With a new module from Dwyfor Tech comes newly sparked curiosity on what rare, unique and novel ideas will have led to different sound or behaviour in it, as each of the Dwyfor Tech modules has something different and fascinating about it. So I put some questions to Dan of Dwyfor Tech (as we have before) for a little story time.
Hi Dan, pleasure to have you answers some quetsions again. I’ve just had my first patch play around with Modrwy, which offers a ring modulator into wavefolding style behaviour. I say “style behaviour” as I aren’t 100% on what the circuit is doing. How do you describe Modrwy to people?
Lovely to hear from you again, Ben! Modrwy is a four-quadrant multiplier for CV or audio, built around a vintage transistor array IC. It has a slider that lets you overdrive one of the inputs, saturating some of the transistors and causing the output wave to fold back on itself. It’s sort of like you’re abusing the ringmod into acting like a Lockhart wavefolder, in a way. There’s a full description with diagrams in the manual, but there’s no additional wavefolding circuit, it’s exploiting a quirk of transistor ringmod behaviour.
We’ve spoke a couple of times before for interviews like these as each time you design a module there’s some interesting back story, rare unknown or little used circuit idea that sparks something or combination of circuit or design ideas which I find fascinating. What can you tell us about the development and ideas behind Modrwy?
PREVIOUS DWYFOR TECH STORY TIMES INCLUDE
Dwyfor Tech origins, “forgettable” Buchla circuits & Korg MS-50 love
Dwyfor Tech on Cryfder dual VCA and tube mixer
I find that my modules come about in one of two ways: Either I have a burning desire to solve a very specific problem/niche in Eurorack (VCF core diversity with Pas-Isel, tube size and current draw with Cryfder), or I accidentally stumble upon something that’s just way too fun not to make into a module. Deuawd was one of the latter, and so was Modrwy. The IC that makes it work just happened to be in plentiful stock at the place I get all my tubes from, I got it to wavefold by designing it slightly wrong in circuit simulation. Happy coincidences. Also, as far as I can tell, the ringmod IC itself (TBA673) is the exact same silicon as in the EMS VCS3’s ringmod but with a slightly different pinout! So there’s some pedigree there.
I should ask … how do you pronounce Modrwy? Did I hear Brian from Robots Are Red say that Mod means modulate and Rwy means ring in Welsh? Or that the whole word means ‘in a ring’?
‘Mod-roo-ee’ will get you close enough. It just means ‘ring’, that’s all. I try to keep my names short, punchy and descriptive of what the module actually is.
I mentioned the Robots Are Red video I really like the video idea you two had where you challenged Brian to achieve certain results or try certain things with Modrwy. Were those things your favourite patches and approaches to Modrwy? (note to Dan, repeat those questions, if you have a picture of the note I could use that too – or screenshot the video)
That was Brian’s idea! It was a lot of fun to see what he came up with. He didn’t have any visibility of what they were until he had the box in hand.
I asked him to:
- Use Deuawd’s two outputs with Modrwy’s two inputs in some creative way (tricky due to phase cancellation!),
- Get Modrwy to double a sine wave frequency, and turn a sawtooth into a triangle (two different ways to do the latter),
- Use Modrwy as the core of a Buchla/Serge/West-coast patch (I thought he’d put a VCA before the wavefolder but he took it a totally different direction)
I think I focussed on making the challenges interesting and fun rather than reflecting what I like to do with Modrwy – Mostly I like just using it as a two-input wave-mangler, on LFOs and VCOs alike. It’s a good ‘character VCA’ too, in the same way that the Make Noise ModDemix is.
You stumbled upon a really cool phase modulation trick with wavefolders while playing with or developing Modrwy, can you walk us through that idea?
Oh yes! I realised that you can use any wavefolder for true phase modulation. You need to put a mixer before the wavefolder, apply your carrier signal to one input, fold the wave over so the start and end ‘touch’ on your oscilloscope (so triangles and sawtooths are perfect for this), then apply your modulator to another mixer input. The basic upshot of this is that the carrier wave is offset up and down the folds by the modulator, essentially shifting its phase about. The more stages to your wavefolder the better, so Modrwy isn’t actually ideal for this, but since anything beyond about 50% fold depth will meet back with itself, it does work, so long as you’re not after a ‘nice’ waveform here.
(Side note to readers, I’ll be working on a video in the future referencing this idea as I think it’s really interesting so put your questions to me if you have any)
Anything else you’d like to mention with Modrwy?
If anyone has bought a Modrwy, or any of my modules for that matter, I always love seeing what people come up with with them. Please do share photos and videos with me, and tag me in things on social media! It’s always such a thrill to see people enjoy my work.
I saw you note recently you were taking a break from development of Dwyfor Tech modules while you focus on other the procedure of a new house. What’s left in terms of the kits you offer, where can people get them and are you still offering to make the kits up as assembled modules to order?
I’m very fortunate to be in a position where I’m setting up a home for myself and my young son, where I can be close to the school he’s starting at in September and support him through his education from here. But yes, what with fees for the solicitors, affording the mortgage deposit and so on, I am having to put a lot of Dwyfor Tech on pause until after the move is complete. No spending on parts or PCBs for new module development, and no restocking anything that goes out of stock. There’s still a bit of everything left, full kits and panel/PCBs for all four current modules, and I will absolutely build to order as always. I’ve also brought down the price for a Cryfder full DIY kit as I am a little overstocked and it would be nice not to have to move so much stuff, and that discount will apply to a built-to-order too.
Thanks to Dan for taking the time to answer our questions and share his ideas you can find all Dwyfor Tech modules as DIY kits on Reverb or Etsy and you can message Dan through those platforms to get an assembled unit which will be built to order.
Check out our other videos with Dwyfor Tech modules
