"** Which is consistent with the OP's finding."

If I am understanding this correctly, this is the reason that amps now have floating transformer secondaries and have eliminated the insulators.

Seems like it was not so big an issue in the old days, but now they are fan cooled and they DO depend on the temperature difference to keep from frying out.

And mounting methods ? Jesus H Christ, taking apart this **** now is ridiculous. You got one bad pair of output, the whole damn board has to come out and then all of the outputs have to be dismounted. This is one of the reasons I quit. I am to the point where I do not want to work on anything not old enough to drink. I mean it, and these MFs with their glue, I want to go in that factory with weapons of mass destruction and remove all glue. I do realise why they do it, but damn. The way they do it they might as well just glue the lid on and call it a toaster.

And even supposedly better amps are built in a pan. There is no bottom access. In many you can't even get the board out without the heatsink on which makes for a very awkward situation, and running it without the heatsink is a big nono.

**** like this is why I am pretty much retired and just selling off my equipment. Perhaps I am inferior on that respect, but I also have physical problems that make it very difficult. But manufacturers do not think much of service, all they want to do is sell and have the product in the customer's hand, working. After that they pretty much do not give a ****.