Valab NOS DAC - subjective listening and modifications
Aug 14, 2010 at 5:36 PM Post #1,816 of 2,013
At the risk of revealing just how stupid I really am-here's a question for you guys. Steve Nugents original advice
for moding the valab dac was-
"3.3uFd V-Cap oils bypassed with .22uFd Sonicap Platinums. These require some weeks of break-in BTW"
 
Now, here's my stupid question. Does that mean REMOVING the stock caps and replacing them with the
3.3uf and .22uf in parallel, or does it mean placing the 3.3uf and the .22uf in parallel with the stock cap?
Would it make a big difference either way? And if all three were in parallel would it mean a much longer burn in time
because of reduced current through the smaller caps?
 I went with the second option(all three caps in parallel), and at 730 hours I'm still noticing some major changes
in the sound.
 You guys on this forum are the experts as far as I'm concerned, so I hope you can steer me in the right direction
 
                     Thanks,  Rich W
 
P.S.  to the gentleman who advised me to go with the Duelunds-my budget won't allow that right now, but
when it does I would like to check them out.
 
Aug 14, 2010 at 9:30 PM Post #1,817 of 2,013


Quote:
At the risk of revealing just how stupid I really am-here's a question for you guys. Steve Nugents original advice
for moding the valab dac was-
"3.3uFd V-Cap oils bypassed with .22uFd Sonicap Platinums. These require some weeks of break-in BTW"
 
Now, here's my stupid question. Does that mean REMOVING the stock caps and replacing them with the
3.3uf and .22uf in parallel, or does it mean placing the 3.3uf and the .22uf in parallel with the stock cap?
Would it make a big difference either way? And if all three were in parallel would it mean a much longer burn in time
because of reduced current through the smaller caps?
 I went with the second option(all three caps in parallel), and at 730 hours I'm still noticing some major changes
in the sound.
 You guys on this forum are the experts as far as I'm concerned, so I hope you can steer me in the right direction
 
                     Thanks,  Rich W
 
P.S.  to the gentleman who advised me to go with the Duelunds-my budget won't allow that right now, but
when it does I would like to check them out.
 
 

Not a stupid question at all.
 
I think Steve meant to completely remove the stock Russian caps and replace them with 3.3uF Vcap OIMP bypassed/paralleled with Sonicap Platinum .22uF.
 
I ran out of money so used Auricap .22uF in mine. It is only just now starting to mature and sounds fab using the async Bridge to give it a good signal. I am most impressed. Steve was on to something with this one. I'll know more when I get the Sonicaps in.
 
I socketed mine to play around with other caps, Blackgate NX in regular and Super "E", and some other films I had laying around. GE, CD, Aerovox and Wima, etc.
 
So to answer your question, I think I would remove the stock caps and just go with the others you have. I can't really tell ya what to do, but if you're not all that inclined to remove anything or unsolder anything then maybe(if you don't mind trashing the stock caps) you could just snip the stock ones off close to the body and leave enough of a little stub in the pcb to clip on or solder on your Vcap/Sonicaps to.
 
Agreed. Duelands ain't cheap, so I'll probably know how Vcap teflons sound before them.


 
Aug 15, 2010 at 6:55 AM Post #1,818 of 2,013
you indeed first remove the stock cap, then replace it with a better Quality cap and depending on the type and quality of that new one you may want to add a bypass cap.
 
Lately I find that I tinker a lot less w components and go for the kill zone stuff a lot quicker, saving money in the end.
 
I'd advice anyone who is still learning the sonic fingerprints to keep trying out stuff.
 
 
Aug 19, 2010 at 5:35 AM Post #1,819 of 2,013
BTW; I finally found the time to work on my tube amp, now with a VALAB volume stepped attanuator and hundreds of hours of burn in on my VALAB after the DIR mod and having removed the output coupling caps and filter and exchanging the input coupling caps.
 
So it is time to finally get the TXs installed, find a suitable digital transformer (Lundahl or something else?) so I can get rid of th einput couplig cap as well and add some decent caps to the power supply here and there etc, but more important; listen to music.  
 
Where the amp (all 0.8 Watts) started clipping very rapidly before it now the sound is nicely controlled up until a reasonably loud volume :)
The highs have really matured well with the extended burn in and possibly also improved caus I must have been listening to a clipping driver stage, so I'm a happy camper :)
 
Meanwhile all enthousiasm in this thread (and in the chameleon thread) seems to have dried up? wazzup folks ?
 
 
Aug 19, 2010 at 6:25 AM Post #1,820 of 2,013


Quote:
both th evalab and the chameleon thread seem to be abandoned, but pls describe the outside part of th ebuzz you;re experiencing....
 
Sometimes as chassis starts to buzz when the power phase is reversed.
 


Well it constantly produces buzzing sound when it is turned on, it isn't loud, but noticeable. By 'outside' buzz I mean that the sound through its analog out is clean, just that the box is buzzing, like a cheap wallwart or smth.
 
Aug 19, 2010 at 7:23 AM Post #1,821 of 2,013
I'd guess that yuo have the regular version with a less than perfect power transformer...in that case you probably are hearing the buzz of the transformer windings 'rattling'. I'd get in touch with your supplier as you should have some form of warranty, shipping a transformer should be easy but buying a suitable and better one might be quicker and pretty cheap. (also a cost effective upgrade!)
 
