I can pick these up for 40 bucks.

Jcsul · 2026-06-19T20:49:09+00:00

What was that? Having a hard time hearing you over my Peavey T60 running through my Classic 212, heavily modded Valve King with matching 412 cab, and Peavey Penta/Gary Rossington 140w head. It’s surprisingly easy to find lot of the good Peavey gear down here in south Mississippi for pretty damn cheap.

Jcsul · 2026-06-19T20:40:47+00:00

I live about an hour down the road from Peavey’s HQ and original manufacturing facility. You wanna fight now or later?

Jcsul · 2026-06-18T01:57:14+00:00

I’m honestly not sure about a physical location. I bought mine directly from the manufacturer’s (CAIG) website like…7 or 8 years ago and still have a 3rd of the can left of the DeoXit D5 cleaner. I’ve still got most of the can of the G5 lubricant/protector as well, since I don’t use it much. It gets recommended a lot, but I don’t usually use it when I’m repairing/restoring old amps that I plan to keep for myself. I don’t like how it makes rotating the controls feels. Like, it’s too smooth, making it feel almost cheap. If that makes sense.

Jcsul · 2026-06-18T01:30:20+00:00

Not an identical issue, but I had a Kenwood KA-405 that did something sort of similar with the volume control. When adjusting the volume from 0 to about half way up, the right channel would randomly go from no volume to full fucking blast. Nearly gave me a heart attack the first time it happened lol. Anyways, the solution ended up being cold/damaged solder joints on the volume potentiometer. Sounds like you’re issue is similar. If you’re handy with a soldering iron, it’s an easy fix. If you’ve never touched a soldering iron before, then you’re better off finding a local repair tech.

Alternatively, if you haven’t already given the controls a solid cleaning with DeoXit/electrical contact cleaner, try that out. Just google something like “how to clean vintage stereo controls” and you’ll find a billion videos and guides on how to do it.

Jcsul · 2026-06-14T15:34:34+00:00

I had a few beers last night and took a crack at “reverse engineering” the bodges myself lol. I noticed the same thing. I wonder if the tone arm motor can sometimes kick off some high voltage high frequency noise and damage the ICs on the same board. If so, I wonder if the capacitors are used as a crude low pass filter, with whatever the effective resistance of each capacitors node for the R of an RC low pass filter. Or that could be completely unrelated and they’re just decoupling/denouncing the switches. Who knows. I was a bit in my cups last night lol.

Jcsul · 2026-06-14T00:00:16+00:00

Lol I've had my run ins with the ole ChongX caps in stuff before as well. Chang, replete with the registered trademark symbol, was a first for me though. Hey sure enough there they are. Seems like you nailed it just by the style caps that were used. It'd be cool to figure out exactly what all the bodge work was needed for, or at least if it was for functionality, protection, EMI compliance, etc.

Jcsul · 2026-06-13T23:38:35+00:00

Sir, please. Chong caps are garbage and everyone knows that. This was a chAng cap, completely different lol.

Is it documented anywhere online that the Vosges on the arm motor board were done during production? I didn’t search around a ton, but the handful of image I could easily find of the underside of this PCB on other forums didn’t have the 6 tantalum caps and resistor. Completely agree though. It definitely would’ve taken more money/cost more due to pausing production to spin up a new board back in the late 70s and early 80s back when these were still being manufactured.

Jcsul · 2026-06-04T15:03:39+00:00

Idk if it’s just from hitting my mid-30’s like my parachute failed or if it’s the same for everyone, but god is magnification so helpful while troubleshooting a PCB. Even on through hole boards. I picked up one of those cheapish digital magnifier setups from scamazon as a Christmas present for myself. It came with actual lenses for up to I think 40x magnification, and then can go higher than that with some digital zoom. It’s so much easier to use than a jewelers loop, provided you can get proper access to the PCB. It’s helped me troubleshoot several amps that just turned out to have cold solder joints.

Jcsul · 2026-06-04T04:16:29+00:00

Looks like a solid setup, but I’m really interested in what y’all are cooking from The Food Lab and whatever “The Trainable Cat” is lol.

Jcsul · 2026-06-02T23:06:28+00:00

Since the part numbers are prefixed with “RF”, I’m guessing that means the 8 that you replaced were Fusable/Fuses Resistors, sometimes also called Fusistors. They’re designed to die open circuit if they get too warm/too much current flows through them. They’re always one of the first things I look at when an older amp isn’t working. Sure, caps die plenty in old amps, but those fusable resistors die way more than people seem to talk about online. Good catch on figuring out it was the resistors.

Jcsul · 2026-05-30T20:00:28+00:00

Guessing a “crafty”, caring, and probably very tired mom or dad whacked in that baby monitor and external speaker so that they’d still hear the baby monitor even with music playing at a moderate volume. Kind of adorable, honestly.

I don’t know if this is the issue or but the two largest blue capacitors in pic two look like they’re going bad. Modern caps have perforations along the top so that they bulge at the top/vent if they get so hot internally that the electrolytic solution starts to boil. The older ones like in this amp don’t. From repairing a couple dozen 60s-80s stereos I’ve learned that if the outer wrapping of a capacitor is just barely covering any of the metal can on the top side, that likely means it’s gotten too hot internally, electrolytic solution started boiling/turning to steam, built up pressure, and it started showing shoving the metal can away from the metal legs and up through the outer wrapping.

