BHK Preamp: Volume-specific buzz between 40 and 56 on the volume control

Audio Components Amplifiers
1

My 5-yo BHK signature preamp has developed a low (but noticeable) buzz on the right channel only when the preamp’s volume is between 40 and 56. These nodes are also points where an internal relay clicks, I assume to activate/deactivate a specific part of the circuitry in this range of gain. Anyway, volume below 40 or above 56 are devoid of the right channel buzz. (FYI: I now routinely keep my preamp at 57 or higher and adjust volume via the gain control on my PS Audio DirectStream DAC.) I’ve contacted PS Audio support and they believe, as do I, that there is fault in the circuitry that requires their service. I’m currently working out the details for this.

I’m writing out of curiosity to ask if other BHK owners have experienced similar volume-range, channel-specific buzzing? There is no insinuation about PS Audio quality; I like their equipment and plan to continue to include their components in my audio system. As I said, this is simply provoked by curiosity if my situation is a one-off.

Best,

 Bob
2

I do not recall this coming up previously.

3

You might have already tried this, but switch the tubes left for right and see if the noise switches to the left channel.

4

Thanks for the suggestion, and have done the switch. I’ve also bought new tubes, disconnected all inputs, switched speakers around and just about everything else that could be done to dissect the problem. The give-away is that the buzz only occurs between a gain setting of 40 and 56 on the BHK preamp.

1 Like