we post a new one with part values. 

 I won't touch the other questions for now. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## Lifthanger

no problem! they don't fit the thread topic anyway 
	

	
	
		
		

		
		
	


	




.

 thanks for the answers


----------



## indikator

the DAC and COD modules and PCBs seems to be out of stock, any other way to get one? or you are going to restock?


----------



## Russ White

They are slated to be ordered with the next batch of boards. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## luvdunhill

I have a quick question for a usage of the SPDIF receiver. Theoretical setup would be as follows:

 1) external CD transport (standard plain-jane commercial box)
 2) diy CD player, which consists of a philips transport and DAC

 The DIY player currently has I2S using the Philips specification directly from the transport mechanism to a DAC. For the sake of discussion, let's say the DAC only accepts i2s, specifically Philips (16-bit I2S, 64 BCK/WS and BCK is 44.1kHz * 64, 2's compliment data, WS 44.1kHz, standard Philips spec). The player has a readily available +10V supply.

 Seems that I might be able to use the Wolfson 8804 receiver to allow me to toggle between a direct I2S connection from "internal" CD transport to DAC and another the external transport. Furthermore, I could also support PCM input from the external transport, assuming there was a easy way to toggle the jumpers on the SPDIF receiver. Would I need any special settings other than setting AIF_MS to MASTER, TXSRC to SPDIF, AIFCONF1 low, AIFCONF0? Looks like +10V should be fine?

 Also, would the Metronome allow conversion from higher bit rate sources (24/96 DVD Audio discs, via PCM) to 16-bit I2S? Seems looking at the datasheet, that it can support I2S on both input and output, but I'm not sure if your implementation will allow it. Again, looks like I could do both input PCM and output I2S *and* input I2S and output I2S, the latter giving me the ability to to insert the Metronome between the internal CD transport and DAC, thus bypassing the receiver all together. 

 Thanks guys!


----------



## Russ White

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_I have a quick question for a usage of the SPDIF receiver. Theoretical setup would be as follows:

 1) external CD transport (standard plain-jane commercial box)
 2) diy CD player, which consists of a philips transport and DAC

 The DIY player currently has I2S using the Philips specification directly from the transport mechanism to a DAC. For the sake of discussion, let's say the DAC only accepts i2s, specifically Philips (16-bit I2S, 64 BCK/WS and BCK is 44.1kHz * 64, 2's compliment data, WS 44.1kHz, standard Philips spec). The player has a readily available +10V supply.

 A)Seems that I might be able to use the Wolfson 8804 receiver to allow me to toggle between a direct I2S connection from "internal" CD transport to DAC and another the external transport.

 B) Furthermore, I could also support PCM input from the external transport, assuming there was a easy way to toggle the jumpers on the SPDIF receiver. Would I need any special settings other than setting AIF_MS to MASTER, TXSRC to SPDIF, AIFCONF1 low, AIFCONF0? Looks like +10V should be fine?

 C)Also, would the Metronome allow conversion from higher bit rate sources (24/96 DVD Audio discs, via PCM) to 16-bit I2S? Seems looking at the datasheet, that it can support I2S on both input and output, but I'm not sure if your implementation will allow it.

 D) Again, looks like I could do both input PCM and output I2S *and* input I2S and output I2S, the latter giving me the ability to to insert the Metronome between the internal CD transport and DAC, thus bypassing the receiver all together. 

 Thanks guys!_

 

A) I think what you might really want here is the OTTO. But I am not sure...

 B) You would need to reset the receiver for the changes to take effect.


 C) Yes the metronome can output 16 bit from a 24 bit source.

 D) Well yes, but not at the same time.

 Cheers!
 Russ


----------



## luvdunhill

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_A) I think what you might really want here is the OTTO. But I am not sure...

 B) You would need to reset the receiver for the changes to take effect.

 C) Yes the metronome can output 16 bit from a 24 bit source.

 D) Well yes, but not at the same time.

 Cheers!
 Russ_

 

Russ:

 yeah, I assumed something like the OTTO would do the switching, preferably a 3:1 version of the OTTO... 

 So, thanks for the answers. I'm glad to know that the 16-bit Philips I2S format is supported by the Wolfson 8804 receiver and my 10V supply will work. Looks like I need to place an order 
	

	
	
		
		

		
		
	


	




 edit: without the Metronome, how do I set BCK to be 64 * fs? I see the example in the datasheet, Table 23 and the 2.8224 MHz is there...


----------



## indikator

will OPUS benefit from clock upgrade? any guide how to use external clock?


----------



## johnsonad

My power boards are finally finished and boy were they easy! Russ, you guys put together one hell of a product and I thank you for it! Nebby was over last night and talked me through the basics (and put together one of the boards), once started they only took a few minutes to solder up. I only wish wiring them together was as fast


----------



## luvdunhill

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_I have a quick question for a usage of the SPDIF receiver. Theoretical setup would be as follows:_

 

heh, reading back through my post, I confused myself. Let me try again. 

 I really have only a single question at this point. Currently, I am using a "direct" transport to DAC connection using i2s and the requirements for my DAC are 16-bit I2S, 64 BCK/WS and BCK is 44.1kHz * 64, 2's compliment data, WS 44.1kHz. Can I "substitute" the transport mechanism for the Wolfson 8804, which would configured as: AIF_MS to MASTER, TXSRC to SPDIF, AIFCONF1 to low, AIFCONF0 to low and powered using 10V?


----------



## soloz2

has anyone compared the opus USB module to the Alien DAC?


----------



## spendorspain

Hi all

 Although this forum thread is for Opus DAC, I'm going
 to put here my questions, as I've read several posts regarding 
 the Ballsie module. 
 I’m interested in upgrading my universal 
 Denon DVD-2930 player. I haven’t yet the Service
 manual for this model (do you have any idea about where to 
 find one?) but it uses the digital to analogue
 converter Burr Brown 1791, that outputs a balanced
 voltage signal per channel (no need for I/V conversion). 
 I have the output schematic for the Denon DCD-1500AE 
 which uses the same DACs and probably has a similar 
 design. In this case, the vL+, vL-, vR+ and vR- signals 
 from the BB-1791 are summed
 and converted to a single-ended L & R signals using
 the two sections of a SA5532 dual op-amp. Next, this
 signal is filtered and buffered by a half of another
 SA5532 (the other half is used for sending the L&R
 signals to the headphones section). Then, the signal
 goes to the RCA output sockets through an ELNA RFS
 (silmic II) electrolytic output capacitor and a carbon
 output resistor. You can see this signal path in the
 diagram attached to this post.

 My questions are:

 1) Can the Ballsie module do the job of all these
 rather old op-amps and avoid the use of the stock
 output capacitor and resistor? (this with the added
 benefit of having its own LCBPS supply and
 transformer, therefore avoiding the Denon switching
 mode PSU in the critical analogue stage). For each 
 channel, two of the four sections of the LME4974 
 quad op-amp (IC1) do the balanced to s.e.
 conversion and one section of the dual LM4562 (IC2)
 filters and buffers the signal and drives directly the
 RCA outs and the interconnect cable attached to it. 
 Can the Ballsie drive directly the interconnects?
 Is the LM4562 output stage up to this task, without
 the need of an additional buffer?

 2) If this use is possible, how is the Ballsie wired
 at its input? For each channel, the BB1791 DAC has a
 3-leg out but the Ballsie has a 5-pin input.

 3) How does the Ballsie deal with the possible DC offset
 from the DAC? Does it rely on a DC-free input signal
 (I think the other Twisted Pear DAC modules have their 
 own output caps)? Can I safely connect the RCA
 sockets to the Ballsie output, without any series cap? 
 Is it needed a DC offset protection circuit (like the diy 
 AMB Epsilon module)? 

 I hope you can help me. Thanks in advance

 Jose


----------



## BrianDonegan

Quote:


 1) Can the Ballsie module do the job of all these
 rather old op-amps and avoid the use of the stock
 output capacitor and resistor? (this with the added
 benefit of having its own LCBPS supply and
 transformer, therefore avoiding the Denon switching
 mode PSU in the critical analogue stage). For each
 channel, two of the four sections of the LME4974
 quad op-amp (IC1) do the balanced to s.e.
 conversion and one section of the dual LM4562 (IC2)
 filters and buffers the signal and drives directly the
 RCA outs and the interconnect cable attached to it.
 Can the Ballsie drive directly the interconnects?
 Is the LM4562 output stage up to this task, without
 the need of an additional buffer?

 2) If this use is possible, how is the Ballsie wired
 at its input? For each channel, the BB1791 DAC has a
 3-leg out but the Ballsie has a 5-pin input.

 3) How does the Ballsie deal with the possible DC offset
 from the DAC? Does it rely on a DC-free input signal
 (I think the other Twisted Pear DAC modules have their
 own output caps)? Can I safely connect the RCA
 sockets to the Ballsie output, without any series cap?
 Is it needed a DC offset protection circuit (like the diy
 AMB Epsilon module)? 
 

1) If tis is fact still the design of the output stage of the newer player, then yes, the Ballsie is quite similar in function and should work fine. It is designed to drive your interconnects directly (it is a buffer).

 2) The five inputs are to allow connection of dual-mono Opus modules. The two positive and two negative terminals are joined together after going through isolation resistors. To use a standard three input (+/GND/-), just leave the other two inputs empty.

 3) If the input signal has any DC-offset, it will still be present at the balanced outputs, but will be effectively nulled at the single-ended outputs. In your case, you should be fine with no capacitors in the signal path.


----------



## sleepy dan

Quote:


  Originally Posted by *indikator* /img/forum/go_quote.gif 
_will OPUS benefit from clock upgrade? any guide how to use external clock?_

 

It may be worth it- you'll have to try it to find out!

 You will need to either replace the 12Mhz clock on the Wolfson receiver board (I remember reading someone did this with good results) or, replace the clock on the Metronome if you are using one.

 There are plenty of clocks out there to buy or you could build one yourself. An easy place to start experimenting would be to feed the Crystek clock on the Metronome with it's own low noise regulator. If you notice any improvements then you can think about taking it further.


----------



## spendorspain

Thank you for your answer, Brian. I'm sure that the Ballsie module will sound a lot better than the stock Denon analogue output stage: better op-amps, independent linear power supply, no caps directly in signal path, no muting transistors, better PCB layout... BTW, in the assembled and tested Ballsies Twisted Pear sells, do they leave empty the positions not needed for single ended use (CF3, 4, 7 & 8, RI1, 4, 5 & 7 and RO2, 3, 5 & 6)? Is there any critical part that could be upgraded for maximum performance? Are there any suggestions regarding the Ballsie modules from builders and users?

 To be sure before any modification, I hope to have soon the service manual for the DVD-2930. However, the usual service manual suppliers, from which I have bought other Denon manuals for reference, don't have it (although it is a model two years old). Of course, any help to find out this manual will be welcome.

 Best regards
 Jose


----------



## johnsonad

Well my 8 month project is finally finished and the Opus is up and running. Thanks to Nebby for getting me off of my rear and teaching me how easy it is to solder the boards together. The rear case work was surprisingly difficult at least cutting the holes and found out the hard way that I didn't have the right tools. Someday I will have cleaner cuts on the rear panel but for now it will do. I replaced the stock caps with BGs and they are most definitely bright. Here are a couple of pics. 



][/url]





][/url]





][/url]


----------



## Russ White

Quote:


  Originally Posted by *johnsonad* /img/forum/go_quote.gif 
_Well my 8 month project is finally finished and the Opus is up and running. Here are a couple of picks. _

 

very nice work! You should be proud. 
	

	
	
		
		

		
		
	


	




 I hope you enjoy it.

 Cheers!
 Russ


----------



## johnsonad

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_very nice work! You should be proud. 
	

	
	
		
		

		
		
	


	




 I hope you enjoy it.

 Cheers!
 Russ_

 

Thanks Russ, that means a lot coming from you 
	

	
	
		
		

		
		
	


	




 I used Brian's layout but didn't have enough wire to make my power runs look as good as his. Right now it is filling the room with a little Maria Callas and her beautiful voice.


----------



## akione

Quote:


  Originally Posted by *johnsonad* /img/forum/go_quote.gif 
_Well my 8 month project is finally finished and the Opus is up and running._

 

 Nice Layout. One of the best, I've seen.


----------



## indikator

I wonder, what is that white thing near the transformer?


----------



## BrianDonegan

Quote:


 I wonder, what is that white thing near the transformer? 
 

It's a terminal block for joining the Mains to the transformers.


----------



## luvdunhill

Quote:


  Originally Posted by *johnsonad* /img/forum/go_quote.gif 
_Well my 8 month project is finally finished and the Opus is up and running. Thanks to Nebby for getting me off of my rear and teaching me how easy it is to solder the boards together. The rear case work was surprisingly difficult at least cutting the holes and found out the hard way that I didn't have the right tools. Someday I will have cleaner cuts on the rear panel but for now it will do. I replaced the stock caps with BGs and they are most definitely bright. Here are a couple of pics._

 

why not stack the 2 toroids?


----------



## johnsonad

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_why not stack the 2 toroids?_

 

Thought about it but I was coping Brian's build and it was just as easy to do it this way as I had the room to work with.


----------



## luvdunhill

Quote:


  Originally Posted by *johnsonad* /img/forum/go_quote.gif 
_Thought about it but I was coping Brian's build and it was just as easy to do it this way as I had the room to work with._

 

Try it, see if you measure/hear/feel/whatever a difference.


----------



## BrianDonegan

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_Try it, see if you measure/hear/feel/whatever a difference._

 

Is there some theory behind why this would make any difference? 

 IIRC, most of the exposed field from a toroid is on the axis of the hole, so would this not increase the chance of interference/reduced performance, if anything?


----------



## n_maher

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_IIRC, most of the exposed field from a toroid is on the axis of the hole, so would this not increase the chance of interference/reduced performance, if anything?_

 

I don't know jack when it comes to theory but experimentally I can tell you that I have directly observed the difference in simply rotating a toroid w/ regard to the induced noise. This was with an Avel trafo similar to the ones that you guys use, just a larger model (probably with a bigger field). But I've experienced the exact same phenomenon in two different projects. 

 I'm not sure that stacking would make a difference since I haven't tried it but it might simply help with proximity to sensitive wiring.


----------



## BrianDonegan

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_I don't know jack when it comes to theory but experimentally I can tell you that I have directly observed the difference in simply rotating a toroid w/ regard to the induced noise. This was with an Avel trafo similar to the ones that you guys use, just a larger model (probably with a bigger field). But I've experienced the exact same phenomenon in two different projects._

 

I agree with that. The emitted field can definitely affect surrounding wiring. Don't think there is a problem with that here though.


----------



## luvdunhill

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Is there some theory behind why this would make any difference? 

 IIRC, most of the exposed field from a toroid is on the axis of the hole, so would this not increase the chance of interference/reduced performance, if anything?_

 

someone suggested it to me that parallels large toroids for power amps, and to me it was a noticeable change. Also, toroid inductors are being used in speaker crossover applications now and while they are not as particular to placement as their cousins, people are finding that it does matter.


----------



## johnsonad

These are 15v trannies. Right now I don't have any extra noise but given the amount of space in the case I would like to put a barrier of some sort "L" shapped up and over them. Any suggestions on what material to use and where to get it? High nickel content has been suggested. 

 Sound wise it is bright and a little lean in the mid range compared to my TP at the moment (these are very small differences). I'm hoping with break in it will bloom. Otherwise it sounds remarkably like my TP.


----------



## johnsonad

Anyone get the new modules?


----------



## BrianDonegan

I have some! 
	

	
	
		
		

		
		
	


	




 I have not started shipping them yet, but I have built some. I have not yet had a chance to listen to the 8741 though


----------



## soloz2

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_I have some! 
	

	
	
		
		

		
		
	


	




 I have not started shipping them yet, but I have built some. I have not yet had a chance to listen to the 8741 though 
	

	
	
		
		

		
		
	


	


_

 

Can't wait for my Opus and Darwin!


----------



## threEchelon

Hey, Brian. Will the first production Buffaloes be compatible with the oh-so-anticipated Uber Controller?


----------



## BrianDonegan

Quote:


  Originally Posted by *threEchelon* /img/forum/go_quote.gif 
_Hey, Brian. Will the first production Buffaloes be compatible with the oh-so-anticipated Uber Controller? 
	

	
	
		
		

		
		
	


	


_

 

Yes. There will be firmware for the AC1/Femto that will control the Buffalo. Same is true for the Opus.


----------



## threEchelon

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Yes. There will be firmware for the AC1/Femto that will control the Buffalo. Same is true for the Opus._

 

Great. Thanks.


----------



## regal

Does a PCB order include a BOM with Digikey or Mouser part numbers?


----------



## regal

Also where can you buy the WM8741 DAC chip ?


----------



## Russ White

We will have a BOM up on the site soon.

 You can get the chip direct from Wolfson or it distributors.

 Cheers!
 Russ


----------



## srserl

Yaaay! While everyone else was waiting to snipe a buffalo dac, I snagged an Opus, and it arrived today! I couldn't wait, so I just put the usb module together and hooked it up to my starving student Millet hybrid. Sounds REALLY good by itself, so I can hardly wait to put it on the Opus mudule. Now I'm hoping the transformers I have in a box somewhere will work...otherwise I'll have to wait for another shipment from Twisted Pear 
	

	
	
		
		

		
			





 Scott


----------



## akione

Quote:


  Originally Posted by *srserl* /img/forum/go_quote.gif 
_Yaaay! While everyone else was waiting to snipe a buffalo dac, I snagged an Opus, and it arrived today! I couldn't wait, so I just put the usb module together and hooked it up to my starving student Millet hybrid. Sounds REALLY good by itself, so I can hardly wait to put it on the Opus mudule. Now I'm hoping the transformers I have in a box somewhere will work...otherwise I'll have to wait for another shipment from Twisted Pear 
	

	
	
		
		

		
		
	


	




 Scott_

 

Good Move !

 The Opus seems to be being overlooked with all the fuss over Buffolo. As I've said elsewhere, the Buffolo will have to be something VERY special if it's to equal a dual-mono opus with ASRC and IVY as output stage. I'm sceptical. 
	

	
	
		
		

		
		
	


	



 Of course, it's real advantage is less boards are needed.


----------



## indikator

how can I get the USB module? it seems to be out of stock?


----------



## soloz2

I received a package from Twisted yesterday as well. However, I didn't get home till late after working a double and only got a chance to look at it and go to bed.


----------



## TimJo

Brian, I know you are trying to recover from the Buffalo stampede, but do you have an idea of when the receiver modules may be back in stock? I'd like to place an order, but would rather order one of the 'combo' packages.


----------



## BrianDonegan

Quote:


  Originally Posted by *TimJo* /img/forum/go_quote.gif 
_Brian, I know you are trying to recover from the Buffalo stampede, but do you have an idea of when the receiver modules may be back in stock? I'd like to place an order, but would rather order one of the 'combo' packages._

 

I just got the new boards in yesterday. I need to build some up, but I am heading out for the July 4th weekend on Wednesday through Monday, so I won't have time to build any until *maybe* next week, but also have a ton of Buffalos to build.

 I will open up orders for them I guess, with a note that they may not ship for a a couple weeks.


----------



## TimJo

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_I just got the new boards in yesterday. I need to build some up, but I am heading out for the July 4th weekend on Wednesday through Monday, so I won't have time to build any until *maybe* next week, but also have a ton of Buffalos to build.

 I will open up orders for them I guess, with a note that they may not ship for a a couple weeks._

 

Thanks Brian. No worries, I am just trying to plan what to buy and when. 

 Have a good break for the 4th!


