As the network is hard to find a 5xLM3886 chip on one PCB, and I will add that I did not succeed, I just did it.
I think that this system does not need to be described. The system is tested, it sounds very good, but the radiator is too small and I need to cool it with air. After adding the right size heatsink will be grand
Download files project in Eagle
View attachment 5xLM3886.zip
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That is more heatsink than I use on my My_Ref amps and I run them very hard (because they sound great) and their sinks are fine.
There are power supply hf and lf for each chip (bonus) but they look like they are coming from the right instead of the left ;
to keep the track inductance low (see TOMCHR).
This could lead to osc which is causing your heat problem.
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Exactly. Is it a test amp or a music amp? That is enough heatsink for home music use. I dare say even enough for home theater use which is typically run a little louder.
It looks like you missed the local decoupling caps on the LM3886es. They'll need at least 470 uF per rail of bulk cap plus 10uF||100nF located as close to the IC pins as you can.
See here for more detail:
LM3886 chip amp supply decoupling.
I doubt the heat sink is enough for even the "home theatre test" of running all channels at 1/8 the rated output power. You may want to fit the heat sink with a thermal switch that turns the amp off when the heat sink reaches a set temperature. Of course, the LM3886es have their own thermal cutoff as well.
Tom
See here for more detail:
LM3886 chip amp supply decoupling.
I doubt the heat sink is enough for even the "home theatre test" of running all channels at 1/8 the rated output power. You may want to fit the heat sink with a thermal switch that turns the amp off when the heat sink reaches a set temperature. Of course, the LM3886es have their own thermal cutoff as well.
Tom
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