[PatOMalley]

Using the DC-30W will bypass the DAC's internal power supply caps.
You could always replace the caps in the PSU but he is already using Rubycon's now in the PSU. Not Blackgates but good caps nonetheless.

Maybe you can use them in the power supply of your transport?

 

[hifi2001]

Quote:

Originally Posted by gfontes /img/forum/go_quote.gif I have some Blackgate FK's for the power supply and the regulator cap that I have yet to put in my Valab. If I added the outboard power supply, I assume that woulds bypass the blackgates in the power supply. Right? Bear w/me I'm still somewhat of a newbie with some of this. Thanks

Since the external power unit supplies all the power to the DAC, I am quite sure everything from the regulator to the IEC connector is no longer used, so save your FK caps if you are thinking of DC-30W...

I believe the magic in the DC-30W is in the transformer, caps and regulators used (in that order?) compared to what is on DAC pre-V3...

 

[gfontes]

Thanks for the quick replies! I figured that was the case but wanted to be sure.

 

[Bill Allen]

Norm,

As our new liaison to TeraDak, first off I would like to see a version of this DAC with no onboard AC/DC power supply and associated parts. This would leave plenty of room inside the DAC case for large film caps. This version would of course be prewired for use with the DC-30W. (Perhaps this stripped down 3.0 circuit board could also be made available to us legacy Valab DAC owners).

Aesthetically it would be 'really nice' if both the TeraDak DC-30W and 'new' TeraDak DAC have identical looking cases. Myself I prefer the slightly taller case of the DC-30 with the silver faceplate and black casing. This could be the TeraDak signature look.

Perhaps the 'new' TeraDak DAC could come pre-installed with some decent sounding low cost film caps. This would really separate their product from the pack. Upgrading to different film caps and I/V resistors should also be designed for simplicity, yet sturdy enough to withstand multiple replacements. I like the idea of the film caps soldered directly to the RCA jacks if possible.

Speaking of the DC-30W, it should really be marketed as a universal DC power supply. As configured it can be adjusted to output anywhere from 3 VDC to 12.8 VDC. By soldering on the unused yellow wire (12VAC) DC output voltage increases to around 16VDC. Very useful for numerous Audio Projects.

Moving on from there, I would like to see a 16 DAC chip Teradak DAC, which of course the DC-30W power supply could easily handle.

That's my wish list ......... for now!

 

[Paul_B]

Hi all, first post here...

I have a Feb 09 Valab DAC which I bought after seeing the pages and pages of comments from you guys on the original thread. If it wasn't for the volume of positive comment on headfi I might have look elsewhere - so I have you to thank for this brilliant DAC.

I've never soldered before and decided to ignore all advice about working on an old board before attacking the dac - I upgraded the output caps with Steve's V-cap/Sonicap combo. Right out of the box these made a huge difference. I'm very happy and looking forward to the next few weeks with these (also happy i didn't burn the board or the stock caps).

The legs of the new caps didnt seem long enough to allow neat placement of the new caps along the side of the dac - is there any way to get around this? Can you extend the legs?


Thanks again for the ideas, suggestions; pics etc.

Paul

 

[hifi2001]

Quote:

Originally Posted by Paul_B /img/forum/go_quote.gif Hi all, first post here... The legs of the new caps didnt seem long enough to allow neat placement of the new caps along the side of the dac - is there any way to get around this? Can you extend the legs? Paul

Great job on your first mod Paul_B!

Yes, you can definately extend the legs of your cap. just make sure you add enough shrink heat tubing or insulation material so that the leads are not touching anything else on the board and you should be fine....

Norm

 

[gfontes]

Norm,




"Perhaps the 'new' TeraDak DAC could come pre-installed with some decent sounding low cost film caps. This would really separate their product from the pack. Upgrading to different film caps and I/V resistors should also be designed for simplicity, yet sturdy enough to withstand multiple replacements. I like the idea of the film caps soldered directly to the RCA jacks if possible."