----------



## fierce_freak

Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_The Opus seems to be being overlooked with all the fuss over Buffolo. As I've said elsewhere, the Buffolo will have to be something VERY special if it's to equal a dual-mono opus with ASRC and IVY as output stage. I'm sceptical. 
	

	
	
		
		

		
		
	


	



 Of course, it's real advantage is less boards are needed._

 

For me, the Buffalo was a clear step above WM8740 dual mono opus with Metronome and Ballsie. Of course, things could be rather different with the WM8741 + IVY.


----------



## naamanf

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_For me, the Buffalo was a clear step above WM8740 dual mono opus with Metronome and Ballsie. Of course, things could be rather different with the WM8741 + IVY._

 

I am trying very hard not to give the WM8741+IVY combo a try.


----------



## fierce_freak

Me, as well. It helps to not have the funds available ;p


----------



## penger

Is there a reason/advantage to using the IVY over the Ballsie in the case of the new Opus?

 Edit: And how are the kits for each DAC different?


----------



## Russ White

There are at least four technical advantages of the IVY. And one for the Ballsie. 
	

	
	
		
		

		
		
	


	




 IVY advantages
 1) IVY is super symmetrical which helps to cancel out 2nd order harmonics while maintaining very low THD across the spectrum.
 2) Greater output current capability for driving headphones (up to 100ma or so).
 3) Better balanced dual mono setup (requires one IVY for each mono Opus)
 4) its designed to be DC coupled, so no coupling caps while still providing zero offset at both balanced and SE outputs. This helps to deliver nice clean bass and removes phase issues at low freqs.

 Ballsie has high input impedance and allows for dual mono with just one Ballsie (though technically you can do this with IVY too).

 Cheers!
 Russ


----------



## penger

Ahh should have bought an IVY then, silly me. And how does the Haiku fit into all of this might I ask?

 Also... so the two IVYs for dual mono can be powered by the same LCBPS, right? And what might the wiring look like from Opus (dual mono) to IVYs?

 Thanks for the reply!


----------



## Russ White

Don't get me wrong. The Ballsie sounds great.

 Haiku is a pure I/V stage. It cannot drive a low impedance like headphones without a buffer.

 I am putting the finishing touches on the IVY manual which will answer the connection questions.


----------



## penger

I guess that just means it's another thing to try instead of replacing. 
	

	
	
		
		

		
			





 Thanks again.


----------



## soloz2

When using the Opus single-ended without one of the output stages are the output caps still necessary? I seem to recall a previous discussion about not having any caps there, but that may have been for balanced.


----------



## Russ White

Quote:


  Originally Posted by *soloz2* /img/forum/go_quote.gif 
_When using the Opus single-ended without one of the output stages are the output caps still necessary? I seem to recall a previous discussion about not having any caps there, but that may have been for balanced._

 

If you mean from the Ballsie you are correct.

 Ballsie will cancel the common mode voltage at the single ended outputs even with no output caps on the opus. The balanced output however will have a common mode offset voltage of 2.5V.Some So if you plan on doing SE only from Ballsie that's the way to do it for best sound.

 Cheers!
 Russ


----------



## Beefy

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_I am putting the finishing touches on the IVY manual which will answer the connection questions._

 

Excellent. I'm trying to soak up as much information on all of this before my Buffalo and IVY arrive, and an IVY manual would be perfect!


----------



## soloz2

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_If you mean from the Ballsie you are correct.

 Ballsie will cancel the common mode voltage at the single ended outputs even with no output caps on the opus. The balanced output however will have a common mode offset voltage of 2.5V.Some So if you plan on doing SE only from Ballsie that's the way to do it for best sound.

 Cheers!
 Russ_

 

Thanks for the reply, but I don't think I was clear. I meant when not using the Ballsie. I'll just be using the analog out from the Opus board. I was planning on upgrading the caps, but then remembered someone saying no caps was better, but you could only do it either balanced or SE and I couldn't remember which was which.


----------



## Beefy

Quote:


  Originally Posted by *soloz2* /img/forum/go_quote.gif 
_Thanks for the reply, but I don't think I was clear. I meant when not using the Ballsie. I'll just be using the analog out from the Opus board. I was planning on upgrading the caps, but then remembered someone saying no caps was better, but you could only do it either balanced or SE and I couldn't remember which was which._

 

I think that you have to have either the caps and/or Ballsie. You cannot use OPUS without both of them, otherwise you get large DC offset.


----------



## Russ White

Going direct from the Opus SE out (say +OUT and GND) you will want a cap, as otherwise you will have 2.5V offset.

 Cheers!
 Russ


----------



## rodentmacbeastie

Beefy, I love your picture! I nearly wet myself laughing everytime I see it. 


 I am really interested in the Buffalo/Opus WM8741 battle. I was originally waiting for the new Wolfson chips when they released the Sabre, and so I got hyped about the Buffalo. Now, I am hearing great things about the new Opus and i am thinking again... I will be taking the pure DSD and I2S signals from my "ready to be gutted" Denon DVD and sending the output to an Aikido 24V. I was originally going to go balanced, but this will cost me a whole bunch more money so I will go SE for now. Decision will be made on the merrits of each DAC and price. 

 1. I intended to use the apparently quite good volume control onboard the Sabre, how does the Wolfson compare with it's onboard control? If the Wolfson's volume con. sucks, I have to buy an attenuator(+$100)

 2. Which DAC in voltage out sounds better in SE without additional circuits?Just hook them up and play, which one is more "complete?"

 3. The Buffalo's current output will outperform the Wolfson, but does it sound better? 

 4. If I ever decide to use a S/PDIF input I would have to buy a module with the Opus, Buffalo could be rigged with a switch(+$75)

 Any other considerations to add?


----------



## soloz2

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Going direct from the Opus SE out (say +OUT and GND) you will want a cap, as otherwise you will have 2.5V offset.

 Cheers!
 Russ_

 

Thanks guys for clearing that up. Black to plan A, blackgates. I'll have to doublecheck the size to see if I have anything around here or if I'll have to order some.


----------



## rodentmacbeastie

What about Buffalo, SE? Same as Opus?


----------



## Russ White

On its own yes. 
	

	
	
		
		

		
		
	


	




 Except 1.65V offset.


----------



## Russ White

Both the Wm8740 and the WM8741 have excellent volume control. Certainly no worse than the ESS9008


----------



## Beefy

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_On its own yes. 
	

	
	
		
		

		
		
	


	




 Except 1.65V offset._

 

Just a quick clarification..... in a default Buffalo config with IVY you get no DC offset on balanced or unbalanced, and the signal never passes through an electrolytic?

 But for OPUS/Ballsie, you still need C5-C10 on OPUS to get no DC offset on the balanced connection, but unbalanced is OK?


----------



## BrianDonegan

Quote:


 Just a quick clarification..... in a default Buffalo config with IVY you get no DC offset on balanced or unbalanced, and the signal never passes through an electrolytic?

 But for OPUS/Ballsie, you still need C5-C10 on OPUS to get no DC offset on the balanced connection, but unbalanced is OK? 
 

Correct


----------



## Beefy

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Correct_

 

Righto..... so I can definitely see a place for the OPUS/IVY combo then. But I'll just wait for the IVY manual before asking more inane questions about that


----------



## rodentmacbeastie

I remember one of youTP guys saying that one should use the internal volume on the Buffalo where at all possible. Would a Jacob's Ladder be better or are these internal ones just as good? I am sure that you two have also had some time with the Opus and the Buffalo with the IVY, any impressios yet?


----------



## Beefy

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_Would a Jacob's Ladder be better_

 

HEH!


----------



## glt

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_If you mean from the Ballsie you are correct.

 Ballsie will cancel the common mode voltage at the single ended outputs even with no output caps on the opus. The balanced output however will have a common mode offset voltage of 2.5V.Some So if you plan on doing SE only from Ballsie that's the way to do it for best sound.

 Cheers!
 Russ_

 

Russ/Brian, 

 Is 2.5V offset detrimental to a PGA-2320? I just got the new OPUS and want to try it without the caps. My amp is balanced and already has DC blocking capacitors. Thanks


----------



## akione

The trouble with living on this side of the pond is you get up and find you've missed an interesting discussion. 
	

	
	
		
		

		
		
	


	




 Looks like I started something..... 
	

	
	
		
		

		
		
	


	




 Just for information, my setup is now dual-mono opus (8740) with ASRC. I then have in-line 0.1% 18R resistors for load-balancing duty and these are fed via input selector (Balanced Darwin) and volume (Balanced J/Tree) to a customised IVY. It's built with precision resistors (0.1%) to give a small gain on the balanced stage. It's this that drives my 'phones direct. The Unbalanced part is as normal, with 2kR resistors. There are no capacitors needed anywhere, except for filtering on the IVY.

 On balanced headphones (HD580), this config is superb and betters the original Ballsie output by a very large margin. The biggest difference came when I put the 18R resistors in, in place of the 47R ones I had in previously. I also had to play around with the IVY resistors and filter caps a bit, too, till I found the best combo from what I had available.

 For anyone with balanced wired phones, I highly recommend that you try the IVY with a little gain (I use 1.8k input and 3.01k feedback resistors), it sounds very smooth and detailed. Of course, as Russ said, the big advantage with this approach is that no caps are needed, and you still have 0v offset. 
	

	
	
		
		

		
		
	


	




 This is crrently my favorite headphone amp out of: CKKIII, Beta22! (was 3-ch currently wired as 2-ch), a JLH designed 'Chiara' clone, and a balanced Jisbo buffer (I suspect this could be best with low impedance phones) . I also think it betters the Stax 2050 in everything but Bass.( The bass on the Stax when driven direct from the Opus is really something!). I'm currently starting a MMax build, but don't really expect miracles 
	

	
	
		
		

		
		
	


	




 I thought I'd better clear this up, as a comparison of 8740/8741/Buffolo might not be a case of simple substitution but might well depend a great deal on the rest of the system it's built into. As I said earlier the Buffolo will have to be VERY special to better this IMO. YMMV, of course.

 Happy building everyone.


----------



## Beefy

Interesting observations akione! 
	

	
	
		
		

		
		
	


	




  Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_I thought I'd better clear this up, as a comparison of 8740/8741/Buffolo might not be a case of simple substitution but might well depend a great deal on the rest of the system it's built into. As I said earlier the Buffolo will have to be VERY special to better this IMO. YMMV, of course._

 

From everything that I have read, I'm starting to get the impression that the differences between the digital component of these DACs is all very much of a muchness. It is the analogue section where things are make-or-break.

 For example, the 8741 apparently sounds better than the 8740 and is probably due to improved analogue filtering. Buffalo sounds great, but needed IVY to be tweaked substantially. Your own observations that small changes to IVY makes it sound much better.........


----------



## akione

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Interesting observations akione! 
	

	
	
		
		

		
		
	


	






 From everything that I have read, I'm starting to get the impression that the differences between the digital component of these DACs is all very much of a muchness. It is the analogue section where things are make-or-break.

 For example, the 8741 apparently sounds better than the 8740 and is probably due to improved analogue filtering. Buffalo sounds great, but needed IVY to be tweaked substantially. Your own observations that small changes to IVY makes it sound much better........._

 

Thanks Beefy. Exactly my point. 
	

	
	
		
		

		
		
	


	




 edit: just to expand ...... The point I'm trying to get across, is that perhaps we shouldn't be too hasty to change. Just swapping for a Buffolo/8741 without attention to everything else could result in something worse than the original was capable of. The Buffolo is probably better out-of-the-box, but when the surrounding components are optimised, then the differences may not be that great.


----------



## penger

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Don't get me wrong. The Ballsie sounds great.

 Haiku is a pure I/V stage. It cannot drive a low impedance like headphones without a buffer.

 I am putting the finishing touches on the IVY manual which will answer the connection questions._

 

So what advantages exist in using the Haiku over the IVY?


----------



## regal

Beefy;4413687
 
 
 
 From everything that I have read said:
			
		

> Your statement holds true for all DAC's and CDP's. The perfect zerofeedback class A analog stage is the holy grail of digital music.


----------



## Cauhtemoc

Quote:


  Originally Posted by *Beefy* 
_From everything that I have read, I'm starting to get the impression that the differences between the digital component of these DACs is all very much of a muchness. It is the analogue section where things are make-or-break.

 For example, the 8741 apparently sounds better than the 8740 and is probably due to improved analogue filtering. Buffalo sounds great, but needed IVY to be tweaked substantially. Your own observations that small changes to IVY makes it sound much better........._

 

That's pretty much spot on; implementation is everything. Russ does a good job, though he still has a few things to learn.


----------



## Russ White

Quote:


  Originally Posted by *Cauhtemoc* /img/forum/go_quote.gif 
_Russ does a good job, though he still has a few things to learn. 
	

	
	
		
		

		
		
	


	


_

 

I certainly hope so, or this just won't be any fun anymore. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## fierce_freak

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_For example, the 8741 apparently sounds better than the 8740 and is probably due to improved analogue filtering. Buffalo sounds great, but needed IVY to be tweaked substantially. Your own observations that small changes to IVY makes it sound much better........._

 

My comparison was Dual WM8740 Opus with Metronome and Ballsie versus a Buffalo with sound taken directly from the buffalo board (no IVY). I do certainly agree that a simple swap of one board to the other in the same setup is not sufficient.


----------



## TimJo

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_There are at least four technical advantages of the IVY. And one for the Ballsie. 
	

	
	
		
		

		
		
	


	




 IVY advantages
 1) IVY is super symmetrical which helps to cancel out 2nd order harmonics while maintaining very low THD across the spectrum.
 2) Greater output current capability for driving headphones (up to 100ma or so).
 3) Better balanced dual mono setup (requires one IVY for each mono Opus)
 4) its designed to be DC coupled, so no coupling caps while still providing zero offset at both balanced and SE outputs. This helps to deliver nice clean bass and removes phase issues at low freqs.

 Ballsie has high input impedance and allows for dual mono with just one Ballsie (though technically you can do this with IVY too).

 Cheers!
 Russ_

 

 Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Don't get me wrong. The Ballsie sounds great.

 I am putting the finishing touches on the IVY manual which will answer the connection questions._

 

So I am holding off ordering a line stage until I get a better understanding of using the Ballise vs. the IVY for _single-ended_ output.

 The most obvious question I have is when reading the description of the IVY, it provides I/V conversion, but the Opus is a voltage output DAC. What am I missing here?

 Also, any idea when the manual for the IVY will be available?


----------



## fault151

Russ= Can the IVY owrk the opposite way? What i mean is, can it convert unbalanced signal to balanced?


----------



## Russ White

Yes it can. 
	

	
	
		
		

		
		
	


	




 Just tie -In to GND. Then input your signal to +IN and GND.


----------



## fault151

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Yes it can. 
	

	
	
		
		

		
		
	


	




 Just tie -In to GND. Then input your signal to +IN and GND._

 

So will it operate well as a line stage for a b22? Wouls i need to use some sort of power supply with it? I don't really know much about them at the minute. This is what i was going to use as a line stage. link

 Is your IVY more suited to the b22 or the other one?

 Thanks for your help!


----------



## MrMajestic2

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Yes it can. 
	

	
	
		
		

		
			





 Just tie -In to GND. Then input your signal to +IN and GND._

 

Really cool 
	

	
	
		
		

		
		
	


	




 Would any parts need to be changed or left out when using it this way?


----------



## Russ White

Quote:


  Originally Posted by *fault151* /img/forum/go_quote.gif 
_So will it operate well as a line stage for a b22? Wouls i need to use some sort of power supply with it? I don't really know much about them at the minute. This is what i was going to use as a line stage. link

 Is your IVY more suited to the b22 or the other one?

 Thanks for your help! 
	

	
	
		
		

		
		
	


	


_

 

I don't know why it would not work. You would just need to set it up for the appropriate gain. the input impedance will be on the low side, but as long as that is not a problem you will be fine.

 You would need a +/-15V supply the LCBPS is great choice. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## Russ White

Quote:


  Originally Posted by *MrMajestic2* /img/forum/go_quote.gif 
_Really cool 
	

	
	
		
		

		
		
	


	




 Would any parts need to be change or left out when using it this way?_

 

You would not leave anything out (except possibly the BAL/SE section), but you will want to be sure calculate the gain correctly for your application.

 Or if you creative you can rework the BAL/SE section to be a buffer for the SE/BAL section. 
	

	
	
		
		

		
		
	


	




 Cheers!
 Russ


----------



## naamanf

Quote:


  Originally Posted by *fault151* /img/forum/go_quote.gif 
_So will it operate well as a line stage for a b22? Wouls i need to use some sort of power supply with it? I don't really know much about them at the minute. This is what i was going to use as a line stage. link

 Is your IVY more suited to the b22 or the other one?

 Thanks for your help! 
	

	
	
		
		

		
		
	


	


_

 

The Ivy in standard config works just fine with the B22


----------



## soloz2

just put together my Opus USB module. It installed in Vista right away, but I only et sound from the left channel. Any ideas?

 edit: nevermind... figured it out. Had nothing to do w/ the DAC (which is why my initial overlook didn't see anything) I had bumped one of the speaker wires out the back of my t amp... stupid tiny pin terminals!


----------



## dgbiker1

Does anyone have any experience with using the IVY for both SE and Balanced output? I was planning on wiring the both balanced and SE IVY outputs to a switch (probably an OTTO) to route the output. Does anyone know if this is a kosher implementation?


----------



## Russ White

Quote:


  Originally Posted by *dgbiker1* /img/forum/go_quote.gif 
_Does anyone have any experience with using the IVY for both SE and Balanced output? I was planning on wiring the both balanced and SE IVY outputs to a switch (probably an OTTO) to route the output. Does anyone know if this is a kosher implementation?_

 

I was designed to output both at the same time at the same level.

 Just wire the SE output and the Balanced output to appropriate Jacks.

 Nothing special required. No switching.

 Cheers!
 Russ


----------



## akione

Quote:


  Originally Posted by *dgbiker1* /img/forum/go_quote.gif 
_Does anyone have any experience with using the IVY for both SE and Balanced output? I was planning on wiring the both balanced and SE IVY outputs to a switch (probably an OTTO) to route the output. Does anyone know if this is a kosher implementation?_

 

Yes. I use it all the time like that. 
	

	
	
		
		

		
		
	


	




 I have the balanced outs driving balanced phones and the unbalanced outs switched 
 to any of 3 outputs by a (partially built) Darwin. I use this to feed into my other unbalanced amps.


----------



## glt

How do you control the volume?

 Thanks.


----------



## akione

Quote:


  Originally Posted by *glt* /img/forum/go_quote.gif 
_How do you control the volume?

 Thanks._

 

The IVY is the output stage of a balanced Opus Dac/Pre-amp. 

 It has a balanced Joshua Tree for volume just before the IVY.


----------



## BrianDonegan

Quote:


 Originally Posted by glt View Post

 How do you control the volume?

 Thanks.

 The IVY is the output stage of a balanced Opus Dac/Pre-amp.

 It has a balanced Joshua Tree for volume just before the IVY. 
 

Or you could control the volume in the DAC itself. More to come on that shortly.


----------



## dgbiker1

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_I was designed to output both at the same time at the same level.

 Just wire the SE output and the Balanced output to appropriate Jacks.

 Nothing special required. No switching.

 Cheers!
 Russ_

 

 Quote:


  Originally Posted by *akione* /img/forum/go_quote.gif 
_Yes. I use it all the time like that. 
	

	
	
		
		

		
		
	


	




 I have the balanced outs driving balanced phones and the unbalanced outs switched 
 to any of 3 outputs by a (partially built) Darwin. I use this to feed into my other unbalanced amps._

 

Thanks for the responses, that sounds fantastic!


