Rockin the Mockman!

Way back in September 2021 I built a RunOffGroove Mockman. The circuit is based off the distortion found in the Rockman amp line, from Tom Scholz Research and Development Inc. Once it was built it sounded amazing, but I still wasn't completely happy with the circuit. Firstly it was way too loud, of course it could be turned down but it felt odd that the volume was on five or six and my ears were bleeding. Second, there was no way to control the gain, which really isn't the point of the circuit, but still it would be a nice option to have. Finally there was no tonal adjustment at all, leaving you to shape everything else around the Mockman. Again, the circuit sounded great as it was, but I felt it could be improved.

The circuit sat in my done, but no clue what to do with box, and from time to time I would ponder what its future would be. Eventually I decided to search around to see if anyone had added a gain control to the circuit, and to my surprise there seemed to be only one person, besides myself, who wanted to do so. A person by the name of Elijah-Baley said they adjusted a resistor value, replaced a jumper with a potentiometer and created a working gain control. I decided to try this out and see how well it would go. As suggested by Elijah I replaced the furthest left 1Meg resistor with a 22k-47k resistor, I split the middle (kind of) and used a 33k. Then I replaced the jumper that is left of that with a 1Meg potentiometer, I used a C1Meg on mine. And to their credit, it works! It doesn't clean up the pedal entirely, but if you need a clean signal just turn the pedal off. As far as the gain control goes, it does work.

Stock layout from
http://tagboardeffects.blogspot.com

Gain Mod
(Wired for Reverse Log)

Now that I had a working gain control I felt I'll take it one step further (in for a penny!) and try to get more tonal adjustment out of it. A well known mystery of the ROG Mockman is the bass switch, which really only seems to serve as some kind of placebo. I mean, if you flip a switch you expect something to happen, so your brain does something to fulfil that request, but in reality whether the switch does anything is still up for debate. Still being new to building and modifying circuits I looked for the easiest way to add tonal control, and the answer came in the form of a BMP tone stack. The BMP tone stack is named such as it is the tone stack used within Big Muff Pi pedals to give some form of tonal control.

Stock BMP Tone Stack

The BMP tone stack is super simple, highly customizable and doesn't require very many components at all. I downloaded the tone stack calculator and fiddled with the components until I found what I thought would be a pleasing tone stack. In the end I used two 22k resistors for R1 and R2, and upped C1 to a 47nf capacitor. This gave me a bit of a scoop but also allowed me to adjust for single coils and humbuckers. Now I'm not saying this is the definitive tone stack for this circuit, it's just what worked best to my ears. Many of you familiar with BMP tone stacks will also notice I used the passive version, which helped cut down the extra volume from the Mockman perfectly! You know what else adding the tone stack did? It made the bass switch noticeable. Before there honestly seemed to be no change whatsoever, but now there is a noticeable bit of bass/bass cut, depending on which position the switch is in.

Now that my Mockman has a working gain control, tone control and, while still loud, it no longer makes my ears bleed, this circuit is much more versatile and useable than I felt it was stock. These mods might not be for everyone, and that's fine, but I figured that someone else out there might enjoy tinkering with theirs, and these are a few good mods to start with. Both mods are highly adjustable, super simple and add much more versatility to the circuit. I give all the credit of the gain control to Elijah-Baley (if there was a way to link to them I would) and the BMP tone stack to Beavis Audio. I hope this starts someone on their own journey in modifying not just the Mockman, but other circuits as well, the same way it did for me. Please use these mods, adjust these mods and perfect these mods, and report back as to how you adjusted them to your own tastes. My chosen values might not be the best, and I'm very interested in seeing what someone else comes up with.