Question about Amplifiers & Preamps

2 Answers

Peavey classic 50/50 keeps blowing fuses.

I put new gt el84 power tubes in my peavey classic 50/50. It ran fine for a couple days and then started blowing fuses. Now when I turn it on it hums very loud for a second or 2 then pops the fuse. Did I Blow the power OT by not rebiasing the amp. Any Info would be nice.


Posted by on

2 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer
Re: peavey classic 50/50 keeps blowing fuses.


I have a classic 50/50 as well and re-tubed it with JJ el84s, vintage teslas and mullard 12at7s. As long as you replaced it with EL84s, I can't imagine that the output would be increased enough to damage the OT. When I got my 6505 Combo, one of the 6L6s was bad, and it kept blowing fuses and howling like a banshee. I would think that an OT problem would result in a significant loss of output...or none at all. I've gotten DOA tubes from a few places. I would suggest swapping each tube out 1 by 1, until you find it...if that is indeed the problem...before you pay the cash to have it worked on.

Posted on Oct 29, 2007

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has answered 1,000 questions.

  • Master
  • 1,175 Answers
Re: peavey classic 50/50 keeps blowing fuses.

The BIAS circuit may have failed and is allowing the power tubes to max out over their spec?

Or you have a tube with an internal short that's killing the high voltage every time you power up.

I have yet to see an output transformer fail out of over 100 amps I've done

Posted on Dec 16, 2014

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

1 Answer

Amp blow fuses immediately when power is switched on

There could be so many things wrong with it, but personally I find the most likely problem is the power supply.

Mar 15, 2015 | Peavey TNT 115 1x15"" 600W Bass Combo...

2 Answers

Wy fuse keeps blowing

Fuses blown when an overload occurs. More often than not caused by a short circuited transistor in the main amp section. Possibly also on the power supply too.

May 22, 2014 | AMC Multimedia CVT-2030 2-Channel...

1 Answer

Peavey Ecort is working fine but has a loud buzzing that slowly gets

This is often caused by the failure of the large capacitor(s) in the power supply. The noise being the 50/60hz mains hum getting in. They will be the biggest Capacitors in the system with a value around 4700UF or greater, so you can't fail to see them.

Jun 14, 2013 | Peavey Amplifiers & Preamps

2 Answers

Peavey XRD 680 wont power up

Fuses blow because of an overload. Generally caused by a short circuit transistor(s) in the power amp section. Easy to spot with an ohm meter it will be like you have touched the test probes together!

Feb 24, 2013 | Peavey Amplifiers & Preamps

2 Answers

I have a peavey Renown 400 model 212 without speakers. What speakers should I install to replace the missing ones?

THe speakers should be a good quality and rated jointly at 1.5 times the power of the amp.

Nov 15, 2009 | Amplifiers & Preamps

2 Answers

Peavey 5150 II guitar amp! Power Tubes don't light up and only

peavey 5150 II has low humming sound but still plays and sounds pretty good...should i re-tube it?

Jul 18, 2009 | Peavey PV-3800 2-Channel Amplifier

1 Answer

Hi, Peavey Classic Guitar amp , Has NO SOUND

Hi Mike,

If you switch on the amplifier, do you hear nothing at all?
Or do you hear low level noise or hum out of the speaker?
Don't know if you're technician.
If the tubes are glowing, you can measure the high voltage.
Check also fuse 3 and 4, thats the neg. voltage -27V and -14V.


Jul 06, 2009 | Peavey Amplifiers & Preamps

1 Answer

PV 2600, couple years old, light usage. Connected to two PV SP3K speakers. One channel started to cutout somewhat but not all the way, Switched a few input cables, swapped L&R. Then whole amp shutdown....


I've worked on similar units.
Things I'd check first :
Dust in the unit.
Weak solder connections /crusty debris stuff on the input jacks or output terminals
Any flex cables soldered in tend to be a problem on peavey amps I resolder all those contacts.
Checking the amp w/o a load IS NOT a good suggestion.
What style output connections are you using?
1/4 inch, binding post, or Neutrik style?

Dec 29, 2008 | Peavey PV® 2600 2-Channel Amplifier

1 Answer

Peavey classic 30, new tubes and PT with absolutely no sound

I'm not sure what "PT" is , but the heater voltage is separate from the other voltages required for this unit to function properly. Please note that with tube systems, there are voltages in the 300-400V range that can cause injury. If you do not have experience with tube based electronics, I would suggest that you bring this to a service center for repair.

Please update this with what you mean by "PT" and we'll continue from there.


Nov 12, 2008 | Amplifiers & Preamps

Not finding what you are looking for?
Amplifiers & Preamps Logo

Related Topics:

1,472 people viewed this question

Ask a Question

Usually answered in minutes!

Top Amplifiers & Preamps Experts


Level 3 Expert

4518 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17129 Answers

The Knight
The Knight

Level 3 Expert

66623 Answers

Are you an Amplifier and Preamp Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides