Hi folks,
I purchased a Music Man 212-65 back in October 2018. The original owner said it's probably from about 1977 and it has the 12Ax7a phase inverter tube. I love this thing. That said, I've had a persistent issue that comes and goes. A "fizzy" or static-like sound that hangs out behind the notes/chords that I'm playing.
I replaced both the phase inverter 12Ax7 and the power amp tubes with JJ E34Ls. The problem persisted despite the new tubes.
I took the amp to have it looked at. The technician replaced a few of the pots and biased the tubes. That took care of an issue I was having with the volume dropping off. However, this issue with the fizz remains. Before I take it back to have it looked at, I thought I'd give this forum a try.
I am posting a couple of links to YouTube videos that I uploaded trying to give an idea what the sound is like. My apologies ahead of time for the horrible quality.
Clip: https://www.youtube.com/watch?v=C6lAPjfHiyA
Other Clip: https://youtu.be/svoD69qMurw
Searching this forum, I ran across some folks who described a similar problem. The replies talked about something called "crossover distortion." Might that be the case here?
Thank you for your help and input!
Update:
Update:
I brought the amp in to a technician. He replaced the tubes and re-biased them. I had put in a pair of Electro-Harmonix EL34s. He put in a new 12Ax7 phase inverter and a pair of Valve Art EL34s. Whatever he did took away the fizziness that was coming through.
The only issue I have noticed since is that the amp began to distort at low volume when I was playing through it on the low power setting. When I play with the power setting on high, I didn't notice it distorting as quickly.
Hope this can be of help to anyone else with a similar issue.