[krisno]

Does the resistor 'mod' make a difference even if you bypass them by soldering the output cable( to the output caps) on the input leg of the resistor ??? This is a mod that Bill Allan etc did before.

K

 

[Jogi]

Yes, no difference. It converts current into voltage in every case.
I was really surprised about the change in tone and refinement.
And the direct coupling to the output cap is also very rewarding. Very easy, just two solder joints in your case, 5 minutes of work.

As Bill Allan stated somewhere in this thread, the dac is very simple, so every part has a big influence on the result. And he is right.

But I don't think it has to be expensive, for electrolytics there are very good industrial alternatives nowadays which are similar or better than BG. Think of Panasonic FM, Rubycon ZL or ZLH for analog part, Oscon SP or SEP for digital part of the dac.

I didn't spend more than 20 bucks to make my jaw drop

And the Mundorf silver gold stays in the drawer...
I think one of the biggest misunderstandings in Hifi is, that good sound cost good money.
My CD player with tubes and all technical mumbo Jumbo got rave reviews and set me back about 1500$. And the Valab blows it away...

BTW I don't see such a bad USB input in the Valab, but when the input was still working

I had a slight switching noise in the speakers. But I think this is more due to poor USB drivers in the computer and high frequency hash from the CPU.
Sound was a little better with running the netbook through battery.
The dddac has old receiver from Crystal, the Valab the dir9001with much less jitter.
But I did not dive so deeply into this stuff, so I can't figure whats better.
In my system this dac plays with no grain of harshness, be it USB or Coax.

Turntable isn't spinning since the Valab arrived....

But still no reply from Valab...

 

[Ranchu]

Something just occured to me. Is there any reason (other than sanity) that you couldn't make "coupling cap interconnects" with inline boxes for the caps, and make a short where the caps were inside the dac?

I mean, would it work?

 

[r8833]

or solder interconnect wire directly to caps from board thus removing male and female rca's ...should yield better sound

 

[PatOMalley]

Just got around to making my order for two Cinemag CMOB-2S transformers.
We'll see what they do. Might try them between my phono pre and line pre.

They are inexpensive at $22.10 each + $8 shipping. breadboard and RCAs should get me into a <$100 prove the concept arena.

'bout time, huh?

 

[Ranchu]

r8833 - My thought was that by by building such things, you could try different caps with less wear and tear on the Dac, and in less time switching them, and install the ones you finally decide on. Seems very convienient if it works...

Looking forward to your transformer experiences, Pat!

 

[PatOMalley]

you could run a wire to sets of alligator clips to try out caps .... When you find what you like solder them direct. Gotta leave the lid off and hope the dog doesn't lick them.

 

[Ranchu]

lol!

Good points, Pat.

 

[dubai2000]

Pat,

if you don't mind: what are you trying to achieve? Wouldn't a transformer be just be in the way of the signal? Just curious....

 

[r8833]

Pat,

Some good reading about transformers



diyAudio Forums - Experience with this DIY DAC ? - Page 9


Rich

 

[Ranchu]

Very interesting link, r8833.

Dubai, I guess the transformer will filter out the frequencies over 20k, very elegant solution.

Pat, I ran across this stuff, don't know if you're interested...

Rare Ultraperm 80 Shielding Sheet-The Electronic Goldmine

My dac still ain't arrived, sigh.

 

[mrdon]

Quote:

Originally Posted by PatOMalley /img/forum/go_quote.gif Just got around to making my order for two Cinemag CMOB-2S transformers. We'll see what they do. Might try them between my phono pre and line pre. They are inexpensive at $22.10 each + $8 shipping. breadboard and RCAs should get me into a <$100 prove the concept arena. 'bout time, huh?

I assume you are going to use them in your VALAB first?

Can't wait to hear the results! Please let us know.

 

[PatOMalley]

Quote:

Originally Posted by mrdon /img/forum/go_quote.gif I assume you are going to use them in your VALAB first? Can't wait to hear the results! Please let us know.

The DAC is up first for a try /w the Transformers. I have a little hum with my phono pre that I might be able to take care of but ... they respond slow to small quantity purchases it seems. They are more geared to industry rather than the individual audiophile nut. I got a quote but am still waiting for a reply on my request for a paypal invoice. They better hurry up before I fritter the money away on tube dampers or cd mats or more tubes.

 

[PatOMalley]

I found some adhesive backed copper that is used for wrapping around the bottom opf a tree to keep slugs off. Very cheap for a small roll. They had some of the same stuff in the electronics sections but at several times the cost.

This is good for small jobs.


Quote:

Originally Posted by Ranchu /img/forum/go_quote.gif Very interesting link, r8833. Dubai, I guess the transformer will filter out the frequencies over 20k, very elegant solution. Pat, I ran across this stuff, don't know if you're interested... Rare Ultraperm 80 Shielding Sheet-The Electronic Goldmine My dac still ain't arrived, sigh.

 

[krisno]

The final version...

So, how does this sound?

Well, extremly alive and natural! Magical... a bit less bass than I got with the 4.7uf obbligato's and music a bit more creamed together. Maybe it gets better after some burn-in, i dunno....

But what regards musicality, this is the best I have heard ever.... with tubes this will be the most realistic experience ever. But still, hard bass and rock music other caps might be better. Anyways, this config is a stayer...

These caps, 40years old, they really show off what american manufactoring was all about in those glory days of the united states. Too bad they lost it all ..........

P.S. But I have to say, these are not just smooth as some people might think... they are sharper in the treble than the obbligato's.