Delta Build Blog #1 (The truth hurts)

These days I build synths for a hobby, yes I sell them, so it’s a “self funding hobby” and I’ve been very lucky to be in that position.
So I thought I’d share some of the joy, and pain, of designing and building a synth in today’s world. This will be an ongoing blog, so if you’re thinking about building synths professionally this might help you in some way.

As you may, or may not know, I like synths and I really enjoy making new and interesting synths, I like modular synths because they allow you to connect things in ways that conventional mono and poly synths don’t always permit. On the plus side for mono and poly synths, you can usually store and load patches.
So there are pros and cons for both, and both modular synths and fixed architecture synths have their place in my life.

One of my passions is making something new. 002 did that in many ways with it’s internet updating (not new to us, but new to synths), HTML editable patches and control morphable ladder filters in hardware and a bunch of other things.

The WTF (Window Transform Function) Oscillator also came out of my wondering what it would be like to switch at audio rate between two waveforms, it didn’t imagine how I thought it might, it sounded totally different, but it’s a very cool thing.

The waveplane oscillator was a way to allow people to sort of create their own tables, at least a way for people to morph between waves in any order they wanted, something that’s difficult to when you create wavetables (believe I’ve created lots of wavetables in my life and it’s a lot of work involving hex editors, audio editors, spreadsheets and code editing to make them come to life).

The natural step, for me at least, was to move to a poly synth. So whilst I’m finishing the MuSeq I’ve begun working on what I’ve tentatively called the “Delta” polysynth.

What are the specs? Well I’m keeping what I’m working towards close to my chest, but it will have both the WTF and Waveplane oscillators in, along with some new features (remember I like making new things, move forward, not backward).

First step on the development path was to prove the oscillators, Having done that by selling both as modules for Eurorack and MU systems I’m quite pleased they sound good.

Next step was prototyping the VCFs, this time I did this on breadboard.

Then we moved on to prototyping the voices for a poly synth, I found that I can get 4 voices of oscillators and 12 CVs from a single 600Mhz processor.

So we have all the parts!
The next challenge is getting down the cost, and here is were things get tricky, thanks to some budget brand companies, people now expect the moon on a stick for $300.
Ok, I get it, I’m on a really tight budget (still paying of debt thanks to a certain someone from a few years back) and I certainly can’t afford £3000 for a synth.

So how do you get the cost down?
Well there are a number of ways, firstly you go all digital/DSP or you could compromise on the quality of the parts used, You could use lots of menus and reduce the panel complexity (complexity = cost), you could reduce the feature set and so on.
So you have to find what works for you, I have a target retail price in mind, now one thing consumers of synths probably don’t know is how the synth market works.
Let’s say a synth costs $1000 (nice easy number to work with), that is split 4 ways… $250 to the dealer, $250 to the distributor, $250 for the raw parts which leaves $250 for the manufacturer.
So next time someone moans about the cost and has a go at a company for the “excessive pricing” please, keep in mind that the company in question has only made 25% of the retail, if that.

How I’ve chosen to keep costs down?
I’m trying to keep things small and light, yup big boxes and weight cost a fortune to ship to distributors, and to dealers (this all has to come from somewhere!). So my Voice PCB is 100mm by 110mm for 4 voices currently, I hope to make it smaller.

So, we’ve chosen a design approach, we’ve proto-typed our oscillators, our filter and worked on the cost down. Now we roll a PCB.

Delta 4 Voice Prototype PCB

Now, let’s be clear, this stuff isn’t cheap, I have 4 of these quad voice PCBs, that cost £1100, in volume they’re much cheaper. Remember that rule of thumb? as a one off this synth is already at a £4400 retail price.
Which brings us to the next bit of your “mega synth project”, how many are you going to sell? if you can sell a thousand of them, then yup you can get the cost down, if you can only sell 20 then the cost is going to increase.
Let’s say the board in 1000 off costs you £50 each, that’s £50,000.
That’s the world we live in. And don’t forget, YOU have to pay this upfront!

Yes, my aim is to make this commercially available, how possible that is depends on potential sales, pre-orders, investment and what the final cost will be, at this stage I have a target cost but nothing firm.

So your PCBs are here, you power them up and…… nothing quite works…
Welcome to Research and development. The first PCB you roll in any project will not be the one that goes into production, there will always, always, be a change. The WTF had 3 iterations of PCB, the Waveplane had 2.

In my case, I have two mode wires (I got two chip selects the wrong way around for my sample and hold circuit). and I will be changing the value of some resistors (the range on the cut off doesn’t quite cover what I’d like, it’s close, but not right).