----------



## Ech0

I've been going thru the posts here and at diyaudio forum and finally pulled the trigger and ordered the Opus/Spdif Combo and the Ballsie. I intend to bypass the output caps on the Opus as I'll be running this in SE only. I was torn (still am) between ordering th Ballsie or the IVY. Most of the information/observations here seems to concentrate more on the ballanced aspect of the Opus w/the IVY combo. So, I thought I'd use the Ballsie and possibly the caps/filters on the Ballsie as well. Still need to investigate this further. 

 What I'm thinking about now is if I should just go ahead and buy the Metronome as well. Is this a worthy upgrade? I was also thinking about trying the IVY later if I feel the need. I don't actually want to do both, from a monetary stand point of course. 

 On another issue, I want to use a case from Par-Metal. A two inch high case would work nicely in my AV rack but that would most likely leave stacking the modules out of the question. Would a three inch high case be considered a "must"?


----------



## dgbiker1

Ech0:
 I'm doing a 3.5" case to stack my modules- 1 input stage stack, 1 dac stack, and 1 output stage stack. I also plan to pop a metronome into one of the stacks, but that's for down the line. I wanted the extra room because I'm putting a baseplate under the boards to conceal the wires, so that'll add .5" to whatever the stack height would be, and because I'm building a "convertible" top that eats up another .75" above the boards.

 Someone in the cheap diy enclosures thread (pabbi I think) recommended the NABU case, and it's an absolute bargain. (Metal Project Boxes). It's much cheaper than the par cases ($17), comes with a pre-installed shielded compartment for power sections, and it has a power supply for my microcontroller. It's pretty big for the opus boards (18"x10"x3.5"), but leaves room for expansion


----------



## akione

Quote:


  Originally Posted by *Ech0* /img/forum/go_quote.gif 
_....What I'm thinking about now is if I should just go ahead and buy the Metronome as well. Is this a worthy upgrade? I was also thinking about trying the IVY later if I feel the need. I don't actually want to do both, from a monetary stand point of course. _

 

IMO, the Metronome is a must, but that's purely IMO. 
	

	
	
		
		

		
		
	


	




 My personal preference is for the IVY rather than Ballsie.
 I find it sounds smoother and more seductive. 
	

	
	
		
		

		
		
	


	



 The Ballsie sounds more 'Hi-Fi' to me, although both are excellent.

 My stack of Metronome + 2 x dacs is 2 1/2 inches high, so 2 high in a 
 2 inch case should be a doddle. I can just get 4 high in my case which 
 measures 80mm (~3 1/8 inches) internally.


----------



## Ech0

Okay, you guys have swayed me to pick up the metronome too. 
	

	
	
		
		

		
			





  Quote:


  Originally Posted by *akione* 
_My personal preference is for the IVY rather than Ballsie.
 I find it sounds smoother and more seductive. 
 The Ballsie sounds more 'Hi-Fi' to me, although both are excellent._

 

I've seen similiar comments. I've already ordered the Ballsie though, so, I just hope the Opus/Ballsie/Metro couples well w/the SE Beta22 I built. In any event I think it will be a step or two (maybe more I hope) above the Zhaolu I have. 

 It's good to know a 2" high case will work. I didn't want to go beyond that unless I had to.

 Thanks guys.


----------



## fierce_freak

Yes, I definitely recommend the Metronome, too.


----------



## srserl

I am thinking about making my USB receiver module into a portable DAC and casing it in a Hammond 1455C802. What would be the best way to connect it to the Opus from the portable case? SPDIF? or I2S? If I use I2S would I jumper DO to DI and have both analog and digital available at the same time, or should I use a switch to put it in SPDIF, thereby making the analog outs available? I guess the connections would be easier with SPDIF because it would be a simpler connector and not require a switch, but would it introduce more jitter or other distortion than I2S?

 Scott


----------



## BrianDonegan

I would use S/PDIF. It was designed for inter-component communication. I2S was not; it *can* be done, but is going to be a lot trickier.

 I have one in a Hammond case in front of me, but with no outputs. I built one a while back for my brother with a headphone jack on the front and stereo RCA jacks on the rear (either side of the USB jack), so adding an S/PDIF jack on the back would be pretty simple.

 For mine, I used the shorter case (1455C801), which is slightly too short for the USB board. I just chopped the very end of the USB module off on the chop saw (could score and snap with a utility knife). If you cut it to the exact length of the case, it leaves the USB jack mounting points and allows a nice overhang of the jack that will stick through the rear panel.

 The only other issue is the height of the included SILMIK caps, but you could swap them out for something smaller.


----------



## srserl

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_I would use S/PDIF. It was designed for inter-component communication. I2S was not; it *can* be done, but is going to be a lot trickier.

 Let me dig up some pictures if I can find them..._

 

I was thinking the same thing about SPDIF, but then started thinking (very dangerous) about somehow docking the portable dac to the Opus. Maybe use a mini din connector with some physical docking mechanism. I don't really need to do this since I ordered another usb module and can have one inside the Opus and one portable, but I just thought it would differentiate my build from all the others.

 Scott


----------



## BrianDonegan

While you are thinking about it, there's no reason you couldn't power the Opus off the USB's VBus power (5V)...


----------



## error401

A potentially good solution to both problems would be to use S/PDIF and transmit the clock as well. You still need the S/PDIF receiver though.

 I2S is a bit more difficult and unwieldy, but should work okay over short distances (2-3 feet at most). CAT5 gets you 4 tight tolerance twisted pairs, easy to get connectors and cables, and just happens to be the right number of conductors for I2S. 
	

	
	
		
		

		
		
	


	




. Using them with differential signaling would help a lot for some distance (and require transceivers), but it does work over short distances. A signal transformer might help too if crosstalk becomes a problem. Put a signal and ground on each pair, should work fine with nothing fancy for a couple feet.

 Edit re your last post: I think it's a good idea! Not crazy at all. Should be quite trivial to get working too if you go the S/PDIF route.


----------



## srserl

Funny you should mention CAT5...I was also thinking that a RJ45 jack might be another good way to connect the usb module to the main dac. I was even thinking about cutting a large hole in the front panel of the main dac where the whole usb module would be inserted, then the RJ45 would be engaged when the module is fully inserted. I would just leave enough of the usb module sticking out the front to be able to get a grip to extract the it.
 The distance from the usb module to the boards inside would only be about 3 inches, so I2S might still be an option. I would try the usb powered Opus as well, but I will also be using other receiver boards and a balsie, so I will need power for when I forget my usb dac at work.
 OK, sounds like I have a plan...if it doesn't work, I'll just build it with a dedicated usb module.

 Scott


----------



## penger

Went through the thread but couldn't find them... Assuming I'm not crazy... Whatever happened to those dual mono wiring diagrams you posted, Brian? Is there one that includes the Metronome?


----------



## alxwang

Does anyone know where I can find a build instruction so I can know how difficult to build it? Thanks


----------



## MrMajestic2

Quote:


  Originally Posted by *alxwang* /img/forum/go_quote.gif 
_Does anyone know where I can find a build instruction so I can know how difficult to build it? Thanks_

 

There is information on Twisted Pear Audio. Check there first, then ask here if you need more input.


----------



## penger

What spec'ed fuse have you guys who've built the Opus been using?


----------



## johnsonad

Quote:


  Originally Posted by *penger* /img/forum/go_quote.gif 
_What spec'ed fuse have you guys who've built the Opus been using?_

 

500ma, it worked fine in my build with a full set of boards.


----------



## dgbiker1

A quick question about the IVY: I just finished building my ver 2.0 kit and I don't have caps C13-C16. Looking at the board traces, they look like filtering caps, but I just want to be sure they're the optional filtering caps and not a required component that I'm missing. I want to start with an unfiltered configuration, so should I just leave C13-16 open?

 Also: The electrolytic caps that come with the Opus, those are coupling caps if you run the Opus in SE w/out an output stage (I will jumper them since I'm using the IVY) right? 
 Thanks.


----------



## Russ White

Quote:


  Originally Posted by *dgbiker1* /img/forum/go_quote.gif 
_so should I just leave C13-16 open?
 Thanks._

 

Yes, leave them open. 
	

	
	
		
		

		
		
	


	




 There is a IVY manual written, and it should be up on the site soon.

 Those caps are only used for a hybrid configuration for the Buffalo DAC.

 In most cases they should left open.

 Cheers!
 Russ


----------



## BrianDonegan

Ivy manual is now posted:
http://www.twistedpearaudio.com/docs...manual_2.0.pdf


----------



## dgbiker1

Thanks Russ! 
 EDIT: Thanks Brian for the manual too


----------



## penger

So just to clarify, you need 3 IVY boards to have both SE and Balanced outputs?


----------



## Russ White

Quote:


  Originally Posted by *penger* /img/forum/go_quote.gif 
_So just to clarify, you need 3 IVY boards to have both SE and Balanced outputs?_

 

Only if you are running Opus or COD in dual mono setup. If you your running stereo you only need one. 
	

	
	
		
		

		
		
	


	




 You can actually just take the +OUT and GND to get SE outputs instead of adding one more IVY but it will be -6db and the DNR/THD will not be quite as good.

 Cheers!
 Russ


----------



## sleepy dan

Hello Russ,

 Do you find the Opus sounds better with the IVY, compared to running it's outputs direct?

 I'm simply curious, because as you know the IVY will present a more difficult load (although still within spec) to the Opus compared to the input Z of a typical pre-amp. Usually if a voltage follower sounds better it's regarded as due to its presenting an easier load to the source.

 Cheers,
 Dan


----------



## mwofsi

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_Ivy manual is now posted:
http://www.twistedpearaudio.com/docs...manual_2.0.pdf_

 

Hello Brian and Russ.

 What's going on in the diagram on page 8 of the pdf manual?

 It shows a Ballsie going to two IVYs but the IVYs seem to me to be completly bypassed? They are labelled "Normally Configured MONO IVYs"


----------



## Russ White

Quote:


  Originally Posted by *mwofsi* /img/forum/go_quote.gif 
_Hello Brian and Russ.

 What's going on in the diagram on page 8 of the pdf manual?

 It shows a Ballsie going to two IVYs but the IVYs seem to me to be completly bypassed? They are labelled "Normally Configured MONO IVYs"_

 

There is no ballsie involved. Those are Three IVYs. 
	

	
	
		
		

		
		
	


	




 The two IVYs on the right are configured for mono DACs (either Opus or COD). They have balanced only outputs.

 The IVY on the left is simply doing balanced to single ended conversion. This way you can have SE outputs that are the sum of balanced output at the same level as the balanced output. The best way to get a clean SE signal is to sum the balanced signal.

 The text expands on this a bit.

 Cheers!
 Russ


----------



## mwofsi

Thanks, got that now


----------



## Russ White

Quote:


  Originally Posted by *sleepy dan* /img/forum/go_quote.gif 
_Hello Russ,

 Do you find the Opus sounds better with the IVY, compared to running it's outputs direct?

 I'm simply curious, because as you know the IVY will present a more difficult load (although still within spec) to the Opus compared to the input Z of a typical pre-amp. Usually if a voltage follower sounds better it's regarded as due to its presenting an easier load to the source.

 Cheers,
 Dan_

 

Hi Dan,

 The 2K load the Opus sees presents no problem at all, and the additional filtering/summing(in dual mono) of the IVY does help.

 Also using the IVY allows you to drive headphones. Which is what many people here will do. 
	

	
	
		
		

		
		
	


	




 So yes, I use the IVY with Opus even into a poweramp with 100K impedance. 
	

	
	
		
		

		
		
	


	




 It just sounds better with it than without it.

 Cheers!
 Russ


----------



## Russ White

Technically you can use a single IVY even for a dual mono Opus setup by putting a sereis resistor (10-221R is fine) at the outputs of the Opus, and wiring like you would a mono Ballsie. But I would personally not recommend this as you lose a lot of the benefit of dual mono operation this way. Which is to say you won't get as good THD specs, or as much common mode noise cancellation.

 For dual mono COD this does not apply, you need two IVYs for I/V, and one for BAL/SE if desired.

 :EDIT: actually, I am sure single IVY can be done with COD, but with no load sharing resistor, but you would need to recalculate the I/V gain resistor and filter cap, and I have not listened to this configuration or tested it, so I hesitate to recommend it yet as it drops the feedback resistor to a value that is less optimal for the THS.:/EDIT:

 Cheers!
 Russ


----------



## sleepy dan

Cool.


----------



## penger

Here you are still answering questions... on vacation my butt! 
	

	
	
		
		

		
		
	


	




 Thanks, by the way.


----------



## TimJo

Cool, just printed the IVY manual. Thanks for the link.

 Enjoy some time off!


----------



## koike

hi guys. sorry to intrude.
 but i would like to know what is the main difference between the opus and the buffalo?
 what are the sonic differences between them?


----------



## dgbiker1

I just spent the day laying out my build and I'm in a bit of a pickle with the power section. My case has a small shielded compartment that makes for a tight fit w/ 2 power supplies, 2 transformers, and the input box. I'm a bit torn with transformer placement.
 OPTION 1: Transformers side-by-side. The only thing that worries me is how close the middle tranny gets to the power supply (~1cm from the heatsink). Seems like it could add some noise to the DC output.








 OPTION 2: Stack the trannies. I've never seen it done, but it seems like it wouldn't hurt anything. As long as I stack them the right way (in-phase) with the foamies in between, shouldn't this be okay? It seems better since it puts more space between the power supply and the tranny, but I just want to get other opinions since I've never seen them stacked before.


----------



## pabbi1

You can definitely stack them - and IIRC, there is some benefit in reducing stray voltage in doing it that way. I had a config like that, and it was just fine.


----------



## dgbiker1

Quote:


  Originally Posted by *pabbi1* /img/forum/go_quote.gif 
_You can definitely stack them - and IIRC, there is some benefit in reducing stray voltage in doing it that way. I had a config like that, and it was just fine._

 

Excellent! Thanks for confirming that Pabbi. 
 Do you recognize the Nabu? I think that was your find if I remember correctly. Nice find on that one, thanks
	

	
	
		
		

		
			





 I'm ordering two more for my eventual beta22/sigma11 build.


----------



## fordgtlover

Does anyone have listening impression and comparisons to commercial DACs?

 Heaps of people seem to have gone down the TP path, but I can't find too many reviews.


----------



## BrianDonegan

Quote:


 I just spent the day laying out my build and I'm in a bit of a pickle with the power section. 
 

You could also stack both PSUs and place their inputs right next to the trafos.


----------



## dgbiker1

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_You could also stack both PSUs and place their inputs right next to the trafos._

 

Thanks for the suggestion Brian, that was my first inclination, I just thought it would affect the performance of the heatsinks. But if you say it's kosher I'll definitely stack the PSUs as well, I still need room for a third PSU for my logic boards. For peace of mind I might just stick a thermistor on the bottom board so that I can flash an alert on the LCD if things get too toasty.


----------



## BrianDonegan

Quote:


 Thanks for the suggestion Brian, that was my first inclination, I just thought it would affect the performance of the heatsinks. 
 

If this is a concern, put the bipolar supply on the bottom. It has less voltage drop so it's heatsinks should be a little cooler.


----------



## dgbiker1

Thanks for all the help and the fantastic work Brian and Russ, another Opus lives! Everything fired up on the first shot to my amazement. It's a pretty successful build in my book when my biggest problems are the lack of an RCA-RCA interconnect and that I need to order some insulated RCA jacks
	

	
	
		
		

		
		
	


	







 Sounds great! I'll post a couple pictures when the faceplates come in and I have the interface programmed.


----------



## Russ White

dgbiker1,

 Excellent work!

 Please let me know what you think of that combo.

 Cheers!
 Russ


----------



## Ech0

@ dgbiker1

 Very neat work & a good shot of the wiring. Well done! 
	

	
	
		
		

		
		
	


	




 Is the shielding recommended / required in this build? I hadn't planned on doing this, but, certainly can change if need be.


----------



## Russ White

Quote:


  Originally Posted by *Ech0* /img/forum/go_quote.gif 
_@ dgbiker1

 Is the shielding recommended / required in this build? I hadn't planned on doing this, but, certainly can change if need be._

 

If you are neat with your wiring, no its not strictly required, but it certainly will not hurt, and in fact will make a more bullet proof DAC to be certain.

 Cheers!
 Russ


----------



## dgbiker1

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_dgbiker1,

 Excellent work!

 Please let me know what you think of that combo.

 Cheers!
 Russ_

 

Thanks Russ
	

	
	
		
		

		
		
	


	




 I'll post my impressions soon, right now I'm just waiting on some wire from navships to replace the cheap wire I used for now. It's already amazing though, I was listening to one of my best test tracks (probably top 3) that I had always thought was recorded as a live studio session. For the first time with ANY equipment, I picked up that one of the instruments is actually recorded loop from the barely audible shuffle of one of the musicians. More important than "technical" feats like that, everything sounds much more realistic and grabs your attention. I would describe it as fun/engaging without loosing out on the realism. It's also dead quiet, my amp can't even go loud enough to hear any hiss coming from the DAC.
 In a nutshell: I won't have source upgradeitis for a LONG time
	

	
	
		
		

		
		
	


	




 The only thing I plan on adding down the road are a metronome (as soon as they're available), and later a ballsie so that I can switch between IVY and ballsie.

  Quote:


  Originally Posted by *Ech0* /img/forum/go_quote.gif 
_@ dgbiker1

 Very neat work & a good shot of the wiring. Well done! 
	

	
	
		
		

		
		
	


	




 Is the shielding recommended / required in this build? I hadn't planned on doing this, but, certainly can change if need be._

 

 Are you talking about the silver colored plate? It shields... but only as a secondary benefit. The real reason for putting it there was aesthetics
	

	
	
		
		

		
		
	


	




 "Phase 2" of this project is building the top of the case to open up (I was torn between a clean looking closed top and a nerd eye-candy clear top... so I'm doing both). I have a microcontroller that will operate a servo to open up a 7" square in the top over the boards, all you'll see are the three boards over the silver plate with aluminum mesh around the sides, a red glow under each board, and white spotlights lighting each board. I just wanted the silver plate to cover up some of the wiring and the hideous oxidized gold look of the case interior. It also leaves room to route LEDs under the boards for background lighting. 

 The shielded power section was already there with the case so I made use of it, but putting a few inches between the PS section and the boards would have probably been fine.


----------



## Ech0

Thanks for the info guys.

 I was talking about the shield that apparently came w/the case that one of the power supplies is hooked up to. 

