Planning to make Dr Boras 4s Class A amplifier

[Kannan_madhu]

Hi
4S is a class A amp by Dr Bora Jagodic. It is a simple amplifier with few components. I have made a layout for the schematics. Now, I have to make the test PCB, and soon I will update the progress.

 

[Kannan_madhu]

got the pcb made starting the assembly

 

[Kannan_madhu]

Finished the board and it worked but sound was not clear and while probing accidntly shorted it with the multimeter probe something went kaput . But no visible burns hope the mosfets are ok .

 

[sashijoseph]

Nice work Kannan.

Is the other preset for centering the dc voltage on the output cap?

Hope you get it working....and please share your observations on thermal stability as also the tonal quality compared to a JLH classA.

 

[Kannan_madhu]

Nice work Kannan.

Is the other preset for centering the dc voltage on the output cap?

Hope you get it working....and please share your observations on thermal stability as also the tonal quality compared to a JLH classA.

Yes, it's for setting midpoint, one resistor was gone and I replaced it and it worked, but the gain was too high,h found that I put 4.7R instead of 4.7k
changed it and it worked fine .
I like the warm sound of JLH compared to this. Usually, most FETs give a good amount of warmth, but I felt it's a bit less compared to JLH.

 

[Kannan_madhu]

 

[Kannan_madhu]

recorded with a mobil,e