Mod Wires (not intentionally blurry, it’s just hard to photograph something that small)

So, having figure out why half my CVs were not working or in the wrong place, they’re now fine.

I’m now tweaking the resistors, and one of the tiny little ones gets lost whilst I’m modifying the board (they’re 0402 which is 1mm by 0.5mm), I think nothing of it…. carry on, power up and the CPU is dead… ugh, guess what? that resistor? shorted two pins killing the processor.

Thankfully I had the foresight to NOT put the CPU on this first generation of board, so another one is on order.

Project Progress

It’s been a mad few weeks since our last update and I’m really pleased to say that our first two NJM2069 modules have shipped. We’re waiting on some more panels and then we’ll be adding these to our store, cost will be £250 + shipping. So stay tuned!

And Jon has made a major breakthrough with the MuSeq and has solved the MIDI timing error, it’s now rock solid. Better still he’s spead up the graphics library that is used to display text and graphics so the UI is much slicker than ever.

So Jon is going to continue tweaking libraries whilst I add in the extra functionality, this should speed up the development time dramatically.

Work continues on Delta, we’re waiting for PCBs before we can do much more but things are coming along well.

Life at Dove Audio

I wanted to give a quick update on various projects and so on, so let’s dive into this.

MUSeq
Things are going OK with this, I’ve narrowed down a few more bugs, but the MIDI timing bug remains and it’s now significantly behind schedule.
Right now the code is split across about three files and the majority of the code is in one huge file. So to make life easier (scrolling up and down a few thousand lines of code isn’t easy) I’ve begun splitting the project into smaller part. For example one file for the UI, one for the file manager, one for clock and so on. Now My coding skills aren’t the greatest in the world, however the ace up my sleeve is that Jon, my boyfriend, is a professional coder.
Jon is going to help me split the project into multiple files and get it to compile (my attempts all ended up with hundreds of compiler errors), this won’t be a quick thing, but it will be worth it when it’s done.
The layout of the second revision of PCB is planned to start next week with removal of things like the unused display, but the addition of a mode switch and some other small tweaks. So things should be settling down into their final form.
My hope is to build another couple of these and get them into the hands of a couple of people to beta test and report bugs/problems to me prior to making these available to buy.

2069 VCF+VCA
Things are going well with this, PCBs have arrived and they look fabulous;

We have a small block in that the next generation of panel has been blocked for a while whilst the people making it recover from some COVID related problems.
However I plan to start assembling the first 3 or 4 of these this coming week ready for when the panels arrive. So keep your eyes peeled!

Delta
Delta is something new, something I’ve been thinking on for a while. It’s a poly synth and I’m happy to report things are going well. I’ve proto-typed the VCF & VCA and I’ve got the basic voice code working.
Prototype PCBs have been sent off to be made so further development can be done (somethings you just can’t prototype on strip board).
Here’s a Render from my CAD package of the board.

Delta Prototype Voice PCB

I’m keeping full specs close to my chest right now, I have a clear idea of what I’m aiming for, but until I’ve proven it’s possible and have sound demos I won’t be giving anything away.
Rest assured though, there are a number of innovations that will be going into this polysynth.
I will also add, don’t expect this to be ready quickly, this is probably 10 to 12 months away from being available to beta testers as there is a lot of work to be done yet. But I do plan on providing updates as things move forward.

Other News
In other news, don’t forget we have some Waveplane oscillators left in both Eurorack and MU format and available to buy either Direct or from our dealers.

Moving Times

A number of things have been going on in the world and in my personal life. So I wanted to give a quick update.

The COVID-19 problems are really worrying and very stressful, to see so many people loosing their lives due a disease that can be stopped simply by avoiding social contact is so saddening.
Even sadder is that a portion of humanity seem to feel they’re immune, it’s a hoax or simple that it could never happen to them. So they carry on as before resulting in more avoidable deaths.
I’m finding the headlines increasingly painful and difficult to read.
I can only hope that the selfish people soon wake-up and start acting like responsible adults.
One thing is certain, this is a world changing event and our lives will never be the same. I my one hope for this crises is that humanity changes for the better going forward.

A personal update, I’ve recently moved home, this resulted in about 3 weeks of downtime for my development efforts and a lot of upheaval, things are almost back to normal for my working environment.

