Audio amplifier

redstar1

Joined Mar 4, 2025
4
Hi

Once again, thank you for your replies.
I've checked all the pinouts and made sure all of them are wired correctly. I tried with and without diodes, but still, my fuses burn everytime and the 0.22R's get too hot. I just do not find the cause.
I also measured the mosfets and transistors multiple times and did also check their pinouts.

The only difference in components is that I use a 2N54 trans. instead of the mpsa56 due to delivery issues.
Here is the link to the original blog: https://www.elcircuits.com/2022/02/160w-high-fidelity-amplifier-using.html
 

Ian0

Joined Aug 7, 2020
13,132
Hi

Once again, thank you for your replies.
I've checked all the pinouts and made sure all of them are wired correctly. I tried with and without diodes, but still, my fuses burn everytime and the 0.22R's get too hot. I just do not find the cause.
I also measured the mosfets and transistors multiple times and did also check their pinouts.

The only difference in components is that I use a 2N54 trans. instead of the mpsa56 due to delivery issues.
Here is the link to the original blog: https://www.elcircuits.com/2022/02/160w-high-fidelity-amplifier-using.html
2N54?
Thats a germanium device from decades ago.
 

schmitt trigger

Joined Jul 12, 2010
2,089
Germanium transistors cannot be directly substituted for Silicon transistors, without significantly re-biasing.

QUESTION FOR THE TS: do you have a DMM which you can read the voltages at all the different nodes?

Otherwise we are only guessing.
 
Last edited:

redstar1

Joined Mar 4, 2025
4
Germanium transistors cannot be directly substituted for Silicon transistors, without significantly re-biasing.

QUESTION FOR THE TS: do you have a DMM which you can read the voltages at all the different nodes?

Otherwise we are only guessing.
I do have some gear in house. MM and scope, could get a labPSU if needed. The main problem is the debugging of the issues.
What would be a good alternative for the transistor then?

thank you for your help.
 
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