Peavey Classic 50 Unbearable Feedback:

[Mllerrin]

I've finally dialed in my Peavey Classic 50 (To the point where I don't need my dano eq except as a slight solo boost). But now at band practice when ever I'm not playing a note I get this annoying feedback, and not the controllable good feedback.

Here are my settings:

Pre: 10
Post: 3
Bass: 7
Mid: 10
Treble: 7
Volume: Max

I've tried boosting the post, and bringing the volume down but no matter what in order to get to even band practice volumes I'm feedbacking like crazy, and as you can imagine it gets even worse when I kick in my Blues Driver.

Am I just simply using too much gain for the amp? I am definately not using a ridiculous amount of gain, It's pretty much a classic rock gain, then it gets into slight metal territory when I kick in my blues driver.

It's not my guitar either as it does the same thing with my other guitarists les paul. We even tried a noise gate but the only way to get rid of the feedback was to have it set so high that my tone was pretty much gone.

Anyone have any idea? Could it possibly be a tube? Or is it new amp time?

 

[Buckeyedog]

Re: Peavey Classic 50 Unbearable Feedback:

What kind and how long have the tubes been in there?? I'd start with that first. You can tap on them gently with a pencil (eraser end) with it on to see if you can hear some microphonic noises coming through. Also, if they are run hard, the power tubes can go in less than a year.

Also running max volume with mids on 10 and treble on 7 may be a culprit as well.......!!!
Maybe try bringing back the EQ knobs a bit and see if that has any impact.

 

[Mllerrin]

Re: Peavey Classic 50 Unbearable Feedback:

So maybe bringing all the EQ knobs back by the same increment (I.E bringing them all down by 3, which should in essence give me the same eq curve, just less).

The tubes are El84's which I've heard definately go out faster than most tubes. I hate to spend more money on an amp that already has bad resale value but I guess that's my best option.

 

[Imp]

Re: Peavey Classic 50 Unbearable Feedback:

try a different lead!

 

[Gearjoneser]

Re: Peavey Classic 50 Unbearable Feedback:

First, switch out all the preamp tubes. Borrow them from your other guitarist's amp, if you don't have any lying around. If that doesn't solve it, swap out the power tubes.

I had a Classic 50 several years ago, and it sort of did the same thing when turned up really loud. I started wondering if something in the circuit was causing it to oscillate, or if vibration from the 4 speakers that close to the EL-84's was causing it.

You said the feedback only happens when you're not playing, and often that's pickups that need potting....but you said it happens on other guitars too?

 

[Mllerrin]

Re: Peavey Classic 50 Unbearable Feedback:

Yes I tried it with my other guitarists epiphone les paul custom which are notorious for being if anything, overly potted.

 

[arbiter]

Re: Peavey Classic 50 Unbearable Feedback:

have you tried using different cables? i have a dramatical increase in feedback when using a certain type of 'high quality' guitar cable.

 

[Kosh Naranek]

Re: Peavey Classic 50 Unbearable Feedback:

If it's high pitched, squealing feedback that happens when you'r enot playing, I'd suspect poor potting of the pickups. It's not totally out of the realm of possibility that both your guitar and the other guitarist's Epiphone have poorly potted pickups.

Sometimes one pickup on a guitar is potted better than the other. What about the other pickup(s) on your guitars? Do you get the same feedback when you switch to the neck pickup?

Plug in a guitar that you know has properly potted pickups and see what happens.

Otherwise, it could be a tube. You're playing with the gain on 10 and the volume maxed, so any part of the chain that is microphonic is going to cause feedback.

If you like the amp, I'd say it's not time to sell it yet. Squealing pickups and tubes can be replaced. Keeping fresh tubes in the amp is just a part of life if you play a tube amp. Buy a different amp and you'll run into the same thing.

 

[Imp]

Re: Peavey Classic 50 Unbearable Feedback:

with amps, always bear this in mind...

The simplest answer is usually the correct answer.

it's likely a very simple repair, especially if you still have signal coming through!

 

[J Moose]

Re: Peavey Classic 50 Unbearable Feedback:

If you roll down the guitar volume and the feedback goes away you have poorly potted, or non-potted pickups. The pitch & tone of the feedback will also change as you move around...

If it's really the amp, then it'll feedback on its own with little help from anything else. At least 80% of the time anyway... Preamp tubes are the most likely culprit, try swapping them.