Category Archives: Tech

Korg NTS-1 Editor

Well, the Korg NTS-1 editor is finished! Had to deal with a weird quirk where the randomiser was being triggered by both the note on and note off messages, but I managed to get around that by using the stripnote function which I’ve learnt is perfect for that sort of thing.

It’s available to download from now.

** UPDATE 4th December **
I even got a retweet from Korg USA 🙂

How many projects…

… is too many?

I’ve got lots of things on the go at the moment, so thought I’d take a step back and summarise what I’m up to.

Korg NTS-1 editor

I recently picked up a Korg NTS-1 synth and have had a lot of fun trying out all the user oscillators, particular those from Sinevibes. There are one or two shortcomings, such as the custom controls for the user oscillators not being controllable via MIDI and some audible noise when powering the NTS-1 from my computer. Running on a USB battery pack sorts the latter issue out though I’m pleased to say. And as the user interface is a bit basic, I thought I’d build an editor in MaxforLive.

Korg NTS-1 Editor

I decided to revisit the patch randomiser I coded for my Meeblip Micro editor, but this time, triggering it with incoming MIDI notes. That way, each note will fire off a completely different sound. The seed for the idea came from a twitter post from Finlay Shakespeare, detailing his time working for Novation. The end result is something a bit like the AFX mode on the Novation Bass Station II, but completely random each time as opposed to cycling through presets. Sounds really good – most of the time!

To add some predictability though, you can control which elements are randomised using the toggles. With just cutoff selected, it works a bit like a Sample and Hold.

Still have a bit of work to do, not least to add more elements for randomisation and controls for the effects, but hope to have it available to download in a couple of days. Then I’ll be using it for a 1 synth challenge

Gotek Floppy Emulator

My first sampler was an Akai S2000 and I’ve been meaning to back-up my old sound library for some time now. For years, this was my main sound source and whilst it’s true that nowadays, we’re spoilt with the abundance of gigabyte sample libraries and soft synths, I have fond memories of what I could achieve with much more limited resources at my disposal.

I also know there are some sounds in there from equipment I no longer have, such as the dying EDP Wasp Deluxe that I found dumped outside a neighbours house (true story).

So, I’m going to install a Gotek floppy emulator and back up all my sounds to that. Not exactly sure how to do it yet, but I’m a fast learner!

But, just to be contrary, I’ve also succumbed to the Black Friday sales and bought lots of gigabyte sample libraries including Spitfire Audio’s BBC Core!

Guru Gara Synth Modules

I’ve purchased more PCB’s and Panel’s from Guru Gara Synth and already have a single full voice up and running in my Eurorack system (Oscillator, VCF, VCA and Envelope). Calibration was pretty straightforward and it tracks nicely. I also went with the more expensive CEM3340 reissued chips, as used in the Roland SH101 and MC202, and the oscillator sounds all the better for it!

I have another 2 oscillators and a second envelope to build next as well as a ring modulator.

Orchestral template

Although I’ve been using Ableton for many years now, my sequencer journey started back on Cubase on the Atari ST (That is if you discount the Cheetah SpecDrum module I had with my ZX Spectrum before that). I stayed with Cubase until around version 5, then made the move to Sonic Foundry’s Acid, before finally settling on Ableton.

So why the history lesson on my sequencers? Well, as I’m writing more cinematic stuff at the moment, I thought I’d revisit Cubase 11 and have been really impressed. It’s certainly a different way of working, but it’s amazing how much of it feels familiar too.

One of the main reasons for trying Cubase again was to build up the obligatory orchestral template, and finally make some sense of the various Kontakt sample libraries I’ve bought along the way. It’s a slow, laborious process, and getting the different libraries to play nicely together is a bit of challenge, but it’s strangely rewarding too.

TouchPortal editor

Of course, the downside of a mammoth orchestral template is how you navigate the thing, and this was another factor in choosing Cubase thanks to it’s powerful visibility agents (which I’m not going to even try and explain – lots of head scratching to work those out I can tell you!)

But even then, navigating through menus wasn’t much fun, so I’ve built an editor using TouchPortal that allows me to hide and unhide sections of the template, manage tracks etc. as well as having transport controls. Unlike other similar tools such as Touch OSC or Lemur, it’s a lot more straight forward to program too, although it is at heart, a glorified keyboard emulator. But, it works brilliantly for my purposes and is definitely a good alternative to something like a StreamDeck controller.

Incidentally, I did consider the StreamDeck controller app too, but was put off by the annual subscription for that. Plus, the limitation on 15 buttons.

Anyway, that’s what I’ve been up to. Oh, and I also need to finish my third Meat Beat Manifesto mix tape too. So I better get on, lot’s to do…

Custom MIDI Slider Box Part 2

Thought I’d share a picture of my finished MIDI Slider Box. Really pleased with how it came out considering the limited tools I had access to.

