VH100R drive problem

[Dynomiteguy]

On the clean channel of the VH100R when I turn the switch for the drive on, sometimes the green lamp above it doesn't light up at all (sound stays in clean channel) or sometimes it goes into drive sound (with the green lamp lit up) but after a few minutes of playing the lamp goes off and the sound becomes clean again. Any idea as to what this might be? Thanks in advance.

[Cradlefish]

I had a similar problem with that in the past and I think it will happen to many VH100R's. I initially thought it may be the footswitch, but after some experimentation what I did was replaced V2 for the drive clean and V3 for the dirty. If your sound is lacking or it's not in optimum performance? I would put a fresh set of preamp tubes and possibly power section as well. But for the channel switching issues it's the preamp tubes. After swapped mine, I haven't had problem with it for 3 years now.

[scottWTBR]

dude it might just be a dodgy switch

[mrr3000gt]

Could be a bad relay. There is a relay switch powered with 15 volts of very filtered DC for the channel switch relay. If this fails or plays games with you could cause some rather strange channel switching behavior. Could be the power source for the relay. Some Einstein that owned my VH100 years ago obviously did something to cause both power sections to go bad and need to be replaced (channel switching power supply and amp power supply).