Son of Ben (Benson Preamp)

[jcpst]

This is my first build with smd components on it. When I first fired it up, there was no signal. So I took my audio probe and it was silent on the source leg of Q3. I added a quick little dab of solder and it fired right up.

I’ve had mixed feelings about the whole amp in box with jfets replacing tubes, but I couldn’t quite put my finger on it. The distortion never quite sounded right.

Here’s what I thought comparing pickups and the amount of drive on the pedal.

Single coil	low gain	Good
Humbucker	low gain	Good
Humbucker	high gain	Good
Single coil	high gain	Gross and squishy

This thing really shined when I plugged it directly into my fx loop return, using it in place of the amp’s preamp.

Over all I really like it, but just not with single coils and high gain.

 

[HamishR]

Is that your herb garden? It's very green!

Funny you should that about Jfets. I have friends who swear that Jfet ODs are the best. I've heard some good ones but agree with you about the squishiness sometimes. Some people like that, some don't. I have some great ODs which use the distortion of BJTs and they have a chewy, tactile feel which is cool. But I find that I like the results I get with the regular IC and clipping diodes most of the time.

 

[bechbox]

Did you remember to bias the jfets?

 

[jcpst]

Did you remember to bias the jfets?

I tried with a dmm but it didn’t seem like I was doing it right. So I did it by ear until I got the sound I liked the best.

 

[Noodles]

I tried with a dmm but it didn’t seem like I was doing it right. So I did it by ear until I got the sound I liked the best.

I read through this thread (assume you did too): https://forum.pedalpcb.com/threads/trimpot-adjustment-son-of-ben.1207/

I tried two methods from the first page. Both sounded fine. One was dirtier, one was cleaner, both were usable given the amount of gain I would normally dial in. Thusly, I'm sure doing it by ear would work well too.

I gigged with it for the first time a week ago (and with no band practices or much testing). Worked great. I wound up boosting it with a klone set as a boost most of the time, but that likely reflected my inability to set the amp suitably rather than anything wrong with the Son of Ben.

 

[jcpst]

Thanks for sharing, I didn’t come across that one yet.