Side Project, Quad AD/AR #2

Well, I got the parts and it worked!

I did have to make a couple of changes.
I couldn’t get 1M potentiometers in the RK09 package that I use in my modules, so I went with 50K, now I upped the 4.7uF timing capacitor to 100uF to compensate but I felt the attack/release times were too long, so I changed the timing capacitor down to 22uF and the times seem great to me.

I did notice a bit of attack even with the attack set to 0, this is down to the diode that’s used to ensure the attack pot is used for attack only. So I popped two more in parallel and the attack is all but gone.

I also couldn’t find 2.5mm pitch capacitors for the 10nF and 100nF, so I updated the board layout to fit these 5mm pitch parts and to include the extra two diodes (as my mod looks a bit ugly).

Next step for me is to build three more, wire them up and then get the panel ordered. I’ll be sharing the panel design once it’s complete.

So, below is the KiCAD files, which include, schematic, PCB layout and also the BoM in CSV format. You’ll also find the iBoM html file, which is a super useful plugin for KiCAD that let’s you track which parts you’ve populated and highlights them on the board!
I hope you enjoy it.

Side Project, Quad AD/AR

I love my modular synth, and like a lot of people I’m restricted with space (though I do have 44U in my MU system, oops).

I have a pair of Moon Modular ADSRs (511D) which are fab (even though they do go ADRS in knob order, which drives me a bit nutty sometimes), But for a lot of things, especially sequencing you really only need an AD or AR envelope.

So I search high and low, ok I used google, and found a thread on electro-music.com talking about the Thomas Henry AD/AR envelope. Neat, thinks I, a small compact envelope with minimal parts count, I know I could fit four of those in a 2U wide MU module!

Great, so it all fits. I plan to have the gate inputs connected, such that one gate at the top will trigger the three below unless another Jack is plugged in.

Now this time I wanted to share this, it’s not my design so I didn’t feel comfortable selling it, so I’ve designed a PCB using through hole parts (Rather than 0402 SMD parts).

I Added a couple of features, firstly an LED, because everyone likes blinky lights and secondly a switch to switch between AD and AR modes. There’s a header for a dotcom style power connector and 6 pin “feed through” for the power, so you could put four in a panel and daisy chain the power.

I’ve had a few made at OSH Park to test and they’ve arrived!

So the next step is to build it up (I’ll admit, I didn’t have any CMOS 555 timers) and assuming all is well I’ll be uploading the KiCAD files for the PCB layout and schematic.

I’ll also need to order the panel, but I’ll do that once I’ve got the PCB assembled and working.

Interesting Developments in Modular

I’ve been following the news from Superbooth and the subsequent fall out and other stories that weren’t the big liners, and here’s a few things that slipped under the radar.

They seem to be geared towards making modular polyphonic, storable or both. These are really interesting to me. I mean, I love my modular synths (I’m lucky to have both Euro and dotcom format systems) but there are a few things that ‘niggle’ me a little;

  1. Cables, ok, they kinda cool, but my slightly OCD’ish nature means I find them sightly messy. I’ll use purple for CVs, Red for Audio, Orange for gates, etc. But sooner or later it ends up messy, mismatching cables because I’ve run out of one colour, or worse still, both.
  2. Patch storage, one of the things I love about modular is that you can create pretty much any sound be recombining modules in unique ways. In a way for me that’s great as I can try new ideas and concepts quickly and easily, but when I get that ‘awesome sound’ I have to then do something with it straight away, because in three weeks time the patch will have changed and the chances of my remembering how to get it back are slim (I’ve reached that age in my life where I forget things far too easily, hence I always have a notebook to hand, I’m old school, I like paper).
  3. Polyphony, ok, there are many ways to get polyphonic modular synths, but not many people want to buy 16 VCOs, 8 VCFs, 16 ADSRs, etc to get an 8 note poly system. Not least to add that is a LOT of patch cables and a lot of patch points to remember (see items 1 & 2 before). I love modulars for many things, but I love playing chords too, and multi-tracking a modular to get a poly sound is kind of a buzz kill and can ruin the creativity of the moment.
  4. Ever expanding modular (with a respectful nod to Tonto), each time you want a new feature, you need another module. This is a double edged sword, it’s fab that there are lots of manufacturers out there so you can pretty find the exact module to suit your need, but the flip side is you’re always going to run out of case, patch cables and/or power.

