due to a the heatsinks i bought being mislabeled.... Grrr.
i've got working PLH Monoblocks that run just a bit too warm.
.
they currently run ~40v @2A each channel.
the heatsinks are 2x 0.7 deg/W each monoblock
this gives 28degrees C above ambient, which might be ok if i was back in the UK, but i'm working in China where the ambient with AC is ~30degrees.
currently i've blue-tacked fans on top, but this has low WAF and is a little noisy,
options are reduce Vcc a couple of volts, or reduce Bias.
in the PSU i have CRCRCRC the R's are currently 0.1 or 0.05 i could easily up the first R to 1-2R to drop a few volts,
or would i be better to drop Bias by a similar amount?
advice appreciated
i've got working PLH Monoblocks that run just a bit too warm.
.
they currently run ~40v @2A each channel.
the heatsinks are 2x 0.7 deg/W each monoblock
this gives 28degrees C above ambient, which might be ok if i was back in the UK, but i'm working in China where the ambient with AC is ~30degrees.
currently i've blue-tacked fans on top, but this has low WAF and is a little noisy,
options are reduce Vcc a couple of volts, or reduce Bias.
in the PSU i have CRCRCRC the R's are currently 0.1 or 0.05 i could easily up the first R to 1-2R to drop a few volts,
or would i be better to drop Bias by a similar amount?
advice appreciated
Just about all electronics are rated for 85c or better, 58c shouldn't be a problem.
If your amp is properly set up, think about new heatsinks instead of electrical changes.
If your amp is properly set up, think about new heatsinks instead of electrical changes.
Pluss 1. 58c should be okei. Reducing voltage by up the R in the PSU is not a good idea. That will kill dynamics.
As long as your heatsinks are below 60°C, there is no risk of skin burn.
This is why 60°C is the maximum allowable temperature that something that can be touched may reach.
For the components themselves, my fellows did already answered.
BTW, power supply current is constant in A class amps, so raising R is not a problem, except for the R itself (heat). But again, no need to do that.
This is why 60°C is the maximum allowable temperature that something that can be touched may reach.
For the components themselves, my fellows did already answered.
BTW, power supply current is constant in A class amps, so raising R is not a problem, except for the R itself (heat). But again, no need to do that.
Or use both options together. A couple of volts less and say setting Iq to 1.8 amps would bring the dissipation down by 12 watts or so.
i'm thinking about 10deg less heat, so around 12w
the amps reach 60+ deg. depending on ambient.
i fitted 60 or maybe 70 degree thermal switches inside, and these tripped without the fans. i need to check if they were 60 or 70.
i'd rather not run the amps so hot, it's not great for component life.
as mist speakers are nearer 4 ohm than 8 in reality, i guess losing a couple of volts would be best.
the amps reach 60+ deg. depending on ambient.
i fitted 60 or maybe 70 degree thermal switches inside, and these tripped without the fans. i need to check if they were 60 or 70.
i'd rather not run the amps so hot, it's not great for component life.
as mist speakers are nearer 4 ohm than 8 in reality, i guess losing a couple of volts would be best.
Depends on if you need 40V rails for your speaker load.
A slightly naughty option is to wind on extra windings onto the secondaries in the opposite direction to drop V, but that adds heat, which is already a problem for you....
A slightly naughty option is to wind on extra windings onto the secondaries in the opposite direction to drop V, but that adds heat, which is already a problem for you....
Shame you added a btw!
You are wrong.
Most ClassA amplifiers are NOT constant current !
you could add a small amout of resistance BEFORE the smoothing bank.
You already have an rCRCRCRC supply. The little r is the resistance before the smoothing bank.
Just increase that with an added R of maybe 0r5
That 0r5 + r will directly impact on the effect of the first C since it is a filter in it's own right.
But it ALSO increases the source impedance seen by the second anf third and fourth stage capacitors. It increases the filter effect of ALL 4 stages.
You can also increase the final C to CC to remove the objection made by Audiosan
he considered the wrong end of the smoothing bank. It's the last C that determines the transient current fed to meet the speaker demand, not the first or second r/R.
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