Aleph 2 uneven temperatures

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Thank you. Now a mosfet is cold!

I am thinking the batch was flawed. I ordered 1% 5w 1ohm resistors for the mosfet source. I hope this improves the matching!

The funny thing is that bias drops with time. it is supposed to be 3A and that value is reached only in the beginning when the amp is cold. then it drops to 2.56A. could it be a "cold" mosfet is causing this?
 
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no pictures , no measurements in important points , and you are expecting even additional confirmation of everything we replied to you ?

I understand lack of experience , but you really need to read what people are replying

temperature equilibrium is just that - equilibrium - it doesn't matter is it on 35 or 50C

crank up that bias and enjoy
 
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I haven't measured with new configuration of rc. The amp is completely silent with my ear placed directly on high efficiency speakers. The caps are 50v 69,000uf
The amp is quite manageable. It will be encased in black plexy once finished

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Ok, got it on the transformer front.

Bias for Aleph 2:
Looking at the lower portion of the output stage (the 6 drive outputs):
(voltage across Source resistor / Source resistor value = current in that device)
0.5V/1R=0.5A or 500mA multiply that by 6, which is 3A.(0.5*6)

I'm not quite sure what the voltage across the lower source resistors will be when R19 is removed, but it will no doubt be higher, my guess is prob 10mV or slightly higher. For ex. when I removed R19 in my Aleph5, it jumped from the standard 0.5V to around .64-.66

You don't measure amplifer bias by voltage across a PS resistor. And the positive half of a Class A amp bipolar power supply will generally have a slightly higher draw than the negative half.

Looks to me like you're right on target. Hope that helps! To the experts, correct me if I'm wrong. I just read stuff and regurgitate it.

-John
 
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