Laney VC 50

[el_toppo]

Hi

Im totally new to this forum i found you guys while searching for info to fix my new amp and it seems like a cool place. I recently picked up a laney vc 50 very cheap with some repairs needed. Its a 2 channels amp with a crunch setting for the clean and a higher gain setting for the drive. The clean channel works but the drive channel is causing the problems, the volume is incredibly quiet and it cuts out with intermittent loud humming that comes and goes, staying on this channel for too long also caused the output fuse to blow.

Im hoping one of the valve are causing me problems, all of the filaments are lighting up so I'm going to pick up a new one on my next day off and systematically switch each one out with the new one to see if that helps (I'm guessing not worrying about the bias will be fine for a few minuets just to establish if its that particular tube causing the problem). Any help would be much appreciated i did do an a-level in electronics a few years ago but in honesty i have no idea how to go about testing this or really what I'm doing lol but any advice and or material to read would be awesome.

Cheers Alex

[The Dude]

This amp has two separate effects loops- one for the clean channel and one for the dirty channel. It's possible you have a bad switching jack on the dirty channel. Run a cable from the effects send to return on the dirty channel and see if your volume problem is fixed. However, that would not likely cause the problem of fuse blowing, but you might have 2 separate issues. Best bet without getting way into it would be a defective tube. You're on the right track with tube substitution. Come back if that doesn't work out for you.