Here's a cool original design by DeadAstronaut. It's a cascaded JFET/mu-amp based high gain distortion with a 3-band EQ. Original build doc with schematic found here. Laid out for a 125B enclosure with top mounted jacks.
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DeadAstronautFX Skinwalker
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EQD Bows
Here's Jamie's take on the classic Rangemaster circuit, with a NPN germanium transistor. There's an added toggle to switch between full range and treble input caps. Probably a tight a squeeze in a 1590A but should be doable. Also there will be a 1590A specific PCB with board mounted pot and switch in the store soon (preview below).
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SRS EQ Exciter
Here's a bit of a rare one for Fuzz Friday. It's essentially a silicon Fuzz Face with an output buffer and a mid scoop tone control. Schematic and rundown of the original here. It should fit in a 1590a with 9mm pots board-mounted. I've also kept the pad (marked NC in the schematic) so if anyone wants to implement the mods outlined in the link above they can. Also PCBs of this (with a few mods) are available in the store now along with 5 other new projects!
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And here's a look at the new PCBs on the store now!
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Korg DST-1
Here's the correct layout for the Korg DST-1 that I previously laid out based on an unverified schematic. It uses an AN360 audio pre-amplifier chip (you can still get some on eBay), but I haven't found a replacement other than making a discrete version of the chip. A discrete version wouldn't take up that much space and the schematic is included in the datasheet, but the resistor values aren't included. If anyone has any info I'll gladly add a layout for making a discrete AN360. Original DST-1s used a buffered bypass and I've included the buffer output on the board if anyone wants to build it that way. I left out a few diodes present on the input and output buffers I think are just over engineering as well as a 47k resistor from the output jack to ground (which is probably easier to include offboard anyway). Here's the schematic for reference.
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Music Man StingRay Preamp
Had several requests for on-board bass preamps and what better place to start than the original StingRay circuit? Simple 2 band-EQ with low current draw and should be small enough to tuck into the control cavity of whatever bass you're wanting to add it to. Other single opamps can be used, but the current draw may increase, draining your 9v battery quicker. For example a TL071 draws 10x the current of the LM4250. A good replacement would be the LT1351.
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1981 Inventions DRV
There's been a lot of hype about the DRV and it's a very cool pedal from a very cool builder too. At it's heart is a tweaked RAT surrounded by 2 opamp gain stages and buffered bypass, all running on 18 volts (schematic below). Originals have soft touch relay switching, which has been omitted here. It can be wired either for true bypass or buffered bypass like the original (see wiring diagram below). If you want to use a MAX1044 chip for the charge pump instead of the LT1054, I've added 2 additional pads on the PCB to connect pin 1 to 8. Should squeeze into a 1590B nicely.
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Wire In Jack to In pad on the board.
Wire In Jack to In pad on the board.
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Allies Fuzz
Got a request for this one for Fuzz Friday. Designed by Masaru Kubota it's based on Roger Mayer's Axis Fuzz with a fair bit of tweaks. Here's the schematic for reference.
I revamped Roger Mayer's Axis Fuzz and stuck on a phase stage to make the circuit sound like a tube amp. You probably notice the Dallas-Arbiter Fuzz Face biasing configuration. You can use a regular low-pass RC network, ala the ProCo Rat, to make the circuit sound like a "open" tube amp. This fuzz sounds ALOT like the "Modern Lead" amp model on my Zoom GM-200. You'll be surprised at how much this circuit sounds like a tube amp.
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I revamped Roger Mayer's Axis Fuzz and stuck on a phase stage to make the circuit sound like a tube amp. You probably notice the Dallas-Arbiter Fuzz Face biasing configuration. You can use a regular low-pass RC network, ala the ProCo Rat, to make the circuit sound like a "open" tube amp. This fuzz sounds ALOT like the "Modern Lead" amp model on my Zoom GM-200. You'll be surprised at how much this circuit sounds like a tube amp.
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Nocenteli Magnalous Lunevibe
Stumbled across this design by Nocenteli on FSB and thought it was cool, so here you go. Mashup of the Tremulous Lune LFO and the audio path from the Magnavibe with a toggle to switch between tremolo and vibrato mode. I ended up putting the Fine control internally as a trimmer for 2 reasons: 1) In my experience with this kind of LFO it's not all that necessary, and 2) I miscounted the number of pots in this when I started layout it out and was too far in to start over. 😂 You can always wire it off-board if you prefer. Should fit nicely in a 1590B.
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Diezel VH4
Gotten a lot of requests for this one and I finally bit the bullet and laid it out. It's the pedal version of the 3rd channel on Diezel's VH4 amplifier with loads of tonal control and tons of gain on tap. Originals are buffered effects, with the input jack wired to the In pad, and a DPDT footswitch selecting between the Out and Buffer Out pads (footswitch wiring diagram below). You can also wire it for true bypass if you prefer and just ignore the Buffer Out pad. The pedal can also be used as a standalone preamp with the Power Out going to the input of a power amplifier (the return jack of an amp's effects loop). It's designed to run off a 12 or 18 volt supply, but it will apparently work just fine of a 9 volt supply (and if planning on going that route, I'd omit the regulator and jump its in and out pads). Also, the indicator LED can be hard mounted to the board, and the whole layout will fit nicely in a 1590BB. Schematic and discussion on FSB here.
