# DAC 707 Mods



## rds

Here are some mods I did on the DAC 707 Super Pro.

 But first:

 I have traced the analog output stage of the DAC 707 Super Pro and have drawn the schematic in a way to make it easy to compare to the recommend stage from the CS4398 datasheet. As you can see the 707 using a single ended power supply for the opamp.











 The front side of the 707 with the output stage schematic superimposed:





 Now the mods so far...

 The stock board:





 Some stuff removed:





 Film caps added to the bottom of the board. The blue ones are BC Components 419 mkp are parallel to the output coupling caps (which were switched to Elna Cerafine). The yellow is stock moved from the top because there is no room. The grey one is for filtering the opamp power. I removed two garbage smd caps on the output of the opamp and connected the opamp output directly to the Cerafine/419s with the red wires. If you look closely you can see where the caps were.





 The opamp is socketed and the opa2107 is being used. The opamp power cap is replaced by 470 uF Panasonic FM. The output coupling caps are replaced with Elna Cerafine (bypassed by the blue BC Components caps).
 A second 1000uF Panasonic FM was added for power filtering/stiffening. 





 A power switch was added. I don't like things that spark when you plug them in


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## andrew jc

rds Great work as usual! How does it sound compared to a stock unit? Also how does it compare to the Alien dac?


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## rds

Quote:


 How does it sound compared to a stock unit? 
 

It's much better. Stock this dac is definitely not "hi-fi". Now it sounds very nice.

  Quote:


 Also how does it compare to the Alien dac? 
 

They are very different. The cs4398 is a great chip, but is best left to hi end circuits in my opinion.
 I would take an alien with nice output caps over the stock 707 any day.
 The alien has a much "warmer" and "darker" sound than the 707. You could also say it is more bass heavy and "veiled". I find the textural qualities of the alien to be very nice and it has a lower noise floor.


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## mapstec

Please believe that rds knows what he is talking about, and that there actually are people who agree with him!

 That is not to say that I can not agree with parts of what you say.

 And can we all please include a few more "imho" in our posts?

 Just my two cents 
	

	
	
		
		

		
		
	


	



 Cheers


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## mapstec

So we all agree that we can like this DAC with careful selection of components and/or modifications.

 @creek - The last opamp I had in there was the LT1057 - and I liked the sound.

 btw: I send mine of today to rds for modding - I look forward to the result.


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## CountChoculaBot

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_OP updated with the final mods._

 

You stuffed the hell out of that board, can't wait to hear it


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## rds

Original post updated again with a schematic of the 707 analog output.


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## rds

Modding complete


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## hopeless

I've just finished modifying a Super Pro I had (not the newest that I'm awaiting), a non USB model (I don't care for USB, anyway).



 It's playing right now and wow, is it good.


 I...


 Changed the 4 + 2 caps in the signal path with 6 WIMA MKS2 4.7uF 50V (the two output caps being bypassed with 100nF Evox MMK too).

 Put a Rubycon YXH (high ripple current) 1000uF 25V in the main power line, bypassed with a 100nF Evox MMK.

 Soldered a LME49860NA on the pcb.

 Changed the DAC and receiver power supply caps with 47uF Rubycon ZLH (very low ESR).




 Sounds extremely good (playing Jason Lytle, "Yours truly, the commuter"). Musical, airy, and very revealing; what more can I ask?


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## hopeless

It also served as a test for the possible mods for my next incoming Super Pro 707 (I'm too in love with this little very musical DAC).


 I say possible because when it arrives I'll be comparing the stock one with the modified one, and will decide what sounds better. Will report back.


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## hopeless

Lucky me that I'm loving the sound with the LME49860 inside, 'cause I couldn't change it easily. 
	

	
	
		
		

		
		
	


	




 Actually I'm glad I did so because I quite dislike sockets. 
	

	
	
		
		

		
		
	


	






 Everything works fine, and the sound is very happily warm + analytical. It's very balanced, but lively. I didn't (maybe) expect such a satisfactory result. We'll see if the stock new DAC 707 stands the comparison. If it does, I may not touch it at all.


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## hopeless

Well...


 The brand new Super Pro 707 just arrived today.

 I have briefly switched the two 707's and...


 Well the stock new one is very musically charming, clearly thanks to the LT1364. The other one is probably "more transparent" though, if that's what matters (hmm).

