BHK Preamp Bias

What is the effect when increasing the bias in the BHK Preamp from 4 milliamperes to 5 milliamperes?
Thank you.

I found the answer to my question in the tube rolling section. BHK himself gave the explanation I needed. I am surprised this information is not in the BHK preamp manual.

It’s there on page 10 below the picture :wink: but no effect listed.

Correct - Thank you Serhan.


1 Like

I’m currently adjust to 5ma by using 12au7 , improved the dynamic and more solid bass response

This is interesting. Some people reported lower detail!
What’s the brand of your 12AU7 tubes?

Edit: tested 5mA with 12AU7. System became too harsh for my ears, especially strings. Happily went back to 4mA :slightly_smiling_face: