Built and test this second version of the 22/7 by RunOffGroove.com. Sounds good. This is a great alternative for Big Muff fans. The OSHPark project is public and verified.
22/7 is a Big Muff built around CMOS inverters in place of the transistors used in the traditional BMP circuit. The CMOS inverters have a tube like sound when over driven.
Order PCB here: 22/7 PCBs on OSHPARK
|RANGE||ON OFF ON|
If you don’t want to build your own this one is for sale on Reverb.
Harvesting parts from these old PCBs. I had this need for a A100K pot and Christmas 🎄 has holding up the deliver from Tayda Electronics. So I started digging through my bin of old projects that never made it into a box 📦.
I didn’t my ideal A100K pot, it would have been 16mm with legs, but I did find a couple 12mm pots which might sub. These have a D shaped shaft which makes them harder to fit for knobs.
While not finding what I was looking for was disappointing, I think I may have raided this bin at an earlier date, I did find some surprises. I found at least a half dozen J201 Fets, and a 4049UBE hex inverters. The J201s are great for stomp boxes and hard to get these days.
There was also a few 3PDT switches and a bunch of 1/4” jacks along with a handful of other things. Switches and jacks can always find some use. Personally I prefer the open frame Switchcraft jacks but these plastic ones are a good second choice.
This is the second version of the UBE Screamer board. This version fixes a mistake with the reverse polarity diode. I’m calling this ready for public consumption and will add it to the OSH Park projects pages soon.
The enclosure is grounded through the jacks. The bottom cover though doesn’t make an electrical connection to the main enclosure body due to the powder coat. I used a drill bit to remove the powder coat inside the count sink recess, this allows the screw to make contact with the back cover for full shielding.
|R13||Rx (see note)|
This UBE Screamer by RunOffGroove.com is a unique twist on the venerable Ibanez Tube Screamer TS-808. It replaces the op-amps and transistor stages with a single hex inverter using an inverter in place of each op-amp and transistor. This has a great sound that stands up to all of the other overdrives. Read more about it over at RunOffGroove.com
Well worth the effort, build it yourself! I’ve created a public project at OSH Park. Order boards and follow the build docs.
These are some more PCBs from OSH Park. There is an IC Big Muff, Tube Steak, and a Woolly Mammoth.
The Tube Steak I created from a schematic posted by Charlie Barth at Moosapotamus.net. Tube Steak Fuzz is a cross between the Tube Sound Fuzz, and Way Huge Fat Sandwich. Here’s a link to Charlie’s article read it for yourself: Tube Steak Fuzz.
The IC Big Muff also called the op-amp Big Muff was a version of the Big Muff that used two op-amps in place of the four transistors used in the classic Big Muff Design. Here is a link to more information in the op-amp Big Muff.
The Woolly Mammoth is a PCB design that I made as a clone of the ZVex Woolly Mammoth. I really like the sound of this one. Designed as a fuzz for bass, it sounds good with guitar also. The design is based on the Fuzz Face.
Here are some good articles on using CMOS chips in stompboxes.