Son of Ben biased but sounds farty
- Thread starter prsman
- Start date
Tried finding recommendations but no luck
There's some good info in this thread
Before swapping anything, I'd try biasing by ear. Anything between 3.5-6.5v seems fair game, depending on the particular j201. 4v is really just a starting point.
There's some good info in this thread
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 long, short, or common. Ha. Here ya go..."Benson preamp"
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 long, short, or common. Ha. Here ya go..."Benson preamp"
Before swapping anything, I'd try biasing by ear. Anything between 3.5-6.5v seems fair game, depending on the particular j201. 4v is really just a starting point.
Feral Feline
Well-known member
Some people are paying good money for Fart Pedals. Just sayin'.
Lytt Effects
Active member
I don’t feel like searching it down, but there was a thread somewhere on the interwebs about this. The original Bensons had trim pots for Q2 and 3, but just a 2k resistor biasing Q1. There is an unknown reason for this, but that’s why the build documentation says that.
In the unit tested, Q1 was biased to ~5V while Q2 and 3 were at ~4V. However, Mr. Benson himself has stated that all three J201s should be biased to 4V.
Moral of the story is, just bias Q1 to where it sounds good to you. J201s are finicky as hell, so get it to around 4-5V on the meter and adjust to taste. In all of my Benson builds, I set the bias for Q1 to 5V and Q2-3 to 4V, as this is my preference. I have done all at 4V as well, and it sounds good, I just like Q1 at 5V a tad more. Why? Couldn’t tell you, just feels better, which is guitar player for “reasons”.
In the unit tested, Q1 was biased to ~5V while Q2 and 3 were at ~4V. However, Mr. Benson himself has stated that all three J201s should be biased to 4V.
Moral of the story is, just bias Q1 to where it sounds good to you. J201s are finicky as hell, so get it to around 4-5V on the meter and adjust to taste. In all of my Benson builds, I set the bias for Q1 to 5V and Q2-3 to 4V, as this is my preference. I have done all at 4V as well, and it sounds good, I just like Q1 at 5V a tad more. Why? Couldn’t tell you, just feels better, which is guitar player for “reasons”.
