Four Step Atari Punk Console

I thought I'd mix things up a little this week and post some synth circuits people might be interested in. To start things out, here's a modified version of the classic Atari Punk Console. This has a few additional potentiometers for more control and a more versatile version of this popular synth.

In the layout below note that VR stands for variable resistor as the schematic I laid this out from didn't have names for each control (there are 6, labeled A through F).

Pardon all the jumpers, 555s are uncooperative for single sided layouts. Haha

Electro Harmonix Big Muff - 1590a

Let's wrap up this 1590a week with one of the mightiest fuzzes of all time–the Big Muff. For this one, I've labeled all the components to correspond with the component names on Kit Rae schematics, so find an EHX version on there and populate the board accordingly. This probably won't work for some of the more modified, non-EHX Muffs, just fair warning. Polarity protection and power filtering have been added, as has a pull down resistor at in put. It's labeled as "PDR" on the layout and would typically be 1-2M. The resistor labeled "CLR" is the current limiting resistor for the LED, and can be anything from 2.2k to 10k.

Fairfield Barbershop - 1590A

Continuing on with my 1590A kick, here's one for the Barbershop Overdrive from Fairfield Circuitry. I've modified a few things: first, the polarity protection of the original is a bit excessive, so that's been simplified. And secondly, I included 2 trimmers to help set the bias of the J201s (you're welcome, Cody). With 3 pots you'll need to use 9mm pots and the 220uF cap is on it side to fit better in the enclosure and hopefully not get in the way of the input jack. Drilling template can be found here.

Ibanez TS808 Tube Screamer - 1590A

I've had a couple requests for a 1590A friendly Tube Screamer, and lately I've really been enjoying laying out 1590A boards, so here it is. Since there's 3 potentiometers, you'll need to use 9mm pots, and the 3PDT footswitch is board mounted. I would suggest using small profile jacks for this like these, or just measure really carefully when drilling the enclosure. Note that the 100uF power filter capacitor is folded on it's side for space purposes.

BearFoot FX Arctic White Fuzz

Fuzz Friday is once again upon us, so here's the BearFoot FX (BJFE) Arctic White Fuzz. It's probably based on Tim Escobedo's JFET variations of the Fuzz Face, but with a lot modification. It's set up for board mounted pots and will easily fit in a 1590B enclosure.

Run Off Groove Big Daddy/Grace

Here are two great sounding, yet simple circuits from Run Off Groove. The Big Daddy uses a JFET gain stage to push a 386 chip, while the Grace uses a JFET buffer in front of the 386 for added sparkle. Schematics, sound clips, and more info can be found on the ROG site.

Crazy Tube Circuits Ziggy Overdrive

Here's a cool MOSFET-based overdrive from Crazy Tube Circuits. Apparently it's based on a Neve console input channel stacked 3 times. With the gain down it sounds a bit like an AC30, and with it cranked it sounds like a Plexi. It was traced over on FSB (link here) and I've laid it out for board mounted pots. If you're interested in a fabricated board, check out the Starman in the store.

Valve Wizard Flanger

Mixing it up and doing Flanger Friday this week. Got a request for this circuit designed by Valve Wizard. It's unique in that it uses 2, PT2399 delay chips paired with an LFO. It features a buffered bypass, so it's not a true-bypass effect. I've also drawn up daughter boards for the bypass switching (PCB version has the footswitch board mounted). Here's the schematic for reference. You'll definitely need a 1590BB enclosure for this one.

ProTone Dead Horse Overdrive

I actually own one of these from the Dead Pony run, and the other night when I'd run out of solder I traced it. It's essentially a TS-808 clone with a couple of very minor changes. There was a jumper where an extra diode could be for asymmetrical clipping, so I've included room for the extra diode in the layout. Couldn't read the exact type of diodes, but they looked like 1N4148s. Use your favorites or socket and experiment. Also a lot of the capacitors were axial ceramic types, so the below layout reflects that. Here's the schematic I drew up.

Emerson Customs Paramount

This is Emerson's second offering. Essentially it's an Electra Distortion without the clipping diodes and it's pretty similar to the EM Drive. It adds a tone control that pans between 2 capacitors at the input. It's laid out for board mounted pots and will fit nice in a 1590B.

D*A*M Ezekiel 25:17

Here's a non-Fuzz Face/Tone Bender offering from D*A*M for Fuzz Friday. It's designed for bass, but sound great on guitar as well. It uses one half of a dual op amp to blend in clean signal, and the other half creates the distortion via soft clipping. You have 4 options for clipping diodes, germanium, silicon, LEDs, and bypass, selectable via a rotary switch. The rotary will have to be wired off board, but the rest of the pots are board mounted.

Keeley Katana

The Katana is a highly regarded clean boost pedal that can give a nice clean boost or push your tube amp into breakup. The circuit itself is fairly simple, but achieves extra headroom thanks to the internal voltage doubler. For this you can use a ICL7660 or MAX1044. You may want to socket the two 4.7k resistors or replace them with 10k trimpots. The drain of both transistors need to be around 9 volts. On original units, the switch is a push/pull on the pot (which is why it's mounted to the side of the enclosure), but a regular toggle can be used. If the switch wiring doesn't make sense, reference the General Layout Notes tab for switch numbering. It should be possible to fit this in a 1590A if you're not claustrophobic. Here's the schematic for reference.

Soft-Latch Relay Switching

Switching an effect on and off can be as simple or as complicated as you can make it. 3PDTs are pretty much the standard these days for true-bypass switching. However most of the 3PDT footswitches I've used make a lot of noise (not necessarily in the circuit, it's just loud when you step on them) and while that's not really the end of the world, it'd be nice to avoid the loud "KATHUNK" of the 3PDT. Relay switching fits that bill rather nicely, and there are lots of different ways to trigger the relay, some more complicated than others.

In my search for one that was fairly simple and wouldn't take up too much room in a pedal, I came across this article from a few years back by Paul in the Lab. It uses just 3 transistors, a momentary switch, and a DPCO-type relay. I've drawn his circuit up for use with a board mounted SPST momentary off/on footswitch (if you need a perf layout, check out this one over on lvlark's blog). You'll need a 5 volt Omron G6S-2 relay (I got mine here), and a lot of different transistors can be used. BC547 and 557s are called for in Paul's schematic, but 2N3904 and 3906s or similar can be used as well. Most SPST momentary switches I found had the solder lugs on the side, so the board has been laid out to fit vertically in a pedal enclosure. Everything is mounted to the circuit board on the component side and the board is small enough to fit in a 1590B.

Note:
This has been updated to reflect the discussion below.

Here's how the switch should mount to the board.