This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Friday, July 31, 2015

Flying Guillotine Fuzz

For #fuzzfriday I present to you the Flying Guillotine Fuzz, designed by Freppo over on FSB. Here's what he had to say about it on his blog:

The front end, tonestack and the output stage are all borrowed from the Big Muff, but the two Muff gainstages is replaced with a discrete op amp (by Joe Davission) modified with a odd feedback transistor clipping configuration. It's a VERY loud circuit. Way louder then the loudest Big Muff I've built.

Thursday, July 30, 2015

Guitar Direct Box

Got a request for an active DI, which coincided with a project I'm working on, so it seemed like a good idea. This one's designed by Samuel Groner and modified by Jack Orman. The schematic came from his blog and can be found here, along with some other info about the circuit.

Wednesday, July 29, 2015

Golden Dragon Overdrive

Here's a simple overdrive circuit adapted from the National Semiconductor "Ultra High Gain Audio Amplifier" and Jack Orman's "Minibooster" by Andrew Carrell (Dragonfly). It should easily fit in a 1590a.

Tuesday, July 28, 2015

Bearhug FET Compressor

Here's a simple compressor design by Jon Patton (aka midwayfair) that's good for guitar and bass. In Jon's words:

The Bearhug is a tonally transparent, ultra-quiet, tiny, and easy-to-build compressor. It occupies some middle ground between the ultra-subtle compressors like the Flatline/Afterlife and Orange Squeezer and the super squishy compressors like the Ross.

For more info on the design, Jon goes into detail in this thread on DIYSB.

I built this one last night and it's everything Jon says it is. Very subtle, and a little bit of volume boost if you want it. Here's a few pics of my build.

Monday, July 27, 2015

Tres Hombres

The Tres Hombres is a distortion/fuzz designed by Marcelo Trípodi on the DIYStompboxes forum. In a nut shell, it's three similar germanium transistor stages with fuzz and volume controls. There's also a switch to add an extra capacitor at the input to fatten up the sound. Marcelo recommends 2SA101 transistors with an hFE of 50 and leakage of 150ua. Socket and experiment. The perf side of the layout below is for positive ground, and the PCB is for negative ground.

Friday, July 24, 2015

Kay F-1 Fuzz Tone

Here's the layout for #fuzzfriday! The F-1 Fuzz Tone is one of Kay's budget effects from the 60s housed in a plastic treadle pedal. Essentially it's the poor man's Univox Super Fuzz. The treadle would control the Tone pot, with the overall level of the effect fixed at max. This isn't that big of an issue as output is around unity. The circuit can also produce an octave effect as well. Originals used BCE pinout transistors, but the layout below reflects the more common CBE pinout. Originals also used germanium diodes, but silicon can also be used.

If you want to add a volume control, start with a 100k pot (other values may work better, that's just what I'd try first), connect lug 3 to the Out pad on the board, lug 2 becomes Out, and ground lug 1. It may also be useful to add a pre-gain pot at input. Again start with a 100k pot, lug 3 becomes the new In, lug 2 goes to In pad on the board, and connect lug 1 to ground via a low value resistors (470Ω, 1k, etc). No idea how useful these mods would be, just a few basic things that came to mind as I laid it out. If you're adding a Volume control, it might not be a bad idea to put a booster (LPB-1 would work well) between Tone 2 and Volume 3. YMMV

Thursday, July 23, 2015

DOD FX25 Envelope Filter

The FX25 was initially produced by DOD in the early 80s and is an OTA-based envelope filter/auto-wah. It's a fairly tweakable and you can find various mods on other sites, but this is for the stock layout. The original switching circuitry has been removed, so you can use true-bypass. An LM1458 is listed in the layout below, but just about any dual op-amp should work there (TL072, NE5532, JRC4558, etc.), so if you get a little distortion, try a different op-amp.

Update Aug. 10, 2016:

I've fixed the layout as per NapAlpha and Eduardo's comments below. Thanks for catching that guys. Sorry it took me so long to make the fix.

Wednesday, July 22, 2015

Ibanez Dirt Box

Here's a rare one from the 70s by Ibanez. It was originally marketed as the OD-850 Overdrive II (not to be confused with the OD-855). But since the nature of this pedal is more distortion/fuzz territory, it wasn't a great name and it was changed to the Dirt Box. Whatever you want to call it, the circuit is essentially a Distortion +/DOD 250/Ross Distortion with a dual op-amp and a Tube Screamer-like tone control. The 220n capacitor coming off lug 2 of the Tone pot was originally a tantalum cap, but like the Tube Screamer, using a film cap should give better response. The sound is apparently similar to the op-amp version of the old EHX Muff Fuzz (the one that plugged directly into your guitar, not the BMP).

