So Now My Amp Doesn't Work....Help

[Jeff_H]

I swear I am stinkin' jinxed.

So I get everything set up. Unplug the speaker connection to the combo's speakers and plug just the cab into the combo. I plug into the 16ohm input and set the head to 16 ohm.

The clean channel comes on and sounds great. Click over to the gain channel....almost nothing. I check all the connections again, check the drive channel setting.....nothing. No distortion, no volume increase as normal. I had just been playing the combo on Tuesday. So I unhook the cab, plug the internal speaker connection back in and plug directly into the combo....same story. Clean channel works perfectly.....drive channel won't work. I've checked all the tubes, all are lit and glowing, and all are new. Like I said, the thing was working perfectly on Tuesday...driving my wife crazy.

Am I missing something? Any ideas, thoughts, suggestions? This is simple stuff, but apparently not for me.

 

[flank]

Re: So Now My Amp Doesn't Work....Help

well, it would seem to me that something inside must of come loose or something.... putting in a new cab would not do anything, so it doesnt have to do with speakers. The clean channel is fine, so it doesnt have to do with the output section or at least you know the whole amp is not dead.....it must be that the drive channel connection to the output stage is loose or something, since the tubes all appear to be fine as well...maybe take the preamp tubes out and put them back in?

sorry i can't help you with any technical stuff, just trying to solidify the facts at hand

 

[bryvincent]

Re: So Now My Amp Doesn't Work....Help

was your amp on when you unplugged the speaker?

 

[Jeff_H]

Re: So Now My Amp Doesn't Work....Help

was your amp on when you unplugged the speaker?

Never. I'm a freak about that. I even turn it all the way off before I'll unplug the cable....I'm paranoid about blowing an output tranny.

So I went back up and started with the pre-amp tube in V1, which was a brand new GT12AX7-C. Replaced that with annother new "C", and it started working again, albiet very noisy. So I started swapping each pre-amp tube out one by one with annother new tube until I had checked them all. I ended up replacing V1 and the PI slot. It workes now, but the hum that I just had fixed and the radio interference is all back again....except the hum is now only on the drive channel, not the clean channel. Before it was on both.

I'm really confused, so I'm going back to work on it. Any suggestions are greatly appreciated.

 

[Jeff_H]

Re: So Now My Amp Doesn't Work....Help

OK...so now it's working fine. I messed with the tubes some more, but it really didn't help the noise so I said....F-it, I'll just hook my rig up like normal and deal with it. Pluged in my wireless first in my chain, into my GE-7, SD-1, then into my Boss GT-6 which I use for a tuner and a few effects....then out of that into the amp. THE NOISE WENT ALMOST COMPLETELY AWAY. The clean channel is now dead quiet, and the drive channel only has the slightest his....which is how it was originally when I got it from Jeff Seal originally.

I'm using monster cables for the entire chain. The only thing I can figure is that the wireless unit is somehow filtering out the hiss....although that doesn't make much sense. Direct with the cable is noisy, but quiet with the wireless. Go figure. I still think I have a few gremlins to figure out with this amp, but for now it works and sounds fantastic. I d!cked around with the tubes, and need to do some more switching to get the sound back just how I want it....I have a hodge podge of tubes in different places, and no longer have a balanced triod in my PI slot...I'll have to order another one.

Wierd stuff.

 

[Jeff Seal]

Re: So Now My Amp Doesn't Work....Help



Js

 

[Gearjoneser]

Re: So Now My Amp Doesn't Work....Help

Take the footswitch cord and FX loop cords and jam them in and out of the jacks a few times. Sometimes static or oxidation gets in those jacks and causes wierd gremlins.
Switch between the clean and OD channels rapidly. It's possible that the channel switching relay or whatever needs to flex it's muscle a few times! LOL I know, amps are strange, but sometimes hard useage keeps'em running better than sitting idle for too long.