So, with these three things in mind, I found these items at Superbooth (and online) which seem to address some of these issues, none of these are the ‘holy grail’ solution to my ‘4 modular niggles’, but it’s interesting to see that I’m not alone in my thinking.

Nozori
This is a lovely concept that addresses niggle number 4, and I’ll happily say I bought a Nozori 68 and Nozori 84 modules as part of the Nozori Kickstarter.

Now I really love this idea, a tonne of modules in a single physical module. Just swap a front panel, flick a few switches and go from VCF, to VCO to ADSR, LFO and much more, fabulous!
A real space saver and for the once every 6 months you need say a karplus strong oscillator, you have it!
What I don’t like is that to swap the panel you have to undo the for retaining screws for the module. I think I’d have liked to have seen the four corner screws hold the module in place, and then have two central “knurlies” which hold the function panel in place. I may have a go at modifying mine to work like this. But in short, these are fab modules and work really well. I can see them being great for people with live rigs and people like me who sometimes want extra LFOs or extra ADSRs, but don’t want a bit crusher in permanent residency, but every so often fancy playing with a bit crusher.

Soulsby Synths ecosystem
This I like, again, it solves the problems of polyphony and space, but also retaining a lot of connectivity with existing euro rack modules.

I really like where this is going, it took me a few watches of the video to get the flow, but I think it’s great. Lots of connectivity, lots of expandability and very little space. I also really like the use of LED rather than displays for selecting some things, it makes it feel much less like ‘menu diving’.

Mayer M800 System
This is great, polyphony AND patch storage! result.

I really like this, some fabulous sounds, multi-timbrality, polyphony, patch storage and a gorgeous UI (who doesn’t like LED rings!).
What let’s it down is that it appears to be quite a ‘closed’ system, i.e. it doesn’t look like you can easily integrate a lot of other Eurorack modules with it. it has a few inputs and outputs, but that’s it.
It does have wavetables (I love wavetables)
Perhaps there will be more in the future, definitely one I’ll be keeping an eye on this system.

ACL Sinfinion
This took me a little by surprise when I first saw it, but after watching the video where the guy explains how it works and how he uses it, I’me very impressed.

It’s like a sort of patch manager for modular, but with a whole bunch of really cool stuff built in, For example; chord engine, quantizer, arpeggiator and the ability to route CVs to certain functions.
This seems to me to be an incredibly powerful tool for any modular system, the ability to do some much and route signals and ‘play’ a modular without the need to repatching is wonderful.
I also REALLY love the buttons and panel colour/layout.

Summary
It seems to me there’s a change in the direction of modular, from ‘noise making’ (forgive me) to more ‘musical’ endeavours, plus there’s a push to break the limitations of modular synths in terms of patch memory, polyphony and flexibility.
Exciting times!

Superbooth 2019

I wanted to start writing and sharing some of the things I like and enjoy, and possibly some frustrations that occur during development of a project. This is the first post of these ‘ad-hoc’ blog posts, so do check back often.

Superbooth

Well, Superbooth 2019 has been and gone, it was by all accounts an incredible event, alas I wasn’t able to attend this year, but hopefully next year.
I noticed a few really interesting things in the news that came out of them, so I’d like to share some of my thoughts about things that caught my eye.

UDO Super 6

Wow, such a great synth. I was lucky to be privy to some of George’s prorotyping and it sounded good and original, but this was a whole new level of awesome. Such a great sound and something new.
George loves creating something new and something different but with a respectful nod to what has come before and the Super 6 looks perfect.
I’m really looking forward to having some quality one on one time with this in the, hopefully not to distant, future.

Korg Minilogue XD Desktop

I really liked the minilogue for it’s features and sound, but I really don’t like minikeys (I have sausages for fingers) so the desktop version really got me excited. It’s something I will almost certainly be adding to my synth arsenal at some point.

MFB 8 voice polysynth

Wow, I really wasn’t expecting this! ok it’s a prototype so it’s not the prettiest things yet, but it’s great spec – 3 oscillators with FM, 2 LFOs, 3 envelopes, dual VCF, effects and a small form factor. It promises to be great when it’s finished.

IK Multimedia Uno drum

What a fabulous sounding drum machine, it seems to cover 808/909 style sounds as well as maintaining it’s own unique sound, I’ve got the uno synth which sounds great and this will make a fabulous addition to that.