As a result of my move MuSeq work was on hold, I’ve only just started again. I discovered that the MIDI timing was a bit out, MuSeq was slightly ahead of the beat, so I fixed that and now it’s rock solid.
Bad news is I discovered a bug in the MIDI library I was using, it doesn’t run on an interrupt, so any event that happens like say changing from the CVA page to the CVB page means that some MIDI clock ticks are missed, resulting in a massively out of time sequence, which is really annoying to say the least.
I’ve had a look and it doesn’t look like it’s possible to modify the library to do this, so I’ll be writing my own library for handling MIDI using interrupts. Not a big problem, just a lot of code that will need stripping out and refactoring.

I’ve got a new module in the works. This is something I’ve had in breadboard for about 4 months, and I got the prototype PCBs early march (delayed due to COVID-19). You can hear a quick clip of the new module here;

The module is based on the somewhat infamous Korg NJM2069 VCF/VCA chip used in the Poly 800, DW6000/8000 and DSS1, here’s a picture;

This is only going to be available in the MU format because there are a plethora of really great VCFs for euro-rack, but only a limited range in MU format.
Some of the nice things about this module is that it has a built in VCA, so for people with smaller rigs where space is an issue this module works really well as a “dual function” module.
I’ve also added a switch so you can select 24dB/Oct or 12dB/Oct cut off slopes.
Of course, being designed for a poly synth means the resonance is CV controllable which is a real boon (one of my favourite tricks is to route VCF envelope to both cut off and resonance).
Finally on the back there are jumpers which can be opened and a header cable can be added to bring out the extra two pre VCF inputs and VCAs. I may do an expansion module for this to bring those extras in.

Now the catch, I only managed to get 25 of these NOS (New Old Stock) from a retailer who sells NOS chips, I would love to get more and maybe if I can find some I will. However, this run (when I find my oven for baking PCBs) will be limited to 25 only. I’ve tested these chips and they all work perfectly.
However, I will be publishing me schematics, gerbers and front panel design, so you can make your own if you’re lucky enough to find one of these incredible sounding chips.

For now, please, stay safe and look after yourself and your loved ones, humanity has had some major crises in it’s existence, we will get through this one too.

Dove Audio Update

I wanted to write a quick update, so you don’t hink I’ve fallen off the face of the planet 🙂

Firstly I had some major surgery in November (nothing life threatening) and I’m now finally back on the mend and pretty much back to my normal self and speed.

Secondly during my recovery time I’ve spent a lot of time looking at my projects. One of these is a design for Tangible Waves which you can expect to see in the near future (I have one of their systems and it is simply awesome and so portable it’s nuts!), I will share links and videos once it’s complete and announced by them.

The other one I’ve spent a great deal of time with is the MuSeq Sequencer, A large portion of this was refactoring the code to make things work quicker and more reliably. the bank play mode is now in and there’s a short video on my instagram feed here –

The refactoring has taken a lot longer than I had expected, but is done now.
This leaves me the following things on my “to do” list;
1. Move CVB to second function
2. Save Bank play
3. Resolve a small issue with editing a pattern then switching to bank play (it looses the edits)
4. Add MIDI Clock in/out
5. Add Sync 24 In/Out
6. Add USB MIDI In/Out
7. Add some menus
8. Redesign PCB and panel (with the correct sized holes).

In all honesty, there’s about 3 or 4 months of work in there (remember I have a day job, so this is done in my spare time).

Once MuSeq is completed, I will resume work on the MuTable, I’ve had some ideas on that and I plan to add user up-loadable wave-tables and a few other features.

I’m also finishing off assembling the batch of Waveplane modules (eurorack and MU) inbetween writing code (when my eyes go cross potty from staring at code). You can find these modules in my store and also in my dealers.

Thanks for reading.
Paula

P.s. If anyone is up for helping me with some webdesign of my page, I’m happy to talk trade for a module in return.

Halloween Modular Jam

Started having a play with my modular (I was actually starting to unpatch it) and ended up with a spooky/dark vibe. And it was October 31st, so I dimmed the lights and hit record.

MuSeq and uTable

A few people have spotted a couple of new modules in a recent video I uploaded to YouTube where I was having a play with my modular synth.

There are two modules in use that aren’t available yet, so I’ll explain.

MuSeq

This is, rather predictably a step sequencer, but I’m taking what I’ve learned from developing GorF and starting again which gives me the opportunity to add in a bunch of features that I never had time to implement.

