Fuzz Factory – OSH Park

Just soldered the first of three Fuzz Factory PCBs from OSH Park. Fired up on the first try. The board didn’t come with documentation, I had reverse engineer the board against the schematic to verify part numbers. Here is the schematic I used:


I used some AC128 transistors for Q2 and 3. The random choices from the lot sounded alright. I built this first board with sockets for the transistors for testing. I can test transistors on this board, if they sound good I can solder them into the other boards.

I like this board, the layout has pads for 16mm or 9mm pots. The width fits the narrow dimension of a 1590B box, which gives you the option to arrange the box in landscape like the original, or in portrait, like most standard stomp boxes. The Stab and Volume pots are mounted off board. While this adds some wiring, it saves cost by making the board smaller, OSH Park charges by the square inch, it also provides flexibility in how the box can be arranged. Hats off to the designer. Hats off to mr vex also.
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Osh Park PCBs

IMG_1158.JPGI just received this order from OSH Park. I order four boards. You are required to buy three copies of each board you order. The cost is $5 per square inch for 2 layer boards (with 3 copies of your board included in that price). Which is not bad, if the boards are small it’s a deal. For example, the SHO was $3.20 for three boards! The Fuzz Factory boards, were $7.75 for three, still a good deal. The Haunting Mids boards were just under $5 each, and the Zeke Bass Distortion was about $8.50 each.

Of course getting boards for designs that people upload with little info can be chancey. There should be more options on the site to comment, and mark boards as verified. Looks like not all projects are shared. User decide to share a project. Hopefully people make an order and test it before sharing.

The quality of the boards is great. A couple things I noticed. There is no solder mask. The pads are gold plated, which is nice. I find the solder mask easier to solder with. Look at the firstĀ image. You can see the backside of each of the four boards. Notice the board in the upper right. The pads are fairly small. I think, this is the default pad size in Eagle PCB. It’s not easy to solder, It’s not super difficult either. The two on the left have a more generous pad size. This size makes for a better soldering experience.

I’ll post again when build these boards…

For reference here are some links to the boards I ordered here:











5 Knobs

Here’s an idea I have been wanting to try in a stompbox. Small Bear carries post with long leads that can be used to mount the pot to PCB. I thought these might be good for mounting a board inside an enclosure. This is a clone of everyone’s favorite 5 knob fuzz.

This seemed to work well. But I think the knobs are a little hard to see for adjusting. Then again you might be adjusting by ear abyway. I wanted to place the switch in the center of the box for aesthetic reasons. This left a tight fit in the center of the board for the transistor, which I haven’t added yet.

Overall I would say that these posts work well to support the PCB. Mounting them to the board also does away with a lot of wiring which makes for a nice build. The down side is that they are difficult to solder to a board created with Perf. If the board had plated through holes this would not be a problem. The other down side is that this type of build could be difficult to modify or repair. As the back side of the PCB is hidden behind the pots.