I did initially have a problem with the sliders, but determined the wiper and pos (+) connections were wrong. In the instructions, it shows the wiper as the more central of the two terminals, but in the photos, the wiper is the outside terminal. I switched mine around, and voila, it works perfectly now.

Custom MIDI Slider box

Time for a new project, inspired by this post on Gearslutz. A custom DIY MIDI controller featuring three full size 100mm sliders and based on a Teensy 3.2. This will be used to control MIDI CC’s for my Kontakt libraries.

I sourced components as close as I could to the original post. The Teensy was from Amazon, the sliders and case from Farnell and I’m just waiting for some black 8mm slider knobs from eBay. Was difficult to find 100mm sliders and a case with the right dimensions in the UK so I’ve posted links below.

Bourns B10k Slide Potentiometer
Takachi Plastic Enclosure 30 x 150 x 100

Cost so far is around £50, but I already had some of the components such as LED, USB connector etc. Still quite reasonable though and I’m surprised something like this doesn’t already exist in the market.

Filter update

After some more thorough testing, I determined that the volume of the 3320 VCF was a little on the quiet side, noticeably lower than my other modules. Putting this down to the use of 100k resistors rather than the 91k specified on the circuit board, I decided to replace them and am happy to report this did the trick!

One other interesting thing I noticed is that even with the resonance turned all the way down, and cut-off all the way up, the 3320 VCF does add a little bit of colour to the incoming signal, softening the edges and (dare I use a cliché) making it sound warmer.

Resonance seems to self-oscillate nicely from about 50% onwards and seems pretty easy to tune. There are also optional solder points on the PCB for a 1v/Oct input, so I’ve no doubt it could be quite a capable oscillator too.

All in all, a great addition to my modular synth and looking forward to trying out some other Guru Gara Synth modules in the future!

Pain in the resistors

Well that was a pain in the… resistors.

Finally got the new 3320 VCF module working after tearing my hair out a little. With the lockdown, I’ve had to source the components in dribs and drabs and can’t always get the exact components stated on the circuit board.

About a week ago, I finally took delivery of the last capacitors I needed then excitedly plugged it in and heard… nothing.

A bit of headscratching later, I chanced upon the idea of sending a voltage through the CV input which initially did nothing, until I swept the filter knob, which revealed a comb filter type noise, but only when the knob was pointing straight up. Resonance did nothing to the sound, and I had silence at either end of the filter range.

Where do I start?

My first thought was that perhaps the 100k B potentiometers were faulty, or that I had bought the wrong ones and got my Linear vs Exponentials in a twist. So, I checked stock at and fortunately they had some.

Then, this morning, I had the joy of desoldering the old pots and installing the (arguably superior) new ones. Unfortunately, it didn’t fix the issue.

I checked my soldering again – all looked sound to me – so as a last resort double checked that I’d used the correct resistors. And low and behold, the 91k resistors I had been sent (and which were in a bag labelled 91k) were actually 910k! In fairness, the difference between the two is just a red stripe rather than an orange one, and even my wife wasn’t sure what colour they were when I asked her to check. So I desoldered all four of them, and replaced with 100k resistors (the closest I could find) and I’m pleased to say the module sprung into life.

I still didn’t have any resonance though, but tracked this down to some damage I’d inadvertently caused on the board around one of the resonance knob pins. I could just about work out where the pin was meant to be going though, so added a jumper wire to link to the appropriate resistor, and I have resonance too!

Whether the 100k vs 91k resistors makes a difference to the sound, I’m not really sure, but it sounds good to me and I’m currently enjoying feeding some sample and hold through the CV input.

This was the first time I’d built a module just from a PCB and Panel, rather than a full kit, and it definitely makes me appreciate the convenience a full kit gives you, even if I did save a bit of money along the way.

Korg DDD-1 LCD

So the good news is the Blue LCD I bought on ebay is fully compatible with the Korg DDD-1! The model I went with is the HD44780, although it has slightly different dimensions to the original, so I had to get a bit creative with attaching it to the case. I also had to extend some of the wires from the circuit board so they could reach the solder points.

Unfortunately, my excitement was short lived as I managed to kill the backlight within a few minutes as the voltage was probably too high.

So, after ordering another replacement (Yellow backlight this time), I decided to put an inline resistor on pin 15 to reduce the voltage. A quick google suggested something around 47 ohm should do the trick, but the smallest resistor I had to hand was 100 ohm.

I’m happy to report it all works fine though, and with no annoying whining sound!

