F5m kit

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I'm building it differently this time (many ways to skin a cat, but good for the cat, too) by not the "bigger HS the better" approach
I'm planning to do the same, at least initially, because the existing chassis I want to use has about 70% of the HS of a 2U DIssipante. The chassis already has a useful IEC inlet, power switch, a formed well for the toroid w/bolt hole, a good set of speaker terminals, and is drilled for RCA inputs. The existing tapped holes on the HS are the right distance apart. So it will be an easy and cheap build if it works.

I've already obtained the fans: a pair of 80mm x 25mm AC Infinity fans, sold as a unit called Multifan S5 (avail. on Amazon). The 80mm size works best for my particular chassis, where I will place them directly over the HS where each set of outputs are mounted. The pair are tethered together (can be spaced up to 3ft apart with existing wiring), have an integrated 3-speed control switch, all of which is already wired to run off of USB power (USB-A fitting). That is fine for me as I will be mounting them externally. I've tested them for noise, and they are reasonably quiet on the low and medium speeds, as the rpm are low.

I'm hoping I'll be able to get to the 1A bias territory with the fan assist, but if not, then perhaps there will be a Deluxe 2U Dissipante available by then. In any case, will not be able to start building anything until April as I will be traveling through the end of the month.
 
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The Iron Law of going with fan cooling, use:

- Biggest possible fan.

- Lowest possible RPM.

…If you want the most Silent and still the most Effective cooling possible.

🎺🙂🎸
JeyDee (et al) I like what you said about a fan. I have a problem to solve. We just bought new furniture for the living room. My plan is, now was!, to put the new amp under the new credenza. I have been vetoed by my wife on that so I need to put the amp inside the credenza and be sure it is properly cooled.

I would greatly apprciate any suggestions you or anyone has for brands, models, furniture cabinet mountinglocations, etc, that will do the needed cooling for a well biased F5m.

I think that is the only way I'll ever get one of Papa's amps into my main system. Many thanks in advance,
 
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JeyDee (et al) I like what you said about a fan. I have a problem to solve. We just bought new furniture for the living room. My plan is, now was!, to put the new amp under the new credenza. I have been vetoed by my wife on that so I need to put the amp inside the credenza and be sure it is properly cooled.

Are there ventilation openings on the rear or elsewhere? If not, it will still heat up inside significantly.
 
Rayma, I'll have to cuto holes for fans and inlets. I'm looking for guidacne on what I'll need. i.e. CFM to cool an F5m? IO'll check out the Noctuas Ben Mah recommended but still need to sort out what flavor of fan(s) will be needed. I do have a temp sensor I can use for testing.

You could use some incandescent light bulbs inside to simulate the amplifier, and experiment with ventilation fans mounted on the back, to see what temperatures you will get inside. That higher ambient inside the cabinet will make cooling the amp interior more difficult.
You'll want the exhaust fan very close to the amplifier. And the intake fan should be well to one side,
to avoid recirculation of the hot air. I'd also use a filter in the intake fan.
 
@audiosteve

Are you sure having the fan controlled by temp value is helpful? Its a cool project, however, I'd think "always on" when amp is on would result in reaching an equilibrium state, which is what we want in order to avoid a fluctuating bias current (function of MOSFET temp). By having a fan turn off and on, based on temp, you'll never reach a state of equilibrium, regardless of the delays built into the control code. Maybe I'm misunderstanding how the fan is intended to be used. Or maybe the control system will be so good it maintains a constant temperature perfectly and my question is mute.

[Edited to note my comment may not be applicable depending on control system design/architecture.]
 
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