# Biasing Son of Ben preamp



## cooder (Mar 5, 2020)

So I just populated the Son of Ben / Benson preamp board and it seems to work fine, just wondering about the recommended bias settings of trimmers.
On schematic it says "adjust Trim 1 to 2K" while the other trimmers are given with drain volatges measured at transistor. The later makes more sense to me, why not giving a target drain voltage for Trim 1 as well...? And if it should be 2 k, why a trimmer and not a fixed resistor?
A bit baffled, what am I missing here?


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## Nostradoomus (Mar 5, 2020)

Give this thread a good read through, you’ll get it!






						Trimpot Adjustment - Son of Ben
					

The build doc says  Is there a way to test trim 1 without removing is from the enclosure? For Q2&3, is it the same as when biasing a fuzz face? One probe to ground and the other on the drain?  Thanks!  *Edit for future forum searchers* "son of ben" isn't searchable because the words are too...



					forum.pedalpcb.com


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## cooder (Mar 5, 2020)

Nostradoomus said:


> Give this thread a good read through, you’ll get it!
> 
> 
> 
> ...


Excellent, just adjusted the populated pcb it this way, all good! Thanks for the quick help and pointer, muchas gracias!


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