Mad Professor Simble

This is been traced for a few weeks now over on FSB and I've meant to lay it out since then, but just now getting around to it. If you don't know, it's an amp-in-a-box type trying to emulate a Dumble amp. Apparently it sounds very good with smaller amps. Should fit nicely in a 1590B with board mounted pots as per usual.

Mad Professor Forest Green Compressor

Got a request for this one. It's very similar to Bjorn's Pale Green Compressor in his BearFoot Fx line, but with an extra stage for the Sustain mode. Here's the schematic for reference. From the product description:

FOREST GREEN COMPRESSOR (FGC) is designed to meet the highest standards of guitar and bass compression.  There is extremely low noise throughout the range and a high overload margin, which allows also a wide dynamic input range at minimum distortion and noise.  FGC is equipped with a special tone control to fine-tune the compressed sound for most transparent tone and effect.  The pedal has a switchable compressor and sustainer mode.  In Sustain mode you can get a very dynamic, touch sensitive tone with a long sustain. Here the attack is not lost, making the pedal suit-able even for blues players and works great with slide playing.

I've made 2 versions of the layout, one with SGD pinout for the 2SK170, and another with the more common GSD pinout for other JFETs (J201, 2N5457, etc)

Mad Professor Little Green Wonder

I feel like in the past few months I've done a ton Tube Screamer variants. Well here's another one, but one of the more interesting ones I've seen. Bjorn designed this one for Mad Professor and utilizes a dual-gang pot for the Body control that affects both the treble and bass response. The IC was originally a LF353, but that was changed to the TLC272CP as it was more readily available and worked at lower voltages and breaks up easier. The only schematic I found online was a little difficult to read (it was hand drawn) so I've drawn that up in Eagle as well. Pots are board mounted and will fit nicely in a 1590B.

Mad Professor Stone Grey Distortion

Here's the Stone Grey Distortion from Mad Professor. It's reminiscent of the Distortion +/OD250 circuit, but with a hex inverter stuck after the opamp. It also uses 2 JFETs in the feedback loop of the opamp for clipping. Original op amp is the TL051, but other single opamps can be used (Tl061, 71, etc). Should be an easy fit in a 1590B. Mind the jumper under the CB4069UBE.

Mad Professor Snow White AutoWah

Happy New Year, everybody! I hope this year brings you all joy and much soldering. :)

By popular demand, I give you the Mad Professor Snow White AutoWah. Now stop pestering me for it. ;) This was a pretty complicated circuit to fit on a single-sided board, so there are a few jumpers (one of which is super long–bugs me, but it was the only way to make it work), but if you play your cards right you should be able to squeeze it into a 1590B like the original.

Mad Professor Amber Drive

The Amber Drive is a slightly tweaked Fire Red Fuzz. Not a whole lot of differences between the two other than some value changes, but it's enough to make this not as fuzzy as the FRF apparently.

Here's the drilling template for this one. It should also work for the Fire Red Fuzz.

Mad Professor Fire Red Fuzz

Here's Bjorn's take on the classic Big Muff circuit. JFETs are used as clippers in the first clipping stage, and a JFET-based gain recovery stage is used instead of the traditional BJT one found in the original. You can use board mount pots from the solder side using right angle PCB mount pots.

Mad Professor Sky Blue Overdrive

Here's another BJF designed circuit: the Sky Blue Overdrive. There are 4 controls: Z adjusts input impedance, Distort. controls gain, Texture adjusts the hard clipping, and finally the Volume. It uses 3mm LEDs in the feedback loop of the opamp, and then JFETs for hard clipping.

Mad Professor Sweet Honey Overdrive

This is a great sounding drive pedal from Mad Professor. Very dynamic and tube-like, the Sweet Honey is a medium gain overdrive that can produce a wide range of tones, from jazz to heavy rock. I've laid the board out for right angle PCB pots mounted from the solder-side of the board, and it should all fit nicely in a 1590B.

Mad Professor Deep Blue Delay

The Mad Professor Deep Blue Delay is regarded as one of the best PT2399 based delays out there (with the price tag to match that reputation). It's a warm and natural sounding circuit with an analog direct signal path (aka, no buffers), and plays nice with distortion boxes as well. I've labeled IC1 as a TL072 as it's what you most likely have in your parts drawer, but the originals have either OP275 or AD712 for what it's worth. Pots can be board-mounted from the solder side of the board using right angle PCB mount pots.