marshall_avt50_service_manual.pdfClick image for larger version. 

Name:	Marshall avt50_60_02[1].pdf 
Views:	58 
Size:	233.2 KB 
ID:	40333Click image for larger version. 

Name:	Marshall avt50_61_02[1] loop jacks.pdf 
Views:	42 
Size:	45.9 KB 
ID:	40334Click image for larger version. 

Name:	Marshall avt50_62_02[1] power module.pdf 
Views:	44 
Size:	30.1 KB 
ID:	40332

I have a Marshall AVT50x I acquired on a trade. The original problem was you could hear the distortion channel 2 low and barely hear the clean channel 1. Also it seams like it takes a long time to even hear that.

I replaced the Tube (Valve) I have a few of these tubes around for other amps. I then went over some solder joint with the iron. The results now are it takes over a full minute maybe closer to two to "warm up" just like before. The OD channel 2 seams fine now. Seams really loud and OK for a 50 watt amp. the clean channel seams like about a 10 watt amp all the way up. also if you turn down the bass and treble on the clean channel you get no sound. On the clean channel you can get no distortion at all even with everything maxed. Both pots gain and volume on channel 1 have an even taper and do not make scratching sound. nothing looks burnt this is a very clean amp.

All jacks are clean and functioning correctly. input jack is clean and re soldered.

I have schematics for a second revision of this amp. any ideas? I have a DVOM and a Logic probe.
Thanks for any help.