EasyEi8ht

                                

It's an M4TM EasyEi8ht trigger sequencer whee

This was my very first Eurorack module ever. My very good buddy Nick was willing to do the PCB layout and panel design, and we had a workshop at Knobcon '18 or '19 my lands, has it been that many years!?!?

Real quick before the jump: here's the BUILD GUIDE you might be here hoping to find.

Introducing Etch!

Here's a module called Etch, designed by me and coded by my friend Tyler Klein, is a lo-fi DSP module focused on bitcrush and sample-rate reduction. It's also got a deep quantizer side, which I haven't explored much, since the effects side of things interests me more. Read all about it over at Tyler's Github page!

The build guide is right here. It uses a cheap OLED screen, a screen which is difficult to mount properly, and the quality control on them is poor, so the mounting solution I came up with is quirky and weird, and works great for me, but I expect some builders to find it frustrating to deal with.

I hope you really enjoy the module! The "loop" mode (pushing the middle button) is a TON of fun, I really enjoy playing with that.

ClapClap!!!!!!!

 

Last year at Knobcon (North America's only synthesizer convention) a group of music enjoyers would dance along to the performances. Now you see, modular synthesizer performance is a difficult thing, with many knobs and switches and cables to pay close attention to. It's easy to lose track of the phrasing of your song -- there isn't necessarily a pattern going on besides a single bar or a pair of bars.

So phrasing can be vague, and sometimes wrong if I may be so bold. A meter will be established, a breakdown will occur, there will be a buildup, and then there will be a DROP but sometimes the musician will bring the drop in too early or late by one bar. It's a rough world out there, no shade... it just happens.

Well, a little thing happened where the group of us dancing would go "clap clap" at the end of eight bars of music that we were counting in each of our heads. Often the phrasing would match up, especially for some of the more structured performances, but sometimes there would be disagreements (fortunately it never came to blows).

This little pile of circuitry, my lovelies, is the prototype of a ClapClap module, which counts sixteenth notes and goes "clap clap" at the end of them. That's all it does. Okay fine, it has nine samples, including 4 claps and 5 other short percussion samples. It can serve simply as a percussion voice, if you're good at Arduino, you can swap out samples, and fix my embarrassingly disorganized code.

So anyway, there's a quint of PCBs crawling across the Pacific right now, so we'll see if the module works!

Introducing OctaPass Eurorack module 8x fixed frequency HPF

 

 It's a eight-channel fixed-frequency switchable high-fidelity high-pass filter!

OctaPass

First things first... this is the build guide for this module.


 You've found the blog post for the OctoPass. It's an eight-channel high-pass fixed-frequency four-pole filter (alliteration!) that is a requested build. It's switchable -- there's little toggle switches on the panel that will allow the user to low-cut or not the signal.

The signal switching is done with a ton of Vactrols -- LED and LDR combos. This means very-low-noise, which may be important if you're deciding to cascade all 8 filters with all the normalling going on between all eight channels.

The build is a bit fiddly, with some pads quite close together. Use a sharp soldering iron tip, cleaned frequently, lead-bearing solder if legal, flux if necessary, and double-triple check all your joints. I did have some dry solder joints on some of the op amp legs, but besides that, all four of these I built worked just fine.

DuckMixer progress

 

There it is. I'm thrilled with the texture and pretty happy with the layout and graphics, BUT I PUT THE SLIDER POTS UPSIDE DOWN!!!!

All the arghs and dangits and facepalming. I'm always so careful to put pots the correct way around, but this just tripped me up. There's two other adjustments I had to make to make this run of PCBs work well, (resistor value changes) but other than that I'm really happy with how well they work.

PlusSnare!!

A simple module.

It's an 808 snare drum, with a few tweaks to make it simpler, reduce component count, adjust things here and there... but this adds two things:

Thing it adds 1:

You can plug in an alternative noise source. Any signal. It'll still get enveloped and filtered just like the white noise that makes up the "Snappy" sound. Good to make your snare drum sound like a laser or whatever?

Also, the white noise generator in the 808 has a trim adjustment to get the noise the Correct Amplitude, but I just designed it to be PLENTY LOUD and you can turn down the "Snappy" pot to get it quieter.

Other Thing Added To This Circuit (the "plus" part)

This has a PT2399 delay circuit built in. The "wet/dry" control is managed by an LDR/LED pair (a DIY Vactrol), so you can use a control voltage to inject snare sound into the delay chip circuitry. You know King Tubby? I spent several hours the last time I had The Influenza listening to many of King Tubby's albums. He is a reggae/dub artist, and one of his standout sounds is a reverb/delay on some of the snare drum hits, while most of the snare hits are dry. Dub does this a lot... whatsizname Martin Garrix did a bunch of reverb/effects on occasional snare hits (worked great, love some of his tracks) so I wanted that sound in my modular. 

Oh... side-note... it was entertaining to listen to this effect through King Tubby's discography. His earlier stuff used a spring reverb (twangy thin sound, but definitely reverb vs. delay) and his later stuff used PT2399-based "reverb", so either a single PT2399 or a famous Belkin Brick, which is actually three PT2399 chips on a small PCB encased in epoxy. The Belkin Brick is a lot smaller, more reliable, less delicate, "higher fidelity" reverb, but it lacks the reverberation qualities of a physical thing that allows sound to literally reverberate around. It's just three PT2399s :D

ANYWAY, King Tubby specifically, and dub generally, are great to listen to and I love that sound so I wanted it in my modular! So here we have the PlusSnare.

I printed up five of them, which needed rework.

I printed five more with the problems fixed, and they work great, and other people have them.

I've laid out the PCB better, and am about ready to get a release candidate printed. So here's the article teasing them, to which I will link with a QR code on the PCB