 Honestly the stock one with its "rubbish" SMD output caps and all, doesn't really sound very much less detailed than the modified one (as above), really.

 I would leave the new one untouched, weren't it that in an impulse I aready purchased the parts for modifying it too. 
	

	
	
		
		

		
		
	


	





 However the opamp will either remain the (excellent indeed, in this DAC) LT1364, or will become a EL2227 (just got this) or a OPA2211AID (which I know sounds great).


 The LME49860... I like it, but it lacks that very special LT1364 charm. I think that the OPA2211 is a sweet spot between them. Who knows about the EL2227... so curious to discover.


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## hopeless

I've now modified my newest one too!

 As I opened it I realized that it has been extensively reengineered. Now the regulators are 2x LM317 (no more just one), but especially, all of the components have been made to fit on the upper side of the PCB - not a single resistor, or chip, to be found below. There are some new parts too.

 Oh and interestingly on the leads of each of the 4x stock film 4.7uF 63V caps (which appear to be good BTW) there are small ferrite beads (so 8 beads in total). Also the layout has been rearranged so that a DIP socket fits well without moving anything.

 So did I a socket put. 
	

	
	
		
		

		
		
	


	




 And on it I put a LT1358.



 Well, I've compared the new one with LT1358, to the older one with LME49860 (with the bypass 100nF caps replaced with Wima's, BTW, and the ones in parallel with the output caps just removed because they made the sound worse than without)...

 Clearly the one with LT1358 sounds better (though I also love the other's cool refreshing character). It's more "real". I like this opamp even better than the LT1364. Excellent opamp (not that I'm going to keep it forever...just received some EL2227 BTW).


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## MrSlim

Check out this thread, they've bypassed the output stage all together on a 4397/8 DAC, and have done the same on the 707. Not that it'll fit in the case.. 
diyAudio Forums - Experience with this DIY DAC ? - Page 11


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## hopeless

I don't feel the need for that at all (assuming that it would sound good). Next opamps I'll try are EL2227 and OPA2211AID, and maybe OPA2822 and OPA827.


 EDIT: Thanks, anyway. I'll give it a look (is it transformer coupling?).


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## hopeless

Quote:


  Originally Posted by *MrSlim* /img/forum/go_quote.gif 
_Check out this thread, they've bypassed the output stage all together on a 4397/8 DAC, and have done the same on the 707. Not that it'll fit in the case.. 
diyAudio Forums - Experience with this DIY DAC ? - Page 11_

 

I confirm that I'm not interested. That stuff is only for those who do not know about the OPA211, and the other better opamps (like the LT1358).


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## hopeless

Been comparing a little my 3 modified DAC's: Super Pro older version (like the one in this thread), Super Pro newest version, and DIYEDEN SVDAC05.


 The older Super Pro has a LME49860, the DIYEDEN 2x LME49710, the new Super Pro has a LT1358. For the rest all are tweaked in the passive parts, with Wima's (both polypropylene and polyester), Evox MMK, and low ESR electrolytic caps from Panasonic (DIYEDEN) and from Rubycon (the other two). The DIYEDEN is also completely capacitorless in the signal path.


 Guess... the two Super Pro's not only stand the comparison with the "more sophisticated" DIYEDEN (another CS4398 + CS8416 based DAC); the Super Pro with LME49860 is just a tad warmer than the very rigorous DIYEDEN, while preserving the overall sonic signature; and surprisingly enough, the newer Super Pro with the LT1358 is the best sounding to my ears. It just has the most "life", without losing anything. It also has the most body to sounds. And transient response is fantastic. Enjoy the *LT1358*. 
	

	
	
		
		

		
			






 P.S. listened to an old record by Leonard Cohen, very well recorded anyway.


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## MrSlim

Hopeless, is the LT1358 an SOIC or is it in a DIP pkg? Would it be possible to swap it into the SVDAC05? I was just looking at a SVDAC05 on ebay and it looks like it has a reasonable amount of room for doing mods to it. Of course it's more money than the 707.


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## hopeless

The LT1358 comes DIP and SOIC, at your discretion. 
	

	
	
		
		

		
		
	


	




 The SVDAC05 wants two single LT1357 though (again DIP & SOIC).