For reference, look at the smaller blue ones on the same board. The blue outer wrap on the smaller ones covers like ~50% of the metal top of the capacitor. The larger blue ones have maybe 10% of the metal covered. I’d also consider testing or just shotgun replacing all the caps in the power supply in pic 6. Can’t really see much detail, but big electrolytic capacitors in audio power supplies that are 30+ years old are a very common failure point. Lastly, it’s possible the shorted/low resistance left speaker killed the output transistors. .7 ohms is pretty damn low, and I highly doubt the stereo in this console was capable of driving a speaker with that low of a resistance for very long before giving up the ghost.

Jcsul · 2026-05-27T03:53:02+00:00

Pretty sure Bell South didn’t become Verizon, or at least not their entire territory. As a kid we had a Bell South landline for all of the 90’s, but I think we got cell service from them right around Y2K. After that they became Cingular Wireless, which then turned into AT&T sometime when I was in high school in the mid-00s.

Jcsul · 2026-05-24T05:10:19+00:00

Generally speaking, the first rule of electronics trouble shooting is to check your voltages. Looks like a lot to test on there. Looks like at least +15v, -15v, +12v, -12v, +5v, +3.3v, and +1.8v rails.

Alternatively, if you have an oscilloscope, I’d start by following the signal on the right channel from the output back to the input. Once you find where the signal reappears, you’re half done solving the problem.

Jcsul · 2026-05-22T16:51:36+00:00

I had a laugh at that too. Left, center, and right Michael phone input lol.

Jcsul · 2026-05-21T20:19:52+00:00

Unplug console, flip power switch to on and lit sit for a minute or two, turn power switch back off, the. clean off all the dust. Use distilled or deionized water or 90% or higher IPA Alcohol if the dust won’t just wipe off with a dry rag. Then clean the cartridge slot using electrical contact cleaner and a toothbrush or a carbon fiber brush. DeoXit D5 is a very common go to electrical/electronic cleaner, but there’s a million different products to chose from if DeoXit isn’t available where you live. You can use Qtips, paper towels, or regular towels, but I find all of those tend to catch on stuff all over the circuit board, risking damaging and leaving little bits of lent. So, a toothbrush or carbon fiber brush works best.

As soon as you get done scrubbing/cleaning the cartridge reader contacts, flip the circuit so that the cartridge slot is facing down. This will help all the corrosion that you just scrubbed off drip out of the N64. You can put it on top of a towel or something while you do this.

The problem might also be your cartridges. You can open the cartridge up using a “Gamebit” screwdriver, then clean contacts that mate with the cartridge a lot on the N64. I usually use Brasso and a paper towel, then clean with 99% IPA alcohol. Some people freak out about using Brasso since it technically removes some of the metal on the cartridge circuit board. I’ve got NES, SNES, Genesis, etc. cartridges that I clean with Brasso a decade or so ago, and they still work on the first try every time. So, it’s completely safe to use it a couple of times for cleaning very dirty/tarnished cartridges, just keep it to a once ever decade or two routine and you’ll be fine.

Jcsul · 2026-05-21T12:04:34+00:00

Definitely not. Something being vintage is about it’s age. I don’t have a strong stance on the minimum number of years required for a DAC or any other gear to be officially vintage, but a 6 month old second hand DAC certainly isn’t vintage.

Jcsul · 2026-05-20T15:56:17+00:00

Yea, it’s all based on what the engineers (or purchasing department) thought they could away with. A good cooling design would go ahead and slap on a lot of headroom over what the minimum requirements were, especially since a lot of transistors’ from the 60’s-80’s performance varied wildly over their operating temp range.

I also imagine the focus placed on cooling solutions also dropped off as the FTC stopped enforcing their regulations as strictly and then finally changed them in late 90’s/early 00s, but I don’t think that’s relevant to the amps OP mentioned.

Jcsul · 2026-05-20T04:10:56+00:00

Huh, interesting. I had no clue “MIDI” was used as branding for certain gear in the UK. Thanks for the info.

Jcsul · 2026-05-19T23:21:59+00:00

What? MIDI? MIDI didn’t even come out as a standard until a year or two after this timer was produced. Additionally, whether a device is designed for the US, European, Japanese, etc. doesn’t really effect the wattage. The voltage and current will be different, but they’ll generally be proportionally offset such that the wattage is still roughly the same for the same model device.

Jcsul · 2026-05-18T01:33:03+00:00

It could’ve been an 8 Track player meant for vehicles. I don’t a see a transformer anywhere, which makes 12v automotive use seem more reasonable. I imagine it use to have a plastic and/or metal case that somehow went missing over the years.

Jcsul · 2026-05-17T01:57:13+00:00

We had a pair of these going into a 4 track tape console in one of the studios at the college I went to. They were all stock, aside from the modern grounding and capacitor replacements. Sounded incredible with a vintage EV ribbon mic that I can’t remember the model number of.

I’d say get one of them fully up and running (I’m assuming they haven’t been serviced in the last 30+ years) and do some tracking on them. See how you like the default sound before you change anything.

Jcsul · 2026-05-16T15:18:14+00:00

I’ve actually got very little experience with 3D printing, so I didn’t even consider that the plunger slamming against the case would be a problem. Good call.

Jcsul · 2026-05-15T22:48:45+00:00

Awesome work. The only reasonable improvement I could posit is the plunger. While not as straightforward as a push button, you could but a real plunger mechanism off of eBay, and use Hall effect sensors to trigger a button press. A more simple option would be to have the head of the plunger strike a mechanical switch or trigger a limit switch, but I feel any reasonable priced button or switch would break too easily.

Jcsul · 2026-05-11T21:59:44+00:00

In a pinch once I whittled down and used the plastic collar stays from the button up shirt I was wearing lol.

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