A
ajr64
New member
Hi,
This is my first post but I've been lurking and learning from this forum for a while and this it is unfortunate that my first post is to describe issues with my new(ish) Einstein 50w combo. I bought the amp used and it is stock other than the channel 1 switching mod and some new tubes (described below).
When I received the amp things seemed fine. Then I noticed that the amp would make an odd reverberant rattling noise on all channels and modes whenever I played certain notes, specifically D and G. The noise is more pronounced when I pick harder and persists with all guitars I've tried. Also, the sound gets louder as I turn up the amp; at first I thought it was something loose rattling against the chassis but I have tightened everything I can find and can't isolate the cause. I even swapped out all the preamp tubes just to make sure it wasn't a tube problem but this didn't change anything.
Today the amp began making a loud whining noise on channel 2 and I began to hear an intermittent light scratchy distortion on all channels and modes (not a good sort of distortion, more of a static-like crackle). The pitch of the channel 2 noise is determined by the channel 2 gain knob and the channel 1 mode. I can still play the amp, but the sound quickly disintegrates back into the loud whining noise. The noise is only present when a cable is plugged into the input. Again, I tried swapping preamp tubes, particularly V2, but this had no effect. Tried swapping power tubes and again no change.
At this point I've removed all equipment but the amp and my guitar and these problems persist. The preamp tubes are all the original Ruby tubes except for a new EH 12AT7 in the reverb driver (the original tube was damaged in shipping). The power tubes are Wing C 6550 C's, biased at 95mA. I had to replace the original Ruby EL34s when one of the tubes suddenly stopped glowing and shortly thereafter blew the mains fuse (I replaced the fuse and the tubes; again, this was probably caused by one of the original EL34s being damaged in shipping and causing a short that blew the fuse as it failed). These tube issues have had no impact on the issues I described above and I've tried replacing all the tubes anyway, to no avail.
At this point I'm looking for any advice any one can give. I'm not shy about trying to fix this stuff myself but I'm out of ideas. If any additional information would be helpful just let me know. Thanks in advance.
This is my first post but I've been lurking and learning from this forum for a while and this it is unfortunate that my first post is to describe issues with my new(ish) Einstein 50w combo. I bought the amp used and it is stock other than the channel 1 switching mod and some new tubes (described below).
When I received the amp things seemed fine. Then I noticed that the amp would make an odd reverberant rattling noise on all channels and modes whenever I played certain notes, specifically D and G. The noise is more pronounced when I pick harder and persists with all guitars I've tried. Also, the sound gets louder as I turn up the amp; at first I thought it was something loose rattling against the chassis but I have tightened everything I can find and can't isolate the cause. I even swapped out all the preamp tubes just to make sure it wasn't a tube problem but this didn't change anything.
Today the amp began making a loud whining noise on channel 2 and I began to hear an intermittent light scratchy distortion on all channels and modes (not a good sort of distortion, more of a static-like crackle). The pitch of the channel 2 noise is determined by the channel 2 gain knob and the channel 1 mode. I can still play the amp, but the sound quickly disintegrates back into the loud whining noise. The noise is only present when a cable is plugged into the input. Again, I tried swapping preamp tubes, particularly V2, but this had no effect. Tried swapping power tubes and again no change.
At this point I've removed all equipment but the amp and my guitar and these problems persist. The preamp tubes are all the original Ruby tubes except for a new EH 12AT7 in the reverb driver (the original tube was damaged in shipping). The power tubes are Wing C 6550 C's, biased at 95mA. I had to replace the original Ruby EL34s when one of the tubes suddenly stopped glowing and shortly thereafter blew the mains fuse (I replaced the fuse and the tubes; again, this was probably caused by one of the original EL34s being damaged in shipping and causing a short that blew the fuse as it failed). These tube issues have had no impact on the issues I described above and I've tried replacing all the tubes anyway, to no avail.
At this point I'm looking for any advice any one can give. I'm not shy about trying to fix this stuff myself but I'm out of ideas. If any additional information would be helpful just let me know. Thanks in advance.