  Quote:


  Originally Posted by *dgbiker1* 
_I have a microcontroller that will operate a servo to open up a 7" square in the top over the boards, all you'll see are the three boards over the silver plate with aluminum mesh around the sides, a red glow under each board, and white spotlights lighting each board._


----------



## dgbiker1

Finally got my FPE panels and navships wire today, had everything cased up and running by 11:30 PM. It was fun explaining to the grocery store clerk why I needed 3 tubes of superglue at 11:00 PM
	

	
	
		
		

		
		
	


	



 Overall, I'm extremely happy with the Opus/IVY configuration. It's added warmth to my setup without losing any detail (added more detail in fact). Matched with the MkIII and K701, it's exactly the sound I've been looking for. FWIW the navships wire sounds no different from the 18ga solid core tinned copper wire from Fry's that I initially put in. I'm not complaining though
	

	
	
		
		

		
		
	


	




 (yes, that's a blackberry trackball)




 Home screen says "Opus" / "Twisted Pear"




 Some of the navigation menu:




 I have the servo and gearbox for the convertible top ready... but I need to take a little break from this project


----------



## Reynaldo

First of all, before you all start picking on me, a parmetal enclosure is on its way, the dac won't stay in the packing box forever, now that on the side, I would like to share my experience so far with the Opus. The idea of a Dac came more from necessity than desire, this year I moved from Puerto Rico to Texas, from a house with a dedicated listening room to a two bedroom, two bath. I new I could not have the space for a home theater rig and my 2 channel audio set up with turntable, phonostage, and all, I had to simplify somehow, so with a broken heart I decided to sell my Rega Jupiter Cd player, a very musical cd player, with a very analog like sound. So I start looking for a universal player, and then I started reading all this great reviews about the oppo 980 dvd player, and how good they sounded, even stereophile took the time to review the thing and it did pretty good, so I went ahead and ordered one, of course I wasn't expecting the oppo to equal the performance of the rega, but you know, I thought I could live with it, well I could not. Don get me wrong, the oppo does a hell of a lot for the $170 you pay for it, but definitely it is not a giant killer. They never are. So I had to do something, I had been reading about the Opus for quite a while and intrigued me a lot, no many DIY offers around and Ebay flooded with dacs using old chips, so I took the plunge and ordered the basic configuration for the Opus, oh baby what a pleasant surprise this little device has been, music is alive with good sense of space and timing again, yes I could use a little more gain, so I guess the Ballsie is in order, but the rest of the options are just as exciting, usb, balanced connections, etc, I really don't believe in burn in for digital devices, my opus has played for 10 hr only and it makes the oppo sound 100% better, If with time things will get better, well welcome, but right now I can sit again and listen to cd's again. For those in doubt, go ahead, I am not digital expert, but I know good sound.Thanks to twisted pear audio crew. Great little device.

 System:

 Oppo 980
 Rega planar 3 w/DL103
 Hagerman Bugle phono
 Jolida Hybrid 1501 RC amp
 GR Research AV1 speakers
 canares speaker cables
 canares interconnects


----------



## akione

Hi Reynaldo,

 The basic Opus is very good, but, as you say, it benefits greatly from the addition of an output stage. 
 Either the Ballsie or IVY (or both 
	

	
	
		
		

		
		
	


	




 ) is great. I would also recommend that you add the Metronome, too, 
 it does make a difference. You can, of course, do it bit-by-bit.

 Anyway, I'm pleased you like the Opus. It's been a bit overshadowed recently by the Boffalo, but I'm very pleased with mine.

 What's wrong with the existing case ???


----------



## Ech0

I was hooking up the S/PDIF Module this evening and checked for resistance between signal and ground on the S/PDIF_IN once I was done. There was resistance between the two. So, I pulled the wires off and removed the board. Checked again, still had resistance between signal and ground (no solder bridges). It's only on the S/PDIF_IN side. 

 I "assume" this isn't normal. Any thoughts?


----------



## Russ White

Quote:


  Originally Posted by *Ech0* /img/forum/go_quote.gif 
_I was hooking up the S/PDIF Module this evening and checked for resistance between signal and ground on the S/PDIF_IN once I was done. There was resistance between the two. So, I pulled the wires off and removed the board. Checked again, still had resistance between signal and ground (no solder bridges). It's only on the S/PDIF_IN side. 

 I "assume" this isn't normal. Any thoughts?_

 

This s normal as long as it 75 ohms.


----------



## Ech0

Indeed it was 75 ohms. 
	

	
	
		
		

		
		
	


	




 This puzzles me a bit, but, I'm glad I'm good to go. Thanks for the fast response Russ. I can't wait to finish this baby up. 

 The packaging was outstanding as I've read before. Someone must be a little obsessive.


----------



## manaox2

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_There is no ballsie involved. Those are Three IVYs. 
	

	
	
		
		

		
		
	


	




 The two IVYs on the right are configured for mono DACs (either Opus or COD). They have balanced only outputs.

 The IVY on the left is simply doing balanced to single ended conversion. This way you can have SE outputs that are the sum of balanced output at the same level as the balanced output. The best way to get a clean SE signal is to sum the balanced signal.

 The text expands on this a bit.

 Cheers!
 Russ_

 

Just wondering if all three of these could be powered properly off of one or two LCBPS with one of the recommended Lindberg transformers? (Not along with the DAC too of course)


----------



## Russ White

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_Just wondering if all three of these could be powered properly off of one or two LCBPS with one of the recommended Lindberg transformers? (Not along with the DAC too of course)_

 

Just one LCBPS with one of those dual secondary transformers is just fine for all three. 
	

	
	
		
		

		
		
	


	




 But two would work too.

 Cheers!
 Russ


----------



## Beefy

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_Just wondering if all three of these could be powered properly off of one or two LCBPS with one of the recommended Lindberg transformers? (Not along with the DAC too of course)_

 

Actually, I've been wondering about something similar to this as well......

 I was planning to run both 'channels' of an LCDPS from a single 15V 7.5VA secondary winding (one channel VD for Buffalo, one channel OTTO and LEDs). But with losses from two sets of rectifiers and two regulators, I'm wondering whether it will be enough.

 So Russ: do you have any approximate figures for current/power draw for OPUS, IVY and Buffalo at the recommended supply voltages?


----------



## manaox2

Quote:


  Originally Posted by *Russ White* /img/forum/go_quote.gif 
_Just one LCBPS with one of those dual secondary transformers is just fine for all three. 
	

	
	
		
		

		
		
	


	




 But two would work too.

 Cheers!
 Russ_

 

Thanks for that, I am considering it when I get ready to purchase the Joshua Tree when it finally comes back into stock.


----------



## Ech0

Many thanks Brian & Russ for this fantastic DAC. It was a fun build and I really like the modules concept for flexibility of parts desired, but, it also made the layout attractive, IMO. Once I got the settngs configured properly the DAC w/my amp combo is dead silent when no music is being sent through. I've only listened to the opus for a short while but the clarity is the first thing I noticed. It was as if my previous DAC muffled the sound. My previous setup struggled on some highs particularly female vocals. Sorry, for the poor word choice I've not had a lot of experience having only listened to a marginal amount of gear. 

 Anyway, the only issue I had was following the recommended setting for each module I ended up w/static only. I found the answer at the Twisted Pear website (forum). Someone else experienced this issue and Russ suggested changing the OSR setting on the Opus to "+". The manual (version 2.0) recommends leaving this switch open. Though I'd mention it might help someone else. 

 Setup is as follows: S/PDIF > Metro > Opus > Ballsie

 Thanks again guys and I'll post pics tomorrow for anyone interested.

 Edit: The static issue was with the Metronome set 192khz output.


----------



## Bozz_Keren

hi, i'm newbie in DIY and want to ask something
 what's the difference between Ballsie and IVY module?
 thanks


----------



## pidesd

Quote:


  Originally Posted by *Bozz_Keren* /img/forum/go_quote.gif 
_hi, i'm newbie in DIY and want to ask something
 what's the difference between Ballsie and IVY module?
 thanks_

 

page 66

 laziness is the worst sin


----------



## ezkcdude

I'm trying to recommend the Opus DAC to someone, but the website says all the modules are "Out of Stock". Is that the case?


----------



## BrianDonegan

Quote:


 I'm trying to recommend the Opus DAC to someone, but the website says all the modules are "Out of Stock". Is that the case? 
 

I am on a bit of a vacation (actually getting ready to sell our house). I will have the site back online in a few days, with most things back in stock.


----------



## dgbiker1

Finished... for real this time... until I get a metronome...


----------



## penger

Sweet!


----------



## dukefx

Has someone ever tried the Opus DAC combined with a Zapfilter?


----------



## MrMajestic2

Quote:


  Originally Posted by *dukefx* /img/forum/go_quote.gif 
_Has someone ever tried the Opus DAC combined with a Zapfilter?_

 

Yes, both swt61 and naamanf has done it, and its in this thread too.


----------



## dukefx

Quote:


  Originally Posted by *MrMajestic2* /img/forum/go_quote.gif 
_Yes, both swt61 and naamanf has done it, and its in this thread too._

 

Ty, gonna look for those posts.


----------



## Ech0

Zapfilter was discussed on DIYAudioForum too (used w/the OPUS).


----------



## dgbiker1

Slightly off-topic, but is the LCBPS capable of putting out 24V DC? I assume I would need to wire the transformer secondaries in series to get 30V AC going into the LCBPS?
 Thanks.


----------



## Beefy

Quote:


  Originally Posted by *dgbiker1* /img/forum/go_quote.gif 
_Slightly off-topic, but is the LCBPS capable of putting out 24V DC?_

 

Not sure, but......

  Quote:


 I assume I would need to wire the transformer secondaries in series to get 30V AC going into the LCBPS?
 Thanks. 
 

...... based on my limited experience with a S11 and the Millett Max, you probably only need 24VAC - or possibly less - for 24VDC. This is because 24VAC becomes up to 34VDC after the rectifier diodes. Even with this, you have a LOT of voltage for the LM317 to burn off as heat.


----------



## BrianDonegan

Quote:


 is the LCBPS capable of putting out 24V DC 
 

Yes. The caps are all rates at 50 or higher.


  Quote:


 you probably only need 24VAC - or possibly less - for 24VDC 
 

Basically, multiply the AC voltage by 1.41 to get an approximate DC voltage. Any trafo with 20VAC to 25VAC secondaries will be fine.


----------



## dgbiker1

Should I be worried about R2 and R3 running extremely hot (cannot touch) on the LCBPS? I get the same result with 12 or 24VAC going in.


----------



## Beefy

Quote:


  Originally Posted by *dgbiker1* /img/forum/go_quote.gif 
_Should I be worried about R2 and R3 running extremely hot (cannot touch) on the LCBPS? I get the same result with 12 or 24VAC going in._

 

Any idea how much current are you drawing at the DC outputs?

 Do the resistors remain hot even when you disconnect the load?


----------



## dgbiker1

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Any idea how much current are you drawing at the DC outputs?

 Do the resistors remain hot even when you disconnect the load?_

 

That was with no load. I re-wired the transformer and things are running a little more smoothly now... That was weird


----------



## Beefy

Quote:


  Originally Posted by *dgbiker1* /img/forum/go_quote.gif 
_That was with no load. I re-wired the transformer and things are running a little more smoothly now... That was weird_

 

Hmmmm, something comes to mind about having the secondaries in the correct phase, but it is all over my head......


----------



## fran

Hi Russ/Brian,


 I've just picked up a secondhand opus module and was thinking of adding it to my USB module (currently doing duty as a .... USB module!). Anyway, I read a few pages back where you suggested that it might be possible to run the opus from the USB supply feeding the USB module board - thereby not having to get involved with a PS, power cable and so on.

 I know that undoubtedly there will be some sonic penalty to pay, but this would really only do secondary DAC duty to the buffalo and some NOS DACs I have. Will it work? Where would you tap the power from on the USB board?


 Fran


----------



## Russ White

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_Hi Russ/Brian,


 I've just picked up a secondhand opus module and was thinking of adding it to my USB module (currently doing duty as a .... USB module!). Anyway, I read a few pages back where you suggested that it might be possible to run the opus from the USB supply feeding the USB module board - thereby not having to get involved with a PS, power cable and so on.

 I know that undoubtedly there will be some sonic penalty to pay, but this would really only do secondary DAC duty to the buffalo and some NOS DACs I have. Will it work? Where would you tap the power from on the USB board?


 Fran_

 


 Hi Fran,

 There is a terminal labeled "VBUS" which you can use to power the opus. 
	

	
	
		
		

		
			





 It does work, I have done it. Just run VBUS and GND. You only need to run one GND wire between the USB modules and the Opus.

 Cheers!
 Russ


----------



## fran

Rapid reply!

 Just to confirm my ignorance: I can connect up the USB in I2S mode, use the GND of teh I2S block and run a wire from vbus to the opus... OK?

 Now, if I wanted to preserve the option of using the SPDIF funstionality of the USB module, I could use a double pole switch to take the place of the jumper and also to tie DO to DI as per the user manual - allowing me to switch between the two?

 Would that sound ok?

 Also - to run the opus SE without an IV stage, I can just use the + and gnd outputs?

 Fran


----------



## Russ White

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_Rapid reply!

 1)Just to confirm my ignorance: I can connect up the USB in I2S mode, use the GND of teh I2S block and run a wire from vbus to the opus... OK?

 2)Now, if I wanted to preserve the option of using the SPDIF funstionality of the USB module, I could use a double pole switch to take the place of the jumper and also to tie DO to DI as per the user manual - allowing me to switch between the two?

 3)Would that sound ok?

 4)Also - to run the opus SE without an IV stage, I can just use the + and gnd outputs?

 Fran_

 

1) Correct. 
	

	
	
		
		

		
		
	


	



 2) well I would not do this unless you disconnect the Opus prior to switching to SPDIF.
 3) See above. 
	

	
	
		
		

		
		
	


	



 4) You can but there will be DC offset, so you will want a cap at the output.

 Cheers!
 Russ


----------



## BrianDonegan

Quote:


 You can but there will be DC offset, so you will want a cap at the output. 
 

There are very likely caps there already (brown or blue electrolytics).


----------



## Russ White

LOL, doh, yes. I just was not sure if his Opus still had them in place or not.


----------



## fran

I think the guy mentioned something about upgrading the output caps to blackgates, so I reckon there should be something there.

 Thanks for the help

 Fran


----------



## fran

Thanks Russ for the help. The module arrived today and I have it connected up and running AOK. Took a little figuring out on the dip switches to get sounds, but after a little scouting on the support forum I got the answers and now she sings!

 I have it USB module>>I2S>>opus and then the SE outputs to a aikido amp. Bass is very deep without being over blown. I'm impressed, I thought there would be a bigger penalty to pay for running it off the USB PS, but while I do have some noise in the background, sonics are very good. Its really handy to not have to plug it in - makes it very portable.

 I was watching for the DC offset. When I first powered it up the offset was big (>200mV) but very quickly ran down to nothing. That was without any load. Once warmed up the offset was zero. As it will be plugged into the USB port all the time, it won't matter.

 Thaks guys for the advice.

 Fran


----------



## manaox2

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_I have it USB module>>I2S>>opus and then the SE outputs to a aikido amp. Bass is very deep without being over blown. I'm impressed, I thought there would be a bigger penalty to pay for running it off the USB PS, but while I do have some noise in the background, sonics are very good. Its really handy to not have to plug it in - makes it very portable._

 

Opus and aikido sounds pretty sweet.


----------



## slowpogo

I'm considering the Opus as my external DAC, to be run from my Juli@'s SPDIF. Did some searches in this thread but there's too much to wade through.

 A few questions...the Opus offers balanced stereo output. Do I need to configure it differently, or get the IVY stage to use unbalanced equipment with it (my Millett Max)? 

 My Juli@ has balanced outs, but I just plug in my Max and it works fine. I'm hoping the Opus is the same way.

 And, the kits offered on Twisted Pear include the Opus, in my case the S/PDIF receiver, and a dual power supply. Does the power supply run both items, the DAC and receiver? I had thought all I would need apart from this package was an enclosure, but I wanted to check.


----------



## Beefy

Its been a long time since I read about Opus, so all of this is from memory...... take with a grain of salt!

  Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_A few questions...the Opus offers balanced stereo output. Do I need to configure it differently, or get the IVY stage to use unbalanced equipment with it (my Millett Max)?_

 

You will need IVY or Ballsie for single ended outputs. IVY may be better because you can then remove/jumper the output coupling caps on the Opus.

  Quote:


 And, the kits offered on Twisted Pear include the Opus, in my case the S/PDIF receiver, and a dual power supply. Does the power supply run both items, the DAC and receiver? I had thought all I would need apart from this package was an enclosure, but I wanted to check. 
 

You realistically need the Opus/Receiver/LCDPS combo plus a IVY(or Ballsie)/LCBPS combo. Five modules in total, plus two separate transformers.

 LCDPS powers both Opus and receiver, LCBPS powers IVY or Ballsie.


----------



## rodentmacbeastie

OK, I own a Julia too and if you have single ended inputs on your headamp and balanced output configuration on the Juli@ you are only getting half the signal. The proper way would be to switch the outputs to SE on the Juli@ so you could get a properly summed SE channel. This will have nothing to do with the DAC though as you will use S/PDIF when it arrives. 

 Another option will save some money and likely make it sound better is to mod the Juli@ to get I2S direct to the DAC. If you are only using it at your computer, you would not need the digital receiver board and you would get a bonus in performance! However, if you want to move the DAC more that a foot from the computer this will not work as well. I don't know how stong the I2S signal is from the Juli@ and it may need a buffer to go longer distances. The guys at Twisted Pear have their I2S/DSD leads 4 or 5 feet long and are pleased. Think shorter is better. As for the mod to the Julia, you attach three wires to the large pins, it is as easy as that. 

 If you want to hook up another source you will need the receiver board anyway but you could still bypass it for the Juli@. This would avoid the whole conversion to S/PDIF and then back to I2S. For this all you would need is an OTTO switch for th I2S from the Juli@ and the I2S from the reciever board. Best of both worlds.


----------



## glt

The OPUS can be used single-ended or balanced. The IVY/Balsie is optional and it is used to remove the DC and some harmonic filtering. One single PS will power the receiver, the DAC and even other components such as the Toslink and Metronome. If you can get I2S out of the Juli@, then you won't even need the receiver, and feed I2S directly into the DAC.


----------



## slowpogo

Quote:


  Originally Posted by *glt* /img/forum/go_quote.gif 
_The OPUS can be used single-ended or balanced. The IVY/Balsie is optional and it is used to remove the DC and some harmonic filtering. One single PS will power the receiver, the DAC and even other components such as the Toslink and Metronome. If you can get I2S out of the Juli@, then you won't even need the receiver, and feed I2S directly into the DAC._

 

OK, so I assume in order to use the Opus as single-ended, you need to use different jumper switch settings or something like that? Is there any more specific or detailed documentation available on using it single-ended?

 I only plan on using this with my computer...it would sit right on top of the case, so the I2S wires could be short. Maybe a little more than a foot, but short. Would there be a problem with terminating these wires with an XLR plug, and using XLR input to the DAC?

 So sounds like if I went the I2S route, I'd only really need the Opus module, the low current dual power supply, and transformer? (plus enclosure stuff)


----------



## slowpogo

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_OK, I own a Julia too and if you have single ended inputs on your headamp and balanced output configuration on the Juli@ you are only getting half the signal. The proper way would be to switch the outputs to SE on the Juli@ so you could get a properly summed SE channel._

 

I've gotten conflicting information about this. I have used my Max with the Echo Mia, 1212m and Juli@ - all balanced outputs, and all of them sounded great, not weird at all. I also tried the Juli@ with the single-ended RCA outs, and it sounded almost exactly the same to me, just quieter (-10db nominal).

 So some people say it's fine to do that, others say it's not. I'm confused..


----------



## glt

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_OK, so I assume in order to use the Opus as single-ended, you need to use different jumper switch settings or something like that? Is there any more specific or detailed documentation available on using it single-ended?

 I only plan on using this with my computer...it would sit right on top of the case, so the I2S wires could be short. Maybe a little more than a foot, but short. Would there be a problem with terminating these wires with an XLR plug, and using XLR input to the DAC?

 So sounds like if I went the I2S route, I'd only really need the Opus module, the low current dual power supply, and transformer? (plus enclosure stuff)_

 

No settings. Just use the +output. Some people would put a high value resistor between the - output and gnd, but I think that is also optional. If you use it single-ended, the level is (I think) 6 db lower. Another function of the Balsie is to boost 6db on single ended output.


----------



## rds

It seems we could run the LCDPS from a wall transformer like this one:
553-WAU12-500
 Does that sound right?


