Menatone Blue Collar

Here's an oldie but a goodie from Menatone. The Blue Collar was released around the same time as the Red Snapper and is more compressed and focused in comparison. It's also based around the Tube Screamer without the input buffers and with several mods. This layout reflects a newer version of the Blue Collar, but the older one can be built on the same board. Just increase the input cap to 100n, omit the 56p cap from pin 5 to ground, lower the output cap to 100n, and use an A250k pot for the Volume control. Here's the schematic for reference.

Valve Wizard Equinox II

Here's a reverb circuit that doesn't require a Belton brick–the Equinox II by Valve Wizard. It uses 2, PT2399 delay chips with a pretty standard input/output buffer built around a TL072. The original uses a J112 for switching the tails function, but I've simplified that with a just DPDT footswitch. Use one side of the DPDT for turning the reverb on/off, and the other side for LED indication. If you don't want/need tails with your reverb, just jumper the 2 switch pads. It's gonna be a snug fit in a 1590B, but it will fit.

I was able to verify this over the weekend and it works great and will fit nicely in a 1590B.

Catalinbread Merkin Fuzz

Here's an older one from Catalinbread, but a great sound fuzz for Fuzz Friday. It's based on the Mosrite FuzzRite but adds another gain stage after the Texture (Depth in the original FuzzRite) control. Schematic can be found here.

Menatone Red Snapper

Gotten a few requests for this one. It's a based on the Tube Screamer, but without the input and output buffers and a modified tone section. I've laid it out for board mounted pots and the electrolytic caps are folded on their sides.

Earthquaker Devices Grey Channel

This is the 400th layout on the blog. Kinda hard to believe I've drawn up that many. O_O

The cool dudes from Akron cooked up the Grey Channel, a dual overdrive based on the classic grey spec DOD 250. The 250/Distortion + circuit is one of my favorites and it turns out it's one of EQD's favorites as well:

It is based around a classic hard-clipping gray box overdrive (subtle hint, huh), one of my all-time favorites. Coincidentally, this is the very same pedal that got me started building pedals and launched EQD. It is two channels of a simple hard clipping overdrive that leaves the character of the guitar and amp intact. The Gray Channel retains the classic warm overdrive sound and expands upon it with several clipping options and bigger bass response. Each channel has 3 clipping modes. The Green channel- “Si” (Silicon clipping diodes), “Ge” (Germanium clipping diodes) and “N” (no clipping diodes). The “Si” mode will be bright/loud/fuzzy and has a natural tube type break up. “Ge” mode is a little looser with more lows and warmth and less output. “N” mode acts as a clean boost until you hit roughly 1 o’clock on the gain, at which point it’ll start to saturate the op amp into a biting, loud distortion. Phew! Still with me? Cool, onto the modes of the Red channel. Here, you’ve got “LED” (LED clipping diodes), “FET” (Mosfet clipping diodes) and “N” (again, no clipping diodes). “LED” mode is the loudest, cleanest and most touch sensitive/least compressed. “Mos” mode is the most compressed with a tighter crunch; the biggest hesher of the group. And finally, the “N” mode is the same clean to crazy loud op amp distortion set-up as the Green channel. With a couple of switch clicks you can go from your bypassed tone to warm break up to over-the-top gnarly grind and any/every combination in between.

Using the above info from the EQD product description, I've come up with a work-a-like to the Grey Channel. Using the Grey Spec 250 schematic as a base, I drew up 2 of them using a single 1458 IC (a dual version of the 741), increasing the value of the input capacitor to 22n (feel free to adjust that to taste) for extra bass response and including the various clipping options outlined above. I also changed the value of the gain pots from C500k to B1M, which is a fairly common mod to 250/Disto + circuit.

You can wire two separate on/off footswitches if you want, but if you want to wire it like the original with a master on/off and then channel selection, wire it like this:

Connect X to X and Y to Y. If you want to use a bi-color LED in place of D2-3 you'll need to wire it like this.

