Skreddy Mayonaise MkIII

One of the higher regarded Big Muff derivatives out there, the Mk III is Skreddy's latest version of their Mayonaise BMP. On the board is a dip switch which allows you to switch in or out 2 extra capacitors to the tone section. You could wire these as external SPST switches (you'll need 2 of them) if you like. I used my Triangle Big Muff layout as a starting point, but there are several changes so the two aren't interchangeable. But like the Triangle layout, this one is designed for solder-side mounted right angle pots and should fit just fine in a 1590B.

HAO Rust Driver

Here's another plexi-in-a-box pedal. Fairly simple in comparison to others. I've drawn 2 layouts for this one; one stock and one with an adjustable gain mod. The EQ switch is optional, as some who've built this circuit say it's pretty lackluster. The original uses an MC4558CN, but just about any dual op-amp should suffice (try JRC4558, TL072, NE5532, etc).

MicTester Hot Silicon Tonebender

Here's another one of MicTester's creation/adaptions. The Hot Silicon Tonebender is based on the classic SolaSound Tonebender Professional Mk II, but with silicon transistors and an added tone stack. Pretty much any medium to high gain transistors will work, so socket and try a few different ones out (BC109, 2N5088, MPSA18, etc). 

AMT Legend Series S1

Got a request for the S2, but have been unable to track down a schematic for it, so here's the S1 in the meantime. It's an emulator/preamp of a Soldano tube amp, and like most amp emulators it uses JFET transistors. The original uses mostly SMD components with the exception of some capacitors, which is how they cram it into such a small box. As soon as I saw the schematic I figured this would be a good 1590BB project.  Since it has 6 pots, I wanted to keep the offboard wiring at a minimum, so I made a daughter board to hard mount the pots using 16mm right angle PCB pots. This daughter board can then be attached to the mother board using sockets and pin headers, basically stacking the 2 boards. I would mount the sockets to the solder-side of the mother board, and the pin headers to the component-side of the daughter board (as the pots would be mounted on the solder-side of the daughter board). This might be a crazy idea, and if you opt to just use hook-up wire to connect the 2 boards, you won't need to wire the DB3 or DB6 connections, as they were added mostly for extra stability if you are using the socket and pin header approach.

Not included is the cab sim part of this pedal. If anyone is interested in a 2nd daughter board for this section, let me know and I'll draw it up and add it. Since the original mostly uses SMD parts, some of the members over on the FSB forum modified the circuit a bit to use more common through-hole parts. J201s are substituted for the original SMD 2SK208, and 1N4148 in place of BAT54 diodes. There are 2 caps that they weren't able to determine the value of. Based on the rest of the circuit, a good place to start would be 3.3µ for the first cap below Q1 (which I assume is an electrolytic based on the rest of the circuit), and 47nF for the cap between Q3 and Q4. Socket and experiment. Good luck!

MicTester Buzz-Alike

Like many of the old germanium fuzzes, the Burns Buzzaround can be difficult to get right. It also uses 3 sometimes costly germanium transistors, and unless you also build a power inverter or use NPN transistors, you can't daisy chain it with other negative ground effects. To get around these hurtles, Mictester designed a work-a-like of the Buzzaround using only one (NPN) germanium transistor and germanium diode alongside a dual op-amp. Here's mictester's description of this circuit:

"The original consisted of two stages - a two-transistor amplifier and a distortion stage that could have both the amount of signal sent to it and the bias point adjusted by external controls. The third control was a crude tone control which fed the output. Originally, the output was unbuffered, and the leads and amplifier following would load the unit, and the top end would be rolled off, and often the tone control would have little effect. 

The first stage in the sound-alike is just a high input impedance op-amp gain stage. You may wish to increase the gain by increasing the value of the feedback resistor, but it sounds pretty good as shown. In the original, the first stage didn't really have much effect on the sound - it just amplified it enough to drive the following stage into conduction.

The heart of the beast is the germanium transistor stage. Apart from using an NPN transistor, this remains true to the original (why screw up a classic?), and still gives a wide range of sounds from the thin toppy fuzz beloved of sixties bands through to gated spluttery farts, with smooth warm distortion sounds in between!

The final stage is just a buffer - it isolates the tone circuit from the outside world, and allows a full range of control from muffled to glass-shattering!"

Catalinbread Sabbra Cadabra

This pedal is inspired by Tommi Iommi's classic combination of Laney Supergroup amps and a Rangemaster treble booster. It's not an emulator like the Supergroup pedal I posted a little while ago. If you look at the schematic it actually looks like 2, AMZ mini booster-type stages at its heart, with a transistor-based input stage. It also has a fixed tone array before what I'm guessing is a JFET-based gain recovery stage at the output. The originals have MPF4393 JFETs, but socket and try others with GSD pinout (J201, 2N5457, etc). The layout below says to use 9v, but it can also be run at 18v. I've drawn it so you can use right angle PCB pots, mounted from the solder-side of the board if you want, and it should all fit nicely in a 1590B.