----------



## slowpogo

The Opus needs 7.5v for both digital and analog sections..so wouldn't you need at least a 15v transformer? That one is 12v.


----------



## Beefy

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_The Opus needs 7.5v for both digital and analog sections..so wouldn't you need at least a 15v transformer? That one is 12v._

 

No, 12V will be fine. 15V runs very hot on the regulators.

 Now that my memory is refreshed, I remember that you can run a single Opus straight to unbalanced out, but you lose output voltage. But if it were me, I'd still run an IVY, and subsequently bypass the output caps......


----------



## rds

Thanks.
 It seems that the 12V will also run quite hot since we're regulating from about 17V to 7V. If anyone can recommend a good 9V or 6V replacement that would be great. It's too bad those are hard to find.
 It seems this guy might do the trick: http://search.digikey.com/scripts/Dk...name=MT7117-ND , but maybe 125mA is a little low.

  Quote:


 But if it were me, I'd still run an IVY, and subsequently bypass the output caps...... 
 

Yeah... I know. My idea here is to make the DAC as inexpensive as possible while not sacrificing too much. Also I want to have a switch that allows me to run it from usb power when necessary, and have it in a small case.

 It's not for me. I'm going for the Buffalo since I have a little extra money.
 I'll be very interested to see how the two compare.


----------



## Beefy

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Yeah... I know. My idea here is to make the DAC as inexpensive as possible while not sacrificing too much. Also I want to have a switch that allows me to run it from usb power when necessary, and have it in a small case._

 

If you want something small, I personally think that this will be better and more convenient than an Opus done 'cheaply': γ1: Full-featured modular miniature DAC

  Quote:


 It's not for me. I'm going for the Buffalo since I have a little extra money. 
 

Good call!


----------



## rds

Quote:


 If you want something small, I personally think that this will be better and more convenient than an Opus done 'cheaply': γ1: Full-featured modular miniature DAC 
 

Nah, that DAC chip is not comparable. I know the datasheet says it's "high performance", but it's definitely not in the same league as the WM8741. If the datasheet doesn't say "very high performance..." I'm not interested. Actually, I'm looking forward to Wolfson's next DAC - I wonder if it will be "very very super high performance"? 
 I do like the form factor of the y1 though. If I ever needed a tiny DAC I would definitely go for it.
 I would say I'm being 'reasonable' more than doing it cheaply. No rhodium wire on this baby


----------



## slowpogo

Quote:


  Originally Posted by *glt* /img/forum/go_quote.gif 
_If you use it single-ended, the level is (I think) 6 db lower. Another function of the Balsie is to boost 6db on single ended output._

 

What is the nominal level of the Opus when balanced? Is +4db like all the balanced sound cards?


----------



## glt

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Thanks.
 It seems that the 12V will also run quite hot since we're regulating from about 17V to 7V. If anyone can recommend a good 9V or 6V replacement that would be great. It's too bad those are hard to find.
 It seems this guy might do the trick: Digi-Key - MT7117-ND (Tamura - 212AS12012) , but maybe 125mA is a little low._

 

12V is fine, 9 V is fine. I'm using 15V for my OPUS. If you want to use scavanged wall warts, you need two since the supply requires two secondaries.


----------



## rds

Quote:


 12V is fine, 9 V is fine. I'm using 15V for my OPUS. If you want to use scavanged wall warts, you need two since the supply requires two secondaries. 
 

Are you sure it *requires* 2 secondaries? I understand why people would do it that way for isolation, but I don't know why it would be required.


----------



## Beefy

Quote:


  Originally Posted by *glt* /img/forum/go_quote.gif 
_12V is fine, 9 V is fine. I'm using 15V for my OPUS. If you want to use scavanged wall warts, you need two since the supply requires two secondaries._

 

I run both channels of the LCDPS for my Buffalo from a single transformer secondary. So long as you can supply enough current with the voltage dropping off, it is perfectly fine.

 *

 Offtopic: RDS - I've been offered a job in Vancouver, but it seems like a BIG pay cut compared to Australian wages for scientists. I've heard that the cost of living is quite expensive. Can you give a realistic estimate of what average salaries are like, and how comfortable a living that might afford? Just a really quick idea would be handy, or you can PM me if you prefer......


----------



## rds

Quote:


 Offtopic: RDS - I've been offered a job in Vancouver, but it seems like a BIG pay cut compared to Australian wages for scientists. I've heard that the cost of living is quite expensive. Can you give a realistic estimate of what average salaries are like, and how comfortable a living that might afford? Just a really quick idea would be handy, or you can PM me if you prefer...... 
 

I don't know what average salaries are. I think if you looked at the statistics you'd have to look carefully, because the distribution of wealth in Vancouver is much different than most places. In general it's a pretty wealthy (read expensive) city. I don't know what your definition of comfortable is, but I'd want at least $50k to live well. I believe that is close to the average engineer salary too. 
 Yeah, it's more expensive than a lot of places but it is a beautiful city. I would take a pretty big pay cut to live here.
 Also, keep in mind I'm a student and am very unrealistic about money.


----------



## TimmyMac

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Are you sure it *requires* 2 secondaries? I understand why people would do it that way for isolation, but I don't know why it would be required._

 

LCDPS is pretty close to two TREADs on a single board. So yes one secondary would be fine as long as it's connected in the same phase to both power supplies.


----------



## glt

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Are you sure it *requires* 2 secondaries? I understand why people would do it that way for isolation, but I don't know why it would be required._

 

You are right.


----------



## _atari_

Hi,

 I just assembled my über-amp (USB + Metronome + Opus DAC) and it works flawwless, but...

 physically it builds a stack usb under opus under metronome (for space reasons). The connection metronome -> opus is very short - just don one level.
 The connection usb -> metronome is quite long (up 2 levels, and around to the other side of the board).

 I can only use 192kHz / 256fs (mode0=1 mode1=1). If I switch it to 192khz / 512fs. The rest of the settings is accordint to the twisted pear manuals.
 Why is this? Is there anything I can check or do against it?

 And I am completely confused about the sck of the USB module. Right now everything is connected to the PCMIN of the Metronome. But the manual clearly states that I should not connect it. But if I do so I get no sound.
 Now I am confused, can somebody help me?
 Should I again check something?
 Are both problems connected in any way?

 Thanks

 atari


----------



## rds

Here's a "$200" Opus DAC. 
 It is the $185 usb module, power supply, and DAC kit. To that I added a $8 12VAC wall-wart and 2.1mm jack (for the wallwart). The "casing" is recycled from the DAC module box.
 I did use 12uF Sonicaps which added $50, but you could use the silmic IIs that come with the DAC.
 I thought this might inspire some people who thought this DAC would end up being too expensive. You really can build it for $200, and it sounds fantastic!
 I actually really like the way this DAC looks mounted to a little board. If it was for me I'd just mount it on a piece of wood.
 This is one is not for me and will eventually be cased.
 As seen here it measures 5.5" x 5.5" x 1.75".






 I want to say big thanks to Brian and Russ, not just for their hard work on the Twisted Pear products, but for the professionalism with which the run Twisted Pear Audio.
 I made 4 separate orders, which they pieced together as one package and refunded me the extra shipping costs paid.

 EDIT - Build time was about 2.5 hours going at a relaxed pace.


----------



## n3rdling

haha cool


----------



## rds

I know having the DAC uncased is going to make it susceptible to some noise, but it seems that the usb module injects hiss (maybe due to being unregulated?).
 I can hear this hiss when my amp is turned up far beyond normal listening levels (for pop/rock), which is not really an issue. But when listening to a classical recording, for example, that requires a lot more gain the hiss can become audible. 
 After the music has been paused for about 20 seconds almost all the hiss goes away. I assume this is the usb dac going into standby.
 Any ideas?

 ...still sounds amazing otherwise, but obviously a background hiss can be a little annoying.

*UPDATE* I have got rid of most of the hiss. It was not usb module but it was windows vista 
	

	
	
		
		

		
		
	


	




 . Somehow they managed to add hiss to the usb out (no idea how). I installed Wasapi for foobar and suddenly most of the hiss is gone. It is now independent of whether the usb module is plugged in. I take it this remaining hiss is a result of the DAC being uncased (and sitting beside a wireless router, computer monitor, speakers, etc), or penalty for using a single toroid.


----------



## Bojamijams

What did you use before WASAPI? DirectSound or ASIO?


----------



## smeggy

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Here's a "$200" Opus DAC. 
 It is the $185 usb module, power supply, and DAC kit. To that I added a $8 12VAC wall-wart and 2.1mm jack (for the wallwart). The "casing" is recycled from the DAC module box.
 I did use 12uF Sonicaps which added $50, but you could use the silmic IIs that come with the DAC.
 I thought this might inspire some people who thought this DAC would end up being too expensive. You really can build it for $200, and it sounds fantastic!
 I actually really like the way this DAC looks mounted to a little board. If it was for me I'd just mount it on a piece of wood.
 This is one is not for me and will eventually be cased.
 As seen here it measures 5.5" x 5.5" x 1.75".

 I want to say big thanks to Brian and Russ, not just for their hard work on the Twisted Pear products, but for the professionalism with which the run Twisted Pear Audio.
 I made 4 separate orders, which they pieced together as one package and refunded me the extra shipping costs paid.

 EDIT - Build time was about 2.5 hours going at a relaxed pace._

 

Dang! When you say $200, is that a fully working USB dac that can plug and play?

 If yes, and you were to add the metronome module, would it still work from the wallwart, and would that improve the unit by any significant margin? I'm looking into a single-ended USB Opus myself and am also on a tight leash financially so your solution looks ideal.


----------



## Beefy

Quote:


  Originally Posted by *smeggy* /img/forum/go_quote.gif 
_Dang! When you say $200, is that a fully working USB dac that can plug and play?_

 

It would seem so.

  Quote:


 If yes, and you were to add the metronome module, would it still work from the wallwart 
 

Yeah, you could easily run the metronome from the same VD power supply to the DAC board.

  Quote:


 and would that improve the unit by any significant margin? I'm looking into a single-ended USB Opus myself and am also on a tight leash financially so your solution looks ideal. 
 

Forget the metronome to start with then - you can always add it later.

 *

 I actually really like the idea of mounting something like this on a block of wood. You would just need to add something to hold the power and RCA jacks.


----------



## smeggy

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_It would seem so.

 Yeah, you could easily run the metronome from the same VD power supply to the DAC board.

 Forget the metronome to start with then - you can always add it later.

 *

 I actually really like the idea of mounting something like this on a block of wood. You would just need to add something to hold the power and RCA jacks._

 

Cheers Beefy,
 it looks like this is the way to go for me. Like you say, I can always add to it later as funds allow. Now I just need to find out where to get the boards as TP is always out of stock these days.

 I also have just the board to mount it to 
	

	
	
		
		

		
			






 *edit*
 It looks like I can get the DAC and low power supply, just not the USB board.

 So, does anyone here have a spare USB reciever they want to sell?


----------



## glt

The gamma1 USB board should work


----------



## smeggy

Awesome, I have a Gamma 1 on the way soon. I'll see if I can get a DAC board as well.


----------



## MrMajestic2

Quote:


  Originally Posted by *smeggy* /img/forum/go_quote.gif 
_Cheers Beefy,
 it looks like this is the way to go for me. Like you say, I can always add to it later as funds allow. Now I just need to find out where to get the boards as TP is always out of stock these days.

 I also have just the board to mount it to 
	

	
	
		
		

		
		
	


	





 *edit*
 It looks like I can get the DAC and low power supply, just not the USB board.

 So, does anyone here have a spare USB reciever they want to sell?_

 

Twisted Pear has the USB modules back on sale.


----------



## rds

Finally cased my Opus DAC


----------



## smeggy

nice clean build


----------



## PascalT

Curious, does anyone on Head-Fi assemble Opus DACs? I'm looking into getting one but I know nothing about building these things.


----------



## BrianDonegan

Quote:


  Originally Posted by *PascalT* /img/forum/go_quote.gif 
_Curious, does anyone on Head-Fi assemble Opus DACs? I'm looking into getting one but I know nothing about building these things. 
	

	
	
		
		

		
		
	


	


_

 


 Ping Thrice (Rockhopper). He has done a few.


----------



## glt

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Finally cased my Opus DAC
_

 


 Try the different filters by programming the chip. I've been doing that with Arduino: hifiduino.blogspot.com


----------



## Nebby

I've been following your blog, hope to give the Arduino a try myself after I get some time to do so. Will be my first step into device programming, so it should be interesting!


----------



## rds

Quote:


  Originally Posted by *glt* /img/forum/go_quote.gif 
_Try the different filters by programming the chip. I've been doing that with Arduino: hifiduino.blogspot.com_

 

Looks like you've got some cool projects going on there (...assuming that's you). I'll have to check those out in more detail later


----------



## FallenAngel

_rds_, how did you cut that perfect square hole for the USB receptacle?


----------



## rds

It's not quite perfect, but what I did is draw it with a straight edge, remove most of the bulk using a small bit, and then file with a small flat edge file.
 I assume that's how most people do it. I found it's not too hard to get it pretty nice when I have a pencil line to follow.

 EDIT - actually I didn't use a straight edge. I positioned the board against the case end panel and traced the outline of the socket.


----------



## glt

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I've been following your blog, hope to give the Arduino a try myself after I get some time to do so. Will be my first step into device programming, so it should be interesting!_

 

Thanks. What attracted me was the community around the project. Just like this forum but for microcontrollers.


----------



## glt

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Looks like you've got some cool projects going on there (...assuming that's you). I'll have to check those out in more detail later 
	

	
	
		
		

		
			



_

 

Yeap, that's me. Having been at the receiving end for many years, I hope I can give a little back to the audio community


----------



## rds

I've just set up my Opus DAC with Cubase and The Grand 2 for playing my keyboard in real time.
 I'm very impressed that was able to get a mere 4ms delay using the Opus with USB module and ASIO4ALL. This is totally undetectable to me while I'm playing.

 ...and wow does it sound amazing!! Those of you who've had the pleasure of using The Grand 2 know what I'm talking about. The awesomeness of the grand 2 combined with the opus dac makes me feel like I'm sitting at a Steinway in a concert hall (or anechoic chamber if I want)... well almost. So cool!

This is the Grand 2 I'm referring to.


----------



## mourip

I am in the process of wiring up the OPUS dual mono plus Ballsie boards I bought. For the life of me I cannot find a reference to the supply voltages for the Ballsie. The OPUS is 7.5 v for both the VD and VA but what should I set the regulators for the Ballsie bipolar supply to?

 Also, I bought a partially completed kit which came with two 15v dual secondary trannies. Do you think that I will run into heat issues dropping those volts in the supply to the 7.5 for the OPUS? The digital side will also power the SPDIF input board and a Metronome.

 Thanks!

 Paul


----------



## BrianDonegan

Quote:


 I am in the process of wiring up the OPUS dual mono plus Ballsie boards I bought. For the life of me I cannot find a reference to the supply voltages for the Ballsie. The OPUS is 7.5 v for both the VD and VA but what should I set the regulators for the Ballsie bipolar supply to? 
 

+-15VDC

  Quote:


 Also, I bought a partially completed kit which came with two 15v dual secondary trannies. Do you think that I will run into heat issues dropping those volts in the supply to the 7.5 for the OPUS? The digital side will also power the SPDIF input board and a Metronome. 
 

They will definitely run warmer than the bipolar supply, but nothing to worry about.


----------



## prinz

@rds.. how did You set up DAC with CUBASE?


----------



## mourip

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_+-15VDC



 They will definitely run warmer than the bipolar supply, but nothing to worry about._

 

Thanks Brian!


----------



## rds

Opus with Volumite, Mux, Metronome, Ivy, USB, Toslink, SPDIF; balanced and single ended outputs.






 More pics


----------



## linuxworks

there's still some airspace in that box - what else can you put in there? 
	

	
	
		
		

		
		
	


	




 nice clean holes on the panel work, there, man.


----------



## Bojamijams

That is GORGEOUS! very nice work!


----------



## ShinyFalcon

I might have missed it reading through this thread, but I didn't see dimensions for the boards on TPA or on Head-fi. From the various pictures scattered about, it seems that each of the boards (Opus, LCDPS, receiver, etc) are roughly the same dimension, and are stackable. I probably won't have to worry since I think everything/a lot can fit in a 12" x 8" x 2" case, but I want to make sure.


----------



## glt

Yeah, same dimensions, stackable, each 2"x3.5"


----------



## rds

Thanks for the comments 
	

	
	
		
		

		
		
	


	




 Could someone clarify how to connect the Volumite to the Opus. Right now I have SCL and SDA from the Volumite connected to ML and MD of the Opus, respectively. 
 Are these the only connections I need (or even the right ones)?
 Thanks!

 ...also how do I put the Opus in software mode?
 My understanding is DIFFHW = 0 and MODE = Z (middle switch position)


----------



## holland

rds, did you use a punch for the square holes? If not, did you drill a hole and square it with a file or some other method?


----------



## rds

holland,

 I traced the squares from a CAD drawing and then drilled them out as much as possible (round) and carefully filed them square.


----------



## holland

very nice work. I can never make them truly square.


----------



## rds

Quote:


  Originally Posted by *holland* /img/forum/go_quote.gif 
_very nice work. I can never make them truly square._

 

The most important thing is to be to clamp it the properly. Imo, if it's not clamped well there's no hope of getting a square.

 But for a panel like this now that I know the drawing is good, I would just have hammond do the panels.

 ...well, maybe - it's sick, but I actually like this kind of case work.


----------



## glt

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Thanks for the comments 
	

	
	
		
		

		
			





 Could someone clarify how to connect the Volumite to the Opus. Right now I have SCL and SDA from the Volumite connected to ML and MD of the Opus, respectively. 
 Are these the only connections I need (or even the right ones)?
 Thanks!

 ...also how do I put the Opus in software mode?
 My understanding is DIFFHW = 0 and MODE = Z (middle switch position)_

 

OPUS  s/w settings  for I2C control


----------



## rds

I'm sure I'm being a dumb*ss, but I still don't understand. Apparently the volumite is meant to use the SPI header, but I'm still not sure which wire goes where and to where (ie from the volumite header to the wm8741 header).
 :/


----------



## glt

I see. I connected the two wires to the pads directly across the DSD and DEEMPH switches. Those two pads are also wired to MD and ML (The schematic shows MD connects to DEEMPH and ML to DSD. Then you have to change the switches so the chip can operate in s/w mode. I believe SCL is the same as SCLK.

 In other words
 Volumite SCL -> ML (Same as DSD)
 Volumite SDA -> MD (Sames ad DEEMPH)


----------



## rds

Thanks glt!


----------



## glt

One more thing: The DAC can have one of two addresses. I'm not sure which address volumite uses, but the address is configured with the i2s switch.
 * I2S=0, address is 0011010
 * I2S=1, address is 0011011 (I Used this address since it is already configured this way for hardware mode)


----------



## ShinyFalcon

Could anyone make sure that this setup map is correct? (feel free to make corrections 
	

	
	
		
		

		
		
	


	




)

  Code:


```
[left]IEC -> LCDPS -> (1),(2) #1: (1) (2) ↓ Opus　→ Output (SE) ↑ Receiver ← Optical in (Toslink module) And eventually... #2: (1) (2) ↓ Opus　→ Ballsie → Output ↑ Metronome ↑ TPA 4:1 Mux ┌───┬──┴──┬────┐ Opt USB Coaxial ? (SPDIF module)[/left]
```

As I see it I'll need 2x LCDPS to power the four main modules for setup #2. I'm unsure where the SPDIF module will get its power from, but I'm assuming that it grabs power from one of the modules or direct from the LCDPS. At the moment I can't search the web, AT&T is having problems and sites are really slow


----------



## glt

If the 4:1 mux is the TPA mux, that IS the receiver (but you will need something else for USB). REgarding PS, basically you separate the analog from the digital. The DAC has an analog section so that takes one side of the LCDPS and the other section of LCDPS can power the digital part of OPUS DAC and all other cards.