I believe there are some posts in this monster thread that might point you to supliers, course depending on your whereabouts.
Further diagnostics could be done by unscrewing the lid (caution high voltages inside!!!) and using fe a wooden spoon (nothing conducting for risk of electrocution) as a stethoscope to isolate the source of the buzz.....I give you at least  80% chance that the transformer is the culprit.
 
hope this helps!
 
Aug 23, 2010 at 1:40 PM Post #1,822 of 2,013
Just a thanks to digger945 and marcelnl for your answers to my question. I went ahead and snipped those stock caps
right out of there, and left the 3.3uf v-cap oimps and the .22uf sonicap platinum in place.  With about 160 hours on that configuration,
things are starting to sound pretty damn good.  With that mod, and the M2tech hiface, there's no doubt that the Valab Dac
is sounding extremely good.  Next up - Jkenny's mod for the hiface.
 
    Thanks again-   rich w
 
 
 
 
Win 7 - Foobar/XXhighend - Hiface - Valab Dac - Avi-ADM9.1 - DSPeaker Anti-mode - Veleodyne microvee
 
Aug 26, 2010 at 11:16 AM Post #1,823 of 2,013
good to see that it worked for you, BTW the DIR mod is imho the best mod in the whole series(although it is a pain to perform the microsurgery on the pins)
.
 
Aug 30, 2010 at 9:17 AM Post #1,824 of 2,013
Well finally I got around to put the TX-es to good use, 100R, 75R and two 330 R of these nice gadgets are burning in now, if they do improve over time I'll be even more please than I am already :)
 
The soundstage became more tangible, the music seems to be played slower with much more time to soak in the details and the highs are downright seductive.
 
 
Not really able to find a good supplier (as in cheap and well stocked supplier with decent shipping fees) I could do with some tips on what caps to use for decoupling the DAC and where to source them (pref in the EU)....have to confess I am not current anymore, in the 'old days' I would probably have chosen ruby's or cerafines (never been a big fan of BlackGate) but there must have been progress....
 
 
Sep 2, 2010 at 4:57 AM Post #1,826 of 2,013
Have to admit that I'm no big a fan of a computer as front end for serious audio, but I'd like to ask you why you would not rather use a tranny for this.....Not sure if they exist and what the pro's and con's are for either of the two, but it seems to met that throwing more electronics at your sound source with just the aim to separate the ground planes will hardly improve things overall.
If that result came with lower jitter or whatever other benefit things might look different.
Again, just my two cents....I've yet to hear a computer based system to outperform a decent CD turntable.
(though I find the option tantalizing)
 
 
 
Sep 10, 2010 at 2:13 PM Post #1,827 of 2,013
Hmmm.....valab dac with 3.3uf v-cap oimps bypassed with .22uf sonicap platinum..... or-
 
               valab dac with 3.3uf Mundorf supreme silver oils
 
        Any opinions?
 
        I'm currently using the oimps and sonicaps-sounds sooo good-but I'm detecting a bit of smear, thought maybe the
    Mundorfs(not bypassed) might be interesting to try.
 
 
 
  thanks, rich w
 
 
 
 
 
 
 
Sep 10, 2010 at 2:25 PM Post #1,828 of 2,013
I'd go for the Mundorf Silver gold Oil without any bypass, though I must admit that I do not know the combination you propose.....but having heard my share of caps (bar the duelunds) I dare say they are the best thing next to no output cap....
 
I ripped the output cap out of the valab alltogether and use a 1uF Mundorf S/G/Oil cap as input cap for my tube amp (easily 100k input resistance). Not sure whether that is an option but just as a thought, the smaller value cap would probably not make you break the bank using the more expensive and sonically more interesting S/G/oil.
 
 
Sep 11, 2010 at 9:28 PM Post #1,829 of 2,013

I recommend going with the VCAP CuTF over the straight teflon, the best of both worlds and depending on the input impedance of your amp just some small ones by themselves rather than the potential non-linearities of bypassing. that was my best result lately at least in my pass D1 (only thing in my main rig that still uses caps in the signal path) I really enjoyed the duelund copper VSF too and actually the 2 sound good together, but if I had to pick one (and I did) the CuTF are the ones. rather expensive in the larger values though and large, so if you can get away with smaller do (but you know that) the duelunds are extremely natural and totally unfatiguing, effortless even and with incredible detail, but I find that the CuTF has all of that, but is a touch more dynamic in my system
Quote:
 
I ran out of money so used Auricap .22uF in mine. It is only just now starting to mature and sounds fab using the async Bridge to give it a good signal. I am most impressed. Steve was on to something with this one. I'll know more when I get the Sonicaps in.
 
I socketed mine to play around with other caps, Blackgate NX in regular and Super "E", and some other films I had laying around. GE, CD, Aerovox and Wima, etc.
.........
Agreed. Duelands ain't cheap, so I'll probably know how Vcap teflons sound before them.

 

 
Sep 29, 2010 at 2:44 PM Post #1,830 of 2,013
Ive had my Valab Nos Luxury version mk1 for around a week now and been following this link..It's sounding quite edgy so i'm waiting for it to run in, hope this run in thing is for real and it's not just a case of, get used to it..!!!
 
I intend to change the output caps anyway with some caps that Kevin of Vintage hi fi is selling cheapish, I also have some Charcroft Foil Resistors on the way for the I/V stage, will see how they go on..
 
I'm also interested in the DIR 9001 chip mod but I'm using USB and was wondering if there's any benefit. 
 
Another point on this mod is, why do I have to lift the 2 pins and risk damage..!!!! why not solder to the pins leaving them where they are and cut the track to the pins, just a thought...
 

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