Peavey ValveKing 100w head/ lead ch low volume

[doctorfate]

Ok while I'm at it I'm working on a Peavey valve king 100w head with only a very small amount of volume when switched to the lead channel. The clean ch seems fine/loud so my first inclination was it may be a relay sticking but usually w/o testing them I can tap around on them and get to switch. The only problem I've found so far is in the heater/+14v rectifier section , I'm getting about 24v where there should be 14v. I can't seem to find anything wrong in this circuit yet though.
I'm hoping i'm looking too deep and hopefully this is a known problem with this amp to some of you veterans

[doctorfate]

bump bump... nudge nudge
giving this another try...btw I'm am about lost on this heater/14v supply. I can't see what's causing this problem. I am getting 40v after the rectifier and R213(seems a good bit too high) and then still have a high vltg of 28.5v across R212, which should be +14v. I am thinking maybe one of the caps across the rectifier out (C210,212,213) may shorted or something. I get a low resistance reading across these , not a short but like 8ohms I think. Something has to be amiss here.
I have already replaced the diodes with some 1n4007's just to rule them out , now I will pull those caps and check them I guess. Any ideas what's causing this would be great.
thanks

[Enzo]

Do all the tubes light up? They better, since they are in series. Are any of them SCREAMINGLY bright? No? Then forget the heaters. Having heater voltage off a little won;t make one channel disappear.

But about the heaters: are you taking these readings with the tube in the amp or removed. Readings with tubes removed are pretty worthless. Think about it, how could a shorted filter cap make the voltage HIGHER than it should be? No shorted caps. If you have 40v at the rectifier - across C210 - and 28.5v across R212, then that leaves only 11.5v to be across C216 instead of the 14v you want.

[doctorfate]

well maybe I jinxed myself but somehow now I have no heaters going , none of the tubes are even lighting up and the only change I made was to replace the diodes with new 1n4007's. I see nothing amiss, obviously ignoring something simple. I thought maybe a trace burnt up between the tubes heaters in series but all looks good. ???

[Enzo]

OK, they are in series. They don't light up. There must be an open in the series. They run off the 32v, which comes from that 40 you found. Ground your meter, start at the + end of the diode bridge, now move to the 1 ohm resistor, each end, then to the first tube, then the other end of the first tube, then on to the second tube, etc. SInce no current is flowing, you probably won;t see any voltage drop, so that 30-40 volts will show up until the circuit interruption point. When you cross that gap, all of a sudden there will be no volts. It could be an open tube, a cracked solder joint, an open or unsodered resistor, who knows.

[T9c]

Just an FYI for anyone searching this problem out in the threads. I fixed one today with this very problem, ie. no/low volume on high gain channel only. Turned out it was an open 100k resistor (R102) on pin 6 (B++) of V2. Looked fine, not burnt in any way, but also no B+ on V2, pin 6. Replaced, and boom, works fine.

[Mattstvray]

Hi!! T9c, im having the dame problem whit valve king 50 watt 1x12 combo, the Clean channel works fine but the lead channel is very low almost nothing, i check the R102 and it,s open chance it and problem solved Thank,s a lot for the info my peavey sounds normal now!!!!!!!!

[Beebe999]

Just an FYI for anyone searching this problem out in the threads. I fixed one today with this very problem, ie. no/low volume on high gain channel only. Turned out it was an open 100k resistor (R102) on pin 6 (B++) of V2. Looked fine, not burnt in any way, but also no B+ on V2, pin 6. Replaced, and boom, works fine.

Hello T9c, I seem to be having the same problem as you're describing all of sudden with my peavey vk100 head. Was having some fuzz/humming a couple days prior only on the lead channel (both high and low gain) clean channel was fine, but was still able to continue jamming with my band. however when i stop playing with guitar volume on, obviously the hum was present (playing guitar drowned it out). Hum increased as volume increased. Then, yesterday i went to begin playing after letting her warm up and the low gain is horrible/low volume and the high gain is even lower volume/horrible. I am new to tube amps so i was looking for a little more clarification on the open (R102) resistor on pin 6 of V2 you were describing. Would that be on the preamp tube itself or where the preamp tube plugs into? Just trying to figure out what i need to replace so i can keep playing. Initially i thought it might be the v2 preamp tube itself that was going bad, but then was reading other forums where people had replaced it and had no progress. Any help would be awesome! Thanks a million.