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Messages - Tim Escobedo

#1
Thanks for the schematics and the ideas.

I might give the reverb tank I have try. It's a more normal sized one, not like the little 4 inch assembly they house inside the chassis, so of it works, I'll have to mount it probably on the floor of the cabinet. Both amps seem to have plenty of recovery gain in the reverb circuit, too much, really, in my opinion, with the stock spring unit. So the 600/600 ohm tank might be fine.

That stock foam reverb mount is a regrettable choice, and that they both had failed completely is a heads up for anyone who might come across one of these little amps, of things to watch out for. The one that was loose, but functional, was remounted by cutting some of that open cell eggshell-cut cushioning foam that came from a test equipment case. I cut a cavity for the reverb assembly in a piece of foam, whole whole thing large enough to get securely wedged in the closed chassis, where the unit is suspended within the foam. Seems to work quite well.

I think I'll leave that two prong power cord alone. It isn't causing a problem, leave well enough alone.
#2
I've recently picked up a couple Peavey Blazer amps, from different sources and eras. Amp #1 appears to be a late 90s "Made in USA" version, amp #2 is a "Designed in USA" made in China red stripe version I'm guessing is about 15 years old. Both have some issues.

Amp #1 curiously has a two prong plug that's original, wired directly into the power transformer. The closest schematic I can find seems to indicate a grounded plug, but who knows. I've tried contacting Peavey for the proper schem, but they've never replied. Should I consider replacing the power cord with a properly grounded three prong plug? Secondly, the recovery coil of the reverb tank seems to have gone open. Anyone know the specs for a replacement reverb tank? I have one that's 600 Ohm in and out coils, but I don't know what's optimal.

Amp #2 has an intermittent distorting problem in the audio chain somewhere. Sometimes happens upon powering up, sometimes happens after the amp has been on for a while. It's characterized by a thinner, slightly buzzy tone, more easily noticed on the clean channel, but also happens in overdrive (though a little harder to notice in high gain). I suspect a bad connection somewhere or perhaps a bad solder joint. When it happens, it is always remedied by a good solid whack on the cabinet. However, it's been impossible to reproduce pushing on the PCB with a chopstick at various points while powered up. All the joints have been physically inspected under magnification and look OK. And I'm 99% sure it's before the power amp, as I've been able plug an audio source into the CD/Tape input when it happens, which isn't affected. I have a suspicion it might be the Modern/Vintage EQ switch (which the older Amp #1 lacks), since it is almost, sort of, reproduced when I really fiddle with the switch and kind of balance it in the in-between position. However, it isn't quite the same sound, just similar. Contact cleaner on the switch hasn't seemed to help. Any other leads as to what I could be missing?

Interestingly, the reverb tanks on both amps had become unmoored, as the adhesive foam holding them down disintegrated into fluff. The tank of Amp #1 was wedged between the circuitboard and the chassis, shorting something out, leading the previous owner to think it was not functional. But works fine other than the busted reverb coil. The reverb tank of Amp #2 was flopping around loose inside.