[Lindsay]

Thanks to all who have had input on moding this dac, it's really helped me start to get a handle on electronics.
So far I've done the DIR mod, patience, steady hand and good eyes reqd.

I have a question about swapping out the transformer.
What effect does the output amperage have on the circuit?
I'm able to source a toroid locally 230v, 30VA, 2x9v, 1.67A.
The output on the stock tansformer in mine is 2x9v, 0.5A

Thanks in advance to anyone who takes the time to reply.

Lindsay.

 

[awkwardbydesign]

Is the Blackgates' long burn-in time noticeable when only the 220uF PSU cap is added. Or am I getting really anal?

 

[mrdon]

Quote:

Originally Posted by awkwardbydesign /img/forum/go_quote.gif Is the Blackgates' long burn-in time noticeable when only the 220uF PSU cap is added. Or am I getting really anal?

I did notice that the bass did tighten up after some burn-in, so be patient my young padawan.

My fully modded VALAB with the silver hook-up output wire is burning in quite nicely. For those who want to make the investment, the silver is a nice added touch and removes another small layer of sonic crud.

 

[PatOMalley]

mrdon,

just came across some soft annealed silver/teflon which i earlier misplaced.
since i was going to go back in to set left and right correctly I might as well swap wire.

 

[awkwardbydesign]

Lindsay,
Over-rating current is no problem, over-voltage could be. However, in this set-up, your toroid should be OK, the original tranny is rated 2x9 @240v, the toroid 2x9 @230, =2x9.4 @240.
There are questions about toroid sound quality, though.

 

[krisno]

I have a question. I can buy 2x Audio Note 330R Tantalum resistors...

would these be a good choice for swapping out the I/V resistors?? They are OK priced.

Will 330R remove the distortion but make everything else sound just as before???

I really need answer on this.!

Kris

 

[PatOMalley]

the audionotes are magnetic.
best to use Shinkoh.

 

[krisno]

Is R330 what you are using? ... would 360R be better ?? I have these two choices

Shinkoh 0.5W 330R .... or 360R ...

but it does not change the sound in any way and fixes distortion?

 

[r8833]

Hi Guys,


would this mod work with our valab Dac ..read post 5-8

diyAudio Forums - Diy-dac 1543 - Page 1


Rich

 

[Lindsay]

Thanks awkwardbydesign,

I'd rather go with an R-type, hard to find anything locally though.
I really just don't like the tranny on the board as opposed to the sound quality,
things seem a little too conjested, so I want to make a bigger enclosure and thought I might aswell do something with the power supply.

I'm open to suggestions on improving the power supply (can of worms I guess).

Lindsay.

 

[Pars]

Quote:

Originally Posted by r8833 /img/forum/go_quote.gif Hi Guys, would this mod work with our valab Dac ..read post 5-8 diyAudio Forums - Diy-dac 1543 - Page 1 Rich

Ooops, looking at post 4. sorry.

 

[Bill Allen]

Hello all,

I am back and refreshed from my very first 30 day vacation of my life. While this is common in Europe it is a real luxury to pull off here in the U.S. Ironically this is also my first vacation where I never left home, well except for my frequent trips to Home Depot and down to the 4 Peaks Brewery in Tempe AZ. Ahhh, Good Beer, Good Tunes, Good Times!

So you think I spent my time perfecting a transformer output and battery power supply for the Valab Dac. Think again. I spent my time building a "Man Cave" in my 3 car garage.

Attachment 16717

Yes a audiophile's dream room, 20ft wide by 30ft long with a vaulted ceiling. It was a lot of work but turned out even better than I imagined. In the background you can see that my wife was also able to reclaim her front living room. A win win senario.

Attachment 16716

This is a back shot into the room. Cabinets, Solder Bench, Work Bench and a Tiled area for the messy work. A R12 insulated Wayne Dalton garage door to bring in the Locomotive Battery's to run the entire system someday.

Yes ... my very own Man Cave!

May we all live to own one, set your goals gentlemen!

 

[Bill Allen]

My friend Tony from New Mexico stopped by with his perfected 26 Tube Preamp. It was based on a design from Gary Pimm. Welcome to Gary Pimm

Tony spent the better part of a year perfecting this line stage but man did he ever nail it. Hooked up to my Pace Car, Valab Dac, Ongaku and Bastanis Apollo's it presented the most natural "real" sound to date in my system. Well done Tony. (PM me for details)

Tony also brought along his Valab Dac with the full Blackgate Power Supply/FS/ Caddock Resistor Mods. The only thing different from my modded Valab Dac was he used Blackgate N's for output caps.

Well ... here's the bad news.

It just didn't compare to my modded Valab. Right away Tony looked at me and said "sounds like electrolitic's coupling caps". Yep, that's what it sounded like to me too!
(Tony will be moving on to Mundorf Silver/Gold's which he uses in this 26 Preamp. Good Choice)!

Tony started with "N's" and then upgraded to the "NX Hi Q's". In light of this comparison i would not waste my time using Blackgate as coupling caps in the Valab Dac. If you are looking to save money and also fit film caps inside the Dac, I'm with Pat, simply bypass the stock coupling caps. My suggestion is buying the best .22uf bypass film caps you can afford, with Jupiter's or Mundorf Silver/Gold's being "my" top choice's.

By the way Parts Connection has some of the older Jupiter caps in there Bargain Basement right now, 50% off.

Finally when you get your Dac sounding just the way you want. Then by all means get thy modded Valab Dac to the Cryo Lab.

 

[PatOMalley]

Hey gents,

I went back in to fix my reversed right/left which I did when swapping in Teflon coated 6n solid core copper. I did a back and forth on a few pictures in this thread and I do now know that THIS is the spot to connect the output wire to run to output:

The thing is that with the wire in the wrong spot where I had it previous I was getting a snap when switching source and chaing volume which must mean I was tacking down pre capactier and letting DC out. Luckily I have caps on the input on my linestage. But know with the wire in the right spot it is dead silet and way better. It is crazy how thisthing responds to mods. As Bill points out it so simple and spare at output that the smallest thing can effect for good or bad.

I also added some EMI paper on top of the tranny and replaced blu tac on the DIR9001.

I know that output wire has made the greatest impact but that other stuff must contribute as well. Best yet so far.

More to come? Why not?

 

[mrdon]

This morning I swapped out the 220uf BG FK with the Cerafine of same value. I originally used the Cerafine in my first attempt at modding this DAC and to my ears, it presented a tighter, "faster" Bass response in my system. Will report back after a listen some time today.

BTW, what is the suggested output voltage at pins 6 and 8 as this can be adjusted? Doede Douma suggests b/t 3.8 VDC & 3.9 VDC for his version of the TDA1543 Dac:
Quote:

4. Bias Voltage tweaking.... I had several positive feedback (including my self) that when the Bias voltage (at pin 6 and 8) is between 3.8 and 3.9 results are optimal. It is not a BIG thing, but so easy to tweak...