ProCo RAT Project

Here's the classic RAT distortion with on-board pots. All the ProCo RATs are essentially the same circuit, just with a few value changes over the years. For this project, the board can be used to make 4 different versions of this great distortion box: The original RAT, the RAT 2, the Turbo RAT, and the You Dirty RAT. Here's the basic schematic:

The component names from the above schematic follow those in the layout drawing below.

The project file with a full BOM, scaled transfer images, and drilling template can be found here.

Thanks to Cody for verifying this ahead of time for me. You sir, are a scholar and a gentleman.

Escobedo Tytewadd

Here's a quicky from the Folk Urban schematic archive for #FuzzFriday. It's a simple circuit with low power draw, so if you use batteries, this one won't drain it for a while. Q1 can be any medium to high NPN silicon.

Catalinbread Formula No. 5

The Formula No. 5 is a 5E3 Tweed Deluxe amp emulating overdrive pedal. It's essentially 2 JFET stages (very similar to the AMZ Booster) with the Tweed Deluxe tone and volume (in this case gain) controls in between. A master volume pot is added at the output for more control. Here's a great demo of this pedal from Just Nick, comparing it to an original Tweed Deluxe.

On the PCB I've added extra +9v and ground pads in case you build this with the DC jack at the top of the enclosure. 

Tokai Metal Driver

The Tokai Metal Driver was built in Japan in the early-mid 80s and is very similar to the Pearl OD-5 of the same era. In some ways it's basically a Tube Screamer, with the same input/output buffers, but the tone control is rather unique and the sound is apparently very different from your standard TS-9. Original units use 2SC1571 transistors with BCE pinouts, but I've drawn the layout for CBE transistors that you're more likely to have on hand. Here's one of the few demos I could find of it. Skip ahead to around 2:30.

MicTester's 1969 Fuzz Box

Her's a unique fuzz circuit from MicTester for your #FuzzFriday. Here's what he had to say about it:

Way back in 1969, I heard "Inna Gadda Da Vida" for the first time. I realized quickly after building some simple transistor stages that didn't work properly that "the" sound was coming from abused transistors! Experimentation over some weeks led to [this circuit]! Just two pots give an amazing range of distorted sounds and none of the components are critical. 

Please tweak away until you find the sound you want! Alter capacitors, change the transistors–experiment!

The original FSB thread with the schematic can be found here.

LM13700 to CA3080 Conversion Board

A lot of older circuit designs (DynaComp, Ross Compressor, etc.) use the CA3080, which is now obsolete and rather expensive. The LM13700 is essentially two 3080s in one chip, and much more affordable. Here's a conversion board to use the 13700 in place of the 3080. Use long header pins, mounted from the solder-side of the board. These can then be inserted into an IC socket in place of the 3080. I'm not the first to come up with the sort of board, but hadn't seen one on perf. So hopefully it will be helpful to some of you out there.

Seamoon Funk Machine

The Funk Machine is a filter effect that can be used on either bass or guitar (or synth, Rhodes, harmonica, etc). It's also like an auto wah, given that the wah effect is controlled by the string attack of the player. Original units used 2, LM741 chips, but I've laid it out for an LM1458 (which is 2, 741 in a dual op amp). Don't try to use a TL072 or JRC4558, as they will not work in the circuit. Check out the discussion of this circuit over on Tagboard Effects for more info.

Orpheum Fuzz

For #FuzzFriday, I give you the Orpheum Fuzz. There seems to be several versions of this circuit (germanium and silicon), but it's essentially a FuzzRite. Since I've already done a FuzzRite layout, I thought I'd do a different one with onboard pots. It's meant for use with silicon transistors, but you could use some NPN germaniums if you want. 100-150 hfe should work nicely for both.

BBE AM64 American Metal

Here's the BBE AM64. While "Metal" is in its name, it seems more suited for heavier rock sounds. 70s metal at best. Nonetheless, it's a very good sounding distortion box. The circuit is essentially a Guv'nor with soft clipping instead of hard, along with a DS-1 tone stack.

TubeSound Overdrive

Here's a simple one-knob drive that's ripe for modification. It uses an interesting combination of one NPN and one PNP silicon transistor stacked together. There are a few different values you can tweak to taste. Here's a schematic for reference:

• The input capacitor (C1) could be increased for more bass.
• C2 could be increased to 47-100µF for more drive.
• The output capacitor (C3) could be decrease for more treble.
• R5 could be replaced by a 10-20k pot, lug 1 going to ground. C2 could then be moved between lugs 1 and 2. This would act as a gain control (much like in a Fuzz Face).
• R3 (trimmer) could be moved off-board as an alternative bias/gain control.

I haven't tried these modifications, but they should do something interesting. YMMV

Roger Mayer Axis Fuzz

For #FuzzFriday here's Roger Mayer's Axis Fuzz, and it's the 100th fuzz effect on the blog. Maybe I should branch out more... It was designed by Roger in the late 60s for Jimi Hendrix, and is named after the title track of "Axis Bold as Love." It uses a PNP silicon transistor for Q1 and NPN silicon for Q2. So while it will give you some Hendrix-style tones, it isn't quite a Fuzz Face. The schematic can be found here.

Casper Electronics EchoBender

Today marks the one year anniversary of this blog. Thanks to everyone for your comments, verifying layouts, and just generally being really cool people. To celebrate, I give you a really cool and crazy delay, the Casper Electronics EchoBender. The EchoBender is a development of/modified Deep Blue Delay. I couldn't quite get it to fit with on-board pots in anything smaller than a 1590BB, but the original is in a giant wedge enclosure, so I guess it's still an improvement. If you feel like wiring 6 pots off-board, you should be able to fit it in a 125B or even a 1590B. From Casper:

The Echo Bender is an echo, distortion and experimental, stand alone noise generator.
It’s capable of creating smooth, clean echos as well as delving deep into screeching, noisy realms seldom heard from a traditional echo pedal.

Here's the link to the 1590BB drilling template.

Tychobrahe Octavia

The Octavia is one of the many legendary effects to come out of the late 60s. It is also one of the rarest pedals of the era, as there weren't many built. Like most effects of its day, the Octavia is a positive ground effect. There are several schematics for it floating around, but the one I based this layout on can be found here. Most positive ground effects I layout I also post a negative ground effect version as well. I haven't done so for this one to keep the classic mojo of the original. If you want to make it negative ground, just rotate electrolytic caps, the 1N4001 polarity protection diode, and use NPN transistors for  Q2 and 3.

Colorsound 3-Knob ToneBender Reissue

I was trolling Google Images the other night looking for schematics and I stumbled across this. I think the only thing this reissue has in common with an original is the enclosure and graphics. It uses a single opamp with soft clipping and a Big Muff-style tone stack. If you use 9mm pots you could probably cram it into a 1590A.

Catalinbread RAH

This one's for those of you trying to nail some Jimmy Page tones. The RAH emulates the HiWatt heads Jimmy used live in the early days of Zeppelin. It uses only 3 MOSFET transistors, and features a 3-band EQ section. I'm going to shut up now so you can hear Andy from PGS put this thing through its paces.