A NOS 192/24 DAC with the PCM1794 (and WaveIO USB input)

Hi Howard,

I have three resistor types that have sticked to my (tube) designs since the last 20 years. After dropping metal film (all types), holco, caddock, mills and such.

The ones that sticked and can be used for the dac are:
-allen bradley and even better; riken carbon
-tantalum, shinkoh or audio note ( second choice).

Third type is a wirewound power resistor not suited for the dac.

The carbon is best in series with signal; grid stopper and attenuator.
The tantalum is best connected to ground; grid leakage, attenuator to ground.

All resistors have their strengths and must be used in the right position.
Also each type has it's own sound, so the sound balance will change for better or worse and that has nothing to do with price or quality of the resistors.
Higher wattage is usually better because it is more temperature stable and has less resonance due to the size.

For this application I would use the tantalum. I will try this in the future.

Please keep us posted on your findings.

Regards,
 
Hi Howard,

I have three resistor types that have sticked to my (tube) designs since the last 20 years. After dropping metal film (all types), holco, caddock, mills and such.

The ones that sticked and can be used for the dac are:
-allen bradley and even better; riken carbon
-tantalum, shinkoh or audio note ( second choice).

Third type is a wirewound power resistor not suited for the dac.

The carbon is best in series with signal; grid stopper and attenuator.
The tantalum is best connected to ground; grid leakage, attenuator to ground.

All resistors have their strengths and must be used in the right position.
Also each type has it's own sound, so the sound balance will change for better or worse and that has nothing to do with price or quality of the resistors.
Higher wattage is usually better because it is more temperature stable and has less resonance due to the size.

For this application I would use the tantalum. I will try this in the future.

Please keep us posted on your findings.

Regards,

Hi Supersurfer
Will buy some of the above recommendations and give them a try
Regards
 
Member
Joined 2008
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Looking forward to reading about the comparos IanS1.

As currently just running a single board and with funds for hifi being quite limited for the foreseeable future, bit undecided of which direction to go to maximize the performance of the kit.

Cheers!
 
Secondly, I finally got around to fitting XLR connectors to my DDDAC. The purpose being that all reviews point towards my preamp performing much better in all balanced mode.I left the RCA outputs in place and wired in the XLR chassis by jumping from the RCA with a new wire neg to neg from the board.
Hello, sorry to quote an old post, and sorry if the answer is already somewhere else in the thread.

Using XLR output, I would have put a capacitor on Pos output and another one on Neg output.
Is it not needed? Only one capacitor on Pos output is enough?

Thanks!
 
Hi Grael,

When you use matched IV resistors you will probably have no DC on the output of the dac. In that case it is best not to use a capacitor at all, sounds MUCH better.

When you have DC than there are two ways; use two capacitors on each output (expensive and not optimal sound) or balance the IV resistors ;)

Regards,
 
i/v resistor

traditionally i am a big friend of the rhopoint wire-wound resistors but the vishay-dale cmf series that comes with the dddac kit is actually a very good resistor for audio application and i am very happy with them in my dac. however, last week i had the chance to test the vishay z foil / bulk metal resistors (vta-54zt and var-t series) and i have to say that they do an excellent job in this application, especially, the "var" type.
the var type is more expensive than the rhopoint but it is definitely worth a try; very detailed and very natural !
anyone else who tried them?
 

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Joined 2003
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Thanks to all for keeping on with experiments !!

Indeed, I am a lot away for business these days. Now I am home for a few days and will give first priority to sending kits. 99% sure, all open orders (without USB Board) will be shipped tomorrow morning!. Every one gets an individual mail of course.

Orders including the USB Board will be shipped end of this week (big batch on its way to me (Thanks Lucian, for hard work!)

I have like 200 open emails in the audio box, so will answer these as I have time (today tomorrow etc)

Things will be better starting mid July ;)