Wampler Velvet Fuzz

The Velvet Fuzz is a unique fuzz that combines amp emulation and 2 different selectable fuzz tones. The toggle selects between a LM386 (Tight) circuit, and a 2N5089 (Big) circuit. These then push a Plexi Drive circuit that gives the Marshall amp emulation. The modular nature of this design gives you the option to have not only a Velvet Fuzz, but a Plexi Drive in the same box. The board is laid out for board mounted pots and I've included trimmers to help bias the J201 JFETs. I've also included a switch diagram to show how to wire the toggle switches.

Wampler Cranked AC

Another amp emulation overdrive from Wampler that's supposed to sound like (you guessed it) a cranked Vox. This one has been discontinued, but was very popular. It's very similar to the Plexi-Drive, but doubles the transistors and there are a few component changes. I've added trimmers to help bias the J201s.

Wampler Plexi Drive

I'll give you heads up now. This is going to be Wampler Week. I laid out the Plexi-Drive a long while ago, but I wanted to give this "Marshall-in-a-box" circuit another go with board mounted pots and trimmers for those pesky J201 JFETs.

Evil Harmonic Overdriver

For Fuzz Friday here's a really cool circuit designed by Lubdar over on the Madbean forum. It's inspired by Death by Audio designs and can go from overdrive to full on fuzz. If you can't get a DBA design working, give this one a shot. Here's what he had to say about it:

It's a combination of ideas from the newer Evil Fuzz/Harmonic Transformer/Interstellar Overdriver.
It is comprised of 2 reverse beta gain stages, with level controls for each, that way you can turn level1 all the way down and get fairly clean overdrive tones, or max it out for fuzz, and anywhere in between.  The density knob controls the input capacitance for thin treble all the way to bass bass bass.  The toggles are for switching out a transistor stage in the 1st gain stage, and the second is an output pulldown resistor to give a slight volume boost.

Hungry Robot Mosfet Screamer

About a month or so ago, Hungry Robot Pedals made a limited run of overdrives called the Mosfet Screamer. As the name implies, it's based of the classic Ibanez Tube Screamer, but with a fair amount of modification. Eric from Hungry Robot was kind enough to share the schematic on Instagram, so a big thanks to him. Here's what he had to say about it:

The Mosfet Screamer strips the input and output buffers and adds a pre-gain Mosfet Gain stage to make it a bit more beefy. One thing I wanted was a more usable tone control, so I did some value changes and added a treble bleed on the volume section. Standard Gain, Tone, Volume controls and two toggles switches (One to select between two clipping options and the other to adjust the gain of the Mosfet Stage from low to high).

DOD 230 Optical Noise Gate

Not a lot out there on this one. It's a optical noise gate DOD produced in the late 70s and works best at the beginning of your signal chain. The original had a very strange way of bypass switching, but I've omitted this as your true-bypass method of choice is probably much superior. Originals used a VTL5C2, but experiment with LED and LDR combos, and possibly the value of the resistor feeding the LED (10k right above the LDR and Q1).

Korg MS-20 Filter

Switching it up this week and doing a Filter Friday. This one could be used for both synth and guitar/bass. It's a cool filter effect based around the LM13600/13700.

Tails Bypass Looper

Someone from the Offset forum asked me about building a looper pedal that when used with a delay pedal would have "tails." For those who don't know, "tails" is when a delay is switched off, but the remaining repeats come through the bypass signal. This is a popular mod to the Deep Blue Delay and other delays that feature input and output buffers. What if you don't want to mod an existing delay? Then build one of these. I laid this out 2 ways, one with relay switching and one using a simpler latching DPDT footswitch. With the latter, wire the Send pad to lug 2 of the footswitch, with lug 1 going to the Send jack. The other side of the footswitch can be used for LED on/off indication. The Return jack should be wired directly to the Output jack. The non-relay board could probably be squeezed into a 1590a if using low profile jacks.

Creepy Fingers DoomiDrive

Here's a cool dirt box from Creepy Fingers. It's essentially a modified Fuzz Face with an output buffer. The Bottom control pans between 2 input capacitors and offers a wide range of tones throughout the sweep. Originals used 2SC859 transistors which can be hard to find and have a BCE pinout, but I've also laid it out for CBE pinout transistors. For Q1-2 try 2N5089s and for Q3 try an MPSA18, but socket and experiment.