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Valab Dac-First Impressions - Page 16

post #226 of 1578
12/2/08 at 7:17pm
Quote:
Originally Posted by sum1 View Post
Well i asked Kevin if the reclocker affects the usb (i2s) input as well or is it just for the optical/coax. I'm not really sure of his answer but i think its a yes.

This is his reply
That reply says the opposite: it effects the usb input.
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post #227 of 1578
12/3/08 at 5:00am
Quote:
Originally Posted by tubes View Post
Hey Defec, when you get a chance if you could take a look under the lid and tell me if you have LT1084CT on both vertical heat sinks or if you have 1 x 1084 and 1 x LM317T voltage regulators. Thanks.

Phill
Phill, I'll try to crack it open tomorrow and see what's in mine and let you know.
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post #228 of 1578
12/3/08 at 5:03am
Quote:
Originally Posted by krisno View Post
Tell me guys, how does this NOS dac(or ther old NOS) sound coupled to a tube preamp, or tube headphone amp?

I guess it becomes very sweet and soft, but does it also make it lack detail, 'boring'. How would a NOS dac + tube amp work in movies?? ....

or does it just become more organic and realistic? I know that some NOS dac's come with tube output.


Last thing ... this Valab, how hot does it get. Does it heat up my room alot? Worth the money?

Kris
While I'm not using heaphones with the Valab my system is all tube besides it I can tell you that this dac isn't soft at all but then again neither is my setup. A good tube setup can be very vibrant. Anyway if one is looking for overly warm soft sound they should look elsewhere.
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post #229 of 1578
12/3/08 at 5:06am
Quote:
Originally Posted by Kooka View Post
Ok, here are the first tweaks I made:

Faceplate (a little less ugly) and holes on top to avoid overheating
http://i141.photobucket.com/albums/r...1/Valab010.jpg

Shielded signal cables instead of the original traces on the board
http://i141.photobucket.com/albums/r...1/Valab003.jpg

The traces have been broken to avid keeping noise from sewhere
http://i141.photobucket.com/albums/r...1/Valab004.jpg

I also added a 10K resistor on the blue led (avoiding the "laser" effect)
I am waiting for my 1ppm clock to replce the 20ppm one. These are the 4 points to desolder for putting the new one. As you see in one of the 4 points you have to desolder some components and then resolder them. Be careful. Also, better to remove the heatsink (2 screws) before desoldering the clock.
http://i141.photobucket.com/albums/r...1/Valab002.jpg
Cool. you did the same thing I did with the output cable run. Did you also find it made a good upgrade in sound? Please let us know how the new crystal sounds. I should get off my but and order one.
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post #230 of 1578
12/3/08 at 5:08am
Quote:
Originally Posted by tubes View Post
Kooka, a few holes in the bottom will help the air flow even better. i cant help but think some better coupling caps will improve the sound, problem is there is little room, did you get the russian coupling caps in yours, I didn't, the caps on the dac chips are also different on mine, yours must be the NEC's. My first unit didn't have the parts on the underside connecting to the coupling caps either, my second dac has them, wonder what difference those parts make.

Phill
Phill, Kevin said he was sending me 10 of the new output caps. If they show up 2 of them have your name on them.
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post #231 of 1578
12/3/08 at 7:45am
Quote:
Originally Posted by defec View Post
Cool. you did the same thing I did with the output cable run. Did you also find it made a good upgrade in sound? Please let us know how the new crystal sounds. I should get off my but and order one.
Well, I don't think connecting with a shielded cable means improving the sound, maybe I'll have less noise problems if ever thre were any. Other things, like bypassing the output caps with submultiple good ones can improve some detail, hopefully.
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post #232 of 1578
12/3/08 at 11:48am
Thread Starter 
Defec, thanks, that would be great, try out the caps and see what you think. I am thinking of adding some good chassis wire to the outputs/inputs like Kimber or Cardas, Cardas may be a little too revealing. I also have to order some caps for the board. Also have to wonder how a nice toroidal transformer would improve things, that would involve making a whole new cabinet for this thing with plenty of room to spread things out, this way one would have room to add some sausage caps for the output caps, problem is finding the time and motivation to get started.