The Photon Buzzard

I stumbled across this over on DIYstompboxes. It was designed by David Edgar and it's kind of based on the Fuzz Face circuit, but with a lot of tweaks. Below is his schematic and notes on biasing and transistor selection. I've added the usual polarity protection and power filtering and drawn the layout for on-board pots if you so choose.

D*A*M Meathead

I realized after posting the Meathead Deluxe I hadn't made a layout for the one-knob Meathead. Anyway, the Meathead is one of most well known 1-knob silicon Fuzz Face variants, thanks to the like of Josh Homme from Queens of the Stone Age, among other guitarist. Q2 is a BC182L, which has an ECB pinout instead of the more common EBC, so be careful of that.

Burns Buzzaround

Here's an interesting take on the Tone Bender Mk III. Original units were positive ground, so the perf side of the layout reflects that, while the PCB side is set up for daisy-chainable negative ground.

MXR Micro Amp

The Micro Amp is a classic clean boost circuit first introduced by MXR in the late 70s. It's a great option if you need to stomp on something for solos. Pretty simple op-amp design that should fit nicely in a 1590a.

Soldano 100 Emulator

This was a request by Guilherme. It's a FET adaption of the SLO 100 preamp originally done by OldMike and modded by Brymus. I've changed the resistors going from the power rail to the drains of the various FETs to trimmers. Here's the schematic I worked from and it has a list of the voltages from Brymus' build.

EarthQuaker Devices Ghost Echo

The Ghost Echo is a nice little reverb unit, and uses the Belton BTDR-2H-L digital reverb module, as well as a PT2399. I'm not going to lie, this layout gave me some issues (at one point it made DIYLC crash). Even had to use a jumper (which annoys the heck out of me, as you may have picked up on). You won't be able to squeeze it into a 1590B, but a 125B should be a good fit. The Belton brick can be mounted directly to the board from the solder-side.

Here's what EQD's website says about the effect:

Vintage spring reverb emulation capable of providing a little atmosphere all the way through to vast depths in one tiny box. The attack control sets the delay of the initial pick attack on the wet signal only. When playing staccato this registers as a slap back type echo hitting the reverb but when playing fluid lines it adds a massive depth and “fattens” up the sound. The dwell control is a fine tune function that enhances the decay and the depth controls the intensity of the reverb.

Update: If you're having a hard time getting unity volume, try replacing the 10k resistor of pin 9 of the TL074 just above the 2.2uF cap with a 17k resistor (or something close to that).

D*A*M Meathead Deluxe

Here's yet another Fuzz Face circuit as they say. This is basically the one-knob Meathead with a Filter control that pans between 2 different input caps, and an Attack control which is the standard Fuzz control on a Fuzz Face. Good sounding silicon fuzz.

EarthQuaker Devices Hoof

In honor of it being Pi Day, I thought a Big Muff layout would be appropriate. While not an EHX Muff, the EQD Hoof is a BMP variant. It uses germanium transistors as well as LEDs in place of the typical silicon diodes in the 2 gain stages. It also has a Shift control, which allows you to boost the mids typically scooped in the standard BMP. Pots can be board mounted from the solder-side of the board using right angle PCB pots.

If anyone want to make the Cloven Hoof, use 2N5089 for Q1 and 4, use MPSA13s instead of germaniums for Q2-3, replace D3-4 with 1N4148s, and remove the 470pF cap by Q2.

Dr. Boogie Distortion

100 layouts! Thanks to everyone who visits the blog and a special thanks to those of you who have built and verified some of these layouts.

The Dr. Boogie is a JFET-based amp emulator of the Mesa Boogie Dual Rectifier Solo head, designed by ElectraTabs over on the  DIYStompboxes forum. It creates a unique high-gain distortion effect. 

Most layouts and builds of this effect I've seen are in 1590BB enclosures. This one should fit in a 1590B, but would probably be more comfortable in a 125B. Use right angle PCB mount pots and mount them to the board from the solder-side. Mind the EQ row of pots are oriented 180º differently from the top row of pots.

Lovepedal Karl (2-knob version)

The Karl is essentially a modified Tim Escobedo Tripple Fuzz, basing it's sound around an NPN/PNP transistor network known as a "non-selective frequency tripler." I modified the power section a little bit. The original has an unnecessary 47µ cap at 9v input before the 330Ω resistor which I eliminated. I also moved the anti-popping pull down resistor to before the Intensity pot (the original had it after) and it might not even be necessary at all. But better safe than sorry.

