2. amps-preamps
  3. 192478-110266

Preamp issue

I am having a problem with my preamp would like some feedback/guidance from the members of this forum.

For the past two years my system has been a WIIM Pro to PSAudio Stellar Gain DAC to Backert Labs Rhumba 1.0. preamp to Classe CT2300 amp to Harbeth SHL5 speakers, 

System worked fine and I liked the sound. But, then you get the itch. . .

I was interested in trying to an r2r DAC so I purchased a used (one year old) Denafrips Pontius II 12th DAC. Today I swapped out the PSAudio DAC, fired up the system and listened for about 5-10 minutes, then there was a POP in the speakers and the Rhumba preamp went into its mute mode. I shut everything off and restarted the components now have low frequency(100Hz?), low volume, vibrating sound coming out of both speakers. I have swapped out pieces from a second system an definitely isolated the problem to the Rhumba preamp. 

I am going to have the pream repaired. But since the Rhumba preamp failed shortly after swapping in the Denafrips DAC-

Could the Denafrips DAC have caused the preamp to fail? How? Was it just coincidence? Should I have the Denafrips tested as well or just return it and find a different r2r unit? Your input will be appreciated. Thank you in advance.

Happy Holidays

128x1282tuby

Showing 2 responses by paulcreed

paulcreed
566 posts
 

Hi, did you touch the Pontus when the pop happened, I think there is something in the way the Pontus is wired that static hits it, mostly in the winter time. I had the same problem, there was a definite pop and it originated from the Pontus.

 

I read others have experienced this also. I jumped up and shut down the amp and some of the system shut down on its own. I’ve never seen anything like this before.

 

I ended up running a ground to touch if I was going to touch the Pontus.I don’t use the ground in warmer weather, sounds crazy but that’s what I did. The Pontus is gone now but a nice dac for the money.

 

I also posted on Audiogon what the hell that pop was, good luck with your search. I would contact Denafrips and ask about static and the ground. 

paulcreed
566 posts
 

I was advised by Denafrips to touch the dac chassis with one hand before touching the buttons with the other hand. I’m guessing to ground the dac. I found that odd.  I don’t know if the static charge can damage a preamp but they are connected with interconnects. It could be possible if the charge is looking for a grounding point. 

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