Ntc thermo switch?

[Off-Beat]

I just got some from google as i wont be back at the workshop for a few days.
https://www.google.co.uk/search?q=as...Ym99lKlO6TM%3A

https://www.google.co.uk/search?q=as...VbN2sgEi1zM%3A

U can see th1 mounted to the heat sink.

[J M Fahey]

If you mean this:

that's not an NTC Thermistor on the heat sink but a bimetallic thermal switch, either the 70C NC SW2 which enables the fan when the heat sink reaches what I consider an unsafe high temperature or the 100C one which cuts speakers off when heatsink reaches an even higher unsafer one.

Follow the red wires to see where they connect to, although since they go almost straight towards the speaker relay, it might be SW1 .

For many reasons I am strongly disliking this gimmicky amp where all the brain power was spent on a cool *looking* unit and not much else.

Besides the brain dead indicating inclusion of a frequency divider /suboctaver, and the silly "old style analog needle meter" , layout is horrible: just look at the transformer on the far right, the supply *AC input* connector on the far left, the high current (~6A) 45+45VAC secondaries running the entire length of the preamp (inside the red sheath) and instead of, at least, running close to the back panel, they run over the preamp board with a special intrusion real near the input jacks.
Very amateurish

They *should* have turned the toroid 180 degrees so power wires exit its left, designed the power amp + PSU with AC In connectors in the right, and high current secondaries would have been 2 inches long and away from sensitive inputs.

Wires feeding AC to the preamp supply would also have been much shorter.

Oh well.