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Can't see under the boards, but I'm guessing there are TO3 power transistors down there on the heat sinks? You might need a plan for remounting them (new heatsink compound) depending on how the board can be removed, if you are going to be replacing things.

Since it's an unknown design. Begin by measuring what it's doing now. Before you make any changes. DC offset at speaker outputs. But especially the quiescent/bias current in form of what should be very low voltage (like 10 - 25 mV) across those emitter resisters--the biggish white ceramic...

It's always a good idea to begin by troubleshooting the presenting problem before recapping / shotgun replacing. I'd consider building a dim bulb tester. The AC hum could be caused by failed main filter caps -- the 8200uf ones--if so noise will likely be 120 hz. Much less likely, it could...

Any metal, esp copper, corrosion with it? Might be worth checking to see if it's conductive (or becomes so when wet).

That would drive me crazy. But if it worked audio-wise and there was a grill covering it, I might let them go before testing the various solvents and their unintended consequences. But I absolutely understand the need to fix them.

I think I get your point. How to factor in GDP increase, urbanization/infrastructure build and climate change into the rise of huge natural disaster payouts? The first 90 years of the past 100 is going to be all urbanization and GDP/inflation. I don't think any one is claiming CC has had much...

That's not at all how insurance markets work. Rising state level claims lead to rising premiums, and dropped policies. But if that math were true on the macro/GDP level, it would all wash out in the reinsurance market. That is very much not happening. The premiums insurers pay for their...

Insurance companies, who understand risk better than anyone, are exiting markets with heavy exposure to climate change risks. They are working to untangle themselves from such policies. See Florida.

2nd on fixing the broken channel before recapping. I'd also beef up the rectifier so I could increase the size of those filter caps. Nothing crazy, maybe 4700 instead of the 1500 in there now.

Thanks for all the help. The cyanoacrylate seemed to help a bit. I dripped it in around the steel jacketand clamped. While clamped it remained loud, but once dry and unclamped it was significantly less loud. The problem may be in the plastic bobbin on which the windings sit vibrating in the...

I'm so sorry Chris, you and your mother are in my prayers.

There are many reasons a transformer will vibrate that aren't really warnings of electrical failure: laminated cores aren't entirely tight, the winding might be slightly loose in the core, the jacket covering the core might have a loose point. As I understand, it's mostly a nuisance. I just...

Yes. This didn't look like a best practices implementation.

I realized it was quite a big silicone pad, so I flipped it around and used the other end. Sorry for the noise. I have very thin Kapton from Rod Elliot, which he recommends for his amp builds. I used it in my 3a build and it works fine even when I'm pushing that amp.

Thanks. Why mica and not kapton? Different heat transfer rate?

I'm assuming I can replace a large sheet of grey silicone pad covered in too much compound with a sheet of Kapton. Context: I'm recapping and cleaning up an AB subwoofer plate amp. I had to remove the heatsink to get at the circuit board. Lost a small chunk of pad on a 3rd smaller...

That outer steel shell is held on just with fold over crimp tabs on bottom. Nothing providing compression. When I squeeze it very hard, it quiets. (alas the circuit board contacts make putting a clamp on it a no-go) Any thoughts on dribbling some thin cyanoacrylate in there as easy-potting...

This is an e-core transformer on a plate amp in an AR subwoofer. Definitely physical transformer hum, not electrical. The firm attachment to the plate gives it resonance with the box. I don't see any way to tighten the laminations (I assume that was a much older era of construction) and it's...

I see SimplySpeakers sells some black recone glue that seems similar to the blacken 99. Maybe worth asking them?

I have no direct knowledge, but i've heard people talk about using 3M black weatherstrip adhesive for a different tweeter adhesive need. I'd check that out.

Neutrally noting that an old thread discussed this: https://audiokarma.org/forums/index.php?threads/is-there-an-easy-diy-rca-cable-cooker.492827/ I like the use of tape loop or pre-out/power-in if the device has them.

Electric motor efficiency is generally in the 70% range, car-sized internal combustion engines are generally in the 30% range. That math sets the terms of the debate. Lithium, copper and cobalt mining are destructive, as are iron, coal, petroleum and methane gas. Google them all. Question...

I'd try some heatshrink tubing on the shaft.

I use #16, but only because that's what was available. I haven't used it on this particular problem, but it works very well for acrylic type plastic repairs. I'm guessing the different #'s are just different ratios of MEK and acrylic. Nice thing with these types of glue, is that if they don't...

I would use an acrylic solvent adhesive like Scigrip. It allows some set up time and is more permanent than superglue types.