Sanken CU41

[radardoug]

Hi all, just repaired a Sanken CU41 that was noisy. Sanken were useless, wouldnt supply a schematic, so I had to draw it out. Here it is for anyone who needs it. For refernec it was a faulty cap, C8.

 

[imrc]

Amazing mic, one of my favorite fet microphone with Josephson C700a, Neumann U77 and Neumann U397, thanks for sharing!

All the best from France,
Matteo

 

[dirty1_1garry]

Great mic, great info!

What is dual impedance converter block? One more fet circuit?

Here is what I've collected about CU41 (img, docs):
https://yadi.sk/d/5ni3s2n-g7BQAQ

 

[RuudNL]

This is what is inside the impedance converter block.

 

[living sounds]

Are there really 3 resistors in series (R12, R13, R14)? Why would they do that?

 

[dirty1_1garry]

Are there really 3 resistors in series (R12, R13, R14)? Why would they do that?

You mean R2, R3, R4? I think that's fo adjusting for an exact fet transistor.

 

[living sounds]

You mean R2, R3, R4? I think that's fo adjusting for an exact fet transistor.

Ah, ok. That makes sense. Thanks!