Interesting solution for TO-3 case cooling https://www.mouser.com/ProductDetail/Aavid/PF523G?qs=ozNWbWasnziK5kkroLcDFA==
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I think the junction to case is about 1 degree celsius per watt.With that in mind a 75 case temp would equal 109 celsius junction temp.Close to the 120 celsius max. rating for the sony device.
Oh! Him I trust completely! It is me I am doubting!!! That I may have done something wrong, bias the amp wrong (I did at first measure voltage on the wrong zener
), that my plate may have less-than-ideal contact with the heat sink. I was blaming this on me… not questioning, if this is their normal temp, the design.For what is worth, I live at 2800 meters above sea level, so air is thinner, and therefore has less capacity to cool down things. It’s interesting how that affects so many things here but we don’t pay much attention to it.
If everyone has more or less the same temps and that is indeed Papa’s expected temp, I’m more than happy.
Yes, I have read that review more times than I can count. Those are my speakers, yes. Best I could afford, and they will have to stay for quite a while.
Those look really nice, and would really give the aluminum T a great look in the VFET amp. Still, $70 on extra heat sinks that would cover the nice hand-written 84s by Papa on my kit’s devices would have to be a last resort!
They do look nice.
By way of addressing concerns about the silicone insulators vs mica and
goop, we see that mica and goop are .3 - .4 deg C/watt and the silicone
is about .5 deg. For the 30 watts involved we are looking at 4 or 5 deg C.,
difference, with a junction temperature of about 100 deg C.
Not enough to lose sleep over.
goop, we see that mica and goop are .3 - .4 deg C/watt and the silicone
is about .5 deg. For the 30 watts involved we are looking at 4 or 5 deg C.,
difference, with a junction temperature of about 100 deg C.
Not enough to lose sleep over.
For me it's more a "tap" than a "thump". Really, really mild. Not concerned at all.
It’s not simply because it’s a linear PSU but because there is a cap multiplier that has a slow ramp up. This prevents the sudden voltage spike from a turn on transient.
Cut the amp power off on the smps brick AC side, then the short time thump sound in the speakers is even milder
Your speakers are also less than 90db efficiency. That will be worse with more efficient speakers.
Well, it’s a mild ramp down on turn-off as well. The initial 1000 uF caps that I added to the power rails reduced the thump, but didn’t eliminate it.