I’ve also replaced the main navigation / cursor buttons which are a lot more responsive now. The back-up battery replacement was a bit fiddly, but I’ve done that too 🙂

Interestingly, the HD44780 was also the model I used on my Akai S2000, but that’s working fine without an inline resistor!

Hello again!

Hello again, it’s been a while! The last 18 months have seen me buy a new house, move in, move out again, then pretty much rebuild it.

We are finally getting back to normality though, and I now have the luxury of a dedicated studio space in the house (no more shed at the end of the garden!).

Whilst unpacking my equipment, I decided it was time to give some TLC to some of my more aged items.

Korg DDD-1 Drum Machine

Korg launched the DDD-1 drum machine in 1986. Built like a tank, it’s sounds have arguably aged better than competitor drum machines of the day such as the Roland TR-505 and Yamaha RX series. You aren’t limited to the 18 onboard sounds either, as it has 4 rom card expansion slots and Korg released a large number of expansions which pop up from time to time on ebay.

It also has an optional sampling board but these are very difficult to find, not to mention cost prohibitive on those rare occasions when one comes up for sale. More usefully though, an enterprising individual has reverse-engineered the rom cards and built an adapter that lets you add your own sounds, stored on EPROM chips.

I have a couple of these adapters myself, and have started burning my own EPROM’s with sounds created on my modular system. Of course, as the DDD-1 is only 8-bit, the samples don’t sound exactly the same as the originals, but this only serves to make them more unique.

Time for surgery

I purchased my DDD-1 a couple of years ago, and it generally works fine, but does have a high-pitched whining noise which I suspect comes from the LCD backlight. This isn’t present on the audio outputs though so is something I’ve largely learned to live with.

More recently though, I’ve noticed that the selection slider is a bit temperamental and the plus and minus selection buttons need quite a hard push before they work, which makes it difficult to program. Being over 30 years old, there’s a high probability the back-up battery will soon fail too, so I’ve decided some surgery is in order.

The back-up battery is your usual CR2032 button affair, although in their wisdom, Korg elected to solder this on the board. So I’ll also be fitting a battery holder to make future maintenance easier.

I’ve also noticed my Akai S2000 display is becoming fainter too, so will probably replace the LCD on that too at the same time.

Simple modular sequencing with Max For Live

Have been working on Max For Live patches to sequence my Drum Skiff.

As I mentioned previously, I’m using an excellent Max For Live Mutable Grids emulation by Mots, along with a CVPal controller patch from Spektro Audio. (Check out their CV Toolkit too!).

This outputs three channels of drum triggers (or gates) through the CV Pal module, all perfectly synced to Ableton Live. So I wanted to do something creative with the unused fourth CV Pal output.

Max For Live Patch

I came up with a simple Max For Live patch which outputs a MIDI note at regular intervals ranging from half-notes through to 32nd notes. By using this in-line with the Grids emulation and CVPal controller, it acts as a clock source for the Pico Trigger module giving me lots of trigger options for my drum modules.

Goodbye Drum Machine, hello Drum Skiff!

Have decided I needed a few more HP’s for drum synth modules, both to expand my sound palette and add extra modulation sources. So, I purchased a Make Noise 104HP Skiff and have just finished filling it up – isn’t she pretty!

I still want to revisit using Arcade buttons as triggers in the future, but for now this is providing a lot of random percussion fun! This is thanks in large part, to the three Erica Synths Pico modules which give a nice mix of controlled and uncontrolled triggers, lfo’s, sample and hold and noise. And all in bite-sized 3HP chunks!

More tea vicar?

The Bastl Instruments Tea Kick is another of the new modules and it sounds lovely and clear with a real weight behind it, but still very musical too. It’s inspired by the Twin-T Resonant Structure as employed in the Roland TR808 Kick, but capable of a much wider range of sounds. It also has a CV input for tuning along with a separate square wave output, so can even be used as a rudamentary bassline oscillator. This is in the new, aluminium styling, rather than the quirky wooden front panels Bastl normally use but it looks amazing.

Along with the Synthrotek DSM, and a bargain priced Tip Top Audio RS808 rimshot module (Which is more flexible than it sounds), I can now get a much wider range of sounds that really compliment my two Taiko modules.

But, that also means I need a more flexible mixer with extra inputs, so the Tip Top Audio Mix Z fits the bill.

Integration with Ableton Live

As much as I love the self-contained nature of the drum skiff, you can never have enough trigger sources and that’s where the Mutable instruments CV Pal comes in. CV Pal is being used with Max For Live to emulate the Mutable Instruments Grids, meaning I can keep the patterns locked in tempo with my Ableton Live sessions, and a great job it does at that! Dead simple to set up too, so will put together a post on that perhaps. You can get the CV Pal in a kit at Thonk for under £30 (plus VAT) , and it’s well worth looking into.