I’d suggest hitting up PS Audio’s Support Desk in parallel with working with your local dealer. Provide as much detail as possible. Not owning PS Audio amplifiers I can’t offer any specific insight.
I’m in the UK: I had BHK250’s and BHK300’s and experienced the same issues as you. I changed the valves - it made no difference … The input boards were faulty. That’s the small board where the valves are located.
During and out of warranty. One board replaced by Kevin Akam.
I changed other faulty board(s) by myself.
I’ve had a search and I do have one new input board that’s never been used, but unfortunately it’s for a BHK 250. It’s a different type/configuration to a BHK 300. I would have gifted you the board
to help you out . What channel is noisy - left or right. ?
Not a problem… I just wanted to help you out if I could! The cost ? Not sure…! (£500 ? / £600 ?) pounds sterling per board: - 2019 the last time I fitted a new input board.
As stated previously. “I’ve had a search and I do have one new input board that’s never been used, but unfortunately it’s for a BHK 250 amplifier. It’s a different type/configuration to a BHK 300”.
Dan, you need an input board for BHK300. The two BHK300 input boards in the photo are faulty… I removed them and installed new replacements, both new input boards were sent to me from PS Audio.