drew.spriggs
Well-known member
I've been making these for a while, and it's such an incredible circuit that I definitely want others to try it out. Has anybody seen something similar to this staging? I've done a bit of searching for similar distortion pedals and haven't come across anything at all.
Of all places, it originated from a Redditor who was messing around with designing some interesting circuits. She was big on just breadboarding stuff to see what happened, and designed to try and emulate the response characteristics of a couple of tube stages with BJT's. I took one of her schematics as a basis, made a couple of changes to suit what I wanted (adjustable bias, condensed a few parts to fit on my standard PCB layout I use, etc) and knocked it up - and boy oh boy am I glad I did.
What we've got is a two transistor distortion, with a couple of little tricks up its sleeve; you'll notice some odd values in odd spots, a trimmable bias, diodes to limit gain of transistor stages, etc. The result is a very high gain, very articulate pedal and with a dedicated mids control after a buffer allowing you to dial in anything from Metallica-ish scooped stuff, to anything modern and downtuned. As well as being incredible articulate, I've directly compared this against a stack of other high gain pedals and the noise floor is better than most of them!
All the parts are incredibly common (you've probably got them at home), you can run basically any BJT you've got on hand (I've built with 3094/2222A/5088 and it works fine) and sounds absolutely incredible. Depending on your transistor choice you can get away without C9, but I found that for any higher gain BJT's I needed it to reduce oscillation at max gain. I've got it down as trimming to 2.7v which suits the transistors I used, but you can play around a little - all I've checked sound the best between 2.4 and 2.9v.
I do have offboard power filtering (not shown), but I just run a ferrite bead into a 220u electro/100n ceramic - nothing fancy whatsoever.
I've only got a couple of quick demos one of my very happy buyers recorded for me, but I've taken a few of these in to local pedal shops and the feedback has been universally positive (and I even sold a couple to people who worked at the shop for personal pedals).
Definitely give it a shot if you've got a couple of hours free as I guarantee you won't be disappointed!
Of all places, it originated from a Redditor who was messing around with designing some interesting circuits. She was big on just breadboarding stuff to see what happened, and designed to try and emulate the response characteristics of a couple of tube stages with BJT's. I took one of her schematics as a basis, made a couple of changes to suit what I wanted (adjustable bias, condensed a few parts to fit on my standard PCB layout I use, etc) and knocked it up - and boy oh boy am I glad I did.
What we've got is a two transistor distortion, with a couple of little tricks up its sleeve; you'll notice some odd values in odd spots, a trimmable bias, diodes to limit gain of transistor stages, etc. The result is a very high gain, very articulate pedal and with a dedicated mids control after a buffer allowing you to dial in anything from Metallica-ish scooped stuff, to anything modern and downtuned. As well as being incredible articulate, I've directly compared this against a stack of other high gain pedals and the noise floor is better than most of them!
All the parts are incredibly common (you've probably got them at home), you can run basically any BJT you've got on hand (I've built with 3094/2222A/5088 and it works fine) and sounds absolutely incredible. Depending on your transistor choice you can get away without C9, but I found that for any higher gain BJT's I needed it to reduce oscillation at max gain. I've got it down as trimming to 2.7v which suits the transistors I used, but you can play around a little - all I've checked sound the best between 2.4 and 2.9v.
I do have offboard power filtering (not shown), but I just run a ferrite bead into a 220u electro/100n ceramic - nothing fancy whatsoever.
I've only got a couple of quick demos one of my very happy buyers recorded for me, but I've taken a few of these in to local pedal shops and the feedback has been universally positive (and I even sold a couple to people who worked at the shop for personal pedals).
Definitely give it a shot if you've got a couple of hours free as I guarantee you won't be disappointed!
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