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Does Glue Block Heat? Making The Back Panel and Installing The Amp Boards



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Watch part 1: https://youtu.be/UKhRA_GcmPI
Now that the case is mostly finished, I can get the amplifier boards installed and tested. Not only that, but also to put the project on hold for a while and use it in the meantime. I'm waiting on parts that I haven't even ordered yet to complete the amp, but it's fully functional (as an amp) and figured the best place to store it while I wait is in my listening room hooked up to the subwoofers.
Another issue holding me up is the design for the front panel. I haven't come up with anything I'm completely happy with and the only cure for that is time away from the project.
Regarding heat: if you watched me install the first amp board, you will see that I put mica washers between the output transistors and the aluminum bottom plate of the amp. That washer is needed to electrically isolate the transistors from the case, since these transistors have a metal back that's tied to the transistor collector. Mica has about the same thermal conductivity of the glue I used to fasten the heatsinks (in the previous video), but it MUCH thicker than the layer of glue. As shown with the amp's bias turn up to 200mA+ per output, the heat has no problem finding its way from the bottom plate to the heatsinks. That bias, if you aren't familiar with this stuff, is way beyond anything used for normal class AB amps. Typical value is in the 10 to 100mA range.
The benefit of using aluminum to build the case is that the entire case becomes the heatsink. So even the cover is dissipating heat to cool the amps.

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