Gain be gone...??

[BloodRose]

Ok, I have a PV Classic 30. Not a gain monster, but used to be able to get a nice classic breakup on the lead channel. Was retubed awhile back with some JJs and was even better. The other day, I was playing with some overdrive pedals, trying to see what worked best. Now the lead channel sounds the same as the clean.

So, Ive given it a few days, and played with just the amp. Wanting to make sure that I wasnt expecting the same level of gain without the pedal.. But, it seems that the gain from the amp is gone. Both channels work, but the lead channel, even with the gain maxed, doesnt sound much (if any) grittier than the clean channel.. Any ideas? bad pre amp tubes? As I said, both channels work, but its almost like the preamp knob doesnt..

Thanks!

 

[ehdwuld]

Re: Gain be gone...??

Da Toobs

Naw did your amp tech rebias after the tube change

May have biased it to cool

*(Sent from my durned phone!)*

 

[Darg1911]

Re: Gain be gone...??

Maybe the channel switching. Are you using the Footswitch or switch on control panel? Try both. Unplug footswitch when trying panel switch. Other than that, make sure valves are seated snug. Maybe worth a try to swap out V2 (I think) if you have a spare.

 

[DrNewcenstein]

Re: Gain be gone...??

Did you change your guitar's volume pot? Maybe Alpha to CTS or vice versa? Is your guitar volume knob turned down? I know, I know, Simple Simon Herpaderp, but you'd be surprised at the power of the brain fart.

Could also be that you've baked the amp's Input by slamming it too hard, particularly if it's an Instrument Level input stage receiving a Line Level signal? Then again, could be a cable problem, like a loose solder joint on the plug end from all the swapping back and forth, or the Input jack has a bad connection to whatever it's connected to (PCB, etc).

 

[chadd]

Re: Gain be gone...??

How long ago was "awhile back"? Once you check to make sure all of your tubes are seated and that your channel switching is working properly, I would be inclined to start swapping tubes.

 

[zzmoore]

Re: Gain be gone...??

Good suggestions above about making sure it switches channels at The Amp and with The FS.
V2 is dedicated to the dirty channel. If that is tired, or problematic, you will have said issues.....try a new tube in V2
Other than that, it could be all kinds of things, problems with relays, low voltage supply ,etc etc.
good luck

 

[AlexR]

Re: Gain be gone...??

I'd be guessing you haven't actually switched channels

 

[Nostalgic Distortion]

Re: Gain be gone...??

Yea, my guess is it's one of two things, either by using your O.D. pedals you blew a preamp tube, perhaps pushed it a little too hard or the amp isn't switching channels but I'm guessing the P.A. tubes are where the problem lies? If the channels are not switching from one to the other you would notice?

 

[DrNewcenstein]

Re: Gain be gone...??

I seem to recall some Peavey amps had a little button on the front that had to be engaged in order for the footswitch to work?

 

[zzmoore]

Re: Gain be gone...??

I seem to recall some Peavey amps had a little button on the front that had to be engaged in order for the footswitch to work?

I THINK the button was to manually operate the amp without the foot-switch..... but I could be wrong.
At any rate.....if you just push the Channel button, I think the light goes yellow, and it almost mutes the amp...pushing the More Drive (is that what it is called) kicks in more gain.
Either way, the Master and Drive knobs must be used for "channel two".
Anyway.....the OP said it use to work great, so HE knows how to operate it.
I am guessing he has either had a failure of V2...or that there is a problem in the Low VDC switching supply and/or relay circuit.
If a new tube in V2 does not do it, he will have to yank the chassis.......
good luck

 

[DrNewcenstein]

Re: Gain be gone...??

Well, I was thinking that maybe he fat-fingered the switch by accident while he was tweaking a nearby knob. I know the front-panel switch is for changing channels without the footswitch, but there was one where the switch on the amp had to be engaged in order for the footswitch to work. IIRC, my old TransTube Bandit was like that.

 

[ehdwuld]

Re: Gain be gone...??

my Carvin Belair and My Laney GC80A do that
the switch on Laney decides whether the footswitch changes the drive channel
or switches from the acoustic amp or electric amp

 

[BloodRose]

Re: Gain be gone...??

Thanks all! Maybe the tubes.. First, YES, I notice the diff tween the channels. Second, it's not the vol pot on the guitar. I have separate volumes for each pup and same result and even tried diff guitars. Third, yes the PV has a channel switch button on top that I usually always use instead of the foot switch. I tried changing with the foot switch too when this started happening to make sure I didnt bump something as I keep the switch in the back of the combo. Also, I checked and rechecked to see that the tubes were properly seated. they have retention clips, but the way they dangle out there, its very easy to bump them when putting the chord in the back of the amp or what have you. Ill order some new tubes. And awhile back was about 2 yrs ago, but it prob only has about 10-15 hrs on it with the new tubes.. I never had any problems just running the amp gain, but after a period of juicing it with pedals, they went flat.

 

[zzmoore]

Re: Gain be gone...??

Unfortunately.....the number of hours on a tube (15 vs. 3000) is almost meaningless. A tube can die at any time. Being one of the easiest things to change/check.......
good luck

 

[BloodRose]

Re: Gain be gone...??

Unfortunately.....the number of hours on a tube (15 vs. 3000) is almost meaningless. A tube can die at any time. Being one of the easiest things to change/check.......
good luck

yeah, I know.. I have just been pretty lucky and had good luck with tubes in the past... Im guessing thats what it is. just glad its still putting out sound..

 

[El Dunco]

Re: Gain be gone...??

I know BloodRose at least a little bit. He would have checked all the fundamental stuff by now. I have had a very similar problem once before with av Evil Twin Reverb and it turned out the amp was very picky about which preamp tube type belongs in each socket. Find out if there's some kind of layout for the preamp tubes (some sockets might prefer 12AUVs and so on, sometimes there is a map printed on the amp somewhere).

 

[BloodRose]

Re: Gain be gone...??

I know BloodRose at least a little bit. He would have checked all the fundamental stuff by now. I have had a very similar problem once before with av Evil Twin Reverb and it turned out the amp was very picky about which preamp tube type belongs in each socket. Find out if there's some kind of layout for the preamp tubes (some sockets might prefer 12AUVs and so on, sometimes there is a map printed on the amp somewhere).

Thanks for gettin my back bro! No, there is no special layout.. Just 3 12ax7s and then the el 84s. ( I mean, as far as needing a diff type of tube) It came with 12ax7s in all 3 spots. I swapped the tubes around and no change. gonna get some new ones. The odd thing is, whenever I had tubes fail before, Ive had noise, or no sound. It still sounds great clean. But it has to be the tubes. Matter of fact, it seems to be alittle warmer tonally on the clean channel and slightly more clean/sterile on the gain channel..

 

[El Dunco]

Re: Gain be gone...??

Thanks for gettin my back bro! No, there is no special layout.. Just 3 12ax7s and then the el 84s. ( I mean, as far as needing a diff type of tube) It came with 12ax7s in all 3 spots. I swapped the tubes around and no change. gonna get some new ones. The odd thing is, whenever I had tubes fail before, Ive had noise, or no sound. It still sounds great clean. But it has to be the tubes. Matter of fact, it seems to be alittle warmer tonally on the clean channel and slightly more clean/sterile on the gain channel..

Hopefully the new tubes fix the problem and it's not a smaller component blown out somewhere.