When I got my second Valab dac from Kevin, it came w/upgraded output caps. They were the 10uf 100v caps that he sells on ebay.They were soldered directly to the RCA jacks too. He offered this upgrade for free as I received a faulty dac and return shipping was costly. The dac sounded really great w/these caps. I'm not so sure the upgrade to the v-cap/sonicap output caps completely trumped those he included in my dac. I'd post the link to the caps he sells but cannot access Ebay at work.

I e-mailed Kevin yesterday to see what his intentions were for future Valab dacs w/the external PS. I have not heard back from him yet.

 

[hifi2001]

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif Norm, I would like to see a version of this DAC with no onboard AC/DC power supply and associated parts. This would leave plenty of room inside the DAC case for large film caps. This version would of course be prewired for use with the DC-30W. (Perhaps this stripped down 3.0 circuit board could also be made available to us legacy Valab DAC owners). That's my wish list ......... for now!

Hey Bill,

I'm with you on this one. However, the last time I brought this similar request up with TeraDak they reminded me that there is that magic minimum order quantity they need to meet before the factory that is building the DACs will accept their order... So what that means is as long as we can get 50+ of confirmed orders TeraDak can do it...

In the meantime, it is back to dissambling parts off the current TeraDak PCB... if you have the DC-30W and want to remove on-board AC transformer, Michael confirmed that they DID NOT use any glue between the transformer and PCB on pre 2009 models and they DID use glue on post 2009models... I also think that having a hot soldering iron, more than 40W iron, and a strong solder sucker will help immensely...

Norm

 

[tubes]

gfontes, could you post some pictures to give us an idea how Kevin mounted/positioned the caps. Thanks.

 

[PatOMalley]

the DC-30W is forming nicely. I added larger electrolytics to my tube buffer for a big increase in in bass and presence even above what the Teradac is doing, or in addition I should say.

Then I just added a pulse transformer to the coax input. Now cymbols, when hit, float and trail above/over the rest of the music at it plays. The do not disappear into the background or get in your face but they are now more fully realized as trailing transients.

Taps on the rim, quick movements of strings ... the top of the sound of massed strings, when the bow dances, these are more preset or have stepped out into presence.

The idea is that these pulse transformers reduce jitter. I am going to add one to the coax output on the CDP and see if that does anything.

Things just keep getting better and by musical margins.

Mouser sells these things for about $5, I think. Damn.

edit: coax now beats Toslink in my system; Toslink now sounding a little dull in comparison.

 

[r8833]

Hi pat,

I think you may have incorrectly installed transformer. or I could be wrong

http://ww2.pulseeng.com/products/datasheets/T601.pdf

 

[zzodhi]

looks right to me. 1 & 3 are signal

 

[r8833]

you're right ..I did mine wrong

 

[rhodes54]

Quote:

Originally Posted by PatOMalley /img/forum/go_quote.gif the DC-30W is forming nicely. I added larger electrolytics to my tube buffer for a big increase in in bass and presence even above what the Teradac is doing, or in addition I should say. Then I just added a pulse transformer to the coax input. Now cymbols, when hit, float and trail above/over the rest of the music at it plays. The do not disappear into the background or get in your face but they are now more fully realized as trailing transients. Taps on the rim, quick movements of strings ... the top of the sound of massed strings, when the bow dances, these are more preset or have stepped out into presence. The idea is that these pulse transformers reduce jitter. I am going to add one to the coax output on the CDP and see if that does anything. Things just keep getting better and by musical margins. Mouser sells these things for about $5, I think. Damn. edit: coax now beats Toslink in my system; Toslink now sounding a little dull in comparison.

Hi Patt,

That looks great! I might try a Lundahl LL1572 soon. One thing came in mind: I guess there already is a 75R termination resistor on the PCB (it should be there) but I haven't checked that yet. If it isn't you should add a 75R resistor between pin 3 and 4 of the transformer.

Edit: The resistor is on board (near the two silver 0,01uF decoupling caps)

 

[PatOMalley]

rhodes54,

I was looking at that Lundahl transformer. Looks big so I went with this small job to see if it made any difference and for size. Let me know if that Lundahl works out ...

It's all about about galvanic isolation, as I heard someone say recently.