Peavey Classic 20 ?

[EWBrown]

Anyone familiar with the Peavey Classic 20? it appears to be a variant of the typical "18 Watter" EL84 PP amp, with two Chinese made 12AX7s for the front end gain stages, and since no rectifier tube is evident, I'll presume that it has SS rectification. EL84s are of unknown origin, probably also Chinese made .

The PT and OPT are fairly small, in comparison with what I'd normally use with such a circuit. The cab has "tweed" tolex covering, and it has a 10-inch Peavey "Blue Marvel" speaker. Here's a tiny pic of it I "borrowed" from another website.



Friend of mine found it for the princely sum of five bucks at a local flea market, and gave it to me. He said he figured it was something that I'd like to "mess around" with

Looks to be in pretty good shape, a bit dusty, and a few dead dried up bugs laying in the bottom of the cab, along with a chewed-up toothpick and one fossilized cigarette butt. It was in storage for "a few years" , (probably more like 10 or more years.

I'll give it a good looking over before applying AC power to it, and use a variac for the initial "smoke test"

With a bit of net-surfing, I found a PDF schematic, parts list and PC board layout, so any servicing will be easy now. Also some recomemndations for speaker upgrades - the stock Peavey speaker is somewhat lacking, in some players' opinions. The schematic is dated 1994, so the amp is a bit newer than I originally expected it to be.

/ed B

[Geek]

What size speaker does it need?

One can never go wrong with a Weber Signature series
https://taweber.powweb.com/weber/

Cheers!

[EWBrown]

It has a 10 inch speaker. IIRC, Weber speakers were also on the recommended speakers upgrade list.

I checked it out today, it hummed a bit too loudly, but it worked more or less normally. No scratchy pots, and the input jack makes good solid contact, with no intermittency or scratchies to deal with.

I decided to do a full re-tube, pulled out the two "no name" Made in China 12AX7s and the two really worn out Sovteks (the markings were just barely legible), and plugged in two Raytheon 12AX7As and a MP of J/J EL84s. No more hum!!!

The MP of EL84s was originally a MQ, until, one of them rolled off the bench, and onto the concrete cellar floor, several years ago. So I ended up back then, with a Matched triplet... I rally hate when that happens. D'Oh!!!!!!!!

I suspect that only one of the Sovteks was working and the other one was just lighting up (as it had evidence of some rather stringent pin straightening attempts, so I think it may have lost its vacuum) , so the working tube was drawing all of the plate current for two, and throwing everything seriously out of balance.

80 to 90 mA through a single EL84 isn't exactly a recipe for a long and productive life, and could do some "nasties" to the OPT f it was left running that way

With the new tubes it sounds very nice, better than I expected, but I still have to put it through its paces before deciding on a speaker upgrade.

/ed B