----------



## Nebby

The TPA USB board can output SPDIF, so there won't be any issue with the TPA MUX. I've been tempted to pick up the M-audio transit and tapping the spdif out pins on that instead of using the TPA USB; I like the specs on the 1020 chip a bit better.


----------



## dean0

Need a decent DAC, had a read through the posts, very confusing!
 It will be feed from S/PDIF out on auzentech prelude soundcard, so if get;

 -Opus DAC + S/PDIF Receiver Combo kit $185
Opus - A Balanced DAC
 and transformer, is that all i need, to run to my headphone amp?


----------



## manaox2

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_Need a decent DAC, had a read through the posts, very confusing!
 It will be feed from S/PDIF out on auzentech prelude soundcard, so if get;

 -Opus DAC + S/PDIF Receiver Combo kit $185
Opus - A Balanced DAC
 and transformer, is that all i need, to run to my headphone amp?_

 

If you don't want to run it single ended, and have the hookup wire and connectors, then you will have the minimum.


----------



## dean0

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_If you don't want to run it single ended, and have the hookup wire and connectors, then you will have the minimum._

 

thanks, I will be running;

 Soundcard>DAC>Headphone Amp

 Is this okay? single/balanced, what the difference?


----------



## manaox2

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_thanks, I will be running;

 Soundcard>DAC>Headphone Amp

 Is this okay? single/balanced, what the difference?_

 

Balanced uses XLR four pin or two XLR 3-pin connectors commonly, Single ended uses RCA, 1/4" or 1/8" headphone jacks commonly. It depends on what kind of input your amp has.

 Here is a link to some info about using a balanced DAC and amplifier rig:
Art. I- Balanced vs. Unbalanced - HeadRoom: Stereo Headphones, Amps & DACs, Wireless, Noise Canceling, Ear Canal, Earbud, Audio Cables & Accessories


----------



## mourip

I got my Opus finished last night and have started breaking it in. Sounds very good so far ...trying not to get too critical yet and am just using it to watch movies in order to get so time on it. Lots of detail and a very wide sound stage.

 Question: I have my DAC set up for dual mono, two OPUS boards. Can I just daisy chain them to the Volumite? If so are there any jumper settings that get changed on the OPUS boards? I did look at the manual and cruised the TP Forum but did not see this addressed clearly.

 Best,

 Paul


----------



## ttnl

so, how does the OPUS compare to the Buffalo 24? Thanks.


----------



## mourip

My Opus continues to sound great but seems to have one bad habit. It lets off a pretty loud POP when iTunes goes from one track to the next. Is there a function or setting to mute between tracks? I have not had a DAC do this before.

 Thanks!

 Paul

 EDIT: Fixed. See below.


----------



## ShinyFalcon

Are you using USB? I noticed that with optical my y1 did not pop (at least I didn't notice it as much) when switching tracks because of the "always on" nature of my Realtek's optical out. With USB, my y1 turns off and back on between tracks. Since both the y1 and Opus uses the PCM2707 as the USB chip they should behave similarly...

 Edit: By next track, do you mean manually changing tracks or iTunes automatically changing tracks (at the end of song, etc)


----------



## glt

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_I got my Opus finished last night and have started breaking it in. Sounds very good so far ...trying not to get too critical yet and am just using it to watch movies in order to get so time on it. Lots of detail and a very wide sound stage.

 Question: I have my DAC set up for dual mono, two OPUS boards. Can I just daisy chain them to the Volumite? If so are there any jumper settings that get changed on the OPUS boards? I did look at the manual and cruised the TP Forum but did not see this addressed clearly.

 Best,

 Paul_

 

You connect the volumite to both boards in parallel because they are speaking I2C: H I F I D U I N O: What Communication?


----------



## mourip

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Are you using USB? I noticed that with optical my y1 did not pop (at least I didn't notice it as much) when switching tracks because of the "always on" nature of my Realtek's optical out. With USB, my y1 turns off and back on between tracks. Since both the y1 and Opus uses the PCM2707 as the USB chip they should behave similarly...

 Edit: By next track, do you mean manually changing tracks or iTunes automatically changing tracks (at the end of song, etc)_

 

I have a TP USB board but have not hooked it up yet. I am using the TP SPDIF receiver board. I am feeding the SPDIF board via a Bel Canto USB to SPDIF converter however.

 By changing tracks I mean iTunes automatically going to the next track. If I do it manually it does not seem to pop...

 Thanks for the reply!


----------



## mourip

Quote:


  Originally Posted by *glt* /img/forum/go_quote.gif 
_You connect the volumite to both boards in parallel because they are speaking I2C: H I F I D U I N O: What Communication?_

 

Thanks. That helps. I hope TP resumes shiping soon so I can try the Volumite...

 Best,

 Paul


----------



## Good Times

Got some questions! About to dive into an Opus build, yeeha. Took me some hours to get through all 58 pages but I have. Initially I'm going to use a PC source and output to a single ended amp. So assuming I'll start with:

 1) 1x Opus DAC + USB receiver combo
 2) 1x IVY
 3) 1x Metronome
 3) 1x 15V+15V (15VA) Power Transformer

 and when I want to go balanced (and maintain SE as well), add:

 1) 1x Opus DAC module
 2) 1x LCDPS power supply
 3) 2x IVY boards
 4) 1x 15V+15V (15VA) Power Transformer

 (A) Is that correct? 

 (B) Any recommendations for internal wire? I've got some 22g upocc I was planning to use. 

 (C) I see that stacking the boards can help by keeping wire runs short. Would I be right in assuming that ideally you would stack all boards, but keep the power supply boards seperate? 

 (D) Is it beneficial to twist all power wires as far as is practical, but keep signal wires separated? Looks this way from the posted pics. 

 Thanks for your help.

 edit, just thought of
 (E) I've read the IVY manual, might not be relevant to this thread but what is the difference between running a stereo setup (one dac board) to one IVY, to outputs, than running dual mono (two dac boards) to two IVYs to outputs? Is the former simply an unbalanced output utilising dual xlr connectors, the latter fully balanced? Cheers.


----------



## manaox2

Quote:


  Originally Posted by *Good Times* /img/forum/go_quote.gif 
_Got some questions! About to dive into an Opus build, yeeha. Took me some hours to get through all 58 pages but I have. Initially I'm going to use a PC source and output to a single ended amp. So assuming I'll start with:

 1) 1x Opus DAC + USB receiver combo
 2) 1x IVY
 3) 1x Metronome
 3) 1x 15V+15V (15VA) Power Transformer

 and when I want to go balanced (and maintain SE as well), add:

 1) 1x Opus DAC module
 2) 1x LCDPS power supply
 3) 2x IVY boards
 4) 1x 15V+15V (15VA) Power Transformer

 (A) Is that correct? 

 (B) Any recommendations for internal wire? I've got some 22g upocc I was planning to use. 

 (C) I see that stacking the boards can help by keeping wire runs short. Would I be right in assuming that ideally you would stack all boards, but keep the power supply boards seperate? 

 (D) Is it beneficial to twist all power wires as far as is practical, but keep signal wires separated? Looks this way from the posted pics. 

 Thanks for your help._

 

A)I am guessing:

 1) 1x Opus DAC + USB receiver combo
 2) 1x IVY
 3) 1x Metronome
 4) 1x 15V+15V (15VA) Power Transformer
 5) 1x LCBPS (for IVY)

 and then:

 1) 1x Opus DAC module
 2) 1x LCDPS power supply (for Metronome, Dual mono Opus, because it won't be easily powered by USB with the extra OPUS and metronome)
 3) 2x IVY boards
 4) 2x 15V+15V (15VA) Power Transformer (for LCDPS and the second LCBPS)
 5) 1x LCBPS (for second IVY)

 B) sounds good to me.

 C) I wouldn't stack power supplies with anything but another power supply, LCBPS get hotter usually, so maybe place those on top of LCDPS if stacking. You can also stack toroids in phase.

 D)It doesn't seem good to have power and signal wires crossing and always seems to be better to have shorter cable runs. I twist all the cables, especially since the channels are separated so I'm not concerned about crosstalk.

 There are some recommended updates that can be used with the IVY as well, but I believe that they are different between the Buffalo and OPUS. For the IVY and Buffalo, I changed R1-4 390R, omitted C1-4, jumpered R5-8, and put 1nf multicap film caps at each input to ground. I think the R1-4 value recommended is different for the Opus.


----------



## mugdecoffee

Dual mono configuration is where you have two DAC modules, one per channel, where the each board's two outputs are paralleled to supply one channel. This is different from a balanced setup where a single OPUS board outputs two balanced channels. Since the IVY can do both balanced and SE outputs on one board, you could actually have a fully balanced DAC with only the components in the first list (one DAC, one IVY etc.) There are headers for both SE and balanced ouputs off the IVY.


----------



## glt

For OPUS without the IVY:

 1x USB board
 1x Metronome (optional)
 1x OPUS DAC

 1x 9V+9V transformer
 1X LCDPS (Dual supply, one +7.5V for the analog section of OPUS, one +7.5V for everything else)

 The above configuration will give you balanced output

 ----

 Then you can add an IVY which will 
 a- eliminate the DC offset in the balanced output so you can DC couple to other electronics
 b- convert Balanced to single ended for single ended gear (although balanced can also be used for single-ended gear)

 For IVY power you will need:

 1x 15v+15v transformer
 1x LCBPS (Bipolar supply. Gives you +15V and -15V)

 ----

 Then you can go Dual Mono by adding another OPUS DAC, and I don't remember how you would connect another Ivy...


----------



## Good Times

Can anyone see any issues if the boards are positioned on their side? Ie stacked for the build, then laid on their side for the enclosure? I'm just starting to accrue ideas on the enclosure build.


----------



## Good Times

Got another question, would there be an advantage to building the power supplies in a separate enclosure? If so, assuming transformers plus power boards in that enclosure, then a connector between the enclosures. Is there a preferred connector for this purpose?


----------



## mourip

It has been suggested either in this thread or on the TP forums that having the PS close to the DAC boards is a good thing. In my DAC I put the PS boards about an inch from the OPUS stack but put the trannies on the other side of the case and behind an aluminum partition in my Parmetal case. The DAC is very quiet. I would not bother with the separate enclosure unless you just want to move the trannies out there.

 Boards on their sides could work but make sure that you leave room for the wiring that might need to run beneath the boards. Current wisdom seems to point to keeping any digital wiring as short as possible and away from power lines. BTW. In a three inch high case you can easily get two OPUS boards and a Metronome into one verticle stack.

 Try the TP forums for building hints and questions and follow any links to photographs which can give excellent ideas for case layout and wiring.

 You will love the DAC!


----------



## manaox2

Quote:


  Originally Posted by *Good Times* /img/forum/go_quote.gif 
_Got another question, would there be an advantage to building the power supplies in a separate enclosure? If so, assuming transformers plus power boards in that enclosure, then a connector between the enclosures. Is there a preferred connector for this purpose?_

 

Russ and Brian recommend keeping the power supplies in the same enclosure for best quality. I wouldn't bother. EDIT: thats what I get for not refreshing the page for an hour.


----------



## mourip

I thought that I would post an update so that I did not leave anyone thinking that the boards are noisy. Whatever noise I had was transient and has gone. I did find one power terminal that I forgot to tighten down. That could have accounted for some noise.

 The DAC is very quiet with a very low noise floor and sounds wonderful. I listened to some choral music last night and my jaw lierally dropped. The best sound I have had in my house. Thanks TP!

 Still have the one question regarding the Volumite. Do I need to change OPUS jumpers to software mode or does the Volumite chip do this automatically when in the circuit? I did read the link about Ardunio but I was wondering if this applied to the Volumite. I also looked on the TP web site but it only has instructions for use with the Buffalo now...

 Thanks...


----------



## ShinyFalcon

That's great to hear, mourip! 

 I plan on going single-ended for a while, and so from what I understand I won't be needing the output caps for the DC offset filtering. Do I have to bridge the caps' pads with something like solder? When I get the Ballsie later on will I need the output caps at the Opus' output?

 And lastly, for the transformer wiring, from the data sheet for the rectifier bridge, there are two "power entries" marked ~, which led me to think that it won't matter how you hook up the secondaries, just as long as they're in phase. Am I correct?


----------



## qusp

I apologize if this is lost in the middle of this thread somewhere; but has anyone done a direct comparison between a dual mono opus, with dual-mono COD?? I had planned on building a buffalo32, but not only is it near impossible to get one (which shows how wonderful they are) but I really have to pull back on spending since I just ordered JH13 customs. so the plan now is to build one of those 2, the COD with discrete output, volumite and ballsie added when they come back in stock or opus with LCDPS and volumite with trannie or wire up one of my triad audio LLPs as supply. only need the SPDIF (and perhaps optical) currently, but might add USB later. then flip the result when its time to get the buffalo when they are available more freely and I have recovered from the hole i've recently carved in my poor wallet. 

 thanks in advance


----------



## mourip

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_That's great to hear, mourip! 

 I plan on going single-ended for a while, and so from what I understand I won't be needing the output caps for the DC offset filtering. Do I have to bridge the caps' pads with something like solder? When I get the Ballsie later on will I need the output caps at the Opus' output?

 And lastly, for the transformer wiring, from the data sheet for the rectifier bridge, there are two "power entries" marked ~, which led me to think that it won't matter how you hook up the secondaries, just as long as they're in phase. Am I correct?_

 

For the first question I believe that the oposite is true. As I undertsand it the Ballsie will take care of DC offset and so if you are using the Ballsie you can either pull the OPUS output caps and replace them with a jumper wire or better, jumper the caps while leaving them in place so that you can always reverse the mod easily. I would not use solder to bridge the gap as solder is better used to keep two conductors in constant contact than to be a conductor itself. I would use a short piece of wire.

 Regarding the second question. Originally I thought that as long as they were in phase it did not matter but them I saw a post by Brian which seemed to say that it did matter. I will try to find that text or perhaps someone else will weigh in.

 You will love the sound. I do and I have not even gotten around to bypassing the OPUS output caps yet! I am using the OPUS/Ballsie single ended to my tube amp...

 Best,

 Paul

 PS. On the TP website there are some forums that have a number of good post that helped me work through the build.


----------



## BrianDonegan

Quote:


 Regarding the second question. Originally I thought that as long as they were in phase it did not matter but them I saw a post by Brian which seemed to say that it did matter. I will try to find that text or perhaps someone else will weigh in. 
 

As long as they are paired properly, it should not matter. I like to recommend a fixed order only to prevent accidents.


----------



## qusp

so no input... very difficult to find comparisons; but I think its the COD for me


----------



## glt

Would this help? PS Audio Discussion Forum | DAC in PWD - How was it decided


----------



## qusp

well kind-of (thanks). I guess i would like to get a serious upgrade, but also a slightly different flavour to the 8740 that is in my D10. yes I know the implementation is worlds apart, but I do tend to enjoy BB opamps a lot and I like the idea of the discrete I/V counterpoint, as many comments I have seen on the opus have mentioned the I/V stage as being a weak point in an otherwise good design. is there anywhere I can find an original buffalo??

 I'm set on getting a TP dac, but still unsure which now that I dont think I can really afford the buffalo32 (only got about $650 I can spend in total including casing. I think I have ruled out the opus though. sorry for the OT in that case 
	

	
	
		
		

		
			





 but there is little to no discussion on the COD on the forum. it gets a mention here and there, but nothing substantial. one thing though, if I can really drive headphones balanced directly from the buffalo, maybe that could still be the ticket, because at this stage i'm looking to build a dynalo (actually Dynahi) or balanced M^3 as well.


----------



## Beefy

Quote:


  Originally Posted by *qusp* /img/forum/go_quote.gif 
_as many comments I have seen on the opus have mentioned the I/V stage as being a weak point in an otherwise good design._

 

...... the 8740 is voltage out, and the I/V is performed right there on the chip.


----------



## ShinyFalcon

Got my Opus partially working! My Metronome is letting out static and high pitched chatter, but I can hear it trying to respond to my music changes. Here's my switches/pinout if anyone can pinpoint the problem:

  Code:


```
[left]Opus I2S + DSD - DEEMPH - MODE - IWO + DIFFHW - FSEL O (open?) MUTE O OSRO Metronome OWL0 - OWL1 - OFMT1 - OFMT0 + Open MODE0 + MODE1 - MODE2 - Open IFMT2 - IFMT1 - IFMT0 + Open BYPASS - Open LGRP - 4:1 Mux 1 - 2 + 3 + 4 - Mux > Metronome DOut > D LRCK > LRC BCK > BCK G > G MCK > None Metronome > Opus G > G D > DIN LRC > LRCK SCK > MCK BCK > BCK[/left]
```

I only have my KSC-75, but sounds very nice so far...

 Edit: Will try playing with OSR, seems like that's my problem, leave it open and the Opus won't like oversampling a 192kHz signal...


----------



## mugdecoffee

Would the jisbos buffers be a good substitute for the IVY stage? I'd like to have a discrete, good quality output stage and the jisbos seems to be economical. Also as a more general questions, does the OPUS or any voltage output dac really need an output stage when connected to an amp? Shouldn't the amp have an input stage that serves a similar funtion?


----------



## Beefy

We talked about this in another thread...... the y2 thread I think?

 An appropriate output stage also acts to filter out high frequency noise from the digital side of the DAC. Not essential, but can reduce the performance of some amps. Jisbos would not be appropriate in this role.


----------



## mugdecoffee

In the IVY manual, it says the wm8740/1 has an onboard filter and one isn't needed in the buffer. Besides filtering, what purpose does a DAC buffer serve when feeding an amp?


----------



## rds

Quote:


  Originally Posted by *mugdecoffee* /img/forum/go_quote.gif 
_Besides filtering, what purpose does a DAC buffer serve when feeding an amp?_

 

Google the word 'buffer' or use the search function here and you will have your answer.


----------



## digger945

http://www.wolfsonmicro.cn/uploads/d.../cn/WM8740.pdf
http://www.wolfsonmicro.com/uploads/.../en/WM8741.pdf
 links I found in the Gamma 2 thread.


----------



## rhester

Have everything up and running except for Volumite. How do I get the OPUS into software mode and how do I hook up the volumite to the OPUS? I did based on what had read here but couldn"t get it to work Any help?


----------



## qusp

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_...... the 8740 is voltage out, and the I/V is performed right there on the chip._

 

lol, just looked back at this for kicks; I must've been mixing the 2 dacs up and thinking of the I/V in the original buffalo being talked of as having room for improvement. research stage of builds often gets to me with information overload. the ability to draw balanced output pretty much directly from the dac pins in the gamma 2 apparently didnt sink in lol


----------



## BrianDonegan

Just thought I'd mention it... Opus is now available as a kit.


----------



## BrianDonegan

Quote:


  Originally Posted by *rhester* /img/forum/go_quote.gif 
_Have everything up and running except for Volumite. How do I get the OPUS into software mode and how do I hook up the volumite to the OPUS? I did based on what had read here but couldn"t get it to work Any help?_

 

*Opus Switches:*
 DIFFHW = 0
 MODE = Z (open not high or low)
 SADDR = 0 = LEFT Channel 1 = RIGHT

 If I remember correctly the rest you can leave open.