Currently MuSeq has 8 steps, two CV outputs and two gate outputs.
Each step has it’s own OLED display showing what is going on for that step, note, length, gate, tie, skip, etc
You can skip steps (up to 7), you can also tie steps together and of course not trigger a gate (a bit like a rest, though the CV still changes).
Both CVs are 1V/oct, but currently CV-A shows a scale according to note (i.e. C, C#, D, etc) and CV-B is a value from 0 to 511.
Each step can have it’s own step length, be it 1/4 notes, 1/8th notes, 1/6ths and even triplets, the whole range is there from 1/1 to 1/32 notes.
Each step also has a ratchet option (which you can hear in the video above) with the option to double, or triple fire the gate.
It also can store and load sequences from a FAT32 formatted micro SDCard, so you can back up and share your sequences quickly and easily.

There are a few currently un-implemented sockets, for 5 pin DIN connectors, STG Clock connectors (in and out) on the rear of the PCB and also two inputs (CV or gate) and two outputs (CV or gate).

Things that I will be adding, in no particular order;
* MIDI In/Out (for clock and note)
* SYNC 24 In/Out (For clock)
* CV/Gate inputs for Clocking or anything else (e.g. tempo)
* Bank play mode (like GorF)
* Chain mode (Chain two patterns to get 16 steps)

So there is still a lot of work to do on this, it will take a few more months before it’s completed, and there will be panel revisions also.

uTable

I wanted to have a bunch of oscillators for those ‘big’ modular sounds that modulars are so well known for. Now I also wanted them to be slim as my latest oscillators have been 2U and 3U wide. Me being me I wasn’t content with a regular sine/saw/square type oscillator, so of course I made a single 1U wide wavetable oscillator. But it has a few differences.

Firstly there is a switch on the front that lets you choose between wavetable mode, stepped mode (so waveforms just jump rather than transform) and also pulse width modulation, all the way from 0% to 100%.

Secondly, and this is where it gets special, there is a switch to flip between regular FM and through zero FM. So now you can do through zero FM with wavetables, and it sounds incredible.

What’s the big difference between regular FM and through zero FM, well, simply put as the incoming FM CV drops below zero with a regular FM it will simply “stop” the oscillator, with a through zero FM oscillator the output waveforms starts reversing and then the pitch increases as the CV goes further negative. These creates a much more ‘musical’ sounding FM than you get with regular FM.

Now this also needs some work, currently there’s a small amount of jitter around the crossover point which causes a nasty click with low modulation depths, and I need to modify the crossover circuit to resolve this.
I also need to adjust the range of the fine control, which right now is about 3 octaves (whoops).

Modular Jam

I had a particularly stressful week at my day job, Dove Audio is just part time for me, so I decided to have a play with my modular using the modules I’ve made.

It came out very berlin school esque (predictable given my love of Tangerine Dream and Klaus Schulze)

Here is what I used and how
– Dove Audio WTF oscillator on drone (bottom left, just the one).
– Dove audio WTF oscillator on ‘mid’ PWM for sequence (upper right, second in from right)
– Dove Audio Waveplane oscillator on high notes (upper right, rightmost)
– Dove Audio MuTable (In development) on low notes (3rd in from right, upper)
– Dove Audio MuSeq (In development) on sequencing duties (upper).

There are two modules used here that are in development, and it will be a few months before they’re ready.

My Music

At a recent trade show (Brighton Modular Meet) I was asked a few times if I made music. Now I would say I don’t, at least I don’t consider myself a musician, my passion, the thing that drives me, is making synths. Whilst I enjoy the odd noodle on a synth I wouldn’t say I’m a musician.

That said, a few people asked, so I’m sharing my soundcloud account for people to listen to. There are not many tracks there, and it’s quite a varied mix. But I hope you find something you enjoy.

“Standing Tall” – This is perhaps one of my favourites, and much more like the sort of thing I enjoy playing.

“Transport” – This was written for a compilation album, we were given a few samples and told “do what you feel”, I had just gotten a Hartmann Neuron and so I did the whole track on the Neuron. Sadly the album was never released.

“Soul Defence” – This was probably one of my darker moments, when I was battling with some big decisions and struggling. I don’t sing, but the singer in a band I played bass in (for giggles mostly) did sing on this and played guitar.

Below, you’ll find a link to my page and some of my other stuff, predictably some ‘berlin school’ and just for giggles a cover of the Joe90 theme song.

Side Project, Quad AD/AR #3

I’ve now built another 3 of the PCBs and daisy chained them.

So the power comes from the first and is fed into the others (there’s two sets of power pins on the PCB for this reason. Also the gate from the top feeds into the next, and so on. So one gate can trigger all four, or you can have two gates triggering two EGs and so on.

Next step is to get the front panels made. I’ll probably make a few of these, so if anyone is interested in buying a front panel and spinning their own PCBs for it let me now.

I plan on having two of these quad EGs in my system.