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Valab Dac-First Impressions - Page 8

post #106 of 1577
11/22/08 at 3:56am
Quote:
Originally Posted by tubes View Post
"Defec, I think the value of the caps you speak of are 100uf 10v on my dac."


Funny thing is I think the circuit board has 10uf written on it where the 100uf caps are installed in a few spots, I don't know if that makes any difference.

Phill
Thanks Phill. I really have to open mine up and double check the cap values. I wonder if changing out of them require us to adjust the variable resistors inside.
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post #107 of 1577
11/22/08 at 3:59am
Quote:
Originally Posted by Bozz_Keren View Post
hmmm... when i tried valab to feed my speaker, at maxed volume it hummed too, so neither my amplification is clean..
That's kind of a demanding test. I'd try it here but my amp has a bit of filament hum normally so it wouldn't do you much good. Anyway please keep up us to date on what's inside your dac both capacitor and value wise. Thanks.
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post #108 of 1577
11/22/08 at 4:03am
Quote:
Originally Posted by tubes View Post
You're probably looking at 150 hours for break in, keep us updated!

Phill
I have to also add if it's like mine it will sound great for the first few hours then sound like crap until you have some time on it.
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post #109 of 1577
11/22/08 at 8:26am
Thread Starter 
I'm hoping the new one shows up this morning, I'll open it up then start the break in process all over again. Another point is I wonder why they didn't build this with a fuse, I don't feel comfortable leaving this on 24/7 with the heat it generates, a few well placed holes in the box might help keep it cool/cooler.

Phill
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post #110 of 1577
11/22/08 at 3:59pm
These two DACs have the same functions but different layout and appearence. The most different is the USB circuit. Vablab use CM108 (USB-IIS -> TDA1543) and the Gigalab use CM102 (USB->SPDIF -> Dir9001-> TDA1543). Anyway, the Vablab one can also enable the path (USB->SPDIF->Dir9001->TDA1543) by changing the on-board jump. For USB audio, the XO can be replaced by a higher precision XO to boost the quality. The detail will be improved largely.

Quote:
Originally Posted by Fidelity View Post
The Gigalab version has dropped in price, now sells for $170 USD including shipping, item description seems to have been updated pretty much identical to the Valab seller.
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post #111 of 1577
11/22/08 at 4:11pm
Things will get better!
Cheap parts do not imply bad quality. However, the better parts in the critical positions will improve the quality.
Quote:
Originally Posted by sum1 View Post
Was going for this dac but a bit disappointed now with the news of using cheap parts.

Maybe i should pay more and get the lite-dac ah CAA Mod MKII
Lite DAC-AH CAA Mod MKII

Problem is that there is no usb-i2s connection to the dac-ah but then again i'm not sure how much better that would be compared to using some usb->spdif converter.

oh well i got more thinking to do but thanks for sharing the info about the caps in the VALAB.
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post #112 of 1577
11/22/08 at 4:48pm
Quote:
Originally Posted by TeraDak View Post
These two DACs have the same functions but different layout and appearence. The most different is the USB circuit. Vablab use CM108 (USB-IIS -> TDA1543) and the Gigalab use CM102 (USB->SPDIF -> Dir9001-> TDA1543). Anyway, the Vablab one can also enable the path (USB->SPDIF->Dir9001->TDA1543) by changing the on-board jump. For USB audio, the XO can be replaced by a higher precision XO to boost the quality. The detail will be improved largely.
Thanks for the info, which method is better, via the CM108 right?
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post #113 of 1577
11/22/08 at 5:28pm
Quote:
Originally Posted by TeraDak View Post
Things will get better!
Cheap parts do not imply bad quality. However, the better parts in the critical positions will improve the quality.

