SHO variant...

[GenoBluzGtr]

I built this on Vero. It's the Zvex SHO circuit, but I altered a a couple of components... the 10uF cap was upped to 22uF; I used a C10K pot instead of 5K, and I changed the Source leg resistor to 8.2K. These changes seemed to take a tiny amount of the glassiness out of the top end, and gives me a larger sweep on the single boost control. With this arrangement, I can get well BELOW unity gain compared to the original where it started "boosting" pretty quickly on the dial. I don't think this one gets quite as loud as the original, but that's fine with me, it goes WAY higher than I would ever use.

This was also my first 1590A build that wasn't a kit. Stuffing all the required components in here is exhausting! But it's a very nice boost pedal.

The graphics are a nod to "Leroy Green" of the movie "The Last Dragon".. his tagline was always "Sho-Nuff!", and I couldn't think of a better way to capture the 'SHO' part of the pedal name.

Short Demo here:

 

[Chuck D. Bones]

Nicely done! The 10uF was already overkill, so the 22uF outta sound the same. I think you meant to say you increased the drain resistor to 8.2K. You must have done it after you shot the photo of the board, because I see a 5.1K in the pic. Basically every part in this thing is negotiable.

 

[GenoBluzGtr]

Correct... I am still a Collector Emitter Base guy, and am just getting used to using "Drain/Gate/Source" terminology! And you're right, I first built it with the original components (pictured), but after testing started messing around with the pot/cap/resistor values.

 

[GenoBluzGtr]

Forgot to mention that I moved the pot to the side. I did this because I typically place my lead boost on my board under the wah pedal, and have, in the past, inadvertently hit the volume knob of my previous boost... only to realize I had turned up the volume to painful levels at my next solo! This keeps the knob out of the way of my heel!