Low level buzzing from BHK Pre Amp

Hey guys, I’m having another problem that I think is emanating from my new BHK Preamp that is a few months old. I have noticed a low level staticky buzz coming from both speakers. Been trying to figure it out and here is what I know:

  • the buzz is ever present and does not come and go.

  • the buzz is audible no matter which of the five inputs I am using on the BHK

  • If the volume is set at zero the buzz is not audible

  • If the volume is one or higher the buzz is present although it does not get louder the higher the volume goes

  • only noticed buzz recently and I’m sure it was not present when I set up the new BHK Pre.

I have made sure all my connections are tight but now I don’t know what to do. Hope the “clues” listed lead to some advice.

Here is my system:

PS Power Plant 15
BHK Signature Pre Amp
Rotel RMB 1075 Amp
RCA interconnects
Bluesound NODE 2i
B&W 703 Speakers

Thanks, Mike

Two likely options are you’ve got a pair of IC’s either touching or to close to the Power Plant or another power source or try lifting the ground on the BHK as it’s fully balanced and the Rotel is SE. Could be either or both and since the BHK is plugged into the PP lifting the ground with a cheater plug won’t cause any issues.

Both tubes could be noisy although unlikely it should be on the list of things to try.

Is it a buzz or more like 60/120 Hz hum? This could help determine if it’s a grounding or shielding issue.

Best of luck.

Thanks for your response dawkinsj. Not sure what lifting the ground means? PP is in a separate rack from the BHK.

Thank you for response kclevland. The sound is like a static hum but more on the high end. What should I do to check the tubes, replace? Mike

You could try replacing the tubes with known good ones. It’s strange that the buzzing doesn’t change level with volume though.

Have you tried unplugging all of your source cables to the pre and putting them back one at a time?

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Lifting the ground means trying a cheater plug on the PC for the BHK where it plugs into the PP. If your sure you don’t have a SE interconnect crossing too close to a power cord then it is the most likely solution. It’s is always possible when a SE and Balanced component are connected but doesn’t always happen.

And, have you tried plugging your BHK pre directly into the wall socket or another socket on your regenerator? Could be some weird interaction between the regen and pre?

I experience a staticky clicking sound when my Ethernet over Power receiving unit is plugged into the same wall duplex outlet. It happens when the using the following:

TT with MC cart .28 mv
Stellar phono pre any gain

Noticeable when no music is playing.

Do you have EOP in use?

Removing or moving the unit removes the noise. Do you have Ethernet cable involved?

Thanks gthiel, No there is not an ethernet cable involved.

I had a similar problem, especially annoying with headphones but also present with the amp/speaker connection. It mostly vanished by totally dimming the preamp display. I also found, weirdly enough, that the problem was worse on odd-numbered volume settings.

Thanks vkennedy61, Yes I tried this and no change. M

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I appreciate all the responses. Here is an update on what I have tried to fix the buzzing.

  • Disconnected all source cables and put back one at a time (right now only source plugged in is streamer). No change.

  • I separated all power cords from each other as best I could and put the BHK PRE and Rotel Amp in separate cable sleeves on their own with no other cables. No change.

  • I used a cheater plug for the BHK in the PP. No change.

  • I plugged the Rotel directly into a wall socket. No change.

The buzz might have diminished slightly with the rerouting of the power cables. Hard to tell really but its still there.

Any suggestions of what to do next? M

Another update. I have been systematically connecting and reconnecting different cable to try to track buzzing. When I pulled the SE interconnects between BHK Pre and Rotel amp the buzz stopped. New at this so can someone please tell me what I just learned. :wink: I tried replacing SE interconnects but buss still present.
Is maybe the problem a SE (Rotel) and balanced (BHK) components connected like dawkins mentioned?

That is it but if the cheater didn’t work on the BHK try it on the Rotel just for fun. I own a SE amp in one of my systems and for reasons unknown to me or the amp maker had to try multiple brands of cables to get that low level buzz to stop. In my case only Wireworld worked with this amp. Any other amp I substituted didn’t care which brand I used. Luckily I had two pairs of Wireworld OCC cables to make the connections between the DAC to Preamp to Amp already on hand. So just switched out the analog IC’s and left the digital cables as they were.

So I had the same problem. In my setup I used another pre amp for theater that used RCA interconnects. The sound only occurred while watching movies, not while listening to music. The solution was to use the RDL AV-HK1 “HUM KILLER” Stereo Audio Isolation Module between my BHK pre and my amp. There are other brands, this was just the one i chose. I included the link below. It was a suggestion by one of the tech guys at PSA. It removed all noise and didn’t effect sound quality.

Thanks Jakes, Might have to give this a try.

Thanks, cheater did not work on the Rotel.

Worth a try anyway. What SE interconnects are you using and how close do you have to get to the speakers to hear the noise?