Amplifier fan replacement?

[Boomzilla]

I’ve previously done replacements of 120VAC amplifier fans with 12VDC units of the same flow, but much lower noise.

But the fan in my current amp is a two-speed model that can provide more flow based on internal temperatures.

Are such fans voltage or phase-controlled? If the former, a standard transformer/rectifier module should work (less than 120VAC will output proportionately less than 12VDC). But if the AC frequency is being manipulated to control the factory fan speed, the DC converter may not work properly.

Anyone know? Suggestions?

Thanks - Boom

The original fan:

the best replacement fan I've found so far:

[LuisV]

My humble opinion, nothing better than Noctua.

[housetech]

Phase control applies to high voltage motors. Those 120 vac fans just drop the applied voltage with series resistor or variac, frequency of 60hz remains the same.
I run a 12VDC fan motor with a 6VDC wall wort to reduce the speed, thus the noise. Make it easy on yourself Boom- disassemble a wall wort and use it. (either 12, 9 or 6VDC) Make sure you insolate it physically.

[Boomzilla]

Exactly what I needed to know@housetech - thanks kindly.

Boom

[housetech]

Anytime Glenn, any time I can help