Help with Peavey Classic 30 reverb. - Gearspace.com
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Help with Peavey Classic 30 reverb.
Old 13th September 2012
Here for the gear
🎧 5 years
Help with Peavey Classic 30 reverb.

Hi there,

M'first post here, although I've read the forums many a time. I just bought a used Peavey Classic 30 and although the sound is very good, I am very disappointed by the damned reverb. I almost always like to use at least some degree of reverb. And I literally have to settle for that gross no-reverb sound or else I just get incessant hum/feedback with a really low amount of reverb even when it's at 12 (yes my amp goes to 12, I know).

I have tried to move the tank around, change channels, same crap.

Getting to my point, I want to swap out the tank and throw in a nice one that actually gives me TOO much reverb when it's maxed out (which should be the case always). My question is: Does anyone know of a specific tank that would suit my needs as well as fit/match the amp's impedance? (I'm in Ottawa, so a canadian supplier would be best) And in addition I would like either a web link or a semi-detailed summary of how to do it. (In Layman's terms please!). I know you guys are awesome at this stuff and I heard this is a simple mod so I'm hoping someone has some insight here.

Thanks so much in advance for the help.
Old 16th September 2012
Lives for gear
fireberd's Avatar
🎧 10 years
Weak/noisy (hum) reverb is typical of many Peavey amps. I saw a mod for a Peavey Nashville 400 amp that supposedly helped the reverb, but I don't think it really helped as it wasn't very popular. I had a loaner Peavey Nashville 1000 from a dealer while they ordered a new one for me. It had a 2 spring reverb in it that was typical Peavey (weak compared to Fender), the new one that I got had a 3 spring reverb in it and I couldn't hear any difference. I now have a Nashville 112 and it is identical to the Nashville 1000's reverb.

Most of the Pedal Steel Guitar players, me included, use external reverbs and not the Peavey reverbs. I'm using a POD X3 and the "spring" reverb model in the X3 for reverb.

One thing to check (I haven't checked on your model Peavey amp) but many amps used a "Molex" connector to connect the reverb pan to the amp chassis. This has been a problem area for bad connections and hum. Later model Peavey amps use a different/better connection that does not have the problem.
Old 19th September 2012
Lives for gear
CZ101's Avatar
🎧 15 years
I put a MOD 9EB2C1B in my Classic 30. This was an improvement imo.
Old 22nd February 2017
Gear Nut
jonnybrell's Avatar
🎧 5 years
Old thread, but I can't be bothered to register and post in the Peavey forum. Just done a mod on one of these so you can keep the old reverb...

Ok - I'm assuming you've done stuff like this before, but if you haven't don't - learn the basics from an expert first.

Unplugged, yadder yadder... Take out the tubes, then remove the chassis & tank. Check the main HT filter cap for voltage - anything less than 20V is fine.

Take a photo of all the wires. Pull them off the board. Note if any fall out or seem loose and repair. Remove the knobs, nuts and the jack nuts, gently pull the remote PCB on a ribbon out so it's out of the way. Remove the spring clips from the pressed out tabs on the tube side, and remove the little screws. Now you should be able to gently squeeze out the U-shaped board from the holes. Once it's clear of all holes remove the board.

Now the component you want to swap is on the control board, near the 4558 IC. It's labelled C23 on the schematic, and is a 2.2uF. This gives a break frequency of around 7Hz along with the 10K. You can swap this 2.2uF for a 100nF and it goes up to about 159 Hz (an octave above bottom E, you can choose others, you'll need to do the maths) - I used a dipped poly 400V cap, but there's absolutely no need to be that high voltage, other than the other caps I had at lower voltages seemed too flimsy.

Right, might be worth modifying the bias while you're in here. Look elsewhere for this, but you can do it by replacing the 47K with a 25K preset and a 22K through hole, and a swapping the 25V 22uF with a 63V cap.

If you've got a capacitance meter you can check the main HT caps in-circuit. Anything less than the number stated on the can & start considering replacing, less than 90%, get them all swapped. You can double check by removing one leg of the cap from the board. Might as well service the pots too...

Right, all back together, remembering not to tighten everything, no knobs, simple screwing - bad juju to put it all back perfect at first.

Test the amp.

Take the reverb out of the tank bag (remembering which war round it was), cut a new piece of cardboard the same size as the old, wrap it 1 1/2 times in bubble wrap (bubbles inward), pop it all back in - it'll be a bit more of a squeeze, but as long as you don't foul the springs you'll be fine.

Test the amp with the reverb.

All good? Tighten up the screws and refit all the knobs and things.

It takes ages (even if you do this for a living), but if you're bored some day...

To be fair, you could just do the cardboard and bubble-wrap thing, but it'll still sound really sploshy.

PS The one I have still feeds back an octave above D (293.7 Hz) - 47nF will inhibit this (BF approx 339 Hz), but the reverb may start to sound too thin. Meh! worth a play?

PPS Swapping the speaker polarity stopped the feedback

Last edited by jonnybrell; 22nd February 2017 at 06:00 PM.. Reason: Post Script
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