Phill
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post #233 of 1578
12/3/08 at 12:25pm
BTW, if you want to avoid "laser effect" on the blue led add at least 10/15K resistance, otherwise it will stay too "laser" anyway. On the yellow one 1K is more than enough.
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post #234 of 1578
12/3/08 at 4:09pm
Ok, I changed the two 10uF tantalium caps there. I had to cut away a little part of the black heatsink (you must desolder it from the pcb and then reinstall it). The two Evox-Rifa MMK 2.2uF seem working very well, art a first listen better than the original ones: more clear highs and a huge sensation of "being there". As and example. piano and guitars are much much better from tghe beginning. If I had two 4.7uF maybe I would have used them but anyway 2.2 is not bad at all. We'll see after some burn in.
http://i141.photobucket.com/albums/r...1/Valab012.jpg
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post #235 of 1578
12/3/08 at 4:41pm
This dac looks really cool, I wonder how it compares to other NOS dac's, like Moodlab, Shek D1, and Gigamoon. Also wonder how it compares to the upsampling Zero dac /w HDAM upgrade. They are all around the same price. I like NOS dac's though. The Shek D1 seems to be the best made, though the reclocker is not as good....

/sigh
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post #236 of 1578
12/3/08 at 5:31pm
Thread Starter 
Kooka, thanks for the pictures. I wish there was some more room to mount good caps. Maybe I will build a little piggy back box to sit on top of the main box, feed the leeds from the caps through a couple of holes down to the board, put some insulation on the cap leads, that may look like hell and the lid will sort of be attatched to the board, wherever the board goes the lid goes. Any ideas on the best sounding smaller size caps?

Phill
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post #237 of 1578
12/3/08 at 5:59pm
Quote:
Originally Posted by Kooka View Post
Well, I don't think connecting with a shielded cable means improving the sound, maybe I'll have less noise problems if ever thre were any. Other things, like bypassing the output caps with submultiple good ones can improve some detail, hopefully.
My board is a different lay out then yours. Honestly there was some hash in the high pitch that went away with the shielded run on mine. rf pickup? Maybe the changes in the power supply layout solved the issue.
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post #238 of 1578
12/3/08 at 6:01pm
Quote:
Originally Posted by tubes View Post
Kooka, thanks for the pictures. I wish there was some more room to mount good caps. Maybe I will build a little piggy back box to sit on top of the main box, feed the leeds from the caps through a couple of holes down to the board, put some insulation on the cap leads, that may look like hell and the lid will sort of be attatched to the board, wherever the board goes the lid goes. Any ideas on the best sounding smaller size caps?

Phill
I would not put the caps too far from the board. If you cut tghe heatsink there's enough room for some good caps. Like these
ERO MKT1813 Polyester Film Capacitors 4.7uf / 100v su eBay.it Electronic Components, Electrical Test Equipment, Business Industrial
but even the cheap and industral Evox-Rifa I used are gooood caps, believe me.
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post #239 of 1578
12/3/08 at 6:08pm
Quote:
Originally Posted by tubes View Post
Defec, thanks, that would be great, try out the caps and see what you think. I am thinking of adding some good chassis wire to the outputs/inputs like Kimber or Cardas, Cardas may be a little too revealing. I also have to order some caps for the board. Also have to wonder how a nice toroidal transformer would improve things, that would involve making a whole new cabinet for this thing with plenty of room to spread things out, this way one would have room to add some sausage caps for the output caps, problem is finding the time and motivation to get started.

Phill
Actually a nice shielded toroidal transformer would probably help. I've always stayed away from cardas. I read you have to have a solder pot to really be able to strip the wires right. Does Kimber make a shielded wire for internal runs?
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post #240 of 1578
12/3/08 at 7:43pm
Thread Starter 
I've never seen any shielded Kimber for chassis wiring that's why I was thinking of just replacing the existing wire with Kimber chassis wire. I don't like silver coated copper wire and I wonder if thats what Kevin uses. My new dac (second one) looks like Kookas but with different caps.

Cardas is a pain in the ass to work with, getting the enamel off the litz limits its use.

Phill
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