*I2C wiring:*
 GND -> GND 
 SDA->SDIN 
 SCL->SCK

*Jumpers for PB3 and PB1 on Volumite:*
 V+, V+ (default with resistors installed) - Low sample rate Filter mode 2.
 V+, GND - Low sample rate Filter mode 4.
 GND, V+ - Medium sample rate (96khz) Filter mode 1.
 GND, GND - High sample rate (192khz) Filter mode 1.


----------



## rhester

What is saddr? I did all the other steps and get nothing out. Workis if switch mode back to where it was.


----------



## BrianDonegan

Sorry, SADDR is the same as I2S (I was looking at the datasheet). I was also incorrect.

 To put the DAC in software mode, set DIFFHW to - and Mode to Open and I2S to open.

 Which version of the Opus board so you have?


----------



## rhester

OPUS V2.1. The above didn't work either.


----------



## manaox2

Quote:


  Originally Posted by *rhester* /img/forum/go_quote.gif 
_OPUS V2.1. The above didn't work either._

 






 You can thank GLT for his post on his hifiduino blog.


----------



## rhester

Tried that also after seeing it earlier today. Still no go. The newer version of the OPUS also doesn't have the same controller pinout. May try running wires to the connection points instead of the controller ports.


----------



## rhester

Also, are there any substitute pots for the Voulmite that has more threads on it. The supplied barely reaches thru faceplate and can't get enough contact to tighten the nut on it.


----------



## BrianDonegan

Quote:


 May try running wires to the connection points instead of the controller ports. 
 

Those pins are directly connected to the controller pins (DSD and SCK, DEEMPH and SDIN). Can you post some pictures of your Volumite and wiring? 

  Quote:


 Also, are there any substitute pots for the Voulmite that has more threads on it. The supplied barely reaches thru faceplate and can't get enough contact to tighten the nut on it. 
 

You can try countersinking the hole on the outside of the case, wide enough to accept the nut.


----------



## rhester

Will post tonite.


----------



## glt

I'm not sure how the volumite s/w works, but in s/w mode you have to match the internal oversampling rate to the incoming sampling rate. So the volumite must have a default setting for the internal oversampling rate and that setting must match the incoming sampling rate. If there is a mismatch you will not hear any music. 

 In h/w mode this was controlled by the OSR switch (low, med, high) low for 44.1-48K incoming rate, med for 88.2-96 and high for 172.4-192K material.


----------



## pila405

Has anyone tried this DAC in comparision with the Pico DAC? It uses the same Wolfson chip [8740/1].

 Which one is better?


----------



## lag0a

Changing the automute function on the metronome from OPEN (center) to OFF ( -=0 ) really made the presentation of the music more lively and amazing. Before it sounded like it was too digital, now it is more closer to the music. I can't believe just changing a switch could do so much. I use a dual mono opus dac. There are 3 more other switches in the OPEN position, what are they for? Is it alright to leave them open or close them?

 Here are some details I found at the diyaudio forum.
http://www.diyaudio.com/forums/digit...metronome.html


----------



## Morph

Noob question - does it make any sense to build dual mono Opus with RCA outputs using only two IVY's (I don't need XLR out)? If so - do I just wire the RCA socket just like in a XLR->TRS converter (chassis ground and cold pins to RCA sleeve)?

 Second question - what parts are needed for dual mono Opus with IVY's, Volumite, 4 inputs (2x Optical, 1xCoax, 1x USB):
 2x DAC module
 2x IVY
 1x S/PDIF 4:1 MUX/Receiver Module
 (MUX doesn't require SPDIF modules, does it?)
 1x USB Receiver module
 2x Toslink module
 2x LCDPS (one for MUX, one for both DACs)
 2x LCBPS (one for each IVY)
 4 transformers?!


----------



## mourip

Hi Brian and Russ,

 The Ballsie board in my OPUS DAC seems to have died with only a few hours on it. One channel has developed noise and distortion and has about -13v dc on the output. Switching the inputs to the board coming from my OPUS did not reverse the affected side. I tried to isolate the problem but could not. The fact that there is no longer a schematic for this "full" Ballsie on your web page made my effort tough. I suspect that it is the second opamp but it seems unlikely to me that only one channel of it could die. I ended up buying a new Ballsie "Lite" from you which seems to have "cured" the problem so I am sure that the board is the culprit. I tried to get help from your support page and I also emailed you through your web page but after two weeks of not getting an answer I am now trying here.

 I do not see any information on your website regarding defects or repairs but knowing how helpful you have been on the forums I am hoping you will either consider repairing the board for me or at least check out the board and let me know which part I would need to replace. 

 If you will contact me here via PM I can give you more details and perhaps I can arrange to mail it back to you.

 It sounded great for the couple of weeks it ran. I was very happy with it.

 Best,

 Paul


----------



## BrianDonegan

It sounds like you have a dead op-amp. I don't think this would be considered a defect, but if you need someone to swap an op-amp out for you, I am sure we can work something out.


----------



## mugdecoffee

So I'll be upgrading shortly to a balanced setup. Right now I have the Opus DAC with the onboard output caps jumpered and I've been using two large off board film caps to get rid of the offset for my single ended amp. With the balanced output, I think I could just use the output straight off the dac with the offset still there since it the DC will cancel in a balanced amp. The only thing is I think this would rob the balanced amp of some voltage swing. Instead, could I derive a new signal ground using a simple resistor and/or capacitor divider between L+ and L- and between R+ and R-? I'd prefer this method to adding inline caps because (I think) it keeps the caps out of the signal path.


----------



## aloksatoor

when is the opus back in stock?


----------



## BrianDonegan

The Opus is in stock. I have run out of power supply kits, however. I am building more right now, so they will be back soon. We will be taking a holiday starting next week though, probably Dec 23-Jan 2. The supplies should be back in stock before then.


----------



## luvdunhill

Quote:


  Originally Posted by *BrianDonegan* /img/forum/go_quote.gif 
_The Opus is in stock. I have run out of power supply kits, however. I am building more right now, so they will be back soon. We will be taking a holiday starting next week though, probably Dec 23-Jan 2. The supplies should be back in stock before then._

 

yes, just ordered two 
	

	
	
		
		

		
			





 in fact, the only part for the PSU that is out of stock is the AVX 220nF/63V caps in the proper width. Seems the largest caps that are in stock at Mouser or Digikey that fit are 180nF/63V BC caps... not that it matters, but..

 Also, I've never soldered a SMD cap before, any tips?


----------



## BrianDonegan

Anything 100nF to 220nF is fine.


----------



## AudioCats

how much better does the dual mono version sound, when comparing to the standard stereo version?

 Thanks


----------



## padam

x2 on the previous question.

 Also, if I Only need I2S input and balanced+SE outputs and nothing else, what parts should I order? What about the IVY output stage, does that worth getting?

 Thanks!


----------



## BrianDonegan

Quote:


 how much better does the dual mono version sound, when comparing to the standard stereo version? 
 

I will leave that to others to describe. I don;t like to make subjective descriptions about the sound. The numbers are a bit better though (as far as I will go).

  Quote:


 Also, if I Only need I2S input and balanced+SE outputs and nothing else, what parts should I order? What about the IVY output stage, does that worth getting? 
 

For I2S in (assuming 64fs or higher), you only need the Opus module(s), and the power supply for it. Adding the IVY will give you balanced and SE outputs and eliminate the need for the output coupling caps on the Opus.


----------



## padam

So do I get right that I can only get 16 bit via I2S? Also, is the IVY going to be replaced with the IVY-II? And does the Metronome module worth adding?

 Thanks.


----------



## glt

With the WM8741 you need 256fs for 44.1 material if you want the internal upsampling to work at its highest rate.


----------



## padam

Ok I will get back to this upsampling thing later 
	

	
	
		
		

		
		
	


	




 So I need 2 DAC modules + transformer + PSU and I don't even need IVY (as it is not on stock) to get both SE and balanced outputs? What if I decide to get a Ventus directly connected as well and I also want to have a balanced output?


----------



## glt

You get balanced output by default. If you only connect the +V and gnd, then you get single ended (The caps in the boards remove the DC offset). 

 You can connect directly to the Ventus in balanced mode and you get single ended out of the Ventus. The Ventus removes the DC offset so you can remove the caps in the DAC board if you like

 You can still connect the balanced output of the DAC to another device (amp/preamp) at the same time you connect the outputs to the Ventus.


----------



## lbhajdu

I don't know if this has been covered else where but, in the WM8741 datasheet it says the DAC offers attenuation in microcontroller controlled mode in .125dB steps up to -127.5db. 

 Has anybody ever heard this feature being used (Attenuation in the DAC not from an external pot). Can they compare full output to something attenuated by the DAC. 

 I see this is done in the digital domain. While chopping of bits do not sound like a wonderful idea I see on Wadia's web site they also use a “Digital Volume Control”. Based only on price, (I never auditioned it) Wadia seems to make good DAC's. I'm sure the digital volume control outcome is highly implementation dependent.

 If I ever have the time (which is unlikely (working full time and going for my masters at night in computer science)) I would make such an add-on board. All it really requires is a microcontroller like a small Atmel AVR and an opto-encoder plus a few trivial parts. I've had the AVR programer sitting on my desk for the longest time and I have never used it. 

 Leve


----------



## BrianDonegan

Quote:


  Originally Posted by *lbhajdu* /img/forum/go_quote.gif 
_I don't know if this has been covered else where but, in the WM8741 datasheet it says the DAC offers attenuation in microcontroller controlled mode in .125dB steps up to -127.5db. 

 Has anybody ever heard this feature being used (Attenuation in the DAC not from an external pot). Can they compare full output to something attenuated by the DAC. 

 I see this is done in the digital domain. While chopping of bits do not sound like a wonderful idea I see on Wadia's web site they also use a “Digital Volume Control”. Based only on price, (I never auditioned it) Wadia seems to make good DAC's. I'm sure the digital volume control outcome is highly implementation dependent.

 If I ever have the time (which is unlikely (working full time and going for my masters at night in computer science)) I would make such an add-on board. All it really requires is a microcontroller like a small Atmel AVR and an opto-encoder plus a few trivial parts. I've had the AVR programer sitting on my desk for the longest time and I have never used it. 

 Leve_

 

This is what exactly the Volumite does, but it uses a pot instead of a rotary encoder, so you don't need a display to know what the volume setting it. 

 When you use digital attenuation, you are not "chopping off bits". You are reducing the scale of the digital signal. You end up with better dynamic range and less noise than you get with an analog volume control.


----------



## lbhajdu

I am such a goose, I somehow missed that, even though I am sure I actually looked at the page. Perhaps I assumed it was something else. You sir have truly thought of everything. Now I am kicking myself because I just ordered an Opus Dac from you last week (not put together yet). 

 Leve


----------



## Cata1yst

I figure ill threadjack instead of making a new thread. Lets say i buy a kit (LCDPS, DAC module, and SPDIF board), all i need is wiring, a case, and the appropriate jacks? I assume ill need a 15A transformer that twisted pear sells. And that should be it to get it running on the ground?


----------



## ShinyFalcon

I don't think the WM8741 accepts SPDIF off the bat, unless this SPDIF board you're thinking off is the module that is based on one of the Wolfson chip. You will also need a Ballsie lite + LCBPS + another transformer, but if you want to run unbalanced direct off of WM8741 (+ and ground to RCA out, output caps required) then you can skip the Ballsie lite + LCBPS for now and upgrade accordingly in the future.


----------



## Cata1yst

Yeah the SPDIF module im thinking of runs off of the wolfson chip.

 So all i will need without a ballsie or a zapfilter (for now) are caps? any reccomendations?


----------



## ShinyFalcon

The caps come with the Opus kit, so yes, you can essentially build a complete DAC direct from TPA. Also see if you need coaxial or SPDIF in.


----------



## Cata1yst

im still debating over spdif or usb.... but im leaning towards coaxial, the Spdif transceiver board should be able to handle that duty right?
 And the 15VA transformer is the proper transformer to use? will i need a switch for 115v or 230v?


----------



## glt

You can wire coax straight into receiver board.
 If using optical, you need the toslink adapter

 As mentioned, the DAC board comes with DC blocking capacitors (I think they are Elna Silmic II). To use in single ended mode just connect the + and gnd and leave the (-) unconnected

 I you want digital volume control, you will need the Volumite with the appropriate firmware

 The 9V transformer is more appropriate. But the 15V transformer will also work (just your PS will be running hotter)


----------



## Marcus_C

Hi all, hope someone can help. I am planning on converting my dac to a pre-amp with integrated headamp which in the main is fairly straightforward but i'd also like to have my phono signal going through it. How do i ensure it is at the same level as the output of the dac so i can control either via the same attenuator?

 Also should i put the volume control in the pre-amp or power amp or doesn't it make a difference?


----------



## Vezor

Ok, so i ordered the Power Module, the Dac and the USB module, is this all i need to roll?

 I heard you maybe needed the ballsie for singel ended or will it work without it too?


----------



## Marcus_C

You don't need it to get a signal just use half the balanced signal (+ve and gnd). You can always add the ballsie to improve the sound later, that's what i did. Have you got a transformer?


----------



## Vezor

Quote:


  Originally Posted by *Marcus_C* /img/forum/go_quote.gif 
_You don't need it to get a signal just use half the balanced signal (+ve and gnd). You can always add the ballsie to improve the sound later, that's what i did. Have you got a transformer?_

 

Ok thanks, thats what i needed to hear : )

 No, i aint got a transformer yet i was thinking about buing a wallwart do you know where to get one? and which?

 And which case do you use for your Opus?


----------



## Marcus_C

A wallwart should work fine, I don't know many US retailers but mouser, digikey seem to come up quite a lot. I use farnell for my parts.

 Something like:
http://uk.farnell.com/_/mc090d050u-f...0ma/dp/1217088

 I use a hifi2000 slimline case but I also have 4 inputs, an attenuator and a headamp in mine so you probably won't need one quite so big, the galaxy cases are quite popular though:
modushop.biz


----------



## Vezor

Quote:


  Originally Posted by *Marcus_C* /img/forum/go_quote.gif 
_A wallwart should work fine, I don't know many US retailers but mouser, digikey seem to come up quite a lot. I use farnell for my parts.

 Something like:
--|MC090D050U/F+|ADAPTOR, UNREG, EURO, 9VDC, 500MA | Farnell United Kingdom

 I use a hifi2000 slimline case but I also have 4 inputs, an attenuator and a headamp in mine so you probably won't need one quite so big, the galaxy cases are quite popular though:
modushop.biz_

 

Thank you, that is about everything i need.

 How much did the Ballsie improve the sound quality for you?


----------



## Marcus_C

I didn't add the ballsie on it's own so can't comment there. I started with a single opus on usb power and later added a proper power supply and the ballsie together and it took me about a week on and off to sort out.


----------



## Vezor

I see

 I think i will be upgrading with some more modules later, thanks for the help!
 Will soon try it out.


----------



## 32y0

I'm currently using the Ballsie as an output stage, but I wanted to do something with a tube ouput stage.
  So I saw this one; Universal Tube Output Stage and I was wondering if anyone has experience with it and if it's any good.


----------



## fault151

Hmm. that does look tempting to try. I have a spare opus dac with metranome, ballsie, receiver board and i was thinking about making it up as a dac to use at work. this would be nicer than the ballsie, but wonder how it sounds. it was eiher a case of using the ballsie, trying the zapfilter or a tube output. I recently made the buffalo 2 dac with a valve output an my god does it sound good!


----------



## 32y0

Quote: 





fault151 said:


> Hmm. that does look tempting to try. I have a spare opus dac with metranome, ballsie, receiver board and i was thinking about making it up as a dac to use at work. this would be nicer than the ballsie, but wonder how it sounds. it was eiher a case of using the ballsie, trying the zapfilter or a tube output. I recently made the buffalo 2 dac with a valve output an my god does it sound good!


 

  
  Yes, it's tempting.
  I also wonder how it sounds, that's why I asked.
  I saw your post about the buffalo with the valve output, looked good!


----------



## mourip

I bought a partially completed Opus dual mono DAC with Metronome and original Ballsie last year. It was to tide me over until the Buffalo32 came out. I loved it. I eventually got the Buff32 board and replaced the Opus/Ballsie/Metro. I was pretty disappointed.
   
  The Buff32 had tons of detail and ambience retrival. It also was bright/edgy and I found it to be much less musical and involving than the Opus. Eventually I sold the Buff32 board and reinstalled the OPUS. During the re-install the Ballsie board died of a cold solder joint that lifted so I bought a Ballsie II. I substituted an Audio-GD Earth HDAM for the socketed output opamp on the Ballsie. I can say now that my system sounds great to me. Very musical, plenty of detail and depth, and very involving. It makes me forget about the equipment 
   
  The rest of my system is a Tektron tube amp currently running globe 245's and some Kenrad Vt-231's. Phones are AKG K1000s.


----------



## 32y0

I should have read your thread about your Buffalo II better, because somebody else also asked a question about the Universal Tube Output Stage.
   
  Anyway, is there anybody with experience with the Universal Tube Output Stage?

  
  Quote: 





32y0 said:


> Yes, it's tempting.
> I also wonder how it sounds, that's why I asked.
> I saw your post about the buffalo with the valve output, looked good!


 




  Quote: 





fault151 said:


> Hmm. that does look tempting to try. I have a spare opus dac with metranome, ballsie, receiver board and i was thinking about making it up as a dac to use at work. this would be nicer than the ballsie, but wonder how it sounds. it was eiher a case of using the ballsie, trying the zapfilter or a tube output. I recently made the buffalo 2 dac with a valve output an my god does it sound good!


----------



## Marcus_C

You might have more luck asking that question on DIY audio, They have their own sub-forum.
   
http://www.diyaudio.com/forums/diy-hifi-supply/
   
  There are a lot of tube output kits on the market at a lot of different prices. I am looking for a discrete design and other than what looks like a replacement for the counterpoint from the TP guys which is in development i've not seen many.


----------



## regal

A discrete stage for the WM DAC's is hard to come by,   This is the best I've found for SE output is here: http://www.raylectronics.nl/frame_it_en.html?http://www.raylectronics.nl/audioshop_en.html with a PCB available.   Note it combines the differential outputs for CMRR.
   
  For a discrete balanced output what you need is a Nelson Pass pream design,  I used to have a link to a PCB seller,  but can't find it.
   
   
  Basically IMO a v-out DAC is not compatible with a tube output stage,  Better off building a tube amp with a high input impedance and input stage from the chip.  No sense in putting a 100% NFB cathode follower after a V-out DAC,  it just degrades the sound (and I am a tube guiy.)


----------



## 32y0

Alright, thanks for the responses!


----------



## Forte

Russ at Twisted Pear has said a few times that he wants to have a go at designing a Tube output stage http://www.diyaudio.com/forums/twisted-pear/160782-buffalo-ii.html#post2076705
  May be worth asking  there if this is still a possibility.


----------



## Marcus_C

They do have quite a few projects on at TPA at the moment so I imagine it'll be a while off yet, Counterpoint II (a.k.a legato) is looking good in my book.
http://www.diyaudio.com/forums/twisted-pear/160782-buffalo-ii-56.html (Post 557 and on really)
   
  Thanks for that link, @Regal, that could be just the thing with balanced input and single ended out,
   
  I found this on the pass-labs site, which seems to be the only discrete design on there, SE in/out.
http://www.passdiy.com/order.htm
   
  Also, from browsing diyaudio, this one seems quite popular (forgetting the discrete theme for the moment) would that be suitable for an opus? (Although without user/service manual could be interesting)
http://www.kk-pcb.com/aleph-17.html​​​​


----------



## regal

http://www.kk-pcb.com/xccs-bls.html   This is it,  SE doesn't mean unbalanced here.


