It depends on the bias current and rail voltage. A +/-24v Class A running at 1.25amps is 60w dissipation. I have a 4U and that’s about 45C so 3U would be possibly 55C to 60C, right at the limit of what is acceptably touchable with bare hands. But if running high bias of 1.5amps or 1.75amps, 3U is too small (unless a small fan is also employed).
I personally like Class A amps with small heatsinks and quiet fans now as size, weight, cost are much more manageable with CPU coolers and PWM fans as done on the Alpha series. Here with a Alpha BB dissipating 200w per channel, two compact and silent $25 CPU coolers keeps the MOSFET body at only 15C above ambient.
I personally like Class A amps with small heatsinks and quiet fans now as size, weight, cost are much more manageable with CPU coolers and PWM fans as done on the Alpha series. Here with a Alpha BB dissipating 200w per channel, two compact and silent $25 CPU coolers keeps the MOSFET body at only 15C above ambient.
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My listening room runs at 27c (Arizona) and I use the same 3U that P16 runs. No thermal shutdowns for me, and I'm running max bias at this point.
I probably have the warmest room of anyone here. The amp design has double thermal protection. The 3U is just fine.
ggetzoff and XRK971 (love your website !), thanks for your comments. I agree with you XRK, those are the reasons I asked the question!
Best,
Anand.
Best,
Anand.
I already mentioned these details but to be objective:
Power Supply => +/- 27V
BIAS => 1A
Measurement of heat sinks at 25° in a room => 48°
😉
Hi Tonza
This is not my USSA-5 (except last image) but the USSA-1 but I do not really see the relationship with objectivity.
Can you please specify?
This is not my USSA-5 (except last image) but the USSA-1 but I do not really see the relationship with objectivity.
Can you please specify?
*bla*
🙄
Fine. And now explain us the relation to this topic please 🙄. Hopefully in a language everyone will understand...
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| grp info: #221,#1 , Quebec DIY . Sign up , you find the relation , relative , specfied.
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| grp info: #221,#1 , Quebec DIY . Sign up , you find the relation , relative , specfied.
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Hi tonza75.
It's okay to post in another language as long as an English translation accompanies it. Would you please translate?
-Chris
tonza75
I really have better things to do, and you are not only making me work, but you are not listening to a direct request. Whether good or bad, it is disrespectful to other members when you post in languages other than English.
Next time you get a time-out.
-Chris