Amp is a little over a year old was fine then past few weeks after warmup the volume would dump. All cables, inputs were checked and new JJ tubes put in which seemed like it fixed the issue However when I engaged the Tone Shift button the volume dumped again and when manipulating this button it caused the amp to crackle and seemed to be shorting out the power which intern was dumping the volume.. My tech replaced the Tone Shift curcuit but still when pushing the button in it causes the same issue, we are at a lost..and frustrated...Any Comments or Suggestions greatly appreciated
If the amplifier is still under warranty we would recommend that you take it back to the dealer it was purchased through so they can look at it for you
The only answer Marshall ever give is "bring it back to the dealer". You're just wasting your time if you expect anything else from them.