Buzzing after power cycle for BHK Signature Pre

Was just curious if anyone had any idea what might be causing it or if its normal.

Under any normal use I haven’t encountered this problem, but if I accidentally turn the preamp off and turn it right back on, there is a loud buzzing emitted from the pre itself (not speakers) from the moment it starts warmup, and then once its warmed up the sound with continue until I turn the pre off for a bit and power it back on. As long as I wait like 30-60 sec before I turn it on after powering it down its fine though. It also only seems to be from the right tube, but I could be wrong.

I mostly just wanna make sure it’s not gonna cause any sort of damage to the pre or tubes.

I have the same issue with mine.
The unit has to be off (power switch) for approx. 20 minutes for it not to buzz.
If I just turn the input stage off with the logo button or the “off” button on the remote, it never happens.

Quickly switching on again after switching off generally does harm to several parts of an amp, especially tubes…so I’d just avoid it generally.

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Well yeah, it wasn’t on purpose, I was setting up my harmony during one of the times I did it and the other I just derped and thought the big round button was on not off.

I just heard sudden buzz saw sound and wanted to make sure it wasn’t indicative of something wrong with my preamp being that it’s BRAND new. But I also know electronics just act stupid. I once had my tv go schitzo and it wouldn’t show anything but static no matter what I did until I actually unplugged it waited a bit and gave it juice again. Then it never happened again.


Quick on/off has nothing to do with mine. Mine will do it after 30 minutes off. It’s variable.

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Geez, I have the same problem as well. Ground loop was thrown out there, which I think is rediculous since I didn’t have this problem until recent repair, and especially now that it’s not just me

yup----after a repair trip to the mother ship.

That would definitely peev me off. I have a BHK Pre, what would cause that?

Just a guess, but I’m guessing it’s something related to my tubes. Like it’s just not seated well or something. I just haven’t felt like disconnecting everything and maneuvering it of my shelf. Eventually I’ll pull it out and clean all the pins and sockets and make sure it’s in there good. TBH, I plan to track down some good west german telefunken tubes to swap in eventually with matched triodes and whatnot.

I just don’t think anything else could buzz at the volume it does it. But I am not an electrical engineer /shrug

I changed my tubes. Still does it.

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Never encountered this buzzing problem with my BHK Signature Pre. Funny you should mention setting up your Harmony when your accidental on/off cycle happened. I use a Harmony for my TV, but use the PSA provided remote for my BHK. Turns out there must be one or more IR codes common to both my TV (a LG) and the BHK because I wind up unintentionally turning my BHK on/off when trying to control my TV. Frustrating, but hey not PSA’s fault there are a gazillion IR remote controlled A/V devices … can’t ever be guaranteed all those devices will have unique IR codes. Even more frustrating to know many surfaces not reflective in the visible are reflective in IR so pointing my Harmony at an opposite wall believe it or not will sometimes flip my BHK on or off.
All that said, if you accidentally either turn your BHK on or off refrain from fast cycling it. That’s hard on the components, especially the tubes.