----------



## dsavitsk

Quote: 





regal said:


> A discrete stage for the WM DAC's is hard to come by,


 

 I built one


----------



## Marcus_C

Quote: 





dsavitsk said:


> I built one


 

 What is that by the way? Is it a pass-labs design?


----------



## dsavitsk

Quote: 





marcus_c said:


> What is that by the way? Is it a pass-labs design?


 


   
  Whatever happened to the Y in DIY?  Why is everything just buying a board from someone and soldering some parts down? It's my design.


----------



## Nebby

Perhaps he was just confused by how neat and professional the design looked that he thought it was a commercial part? Very nice design btw, I can't comment on the technical side as I don't know enough, but I like how you have everything on one board. Even a spot for an attenuator eh?
   
  Quote: 





dsavitsk said:


> Whatever happened to the Y in DIY?  Why is everything just buying a board from someone and soldering some parts down? It's my design.


----------



## Marcus_C

Quote: 





dsavitsk said:


> Whatever happened to the Y in DIY?  Why is everything just buying a board from someone and soldering some parts down? It's my design.


 

 Yeah, Sorry, didn't mean to take anything away from you but I was looking for either designs or pcb's. I don't consider myself a total newb, but my circuit design experience/skill is pretty much limited to a flashing bike light I did a few weeks ago. Nelson Pass designs look like a good compromise without having to learn another branch of engineering.
   
  edit: Plus it looks like a professional Job, Kudos for that.


----------



## regal

Ask him if he designed without SPICE software as a true DIYer would!
  
  Quote: 





marcus_c said:


> Yeah, Sorry, didn't mean to take anything away from you but I was looking for either designs or pcb's. I don't consider myself a total newb, but my circuit design experience/skill is pretty much limited to a flashing bike light I did a few weeks ago. Nelson Pass designs look like a good compromise without having to learn another branch of engineering.
> 
> edit: Plus it looks like a professional Job, Kudos for that.


----------



## dsavitsk

Quote: 





regal said:


> Ask him if he designed without SPICE software as a true DIYer would!


 

 regal - I don't know what that means? The circuit was designed on paper, and initial testing was done on breadboard, but we did run it through a simulator to be sure that nothing unpredicted was going on.


----------



## gilles44

Hi
   
  How does the Opus dac sound compared to the Analogmetric Os dac(tda1541a and saa7220) ?
   
  Looking for a better one than my diy dac (ecdesign at diyaudio) 4 X direct interpolation TDA1541A.
   
  Thank
   
  Cheer
   
  Gilles


----------



## atsukita

My OPUS DAC portable


----------



## francisdemarte

Nice how long do the batteries last? How are they charged?


----------



## atsukita

Quote: 





francisdemarte said:


> Nice how long do the batteries last? How are they charged?


 


  Roughly 6 - 7 hours with 1000mAh Li-Po battery.
   
  I am using (external) Li-Po battery charger. (for Radio-Controlled Car)
  To add battery charging circuit, LTC4070 seems good and easy...


----------



## 32y0

I don't know if this have been covered before, but I was wondering if the output caps on the opus can be bypassed (like with the previous ballsie) when using the ballsie lite.


----------



## Rumble_Pak

I can't seem to get the volumite to work with the opus, even after trying the configurations mentioned throughout this thread. Can anyone perhaps be super specific about their configuration with the volumite, such as the switches on the opus, and the exact wiring of the volumite?


----------



## qusp

did you buy the opus version of the volumite firmware?


----------



## Rumble_Pak

Yes, i did.


----------



## Rumble_Pak

I should probably mention i am somewhat confused about what i should do with PB3 and PB1.


----------



## lag0a

Does the Opus DAC Spdif Transceiver need a pulse transformer if you have no ground loop problem? I am wondering if it would make the sound quality better. If so would it be best to use one at the coaxial output of the transport using a computer or after the coaxial input of the DAC near the Spdif Transceiver?


----------



## qusp

ground isolation is only one of the benefits of the spdif transformer, the other is impedance matching. i would recommend if you can only have one, to use it on the receiver side.
   
  Rumble pak: i'm not surprised you are confused with what to do with pb3 etc, i went over to tp to check it out for you, but the only place they are mentioned on the site is in the volumite for buffalo manual and only to say that they arent used. so one would presume that they are used for the opus dac, but its not mentioned anywhere and there is no volumite for opus manual, or even a general volumite manual. looks like a gap in the documentation; have you posted this problem on the tp support forums? i suspect its covered in the wm8740/1 manual/datasheet, but sorry i dont have the time to check it out at the moment.
   
  i use it on buffalo 2 and they arent used, so cant be of much help there.


----------



## atsukita

Quote: 





rumble_pak said:


> I can't seem to get the volumite to work with the opus, even after trying the configurations mentioned throughout this thread. Can anyone perhaps be super specific about their configuration with the volumite, such as the switches on the opus, and the exact wiring of the volumite?


 

 My  Volumite wiring.
   
  OPUS controller terminal                  Volumite terminal
  G                                                    GND
  SDIN                                               SDA
  SCK                                                SCL
                                                         PB1  --------  GND (jump)
                                                         PB3  --------  GND (jump)
                                                         VCC  --------  DC supply


----------



## Rumble_Pak

No luck thus far, ive tried all the various combinations of PB1 and PB3 and various suggested settings on the opus. Honestly, it's not a big deal if i cant get the digital volume control to function, i do happen to have an already populated balanced joshua tree, with the firmware (not labeled but hopefully correct).


----------



## francisdemarte

I just accidentally shorted out and fried one of the 8W resistors on my LCDPS, so I have the Opus and Metronome running off of only one half LCDPS. Is this safe?

I'm thinking of replacing it with a single Placid, will it be okay to power the metronome and opus off of one Placid?


----------



## glt

I thought they were 3 watt resistors.
   
  Measure the voltage across the resistor and calculate power dissipation: P=VI; V=IR. P=VV/R. V in volts, R in ohms. If that is less than 3, then you are safe.


----------



## lag0a

What device do you use to measure the voltage? Where can I buy one cheap? Does the LCDPS and LCBPS come with a device that measures voltage because I've read you're suppose to tweak the voltages of those blue boxes?


----------



## Beefy

Quote: 





lag0a said:


> What device do you use to measure the voltage? Where can I buy one cheap? Does the LCDPS and LCBPS come with a device that measures voltage because I've read you're suppose to tweak the voltages of those blue boxes?


 

 I don't mean to sound negative...... but by the way you asked those questions, there is no way in hell you should be building one of these.


----------



## lag0a

I'm not a DIYer but I'm just trying learn and get things right so that is why I'm asking these newbie questions.


----------



## Beefy

Sure, but a DAC with power supplies is not a great starter project. You will need to deal with mains power for the transformers, and I don't think you're up to it.


----------



## qusp

i'm afraid i have to agree with beefy here. sure you have to start somewhere, but this isnt it imo


----------



## iamthecheese

I've ordered the basic opus kit(opus, LCDPS, spdif transciever), and the 15VA transformer to go with it. I was bored this morning so I drew a potential plan(yes in Paint), all items are scale.
  Here it is:

  It's a dual mono opus with metronome.Outline box is 9x14
   
  I have a couple questions thought.
   
  Can the placidBP power both IVYs?
   
  Is this even a feasible setup?
   
  Is dual mono worth it over a single dac setup?
   
  I would great appreciate any comments at all.


----------



## qusp

i dont understand the use of the ivy with opus, opus is a voltage output dac and ivy is for converting current to voltage with low impedance, only needs a buffer yes? maybe not even that, with dual mono opus i would expect the output is pretty respectable. or are you planning to drive headphones with the ivy?


----------



## BrianDonegan

The IVY has both current-input and voltage-input.  The voltage inputs feed 2.2K resistors to provide a proper load for the WM8741.  You get a fully-differential buffer with filtering.


----------



## BrianDonegan

Quote: 





iamthecheese said:


> It's a dual mono opus with metronome.Outline box is 9x14
> 
> I have a couple questions thought.
> 
> ...


 
   
  A single PlacidBP (especially the new HD version) can power both IVY's.
   
  It is a feasible setup.  You will want to be careful with the routing of the I2S signals, especially in regards to power supply wiring.  Try to not cross them.  You may be better off putting the receiver/metro between the opus stacks, and moving the placidBP to the front of the case.
  
  Dual Mono does increase the performance, and many people swear by that.  Whether it will matter to your ears depends on your ears I suppose.


----------



## iamthecheese

Quote: 





briandonegan said:


> A single PlacidBP (especially the new HD version) can power both IVY's.
> 
> It is a feasible setup.  You will want to be careful with the routing of the I2S signals, especially in regards to power supply wiring.  Try to not cross them.  You may be better off putting the receiver/metro between the opus stacks, and moving the placidBP to the front of the case.
> 
> Dual Mono does increase the performance, and many people swear by that.  Whether it will matter to your ears depends on your ears I suppose.


 


 I had a feeling the power and signal wires shouldn't be routed in close proximity, I'm open to setting up in the case however. Would using sheilded wire for the signals be beneficial there?
   
  Just to make sure 2 output stages, in this case the IVYs are needed for a dual mono setup?
   
  Thanks so much for all of your support for your products!


----------



## iamthecheese

Another thing, is it possible to run an opus module, metronome and spdif receiver from a single LCDPS?
   
  Also how would IVY'(s) be wired for a dual mono setup? Would I even need two? I looked around and saw some people using 1 or 2 ivys for dual mono.


----------



## Lil' Knight

http://www.twistedpearaudio.com/docs/digital/dualmono_BII+IVYIII.pdf ?


----------



## glt

Quote: 





iamthecheese said:


> Another thing, is it possible to run an opus module, metronome and spdif receiver from a single LCDPS?
> 
> Also how would IVY'(s) be wired for a dual mono setup? Would I even need two? I looked around and saw some people using 1 or 2 ivys for dual mono.


 


  Yes, you can run OPUS, Metro and SPDIF receiver out of a single LCDPS. One side powers the digital section of OPUS, Metro and SPDIF board, the other side of LCDPS powers the analog section of OPUS
   
  I would recommend that you get the basic set up running first (SPDIF receiver and OPUS) and then add the other components later to facilitate debugging in case you have problems


----------



## dirkpitt45

I'm looking into building an OPUS as a summer project. Just a non-balanced one, I don't really plan on going balanced anytime soon, too expensive   I've built a MSSH and a bottlehead crack so far. 
   
  Getting kind of confused as to what exactly I have to buy to build it lol. Do I just need the OPUS kit (unassembled), USB receiver module, and then a powersupply option? And of course a case.
   
  Is there large difference between the placid powersupply kit and just the low current dual powersupply?


----------



## RJ Hythloday

This is the most recent thread I could find on the opus dac, I've read a bit here and the diy forum, but I can't really be sure.  I'm currently using a laptop that would either have to be usb out or headjack to rca.  I'd like to be able to use optical or coax in the future.  Would this be a good pairing w/ an indeed G3?


----------



## RJ Hythloday

here's the reply I got from their forum
   
  The Opus is basically just the DAC by itself and it has balanced output. If you want to get SE output you will need to either get the following:

Ballsie Lite Converter

 Or Line stage with built in Ballsie

IVY

 Even if you're going to go fully balanced, I would suggest you get the IVY board, it is much better for sound output.

 You will need a power supply for the DAC. Depending on your budget, you can go these way. Upper is least expensive solution and lower is most expensive but better as well

 1- Use LCDPS power supply to power analog and digital sections of the DAC independently or use one side of the LCDPS to power both analog/digital section of the DAC and the other side of the LCDPS to power the SPDIF tranceiver/MUX/USB

 2- Use a Placid HD power supply to power both the analog/digital section of the DAC or use two of them to power them individually. Use LCDPS to power the SPDIF tranceiver/MUX/USB and use a Placid HD Bipolar Shunt power supply to power the IVY stage

 3- Use any combination you like but the Placid HD Shunt power supplies are the best to power the DAC and IVY Stage. The tranceiver/mux/usb can all be powered by LCDPS.

 If I was going to build this, I would use the following:
Opus DAC
Placid HD Shunt to power both Analog/Digital section of the DAC
IVY III Linestage
Placid HD Bipolar Shunt Power Supply for IVY III
 Your choice of tranceiver/mux/USB
SPDIF tranceiver with I2S output
 or
4:1 Mux receiver with I2S output (new version coming out soon...
 or
USB receiver with I2S output (new version coming out soon...)

 And of course transformers
Power transformers
 You can use the 15V for DAC and IVY and Transceiver/MUX/USB. The 9V should also work well with the DAC and Tranceiver but not the IVY

 Enjoy!


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## qusp

he could also use a pair of line transformers for bal/se conversion, in fact the opus and all voltage out dacs pretty much, works very well with this setup. you do not need an IV stage, so i would suggest getting the ivy is overkill. a simple jfet or mosfet differential pair for a buffer would also do the job nicely


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## lag0a

Why does their SPDIF receiver have 4 I2S options while their current USB receiver only allow 24 bit I2S? Shouldn't the USB receiver just allow I2S and 16 bit or 24 bit depending on the source?
   
  If you play a 16 bit music file from the source to the SPDIF receiver using 16 bit I2S it seems to sound better than 24 bit I2S I think although I also configured my Metronome and my Dual Mono Opus DAC in differential mode to 16 bit too.
   
  Does anyone else have this setup and tried doing this?
   
  In their manuals they keep asking you to set it up for 24 bit but it doesn't make sense if you don't usually play 24 bit files.


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## qusp

standard pcm i2s does not come in 16bit flavor, only philips and perhaps sony format. all it does when feeding a 16bit signal to a 24 or 32bit dac with pcm input is pad the other bits with zeros. it doesnt resample unless you use metronome or similar afaik


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## MisterX

http://www.ti.com/lit/ds/symlink/pcm2707.pdf
   
  Quote: 





> [size=x-small][size=x-small]The PCM2706 and PCM2707 can support the I[/size][/size][size=xx-small][size=xx-small]2[/size][/size][size=x-small][size=x-small]S interface, which is enabled by FSEL (pin 9). In the I[/size][/size][size=xx-small][size=xx-small]2[/size][/size][size=x-small][size=x-small]S interface[/size][/size]
> [size=x-small][size=x-small]enabled mode, pins 4, 18, 19, 5, and 17 are assigned as DIN, SYSCK, BCK, LRCK, and DOUT, respectively.[/size][/size]
> [size=x-small][size=x-small]They provide digital output/input data in the 16-bit I[/size][/size][size=xx-small][size=xx-small]2[/size][/size][size=x-small][size=x-small]S format, which also is accepted by the internal DAC.[/size][/size]


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## qusp

I stand corrected, although thats not pcm, probably as long as its msb justified its ok


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## lag0a

TPA has a USB receiver that uses bus power and I'm looking for a USB receiver out there that uses an external power supply so I'm wondering if anyone else know a USB receiver like this or already using one in their TPA DAC configuration?
   
  I'm looking for a non-TPA USB receiver that works in an TPA Opus DAC configuration that can run on TPA's LCDPS. Please let me know what's out there.


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## Gliding

Will the Opus and associated components be offered for sale again? Right now, every offering is 'out of stock'. It has the look of a dead product line, but there's no such annotation on the web site.


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## grubyhalo

Quote: 





gliding said:


> Will the Opus and associated components be offered for sale again? Right now, every offering is 'out of stock'. It has the look of a dead product line, but there's no such annotation on the web site.


 


*"The Opus DAC is undergoing a redesign, and should be available again in early-2012."*
   
  Source: http://www.twistedpearaudio.com/digital/opus.aspx


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## KimLaroux

I just found this project while searching around for high-end DACs. They released V2.0 which was updated to WM8741.
   
  An unassembled kit is only 55$, which makes it a nice project even for starters. But I'm wondering just where this thing fits in all the current offering. How does it compare to other DIY projects like the Gamma II and PupDAC?
   
What's really interesting about this project is you can get two boards and have a truly balanced DAC at a reasonable price. But would this be considered an Hi End DAC by today's standards? 
   
  edit: Never mind, just realized a single board already is balanced. So what's the point of dual boards? A theoretical gain of 3 dB in SNR?


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## tomb

Quote: 





kimlaroux said:


> I just found this project while searching around for high-end DACs. They released V2.0 which was updated to WM8741.
> 
> An unassembled kit is only 55$, which makes it a nice project even for starters. But I'm wondering just where this thing fits in all the current offering. How does it compare to other DIY projects like the Gamma II and PupDAC?
> 
> ...


 
  The last time I looked (it's been awhile), $55 was far from the actual total.  The Opus as it stands needs the power supply and the input boards (SPDIF/USB).  It starts adding up quickly.  I could swear in its original implementation, it needed I2S output boards, too, but maybe that's the difference with the new chip and the overhauled design.
   
  All that said, it was probably the best in the world at the time, until they came out with the Buffalo.  Just giving you info from what I've read from people I trust, but the Buffalo may represent true top-of-the-line capability on par with any DAC.


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## KimLaroux

Thanks tomb. I realized it needs a PSU, an SPDIF to I²S converter and maybe even an output buffer. But even the Buffalo and the AckoDAC need these things, so the DAC itself is still 1/6 the price of those. 
   
  Though it's not a very good comparison because you can't have the Buffalo as a kit, only as a fully assembled board. I mean, soldering the board up is the best part of the whole DIY hobby, so why not offer a kit? 
	

	
	
		
		

		
			




   
  But yeah, when I look at all the other modules needed, it goes get expensive really fast.


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## DingoSmuggler

Quote: 





kimlaroux said:


> Thanks tomb. I realized it needs a PSU, an SPDIF to I²S converter and maybe even an output buffer. But even the Buffalo and the AckoDAC need these things, so the DAC itself is still 1/6 the price of those.
> 
> Though it's not a very good comparison because you can't have the Buffalo as a kit, only as a fully assembled board. I mean, soldering the board up is the best part of the whole DIY hobby, so why not offer a kit?
> 
> ...


 
  It is my understanding that ESS chips are sold under NDA, so they're not allowed to resell them, they have to sell them as a complete item.
  Even if they could sell them as kits, the soldering difficulty required probably means they wouldn't.


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## KimLaroux

Quote: 





dingosmuggler said:


> *It is my understanding that ESS chips are sold under NDA, so they're not allowed to resell them, they have to sell them as a complete item.*
> Even if they could sell them as kits, the soldering difficulty required probably means they wouldn't.


 
   
  Oh! I hadn't thought about this... I didn't know some manufacturers did that. 
   
  I thought it was because the circuit layout was optimized using the smallest SMD available, and that using larger components spaced farther apart - necessary for it to be built by DIY'er - would compromise on the performance of the whole circuit.
   
  But yeah both are acceptable reasons. At least the other modules are sold as kits.


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## BrianDonegan

Quote: 





dingosmuggler said:


> It is my understanding that ESS chips are sold under NDA, so they're not allowed to resell them, they have to sell them as a complete item.
> Even if they could sell them as kits, the soldering difficulty required probably means they wouldn't.


 
  No, there is no NDA on selling chips.  We sell as complete units because of the difficulty of assembly, and the cost of parts involved.  It would be a bummer to pay for all the parts and ruin them, which is easy to do.  It would also be overwhelming for me to build kits and complete units, time-wise.  I build all the kits myself, and have a full time job and kids, so, I need to make certain sacrifices in what we offer.


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## kugino

reviving an old thread for a hopefully simple answer.
  
 i have an opus with the WM8740, i think it's a v1.0 board. if i order the new board with the WM8741, is it a simple drop-in replacement? can i just re-connect all the various connections and everything should work fine?  thanks in advance...


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