 I'm very happy with both the modified Super Pro (currently with a LT1364, after opening it to add another couple of bypass caps -- different from the LT1358, rather than better or worse) and the SVDAC05, and couldn't say which one sounds better so far.


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## hopeless

Well I've found even better: that's the LT1469. Formerly I had found this opamp to be a little bit dry as a DAC buffer, but this time, in the new Super Pro with added bypassing (Wima 100 nF + another Wima, 220 nF), it works wonderfully.


 It fared quite well also in this test... http://www.sg-acoustics.ch/analogue_...distortion.pdf


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## hopeless

Superb opamp the LT1469. It's an LME49860 with a more natural tonality and just a bit more fullness.

 My favorites of the dual LT opamps tried so far are LT1469 and LT1358. Soon I may try the LT1678 and the LT1632 (if they send them to me).


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## hopeless

Changed the LT1469 with the LM4562 (I hadn't tried this for a long time), just because the former produced little pops when changing track on the player. Don't know why, may be a little problem with DC on the output (though the DAC has output caps).

 It's a bit of a pity because I loved the LT1469. Given this, the LT1358 returns my favorite dual LT. 
	

	
	
		
		

		
		
	


	





 BTW I like the LM4562, it seems to have slightly more meat than the LME49860. Also I like the tonality a bit better?


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## hopeless

LOL, I'm glad I went back to the LT1364. Has smoother sound, better transient response, and especially an unquestionably more natural kind of sound.


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## hopeless

WOW, with Jason Lytle, "Yours truly, the commuter", the DAC, with the LT1364 inside, is really quite impressive. I love how the LT1364 resolves intricate transients, complex situations, especially in acoustic music. Also I love its dynamic, alive & "live" sound.

 By comparison, the LM/LME have kind of a pedantic audiophile sound. To each their own.


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## hopeless

I think that the OPA2211AID will be the "definitive opamp" for this DAC. I need Browndogs...


 Meanwhile the LT1364 sings the sweetest tunes.


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## hopeless

While I wait for the Rubycon ZLH cap for my "main" Super Pro 707, my other one (that with the LME49860, soldered to the pcb) just rocks. One opamp or another (of the good ones), this is a great sounding DAC. 
	

	
	
		
		

		
		
	


	






 BTW when the cap is placed in the "main" Super Pro I'm going to try the TLE2142, an interesting bipolar opamp, particularly so for a 12V supply voltage. Should also go well with the CS4398. We'll see.


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## hopeless

I've found out that there's a 4000 (and more) euro DAC from "Acoustic Arts" that uses the TLE2142, both for I/V conversion and for output buffering. In the review I saw, the reviewer said it's among the very best DACs available, and compares well with a much more expensive dCS.


 This: VIDEOHIFI 26 - AUDIO


 (interestingly it uses Panasonic FC & FM capacitors throughout, along with some tantalums -- I feel reassured about my former capacitor choice for my DIYEDEN DAC)


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## rds

Although component choices are important, at the end of the day it's implementation that decides how good a piece of equipment is.


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## hopeless

Well, consider that in that DAC there are in total 8x TLE2142... So implementation or not (at most I'd say higher supply voltage 
	

	
	
		
		

		
		
	


	




 since the TLE2142 is surely not a 'cranky' opamp), the Super Pro with a single opamp channel here certainly has an advantage - may I call it implementation, too?


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## hopeless

BTW, rds, how do you like your modified DAC ? I'm listening to it (one of them, the older) right now, and loving it. It doesn't sound worse than the modified DIYEDEN (I can switch between them with the touch of a button), even though the DIYEDEN currently has a solid-core silver interconnect, and the Super Pro "just" a Sommercable Classique (coaxial, copper).


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## hopeless

So what's wrong with your DAC? Reading this thread it looks evident that you never fell in love with this DAC. Instead I loved its sound (and size) from the first listen of the first one I bought. Sooooo subjective is the appreciation of this stuff


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## rds

Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_BTW, rds, how do you like your modified DAC ? I'm listening to it (one of them, the older) right now, and loving it. It doesn't sound worse than the modified DIYEDEN (I can switch between them with the touch of a button), even though the DIYEDEN currently has a solid-core silver interconnect, and the Super Pro "just" a Sommercable Classique (coaxial, copper)._

 

 Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_So what's wrong with your DAC? Reading this thread it looks evident that you never fell in love with this DAC. Instead I loved its sound (and size) from the first listen of the first one I bought. Sooooo subjective is the appreciation of this stuff 
	

	
	
		
		

		
		
	


	


_

 


 Like you say I never fell in love with it. I only had it for a short time as I was modifying it for someone else.
 Right now I use an Opus DAC.


