DOD FX52 Classic Fuzz / FX55B Supra Distortion New PCB Layout Verified

[bloxstompboxes]

Hello! So I had an original FX52 a year ago or more, which I bought broken on ebay and fixed it. I sold it back for a little profit and I kind of miss it. Rather than buy another, I figured I'd try and build one. I used the schematic in the build document below and did my own PCB layout. I edited out the switching in the scheme. Thanks to whoever drew it to start with. It works well, and seems to have lots of opportunities for mods so I thought I would share it.

NOTES: The masks in the build documents are just for reference, like checking for solder bridges. They are not to scale and should not be used for etching. Use the last link below instead. R24 and R25 are your LED current limiting and pulldown resistors. I had forgotten the pulldown on my prototype board but added it here. Wire SW1 to your proper switch lug for GND to light your LED, when the effect is active, if you board mount it. It's fairly centered on the board. D1, D2, and D8 are not used on the FX52, unless you want them to be. D8 is for asymmetrical clipping in the feedback loop of the FX55B. Jumper it if you want it stock, or put it on a switch like I did. Watch your pot numbering and wiring. 3 1 2 and 100kb for the FUZZ, 1 2 3  and 100kA for the Vol, and 3 2 1 and 100kB for the tone. On another FX55B scheme it shows 100k for the dist pot, and 27ohms for it's series resistor to GND. I used 100kA for this dist pot and I used the 27ohm resistor too. I found on the tagboard effects site that they had used these values. The distortion seems all bunched up at the end of the pot so I will have to try a reverse log pot on my next part order. The Classic Fuzz works 100% though.

Build Documents:

FX52: https://www.dropbox.com/s/d65va0h6a48f1vc/DOD%20FX52%20Classic%20Fuzz%20Build%20Document.pdf?dl=0

FX55B: https://www.dropbox.com/s/owovul24ss26f7c/DOD%20FX55-B%20Supra%20Distortion%20Build%20Document.pdf?dl=0

Mask for Etching Either One: https://www.dropbox.com/s/v3hz8cyj4r0vfh3/DOD%20FX52%20Classic%20Fuzz%20Mask%20Etch.pdf?dl=0

Please post here if you build it and please put up a video if you want or to show your mods. I did mine stock except for the asymetrical switch on the FX55B.

[Kipper4]

Nice work Eric.
Great docs. Thanks for sharing.
Rich

[bloxstompboxes]

Nice work Eric.
Great docs. Thanks for sharing.
Rich

No problem Kip. Let me know if you build either one and how it all goes!

[bloxstompboxes]

The FX53 Classic Tube seems to use the same layout as well with only a few part value changes from the FX55. I'll add that document when I have a chance.

[bloxstompboxes]

The following link is a build document for the FX53 Classic Tube. While I haven't built it yet, the only thing that changes from the FX55B is a couple of parts values. Once again I would recommend C500k pot for the distortion. I've etched a board and will start putting in the parts once I get it drilled. I'll try to post my results when done.

https://www.dropbox.com/s/rqa3nix87jdr47v/DOD%20FX53%20Classic%20Tube%20Build%20Document.pdf?dl=0

EDIT: Oops. Corrected title and date in document.

[bloxstompboxes]

Found an error on the build doc for the classic tube. I had left out the 120pF or C9 in the BOM. Sorry about that. It has been corrected in the new link: https://www.dropbox.com/s/rqa3nix87jdr47v/DOD%20FX53%20Classic%20Tube%20Build%20Document.pdf?dl=0

As for the sound of the 3, the classic fuzz is the only boxed one at the moment but I have managed to rock the other two with reverse log pots on their respective dist controls. I must say that I am most pleased by the classic tube over the other 2. The classic fuzz might be my least favorite. The supra has a weird boost effect on the bottom and top ends of the tone control. You either have a sudden boost in bass or treble, but it is somewhat interesting. All three use the same tone circuit, of course, but with different values. I think the classic tube is less rare than the classic fuzz and the best out of the 3, strangely. Once I get them all boxed, I might do a side-by-side for anyone interested.

I must add that the mod of having a switch for symmetrical and asymmetrical clipping in the feedback loop is a must. And, I very much prefer the asymmetrical option over the standard one.