Son of Ben (Benson Preamp) Modifications Thread

[Bricksnbeatles]

Inspired by @Big Monk’s recent modifications threads for the Electrovibe, XC Phase, and Hydra Delay, I thought it would make sense to create a dedicated thread to compile all of the popular modifications made to the Son of Ben circuit (Link to the PCB here).

Let's list them and see what we can add/subtract/clarify:

1.) omit c10 (c10 only existed in the first few Benson Preamps produced, and makes the pedal just a little bit more gainy) for current spec/less gain*
2.) reduce c10 value (gives light mid boost effect according to this comment from our resident guru, @Chuck D. Bones)*
3.) 18v charge pump (and increase capacitor voltage ratings accordingly) for more headroom**
4.) omit c5 (and c10) for noticeably lower gain


Not a ton of mods here so far, but it seems like a popular one to modify, so I’m sure we’ll be able to add more to this list together!


* these two could be combined by using a spdt or dpdt on-off-on switch (just depends on how neat you want your off board wiring to be) with a 10u and 4u7 (or other, smaller value) cap, giving you early spec(10u)/modern spec(none)/mids(4u7)

** using the spdt pads on the charge pump daughterboard, you could wire up an external on/on switch to allow both 9v and 18v operation

 

[Big Monk]

Inspired by @Big Monk’s recent modifications threads for the Electrovibe, XC Phase, and Hydra Delay, I thought it would make sense to create a dedicated thread to compile all of the popular modifications made to the Son of Ben circuit (Link to the PCB here).

Let's list them and see what we can add/subtract/clarify:

1.) omit c10 (c10 only existed in the first few Benson Preamps produced, and makes the pedal just a little bit more gainy) for current spec/less gain*
2.) reduce c10 value (gives light mid boost effect according to this comment from our resident guru, @Chuck D. Bones)*
3.) 18v charge pump (and increase capacitor voltage ratings accordingly) for more headroom**
4.) omit c5 (and c10) for noticeably lower gain


Not a ton of mods here so far, but it seems like a popular one to modify, so I’m sure we’ll be able to add more to this list together!


* these two could be combined by using a spdt or dpdt on-off-on switch (just depends on how neat you want your off board wiring to be) with a 10u and 4u7 (or other, smaller value) cap, giving you early spec(10u)/modern spec(none)/mids(4u7)

** using the spdt pads on the charge pump daughterboard, you could wire up an external on/on switch to allow both 9v and 18v operation

I was just checking this PCB out yesterday when i was looking at the Clandestine. I'll ave to throw it on my list!

 

[jrhevron]

For use with bass: I ended up switching out C6 and C8 for 330n (what I had on hand, though I think anything 100n and above would have been fine). That really opened up the pedal and makes it sound a lot fuller and more useful on bass. Also omitted C5 so that there's more gain before breakup.

 

[jrhevron]

I’m also finding that running the pedal at higher than 9v (12/18) also opens things up for bass. BUT it doesn't break up as well. Has way more headroom before breaking up.

 

[Lytt Effects]

1.) omit c10 (c10 only existed in the first few Benson Preamps produced, and makes the pedal just a little bit more gainy) for current spec/less gain*
2.) reduce c10 value (gives light mid boost effect according to this comment from our resident guru, @Chuck D. Bones)


* these two could be combined by using a spdt or dpdt on-off-on switch (just depends on how neat you want your off board wiring to be) with a 10u and 4u7 (or other, smaller value) cap, giving you early spec(10u)/modern spec(none)/mids(4u7)

So, if one wanted to achieve this, how exactly would it need to be wired up? I have extra switches and would love to have the selectable caps, but I’m fairly new to this and adding a switch to on-board components is slightly above my pay grade right now. Any help in wiring and how-to would be greatly appreciated!

 

[jrhevron]

I’m also finding that running the pedal at higher than 9v (12/18) also opens things up for bass. BUT it doesn't break up as well. Has way more headroom before breaking up.

Also…if you’ve built one and biased it to spec, go back in and do it by ear just to see. I just went back in and found that i liked it much better at a very diff voltage for 2/3. Might be because of my bass mods or because I’m playing bass but I was surprised to find a very diff sweet spot.