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Friday, June 28, 2019

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.


Tuesday, June 25, 2019

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.






Wire In Jack to In pad on the board.

Thursday, June 20, 2019

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.

Tuesday, June 18, 2019

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.


Friday, June 14, 2019

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!




And here's a look at the new PCBs on the store now!


Tuesday, June 11, 2019

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. There is also a 1590A specific PCB with board mounted pot and switch in the store now (link below).

Thursday, June 6, 2019

DeadAstronautFX Skinwalker

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.



Tuesday, June 4, 2019

Buffalo Fx TD-X

This one's inspired by the BK Butler Tube Driver made famous by David Gilmour (and a few others). It does away with the tube and replaces it with solid state circuitry. It's essentially a RAT with soft clipping and a 2-band EQ stuck between a buffer and an extra gain stage. Should fit nicely in a 1590B.