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Music Man Sabre II Bass Preamp
Lot of requests for this one after I posted the Stingray pre a few weeks ago, so here's the Sabre II. Pretty similar the the Stingray but with a few value differences and extra resistor in the feedback loop, and the added bright switch.
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Fuzzrocious Ram the Manparts
Happy Fuzz Friday! Here's the now discontinued Ram the Manparts from Fuzzrocious. It's a 386-based fuzz/distortion with a voltage starve control, gain toggle, and volume control and sounds pretty killer on guitar and bass. Should be a quick build and a nice fit in a 1590B.
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Music Man Sabre II Guitar Preamp
Apparently the guitar players were feeling left out with the all the old Music Man bass preamps, cuz I got a ton of requests for the Sabre II Guitar pre. So here you go! Nice and small like the others with active bass and treble controls.
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Fulltone OCD V2
The latest iteration of the OCD has quite a few differences from the earlier models. There's an added transistor stage at the output after the volume control, and a JFET buffer that can be toggled for buffered or true bypass. I've laid it out so it will still fit in a 1590B with board mounted pots.
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The off-board wiring's not the most intuitive, so here's a diagram for wiring up the buffer switch and 3PDT bypass footswitch.
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Hermida/Lovepedal Mosferatu (3-knob)
Came across the schematic (here on FSB) for this and thought I'd lay it out. Essentially a Son of Screamer but with MOSFETs and germanium diodes for clippers, a modified gain control and a few value tweaks. FYI, the transfer pdf is in the Lovepedal folder, and use the AMZ Son of Screamer drill template.
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Foxx Select-A-Fuzz
Happy Fuzz Friday, everybody! The Select-A-Fuzz is a pretty interesting fuzz box from Foxx. It has a rotary switch to select the input cap (the larger the cap the fuzzier the effect), followed by a Fuzz Face-esque stage and an extra gain stage. Here's the schematic for reference with some good notes on alternative transistors and voltages. D1 is silicon in the original unit, but a germanium diode will take the edge off a bit.
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Boss OD-1
This is the precursor to the SD-1 and the TS808. The OD-1 was built by Boss from 1977-1985 and made in 2 versions. Both version are very similar in circuit topology—buffer > gain/soft clipping stage > gain stage > buffer—but the early version used a quad opamp, while the later version used a dual opamp and transistors for the buffer stages. I laid out the later version a while back (and didn't know the quad version even existed at the time), but I wanted to lay the quad version out as most agree this version sounds better. Fits nicely in a 1590B. Schematic for reference.
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Fulltone OCB
What's the OCB you ask? It's the bypass buffer circuit from the new version of Fulltone's OCD. It allows you to switch between regular true bypass and buffered bypass. There are 2 versions: The first (smaller) inverts the phase of your audio signal when engaged (in bypass mode phase isn't inverted). The second (larger) adds an extra inverting transistor stage so that the phase of the output signal is the same as the signal coming in. If you've built an earlier version of the OCD in the past, you can add the 2nd board to make it into the newer version.
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Benson Preamp
This one just traced over on FSB. It's essentially a modified Wampler Plexidrive with an added bass control. Several of the capacitor values are well educated guesses and the resistor just before the Master control hasn't been listed, but I'd start with 10-15k and adjust to taste. Also unless you're really sure any through-hole J201s you have on hand are in spec/authentic, I'd suggest using MMBFJ201s, which are the SMD version which are still in production and much easier to get in spec than the discontinued through-hole version. SMD to through-hole conversion boards here.
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Third Man Bumble Buzz
The Bumble Buzz is sold by Third Man Records, Jack White's record store and was designed and built for him by Union Tube & Transistor. It's a modified Kay Fuzz Tone F-1 with 4 silicon diodes in parallel instead of 2 germaniums like the original and the tone control fixed (so there aren't any controls at all). Easy fit for a 1590B and you might even be able to squeeze it into a 1590A.
There's also a fabricated version of this on the store if you prefer. It mounts directly to a 3PDT footswitch so your board isn't just floating in the enclosure and/or you don't have to mess with standoffs or double-sided tape. There's also 3 other new PCBs on the store as well, so go check 'em out! Use code BACKTOSCHOOL to get 15% off your order, now through Aug. 12th!
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Keeley El Rey Dorado
Here's another Plexi-in-a-box overdrive, this time from the great Robert Keeley. It's a cascaded opamp design running on a bipolar +/-9v supply. The Power Toggle as it's known on the original selects between red LEDs or BAT46s for asymmetrical clipping.
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