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## hopeless

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_Like you say I never fell in love with it. I only had it for a short time as I was modifying it for someone else.
 Right now I use an Opus DAC._

 

Sorry for that.


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## hopeless

Saw the thing... a little board with a chip and nearly nothing else, that sells for $185... now that's (crazy) talking. It makes me feel so fine about my two Super Pro's and one DIYEDEN SVDAC05.


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## hopeless

BTW I should be able to put OPA2822, EL2227 and LME49722 on Browndogs soon. That and trying the TLE2142 of course. I also have the plan to solder that LME49720HA I have on a DIP socket to try it too. Previously (tried it briefly without adaptions except forming its pins like DIP) it had worked so great.


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## hopeless

I'm listening to Gillian Welch, Soul Journey. I've heard her voice deviated from the optimum reproduction in so many ways...

 But not in this case. The Super Pro 707 (still my older one with the unsocketed (soldered) LME49860, at the moment) makes it sound as good as I've heard, soo heavenly... This DAC has everything, energy, control, refinement, presence and beautiful midrange tonality & delicacy, airiness... If only more people heard what I'm hearing 
	

	
	
		
		

		
		
	


	




 (they'd probably give up their DIY projects)


 For the record, the newer, even better Super Pro is still awaiting its new (either 1000uF 16V Rubycon ZLH, because the 1000uF 25V YXH was too long, 28 mm, and interfered with the socket, otherwise it was great, as my other Super Pro is proving) power reservoir cap (with 330nF attached Wima bypass cap in place of the former 220nF), then it's ready to go...



 There's something magical about the musicality of this DAC (also with the original LT1364).


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## hopeless

Tried the TLE2142IP and... how good! 
	

	
	
		
		

		
		
	


	




 It's almost better than the LME49xxx. It has a solid articulate smooth sound, more solid & articulate in the bass than the LME's. I like its tonality as well, it's not cold. 

 Now I understand why that 4500 euro DAC uses it! 
	

	
	
		
		

		
		
	


	





 I'll keep it until the adaptors to try the OPA2211, OPA2822 and EL2227 arrive. At least.


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## hopeless

I guess that this weekend I'll have fun comparing the older (with LME49860) to the newer (with TLE2142, and now with Rubycon YXH 470uF 25V + 330nF Wima MKS2, plus the other 100nF Wima already present).


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## hopeless

It is nice, but maybe it lacks a bit of color. The LT1469 sounded better, pity for those little pops appearing between tracks... maybe I'll try it again now that I have improved power supply bypassing (well...maybe it means nothing).


 The LME49860 is quite good, though. Even better will be (I predict) the LME49720HA I'm about to solder on a socket to be able to use it


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## hopeless

I'm enjoying the TLE2142 though. It has that sonic rigour that you expect to find in German audio products. 
	

	
	
		
		

		
		
	


	





 It sounds not so romantic but... rigorous.


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## hopeless

Some news...

 I decided to replace the LME49860 in the older DAC with the LT1469. 
	

	
	
		
		

		
		
	


	





 Also I have bypassed the 4.7uF MKS2 output caps with 330nF again Wima MKS2.


 The reason is that I wanted a sweeter and more full bodied sound... And that's what I got with the LT1469. 
	

	
	
		
		

		
		
	


	




 Nearly the same level of detail, perhaps just the same (considering the different balance). But the bass is... earth shattering, you say? Anyway it goes incredibly deep and is very dynamic - love it. The vocals are just a tad thicker, and the treble a bit smoother, less digital. Fantastic. 
	

	
	
		
		

		
		
	


	




 BTW the LT1469 doesn't even do those little pops (at all) like it did in the new Super Pro. Apparently the two have some differences in their output stage schematic.


