Popping noise on BHK Preamp to/from HT Mode

My BHK preamp recently starting having a problem where whenever switching to and from an input set as home theater mode, I will get a loid popping noise out of the right speaker.

I’ve been able to determine that it’s definitely coming from the preamp and it’s only on inputs set up as home theater input. It doesn’t matter which input is set that way, it will cause the popping out of the right speaker whenever switching to and from that input.

Any help is appreciated. I’m also concerned for the speaker.

Have you been able to move the popping to the left speaker?


1 Like

Anytime I have experienced popping with my BHK pre, tubes were the culprit.

They have only 350 hours. Should I try to uninstall and reinstall? Or have you had to replace them when you got popping?

Try swapping the tube location and see if the popping shifts to the new channel. If so, you’ll know the issue is the tube. Yes, replacing the tubes is the route you’ll probably have to take. As an aside, Viva Tubes is having a sale this week.

Swapping the tubes did not move the popping. The popping remains on the right side. Looks like it might be a call to ps audio when they open next week. Unless anyone has another idea.

I have the same popping noise when switching between HT mode and other input. But in left channel. Always been there sine BHK was new.

Have you swapped the Pre output cables temporarily plugging in the right output cables in the left output and the left into the right?

Yes. I did that to determine the noise is being generated on the right output of the preamp.

1 Like

Do you get the popping when your HT source is either off or disconnected from the Pre?

Yes, the popping happens even if the HT source is off. Actually I found out it also happens when you turn the volume all the way down to zero (on any input).

I have run out of ideas. I think you are going to have to call PSA.

Have you tried reducing the fixed volume level for your HT input to see whether it changes the level of the pop? That would give an indication as to where in the preamp the issue is occurring. I would also check to see if it occurs over the headphones with no in/out cables connected at all.

I had already tried reducing the levels of the default HT volume, but that has no effect on the popping. However, good call on the headphones. There is no popping on the headphones. So it seems this is exclusive to the right XLR out. I have not tried to right RCA out.

I did find that sometimes there’s no popping at all. Yesterday was a good day. Today the popping is back.

Looks like you are making progress. I have run into an issue on the SGCD with the balanced outputs feeding back on a long run due to interference that I would have expected to be canceled via CMRR but wasn’t. I would try the RCA outputs as that eliminated it for me. This may still be environmental and it’s a pain to send it back only for them to not to reproduce it.

1 Like

For the record, I finally solved this. It was a bad tube in the amp.


So the problem was not in the BHK Pre but caused by a tube in the power amp?

1 Like

I have seen this before.

I have the BHK300 mono’s, so will try to switch the amps and see if the popping noise moves from left to right speaker.