SMD RAT

There's no getting around it, through hole components have long been on the way out and being replaced by SMD. I've had several clients I do board design work for either going full SMD or at least a hybrid with SMD for resistors and a few other components, and TH for caps. This RAT layout goes the more hybrid route, giving you the option for TH or SMD caps (except for electrolytic caps). The opamp remains TH so the LM308 can still be used. 

Build doc with scaled etch image and drill templates here.

Roland AF-60 BeeGee

Happy Fuzz Friday, all. Somehow in 10 years of laying out fuzzes, I've never done this one. Here's the  Roland (pre-Boss) AF-60 BeeGee fuzz. Originals use semiconductors you probably don't have in your parts stash, but nothing in mojo territory, so modern equivalents will work just as well. Fairly simple circuit with a couple transistor amplifiers, an opamp stage, hard clipping, and a BMP-style tone stack. Here's the schematic for reference. Easy fit in a 1590B. (Transfer image in the Boss folder)

Roger Mayer Axis Fuzz

For Fuzz Friday here's the Roger Mayer Axis Fuzz redone with board mounted pots. Schematic for reference. Didn't make a drill template for this one, but the pots are 1.2" apart and should be an east fit in a 1590B.

Earthquaker Devices Hummingbird V2

 New Year, might make Modulation Monday a thing. We'll see. Anyway, here's the EQD Hummingbird V2. It's derived from the Vox Repeat Percussion and now updated to use the 2N6027 in place of the obsolete 2N2646. There's also a couple other improvements from the earlier version so a new layout seemed like a good idea. Schematic for reference.

Jackson Audio Amp Mode

Here's Jackson Audio's MOSFET boost, the Amp Mode. Pretty simple MOSFET circuit with a BJT output buffer. Easy fit in a 1590B. 

Dirt Master

 Here's a little something I whipped up the other night on a whim. Actually built it on the fly before I even drew up a layout. I was trying to build something with some old mojo caps I found on my bench, and it initially started as a treble booster, but I ended up wanting more gain. Initially it was based on the EQD Arrows, but added an extra cap off the emitter (ala the Rangemaster) for more gain and snarl. I used a germanium transistor with an hFE of around 230. Worked well with a silicon transistor as well. Room for experimenting with the input and output caps. Should fit easily in a 1590B. 

Death by Audio Sound Saw

Not quite a Fuzz Friday, but a Filter Friday I guess. Goes hand in hand with some fuzz though. The Sound Saw has two different passive filters selected by the Channel footswitch. The filters then share a 2-transistor gain recovery stage. Here's the schematic for reference. You can use a common cathode LED for the Channel switch or 2 individual LEDs if you prefer. See wiring diagram below. Laid this out for a 125B, but should be easy enough to adapt for 1590BB if you prefer. Will probably be doing a fabricated version of this in the near future as well.

Sound sample:

Hyper Fuzz regular and then the Sound Saw comes on

Clean guitar into Sound Saw changing tones

Bass Guitar into Suppa Tone Bender into Sound Saw

Bass Guitar into Big Muff then Sound Saw

Grind Customs FX De Profundis Delay

Merry Christmas everyone! Hope everyone gets ample time to get some soldering done over the holidays.

Grind Customs had a lot of really great projects, but their site hasn't been up in ages and it seems they're gone for good. Their De Profundis delay was very well regarded and they offered an add-on modulation board, the PLFO. Originals had the tone control as a trimmer, but lets go for broke and have it externally. The delay board will fit in a 1590B, but with the modulation add-on I'd recommend using a 125B. Here's the original De Profundis and PLFO build docs for reference.

Prescription Electronics Depth Charge

Here's a sweet bass fuzz based on the Univox Super Fuzz for Fuzz Friday. Original units used 2N3707 transistors with BCE pinout, which I'm guessing most people don't have in their parts stash. So I laid it out for CBE transistors (2N5088s or BC549Cs should work just fine) and it will fit nicely in a 125B with top mounted jacks and the pots in the same orientation/positioning as the original. Schematic available over on FSB.

Morula Auto Wah

Here's a simple auto wah circuit with a pretty low parts count I thought was interesting. Not a lot out there on it, but it uses a single CD4049UBE to create an LFO and wah audio path. The depth of the effect is controlled by the LFO. Should fit nicely in a 1590B. Here's the schematic for reference.

Budda Chakra Compressor

Here's an optical compressor I came across on FSB and hadn't seen a layout of it before. There's some question as to whether the schematic is accurate on FSB, so build with care. The original uses a rectifier array component, but I've broken that down into 4 discrete diodes (1N4148, 1N4001, etc.) since I figure more people will have those on hand than the rectifier component. Should fit nicely in a 1590B. Schematic and more info on FSB.

Brunetti Taxi Drive

Here's a pretty interesting lower gain overdrive. There's a an opamp gain stage with soft clipping going into a JFET stage that pushes a modified BMP tone stack, followed by a BJT output buffer. One of the diodes in the opamp stage is unknown, so socket and experiment. I also took a few liberties from the original using a TL072 instead of a TL071 for layout purposes and using the second opamp to buffer the voltage reference. Should fit nicely in a 1590B. Schematic available on FSB.

Hornby Skewes Shatterbox

Got a request for this one for Fuzz Friday. Fairly simple fuzz + boost box. Originals used PNP silicon transistors, but you can use NPNs just as well. The perf side below reflects the original's positive ground and the etch side shows daisy-chain-able negative ground. If you want to put 2 footswitches in a 1590B you could, as the board is small enough for that. Schematic on FSB.

Boss FA-1 FET Amplifier

Originally a bit of a flop from Boss, the FET Amplifier was made famous by U2's The Edge. It features a 2-band Baxendall tone stack and the Volume control is more like a gain control. Originals use 2 single opamps that are pretty hard to come by these days, so they've been replaced by a dual opamp. Pots are board mounted and it should all fit in a 1590B.

Prescription Electronics Clean Octave Blend

Got a request for this one for Fuzz Friday. Originals fetch crazy prices online. It's an octave fuzz with a clean blend. If you want a fabricated version of this, check out the Corn Cobb on the store.. Schematic over on FSB. Should squeeze nicely in a 1590B.

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.

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.

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.

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.

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.