Occasional loud popping from spkrs (tube output stage on DAC)

[HeadSh0T]

Hi all...

I just finished building a CS8414/TDA1543 DAC with a tube output stage using ECC99.

I'm getting an occasional loud pop from one of my speakers.

The DAC is based on the Nonoz II design except it uses TL431 regulation for the DIR and DAC ICs..

I used the tube output stage on Thorsten's adagio schematic.

The tube stage is AC heated, and running at 130VDC..


Any ideas?? The speakers also pop when I touch the metal chassis... but they pop even when I don't...

Weird...

 

[JOE DIRT®]

It almost sounds to me like you have a cold solder Joint somewhere???????

 

[HeadSh0T]

thanks...

you were right.. there were actually 2 (!!) cold solder joints.. but after I fixed that, everything was just fine!

 

[PTSOUNDLAB]

Interested by your schematic

Hello HeadShot,

I'm interested by your DAC. Have you a schematic of output stage and how it is connected to the DAC ? (I have nonoz II Dac schematic and I would like to build one but like you with a tube output stage).
Your output stage with ecc99 seems to be more easy to use than adagio E182cc, and ecc99 are more easy to find in France than E182cc.

You can mail me if you want ptsoundlab@aol.com

Thank you very much

"Cordialement".

Pascal.

 

[HeadSh0T]

Hi pascal

I'm using the nonoz II dac schematic.

The tube output stage is from Thorsten Loesch's Adagio DAC. I just followed
the schematic exactly. He uses E182CC but I just did the same thing except
I wired it for an ECC99. You can find how to wire these tubes using the
datasheet.

I also used the power supply from Thorsten's DAC except I did not use the
solid state rectification. The power supply is using a 6X4 tube rectifier
only.

The URL for the Adagio DAC is:

http://www.ndh.net/home/kboehm/T-DAC-P1.htm

Regards...