I remember Davy O’Brian telling me that at McIntosh they cleaned contacts until they got tired of cleaning them. Then they used sealed rotary switches. Then then had to drill holes in sealed rotary switches to clean the contacts. I have a similar problem on my c28 preamp. I turn the rotary switches all the way in one direction and then all the way in the other 4-5 times. My problem may not be your problem but it is cheap and easy. 🙄🖖
Weird crackling from speakers when preamp connected
I've got an MC275 hooked up to a VTL 2.5 preamp, when I reconnected it after some maintenance, whenever I turn the preamp on then the amp, once they both warm up, the crackling starts.
I hooked up the amp to my DAC and had no issues with crackling, swapped tubes, interconnects and power cord, different inputs/outputs, same crackling issue when using preamp but no issue when connected to the DAC as a preamp.
Sonus Faber Olymica !, MC275 Amp, VTL 2.5 preamp, Auralic Vega DAC, nordost interconnects/speaker cables, panamax power conditioner.
My last step is to see if I can either borrow a tube preamp or buy a cheap one to test it.
Any suggestions are welcome as I'm running out of ideas.