Just the other day one of my BHK 300 monoblocks makes a loud popping sound through the speaker whenever I mute my BHK preamp or shut off my BHK preamp.
This is new and consistent. I’ve reversed the cables at the preamp to determine if it’s the preamp or the monoblock. I was suprised that it is the monoblock.
Anyone experience this before?
I’m afraid I may damage the tweeter on my speaker.
The tubes are the issue. I shipped my amp back for this issue. I had swapped some spares I had on hand and they had the issue too. When the amp returned I called to ask what they did and was told they relpaced the tubes. The tubes that they replaced did not have many hours on them. My noise was not very loud but your speakers may be more efficient than mine.
Before you do anything unnecessary like packing up a 90lb amp and sending it to Boulder try taking the two tubes out of the offending amp and swap their positions and re-seat them. If that doesn’t work and you don’t already own two spare sets of tubes order them and try that as you need to have them on hand anyway. The popping noise on mute is unusual but if you turn the tube preamp off before the amp that can happen with any combination.
Just to add one more confirmation, agreed, most likely a tube issue. This is one reason I haven’t traded my beloved BHK250 for the 300s. Pulling the 250 off my rack once a year for tube replacement is about all the energy I can muster for component maintenance. As an aside, I think Viva Tubes is having a sale this month. Maybe you can find a deal on some 6922s.
Good News - I switched the tubes from the right amplifier to the left and vice versa. Same position within the amplifier (right to right, left to left) and was able to reproduce the popping sound to the other amplifier.
I read a lot about those that experiment with tube rolling vs the factory tubes. However, both my amplifiers have GENELEX 2007 Russian tubes in them.
Any thoughts on the sound of these particular tubes?
Hmmm, I get the same issue with my BHK300s. I usually turn on the BHK Pre, wait for it to finish the countdown then turn my BHK300s on. There’s no pop then, but it looks like I have to sort my valves too.
I’d like to take the time to thank Paul and his gang at PSAudio. Paul promptly responded to my problem, realizing that tubes are more hit and miss for reliability, and immediately sent me out a complimentary pair of tubes for my BHK 300.
Thank you Paul and PSAudio (I’m just glad I didn’t have to try to lift and package these amps).