Tuesday, July 21, 2015

Boot-Leg Effectors Rock 'n Roll Party

Here's a very nice sounding British-style overdrive pedal from Boot-Leg Effects in Japan. It uses three-quarters of a TL074 quad op-amp, as well as germanium diodes (most likely 1N60s). Original units use an electrolytic 470n capacitor, but I've laid out the board for a film cap (though the PCB has pads for an electrolytic). I've also added a pull down resistor at the input and some extra power filtering. Here's a demo from another DIY builder.

Friday, July 17, 2015

Sam Ash Fuzz-Stainer

The Fuzz-Stainer is a pretty rare fuzz box made by Sam Ash in the 70s. Don't confuse this with the Sam Ash Fuzzz Boxx/AstroTone, as it's a different circuit. Original units used 2N5173 transistors with BCE pinouts. I've made 2 versions of the layout, one for BCE transistors (on the right) and one for CBE (on the left). 2N2222s or 2N3904s seem like they might be good substitutes. Output is pretty close to unity with the Volume pot maxed, so you may want to replace the 10k pot with a 50k or 100k, and/or reduce or remove the 68k resistor from Volume 2 to Out. To make the trimmer external (like the Jerms clone in the video below), use a B20k pot with lug 3 going to the emitter of Q2, and lugs 1 and 2 going to ground.

Thursday, July 16, 2015

MI Audio Crunch Box

Got several requests for this one. The MI Audio Crunch Box is a versatile distortion box, designed to sound like a cranked Marshall. It's very similar to the Marshall Guv'nor, but with a Rat style tone control. Production models have the Presence control as a trimmer internally, but it makes sense to me to have it externally.

Wednesday, July 15, 2015

ColorSound Wah-Wah

Here's the ColorSound Wah-Wah. I hadn't laid out a wah before, probably because I haven't built one myself before, and I don't use one much when I play. Anyway, the ColorSound Wah-Wah is pretty simple and sounds very good. What makes it unique is that it doesn't use an inductor like most wah circuits. This might be a good candidate to throw a buffer in front, but it's not necessary. There is a volume pot which you could omit if you want (in which case the Volume 3 pad becomes the output). You could also throw this in a 1590a if you wanted a non-treadle/fixed wah pedal. Or if you're really brave, you could mod a 1590a into a treadle pedal like Thomas Hafemann did.

Tuesday, July 14, 2015

fOXX Tone Machine

The fOXX Tone Machine is a classic fuzz box and a very versatile octave effect as well. Pretty standard controls, and the toggle switch controls the octave effect. I've laid this out for onboard pots and octave switch, and added polarity protection and power filtering. 2N3904s or 2N2222s can also be used in place of the original 2N3565. Hope you're stocked up on 10µ caps!

Monday, July 13, 2015

DOD 280 Compressor

The DOD 280 was DOD's first compression pedal made in the late '70s through the '80s. A great sounding compressor, this fairly simple circuit uses an LDR and LED combination (in the form of a VTL5C2) to compress the signal. This one's laid out for on board right angle PCB pots, mounted from the solder side as per usual). I've added polarity protection and power filtering, as well as an input pull down resistor. You can use a VTL5C9 or CLM6000, or a good ol' 1M dark resistance LDR and an LED in heat shrink in place of the original VTL5C2.

Friday, July 10, 2015

Electro Harmonix Triangle Big Muff (again)

Haven't done a Big Muff layout in a while. This is the Triangle version again and is pretty much the same layout as before, but I changed the orientation of the Tone pot. I was going to build this myself and realized that I didn't like how far down the Tone pot was from the other 2 controls, so I tweaked it a little and I'm happier with it now.

Thursday, July 9, 2015

Wampler Distortion Plus Mods

A while back Brian Wampler shared a bunch of mods to the classic MXR Distortion Plus circuit in Premiere Guitar magazine. It adds a tone control, a switchable soft clipping stage, a compression switch, and a bass boost switch.

Wednesday, July 8, 2015

Electro Harmonix Germanium OD

The EHX Germanium OD offers 60s overdrive tones using a combination of germanium and silicon transistors (all PNP). All 3 pots control the voltage is some way. The Bias pot controls the amount of voltage that reaches the Gain control, which in turn controls the remaining voltage that gets to the germanium transistor. The Volts control acts like a sag control on the overall voltage the circuit is running at, so you can emulate a dying battery. I've laid this out for on board pots mounted from the solder-side of the board using right angle PCB mount pots.

