Amp Camp Amp - ACA

I have a pair of Amp Camp amps and I had to put them in a cabinet that really restricted air flow. They were getting to 60-61 deg c heatsink temp. Not good.

The solution for me was to buy an Aircom T10 "cooling system". The T10 has three fans and sits on top of the ACAs and exhausts air to the front.

I run the T10 with the fans full blast and they are barely audible.

The heat sinks are now running at 30-31 deg c. with an ambient temp of 25 deg c.

Just thought I'd share this in case others were having similar problems.
 
Just a small fan doubles heatsink efficiency, and/or you can throw a resistor inline to slow a larger fan down to be really quiet. Too big a resistor and they won’t start though. Nelson P. had a minimal circuit that started the fan on high and then lowered the voltage once it was moving.

Liquid cooling still requires a heatsink called a radiator. Possibly helpful for a huge class A amp but over engineering for an ACA by 5.

I can’t see why to install an entire expensive cooling system, when a bit larger heatsink is all that’s needed to work excellently
 
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Capacitance added

Followed Nelson's suggestion in post #1912 and added capacitors (10 x 1000 uF).

No power-off noise is audible anymore.
 

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Mooly

Administrator
Paid Member
2007-09-15 8:14 am
Midpoint would be the best initial option but anywhere in the 20 to 80% of the range is OK. Its not critical as an initial setting. A third of the way around or two thirds of the way around, it doesn't matter. Just try not to have it set fully at one end or the other.

All that happens if you have it incorrect is that the sharing of power dissipated in the FET's shifts such that one will dissipate more and the other less.
 
Midpoint would be the best initial option but anywhere in the 20 to 80% of the range is OK. Its not critical as an initial setting. A third of the way around or two thirds of the way around, it doesn't matter. Just try not to have it set fully at one end or the other.

All that happens if you have it incorrect is that the sharing of power dissipated in the FET's shifts such that one will dissipate more and the other less.

Thank you Mooly. Much appreciated and great weekend.

cheers

pos
 
Positron, i prefer the ten turn pots in place of the single turn pots, setting the half b+ bias takes time and patience...so depending on your wrists, you can overshoot the target and then go back and undershoot....several attempts are needed, and best to wait for the heatsinks to get warm enough...

Me as well Tony. I use two 15T pots in my speaker crossovers, one pot (tweaking) for blending the full range driver to woofer for seemless match, while the other pot (tweaking) adjusting the tonal balance of the full range driver itself. Even with 15T pots, the adjustment is extremely touchy. I really need 150T pots, not exaggerating. :)

cheers

pos
 
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