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## hopeless

I'm loving the unobtrusive, honest (but with everything I want, like dynamics, detail etc.) sound of the TLE2142. That's the opamp for the new Super Pro. Unless improved upon by the incoming (the Browndog for...: ) OPA2211


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## morfic

Would you consider it bright at all. If you could try to think back, with the LT1364.
 I am close to picking up the new one with the LT1364, and seeing the board shots that there are through holes to take on a DIP-8 socket pretty much makes it a neat tool.

 LM4562 (LME49720) has always been my favorite, it was called pedantic audiophile at some point, not sure how to interpret that as i always found it to be the most musical at cost of being the most "accurate".

 Since the Super Pro 707 '09 would feed a tube amp, i am looking for bright and detailed, nothing laid back or mellow. The tubes can take care of that.

 Any opinion you can offer there are much appreciated.

 The opamp link while very interesting in principle is not too interesting since it lacks LME49720/LM4562 and AD8620 amongst others.
 AD8620 may be my ticket for getting a brighter sound out of the dac into the tube amp. But time will tell, i never heard the LT1364 before, so it may be good as is. unless you ever tried AD8620 or AD8066 and could compare to LT1364?


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## hopeless

To me... no, the stock DAC with the LT1364 isn't certainly too bright. It has good presence at both frequency extremes, but it somehow manages to have present vocals too 
	

	
	
		
		

		
		
	


	





 For me the LT1364 is fine, and one of the best sounding opamps. I certainly consider it musically superior to the AD8620 and AD8066 (and particularly superior to the latter).


 Regarding the LM4562, it is fine and another possible best choice for this DAC apart from TLE2142 and LT1364. Try the OPA2211 too if you like detail. 
	

	
	
		
		

		
		
	


	




 I'm going to try it soon.

 For now the TLE2142 suits me very well both for balance and for timbre.



 For a bright sound the LME49860 is particularly good


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## morfic

I never eard the AD8066 myself, AD8610/AD8620 are interesting but make me tired quick, LME49710s were the nicest in XM5 and are now (as LME49720) in my MkV.
 But what i like in my SS amps, i may not like in my DAC.
 Idea is that as much as the tubes "color the sound", i would prefer for the DAC sound to be very analytical (i think, i may find myself back at the LME49720, who knows, but that's my idea until i find out otherwise.)

 Do you have any board shots of the NEW 707? as it looks now or how it looked along the way?
 From the missing 192K led i think the board shots in OP are from "the old 707" ?

 EDIT: N/M the OP was rds, who did it for someone else, so i may not get any "new 707" interior shots :/


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## hopeless

No shots because no camera, sorry.

 Anyway there are some significant changes over the old one shown in this thread: now USB goes to the DAC via I2S; now all SMD parts are on the upper side of the pcb 
	

	
	
		
		

		
			





 ; now there are two LM317 regulators instead of one; now the main power cap is a 220uF 35V Rubycon YXG (though I changed it anyway) ; and now there seem to be some minor changes to the analog stage. 
	

	
	
		
		

		
		
	


	




 Plus now the PCB is green 
	

	
	
		
		

		
		
	


	





 Regarding the opamps, try the OPA2211 or two (SMD) OPA827 if you like great detail, 
	

	
	
		
		

		
		
	


	




 or the TLE2142.


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## morfic

I got the m-audio transit on order and while i considered it as a way to get 24/96 optical to a dac, i will have to try it's line out into my amp first.
 If it's lacking, i will come back to this little gem, thanks for all the info, i had looked at it months ago, but the easy "socketability" is going to make this one a winner for me


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## Philimon

rds,

 Your PM box is full...


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## hopeless

Quote:


  Originally Posted by *Philimon* /img/forum/go_quote.gif 
_rds,

 Your PM box is full..._

 

I swear it wasn't me


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## leeperry

oops, wrong thread..


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## whitelabrat

I got one of the newer versions of the DAC and fried something within 24 hrs. I noticed that this one was different from the earlier models mentioned here so I started probing around with a multimeter. Then I saw a small wisp of smoke. Now the chips get pretty toasty and I only get static from the output.

 Ugh. Any suggestions for repair? My plan was to do a thorough mod, but now it looks like I'll be doing some SMT work too. I would assume that if the DAC chip were dead I wouldn't get any sound at all. I've got parts to replace just about anything, but geeez, what a bummer.


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## RockinCannoisseur

awesome bump


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