Hi. what XO would you recommend that we get to install in our dacs and what capacitors are the most important to replace? Are there any brands/types/values that you recommend? Thanks.
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post #114 of 1577
11/22/08 at 6:02pm
I'm thinking the Valab is superior in its USB-I2S>TDA1543 right? If I'm not going to be using usb would the gigalab or valab sound better you think?
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post #115 of 1577
11/22/08 at 6:07pm
That is what I thought, USB > I2S better than the USB > SPDIF conversion method, correct me if I'm wrong...
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post #116 of 1577
11/22/08 at 7:03pm
Thread Starter 
Hello TeraDac, are you involved with the Teradac NOS dac? If so, you're input here concerning these dacs would be greatly appreciated. I am not put off by the problems I have had with my dac as the Valab is one of the best dacs I have heard in certain areas, if over time this dac can be improved by parts swap or design improvements I would love to know. I would like to add that if a more refined version of these dacs could be built using good reliable parts I would be happy to pay a modest increase in price.

Phill
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post #117 of 1577
11/22/08 at 10:14pm
Thread Starter 
The following is now listed on the Valab E-Bay ad for the dac, he also has a new picture posted showing Sanyo power supply caps and new coupling caps.

Phill


"On Nov-22-08 at 08:20:09 PST, seller added the following information:

Dacs in this listing, we use new output coupling capacitors, with stainless outer shell , as you see in final pictures. In early version, we use Philips capacitor, it is good, but can be better. Now we change to use Russia made military tantanium cacacitor. Its sweat and open sound do touch our heart. And it keep even better details and extended frequency response. So we eventually choose it as our final decision output capacitor to upgrade this dac.

You may ask why do not use film capacitors? They are great choice, while 1543dac need large capacitor volume to get open sound. Because tda1543 is a very old chip with limited dunamic range. We use 8 chip paralleling to solve this limitation, but not enough. Large volume output capacitor can help us get open sound. We never get good performance from film capacitors. Electrolytics caps become our resonable choices. Black Gate N type do get best sound, actually very very good sound. But it is too expensive and already discoutinue. Russia military tananium capacitor now is our best choice from many caps we very exploration. You will agree our choice if you even hear it.

Many customer ask us what they can do to upgrade this dac. This is question we as ask ourself for long time.
In this month, November 2008, we revised circuit layout to get better signal/noise ratio, eliminate almost all noise and obtain even more music details.
And in this batch of daca we will ship out, we will even upgrade output capacitors used in this dac. We will kept usage of this capacitor until we get even better sound capacitor to replace it.

We will keep revising this dac, our purpose is bulding world best tda1543 based USB DAC. Many customers tell us, we already done. But investments will not stop. If you have any opinions or suggestions, fell free to contact us. Your suggestions will help us to build better product for you."

Sincerely, Kevin
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post #118 of 1577
11/22/08 at 10:27pm
I disagree with the black gate comment having tried them in the dac myself and not liking them. It's probably a matter of taste. I wonder if the circuit layout he is talking about is the below

http://byfiles.storage.live.com/y1pd...UZrO0hGSM9o1-o

it would kind of blow if the board has changed leaving us that already have a unit to have a worse sounding one.
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post #119 of 1577
11/22/08 at 10:54pm
Thread Starter 
Defec, BTW I was reading on a website about Black Gates, one person commented that if the piece of equipment using Black Gates is not used often the BG caps will need to be broken in again.

Yes that does suck if there is a new board but you can always sell it and get a new one if in fact it is an improvement. You can get a discount on buying a new Valab by using Live.com, a new one at the current price of $180.00 can be had for $135.00 with the discount.

Phill
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post #120 of 1577
11/22/08 at 11:15pm
Quote:
Originally Posted by tubes View Post
Defec, BTW I was reading on a website about Black Gates, one person commented that if the piece of equipment using Black Gates is not used often the BG caps will need to be broken in again.

Yes that does suck if there is a new board but you can always sell it and get a new one if in fact it is an improvement. You can get a discount on buying a new Valab by using Live.com, a new one at the current price of $180.00 can be had for $135.00 with the discount.

Phill
That could be the case about the Black Gate N's. I pulled them pretty fast. I did use them in other projects and allowed burn in only not to like them as much as other stuff though. In one thing I ended up yanking all the black gates out of the single path swapping them for Caffines and thought the sound was much better. This stuff is all taste/system specific.

Please explain live.com's discount to me. I've never heard of this.
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