Devi Ever Improbability Drive

The Improbability Drive is a knob-tweaker's dream–equal parts, overdrive, fuzz, and science experiement, and gets its name from Hitchhiker's Guide to the Galaxy. This one was a bit of a challenge (I even had to use a jumper. Gah!). B3ar over on FSB requested a layout with onboard pots and switches. Couldn't get the switches to fit, but they're only SPSTs so wiring those shouldn't be too much of a hardship. Onboard pots are mounted from the solder-side using right angle PCB mount pots. Should all fit in a 1590B.

3PDT Footswitch PCBs

Got a request for a PCB to make wiring up 3PDT footswitches a little less messy. There seems to be about a dozen ways to actually wire up an effect with a 3PDT, but I went with this wiring scheme drawn up by Bumblebee over on DIYStompboxes as it's fairly neat and efficient. The effect input is grounded with the effect is bypassed, which eliminates any oscillation that might happen in pedals like the Small Stone.

I've drawn up 2 different boards–both have the LED and the LED resistor on board, but one has a MAX1044-based charge pump for when you're building a positive ground effect. It has polarity protection and power filtration on-board as well.

D*A*M GB-83 GreaseBox

This is the silicon version of the GB-80. The darlington pair of transistors in the GB-80 aren't needed as silicon transistors have enough gain, and the rest of the circuit has just been tweaked for the silicon transistors. One problem people seemed to have cloning this circuit over on FSB was biasing the transistors properly. The 260k resistor from the base of Q1 to ground could either be socketed and experimented with to get the right value, or replaced with a 500k trim pot to dial in the right sound. The transistors in the originals are BC series, but socket and experiment. Anything in the 300 hfe range should work for Q1 and 400 hfe for Q2.

D*A*M GB-80 GreaseBox

Here's the germanium version of D*A*M's GreaseBox fuzz. It's based on the Tone Bender Mk. III but without the tone control. Q1 and 2 form a darlington pair to amplify the signal, and Q3 provides the fuzziness. The original units are positive ground effects and use PNP germanium transistors. That is reflected in the perf side of the image below, but for the PCB, I laid it out for negative ground for those of you who (like me) have a bunch of NPN germaniums.

Dwarfcraft Devices Robot Devil

Got a request for the EQD Bit Commander, and while there doesn't seem to be a schematic for it, my search for one lead me to this effect. It's no Bit Commander, but it does do the synth-y octave down thing. The original Robot Devil has the octave switch (which allows you to switch between one octave down and 2 octaves down) as a footswitch. If you go that route, you'll need to use a DPDT if you want LED indication. Or you could just use a toggle SPDT if you want to put it in a 1590B and don't like the idea of having 2 footswitches on such a small box.

Here's how to wire the octave switch as a footswitch with LED indication:

As is, the LED turns on if the sub octave (2 octaves down) is activated. If you wanted, you could use 2 LEDs (or a bi-color LED) to indicate which octave is in effect. Just connect the cathode of one LED to lug 6 (anode to +9v via 2.2k resistor) to indicate 1 octave down. 

Greer Amps Green Giant

Needed to do a simple circuit after all those involved 6 onboard pots layouts. They're exhausting ;)

This is Nick Greer's take on the classic Electra Distortion, but with one simple twist: the Blend control allows you to blend in the clipping stage. Expect some volume loss with the diodes blended into the signal, but it will give a bit more crunch and compression.

Laney Super Group Emulator

This was a request that came in from Cody from the They Remained Silent blog. It's an emulator of the Laney Super Group 100 watt head designed by Heuller Pinson (MallerMB). I would assume you should bias the JFETs to ~4.5v then adjust from there. Don't have a ton of info on this other than that. This one's laid out for onboard 9mm pots mounted from the solder-side. Cody asked for it to fit in a 125B, but you should be able to squeeze it into a 1590B.

Here's the schematic if anyone wants it.

Blackout Effectors Musket Fuzz

The Musket Fuzz is a variation of the classic Big Muff. Based on a Black Russian version, the Musket adds a modified LPB-1 booster (the "Pre" section) that pushes the standard BMP circuit. The "Focus" control allows you to pan between 2 different capacitors at the input of the first stage of the BMP. The Musket also adds a "Mids" control to the tone section, allowing you to dial in and be heard in the mix.

This layout allows you to use on-board, solder side mounted, right angle pots, though long-leg pots could be mounted on the component side as well.

Moosapotamus 360 Fuzz

Here's a bass fuzz designed by Charlie Barth from Moosapotamus.net based on the fuzz section of the classic Acoustic 360 bass preamp. It uses a mix of silicon and germanium transistors. I've made the layout to reflect the combination of transistors specified in Charlie's schematic, but socket and experiment. This layout should fit in a 1590B, but if you want to use a larger enclosure, there's a PCB of this effect for sale here with board-mounted pots.