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Peavey Standard 260H - Sound issue on the Effect Channel.

Started by Qittisak, March 14, 2016, 08:11:26 AM

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Qittisak

Hi all,

I searched around in this forum and found very interesting topics about the Peavey Standard 260H, but no clue about my problem. I just got a 260 head. Normal channel sounds perfect, exactly what i was looking for. Effect channel seems killer, but I meet some problems:

There is no sound coming out until I crank up the gain knob almost to the max. But it doesn't seem that the knob is defective: no noise while turning the pot.

It depends on the input signal. If I play soft notes, no sound. If I play a loud notes, there is sound. But as the note progressively dies, the sound will cut off brusquely, like a noise gate.

I made a video to show so you guys can figure it out:
https://www.youtube.com/watch?v=j0VH36P1e5M

Also, we can see in this video that the distortion knob (bottom left) has no effect on the sound. Another weirdness...

One last thing. I got it from the US and I'm using a voltage converter from 220 to 110V. The box is supposed to handle 300W, but the amp use 400W. Although I understand I should get a more powerful converter, I don't think this explains the problem on the Effect channel.

Thanks for your help.
:)

LJN

Is this the 4 channel PA head?  I have one of those and it doesn't have an effect channel, but instead has two effect loops. Well, actually two effect send jacks. I assume yours is a similar amp. If this is the case, that's not meant for plugging into with a guitar and is not an effect channel. Try plugging into one of the other inputs. It will help if you can post some pics of the amp, as peavey used the 260H designation on several different amps.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

Qittisak

Hey. No, mine is not the 4 channel PA head. Here is a picture:



It's a 2-channel guitar/bass amp. The effect channel is actually a distortion channel. You can see that on the video I made: https://www.youtube.com/watch?v=j0VH36P1e5M

LJN

Very nice. Apologies for the misunderstanding. I'm not familiar with that particular model.
If it sounds good, USE IT!

Epiphone Les Paul, Kasino U100- P, Sears 125-XL

Enzo

Get the schematic from Peavey customer service.

I suspect you have a DC offset voltage in that channel somewhere.  So it takes peak voltage from the signal to overcome that.   You wil find little DC voltages noted all over the schematic, so see if any of yours are way off.  There is no layout drawing for PV amps that old, sorry, only schematics.

I suggest finding the specific problem first, but I expect that all those little 2uf/35v electrolytic caps in the signal path will want to be changed.

Qittisak

Thanks for your reply.
Are DC offset voltages the one pointed in red on this schematics ?



I think I'll let a pro handle it, but I would like to know if it's gonna cost an arm and a leg to repair it or just a few bucks ?

Thanks :)

Enzo

To clarify, yes those are DC voltages, and are what I wanted you to check.  However when I said offset, I meant find some of those voltages that are OFFSET from what they ought to be.

I can't say what it would cost you, but since it does make sound, all the expensive things are OK.

A competent technician should be able to sort it out without a lot of trouble.  he will quickly determine if it is in the power amp or the preamp.  And then track it down.

In my shop I'd estimate that as under $75.  I base that on one hour minimum labor (which should be enough). and $15 or less for parts.  My shop rate is, or was, $60 an hour.  Your local techs may charge differently.   if I went ahead and updates all the electrolytics, I still expect the bill to be under $100.

Qittisak

Thanks Enzo for all these explainations ! It's much clearer now :)

mexicanyella

Watched your Youtube vid; I have to say that with the distortion channel problem, you have a sound that rivals some of the more freaked-out crazy distortion effect pedals available now, like the Z. Vex Fuzz Factory and the WMD Geiger Counter. It sounds pretty wild like it is!

I hope you'll post a video of it after you get it sorted out. Do you expect to use the clean channel much? I'd love to try that thing out loud and clean, with a compressor pedal in front of it. I bet it could peel paint and kill household pests.