Tuesday, July 7, 2015

Fender Blender

The Fender Blender would probably just be a blip in the history of fuzz if it weren't for the likes of Billy Corgan (Smashing Pumpkins) and Kevin Shields (My Bloody Valentine), as it was generally regarded as too harsh sounding. This aggressive fuzz is good for metal leads and also can create an octavia sound on the neck pickup with the Sustain control rolled down. The Boost footswitch is actually a tone boost, and uses a SPDT switch (or DPDT if you want LED indication). I've laid the circuit out for on board, right angle pots, mounted from the solder side (or you can use long leg ones mounted from the component side). I've increased the power filtering cap and added polarity protection as well as input and output pull down resistors, and on board LED resistors. With the 2 footswitches, I thought it would be best to design the layout for a 1590BB oriented like this, so keep that in mind.

Monday, July 6, 2015

Seymour Duncan Pickup Booster

The Seymour Duncan Pickup Booster offers 25 dB of clean boost with flat EQ (and it's also a line driver). It uses a combination of two NPN and one PNP transistor. Originals use BC107s and BC177s, but other transistors should work fine as well. Check out the demo video below for more info.

Friday, July 3, 2015

Univox SquareWave

This is a pretty unique fuzz from the mid-70s by Univox. It was designed by Shin-Ei and like a few other Shin-Ei designs it can suffer from volume loss. To get it back up to unity or above, DIYSB forum member LucifersTrip made some mods to the circuit that keep the original sound, but improve the circuit a little bit. (Here's the original schematic, and LT's schematic for reference)

Volume problem:
To increase volume, I slowly increased the vol pot. Even at 1M, it was still below unity. So, I added diodes in parallel. Finally it was above unity, but now the distortion (really a tone control...closer to 0K the more bassy) didn't give me a good sweep.  So, I simply increased the 27K cutoff to 100K and subbed a 1M distortion pot instead of the 250K. Beautiful!  That gave me a nice sweep from just barely too bassy to a nice thin fuzz.

Mild Gating Problem:
Anytime I see an odd small value from an emitter, base or collector to a rail, I always suspect it to be very sensitive, and it was...I slowly increased from 0K and hit a perfect spot around 2.6-2.8K. The mild gating and pick percussion were gone, resulting in a killer smooth fuzz with super long sustain.  It was nearly perfect, but a bit too harsh on the highs. A simple tweaking of the 680 gave me a sweet spot right around 1.8-2.2K. If you raise it much higher, you'll wind up with less power...and around 4-5K will start to gate again. Further, I increased the 2M to 3M, which gave a bit more richness to the higher strings. I tried up to 7M...still good (thicker on the high strings)  but I didn't want to take a chance it would change the tone too much.

Here's a demo of the original:

If you want use this layout to build the SquareWave to original specs, follow the below value changes:

  • Change the 1.9k resistor to 680Ω
  • Change the 2.8k resistor to 3.9k
  • Change the 3M resistor to 2M
  • Use a 2N5458 for Q2
  • Jumper D3 and D4
  • Change the 100k resistor by the diodes to 27k
  • Use B250k pot for Distortion control
  • Use A50k pot for Balance control

Thursday, July 2, 2015

MicTester's Guitar Compressor

Here's a compressor design from MicTester. Here's what he had to say about it over on FSB:

Do you remember the old-fashioned way of doing bass compression? It used an LDR across the volume control illuminated by an incandescent lamp across the speaker terminals! It was a simple method back in the 60s....

This compressor is almost that simple! It uses a handful of cheap components (I built one for £9 including hardware!), but works really well. Guitarists who've tried it often ask "Is it on?", but miss it when it's off! It's quiet, and has good "squeeze" without the gain-change artifacts you frequently get with transconductance amplifiers or FETs.

The LDR should be ~1M in the dark, but almost anything will do.

Some of the component values are quite carefully chosen. The input capacitor (15nF - made up of a 10 and a 4.7 if the 15 is unavailable) is chosen to give some frequency shaping, and the interstage capacitor prevents handling noise affecting the compression. Green LEDs are chosen because they most closely match the response of the LDR, but yellow works almost as well. Obviously, the LDR / LED combination should be facing each other, and must be in a light-tight enclosure.

I've set up the board with pads for both 10nF and 4.7nF in parallel if you don't have a 15nF cap.

Wednesday, July 1, 2015

Univox Super Fuzz

This circuit is most known for being manufactures and sold by Univox, but was designed by Shin-Ei as the FY-6 and licensed to several manufacturers including Ibanez, Teisco, Kent, Companion, Apollo, and several others. The Super Fuzz has been used by many guitarist since it was first made in 1968, including Pete Townsend, J Mascis, Poison Ivy, and Josh Homme, just to name a few.

I did a layout of the Super Fuzz almost 8 months ago, and was always disappointed it wasn't really 1590B friendly. Well, I finally got around to redoing it and this version should fit just fine in 1590B. I based it off the original Super Fuzz circuit board, but with non-standing components and added polarity protection, increased the power filter cap, and added a pull down resistor.