I updated my 22/7 PCB. I had these boards made at PCBWay.com. These boards are great quality. Very cost effective. I’m a fan of OSH Park.com. They are good when you want only three boards, are in the US and need quick shipping. The PCBWay boards are very clean, they offer a range of colors, and their design rules support smaller trace sizes. If you need three boards and need them quick OSH Park is good. If you need more than three boards and can wait for slower shipping PCBWay is the better deal.
The 22/7 is a design by RunOffGroove.com. It’s a very innovative take on the Big Muff. It replaces all of the transistors with CMOS inverters. This version uses a 4049UBE hex inverter. I’m working on a version that uses the 4069UBE. Look for that in the future!
Hex inverters have been used in many popular pedals. These have a great amp like over drive. In the case of the 22/7 I’d say the magic happens in the first and last invert stages. Looking at the schematic you can see the second and third stages use the hard clipping from the Big Muff. The first stage can be over driven from the input and the last stage can be driven from the preceding stages. I think this keeps this circuit from getting that closed off over saturated sound you can get with a Big Muff when the input is too hot or the gain is too high.
I designed this board with the power at the top and other off board connections at the bottom of the board. I used the style from PedalPCB.com. I think everyone should do this. It makes for a clean and easy to assemble board. I didn’t even have to look any the wiring diagram as. I built this one.
With the pots, switch and LED on the board assembly is a snap. It also makes it easy to remove it all from the box if necessary. The clean assembly makes for fewer errors also!
I built this one in a love green powder coated box. I had some of these knurled aluminum knobs. I really like these knobs they have a great grip and the size is good. If the line was on the top they would be perfect.
I also used one of these Taiway short shaft switches from LoveMySwitches.com. I like the feel of these. I feel like I’m not going to break the shaft or accidentally switch it.
Leave a Reply