yorkville ygm-1 guitarmate problem

[stuntdrummer]

Hey all! First post here,hope you can help me out here. I have a yorkville ygm-1 guitar mate reverb, everything works on it but the main tubes(el84) brighten quite a bit when you strum the guitar and dim to normal when you stop,and sometimes the volume will slowly decrease. Could the output trans former be to blame? I replaced the tubes and the caps have been replaced recently. I'm a novice at this so any help would be greatly appreciated.

thanks, Rob

[Mr. Droopy-Drawers]

Get the amplifier to a good tech and have it biased properly. The Guitar Mate (YGM3) was know to do this. Traynor ran the tubes hot, and not many 6BQ5's can handle the heat.

[stuntdrummer]

Thanks for the info,we're gonna take it to a local tech,I don't have the ability to check the bias,some things are better left to the pros.