Bitte nicht nach einer Kalibrierung für das Pitchbend-Rad beim Blofeld suchen. (Macht er selber.)

Waldorf Blofeld Keyboard white, view on the pitchbend wheel

One day, my trusty Blofeld started drifting out of tune – pretty unusual behaviour for a digital synth. Even if it was in tune first, the drifting started as soon as I touched the pitchbend wheel, so I suspected that this was the culprit.

Blofeld wheelbox

Opening the Blofeld (all 18 screws on the bottom – remember?), removing the wheelbox, and measuring the pitchbend pot confirmed that the potentiometer was indeed damaged – while an end-to-end-measurement showed 9k, the end-to-mid-resistance could be virtually anywhere, screaming “Mechanical Damage!” to me.

The potentiometer is 10k lin with a knurled 6.3mm shaft and an M10x0.75 mount. Waldorf seems to have used a Piher T-21Y type (datasheet). As I did not find something fitting in my parts boxes, I took it apart, cleaned it, adjusted the pickup spring, applied a bit of contact grease, refitted the pot and closed the Blofeld

And now for the good part…

Although I measured that the wheel now zeroed around the pot’s 5kOhm mark, it had most definitely shifted slightly, so I started looking for the calibration routine. There has to be a calibration routine, right?

But the good Blofeld seems to calibrate on power-up and on the first usage of the wheel – no calibration routine for the wheels needed. Phew!

Waldorf Blofeld Keyboard white, view on the pitchbend wheel

Important note: Be careful to ensure that the Molex connector for the wheelbox sits correctly – when I pulled the plug, the plastic holder for the pins got pulled towards the edge of the PCB so when I reattached the plug, it did not sit correctly. Rule of thumb: If the plastic of the connector is visible from the top, you might want to push it back under the PCB.

Midifying Jenny, Step 1: Replacing the old keyboard chip with a Teensy

This is the first post in a series of small projects for retrofitting my JEN SX-1000 monosynth with a simple and cheap MIDI interface controller. Read about the basic idea here. Today, I am designing and building the micro-controller brain of the Jenny retrofit – if you are capable of basic soldering, it should not take you more than two hours and a couple of very common electronic parts.

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Jenny getting her very own phaser…

…and my sweet Lord, does it make her shine!

Nothing fancy here. After inserting the booster/overdrive in between VCO and filter section, I took another of those lovely kits for a phaser, built it, drilled some holes into Jenny’s housing and fitted it.

I have been using Jenny as a bass synth recently, and I am quite impressed by the quantities of life and fun this old machine is adding to the mix. She doesn’t do that much in terms of tonal range, but what she does, she does well.

Drilling holes in Jenny’s front

I rediscovered an old trick when drilling metal: use a bit of alcohol, not on the person drilling, but on the surface you want to drill. And don’t go too fast.

A Pre-Filter Booster Stage for Jenny

Giving my JEN SX-1000 a bit of additional low growl by adding a pre-filter overdrive.

A nice little addition: Insert a booster circuit kit where the coupling capacitor between oscillator and the filter used to be. Come on, you’ll have to take out that damn capacitor anyway. And it sounds really nice, punching through the mix (samples below) – especially in combination with the sub-oscillator mod.

I do admit that you might think that this is a superfluous mod. After all, when you drive this circuit – any circuit – into overdrive and into clipping, the resulting wave form will, gradually, start to resemble a square wave.

But I could do it, so I did it. And I like it. So let’s get started.

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Extended iPad control panel for Creamware Pro-12 ASB synth

Certainly the last post in this blog this year – a happy 2018 to all of you, with loads of creative endeavour and technical discoveries!

Version 1.2 of my iPad control panel for my brilliant virtual Prophet, the Creamware/Soniccore Pro-12 ASB. Read here about it. The new version does not only allow access to all the hidden parameters you cannot reach by turning the synth’s knobs, it shows the actual settings for the sound as well – a true addition if you want to look at what the sound actually does. Once again, you need the TB Midi Stuff app for it to work, which is about 4 Euros.

You can get it from my dropbox or from the TBMS forum thread.

Cheat Sheet: How to play notes (and chords) on the Launchpad

A tutorial for using the Novation Launchpad Pro as a synth keyboard.

What this is about

Last summer, I borrowed a Launchpad to take along on my holiday, and fell in love with it. The Launchpad is a new instrument; you have to relearn the movements of your fingers. These considerations and patterns are supposed to make learning easier.

Launchpad Pro sitting on top of my piano

I am not much of a musician, nor do I know that much musical theory. The few musical skills I use these days are mostly self-taught. When I started discovering synthesizers, I got myself a table of the basic minor and major chords and their inversions. This helped me produce the first harmonies, just like someone learning the first chords on a guitar.

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V2.0: A Teensy-based MIDI Controller

Building my own wheels for the Launchpad Pro – once again, with style.

Two weeks ago, I started a little sunday afternoon project, sucessfully building my first own MIDI controller – a pitch bend/mod wheel/midi merge device to serve as a companion to my new Launchpad Pro. Using an Arduino, a prototyping board by SparkFun, and community-made code, I succeeded with surprisingly little effort – the most time-consuming part was finding and fixing the errors I had clumsily soldered into my pathetic excuse for a MIDI interface. But it worked!

Launchpad Companion Controller in actionAs they say, the worst thing that can happen is that you succeed. The quick and easy success made me hungry for more – I started a MIDIfication project for my JEN SX-1000 monophonic synth, based on a Teensy, another microcontroller board that can be used within the Arduino development eco-system but is much better suited to MIDI/USB applications.

V2.0: A Teensy-based MIDI controller

This is actually a side project to that. I looked at my self-made controller and noticed that it is usable but not very playable – I wanted real wheels for the Launchpad, not sliders. So I decided to redo a V2.0 of the controller, based on the Teensy.

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MIDIfying Jenny – A Call To Arms

Isn’t it about time my beloved Jenny got her own MIDI interface?

JEN SX-1000 front with ATMEGA chip

To be sure, microcontroller-based interfaces for the JEN SX-1000 do exist. Apart from the commercial CV/Gate solutions by Kenton, there is Neil Johnson’s keyboard interface design. But even if you can get hold of the PCB – a supplier in the JEN SX-1000 group on Facebook had a batch made – the design has an intimidating parts list, and takes some serious time to build.

Is it possible to do it simpler? Emboldened by my success building a small Arduino-based MIDI controller, I decided to start a midification effort that is

  • easy to do (requiring only basic soldering skills, if any)
  • easy to get (by using components that you can buy on Amazon if you have to),
  • easy to develop (using standard solutions from the Arduino community),
  • easy to schedule (because the project is divided up into little steps, each of which is a small afternoon sub-project with instant gratification),
  • easy to participate (by contributing own ideas and code for parts of the project).

I will describe the basic layout of the MIDI upgrade kit project here. Each step, i.e. each sub-project, will then be treated in a new post, depending how fast I (or the community) get them done.

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Homebrew MIDI Companion Controller for my Launchpad Pro

I have bought a Launchpad Pro, and am still trying to figure out how to play a synthesizer with this thing. (More on this in another post.) It’s like starting over with keyboards, only with a better understanding what this is getting at. Simply great.

One thing I don’t like about the Launchpad is that it may give you velocity and per-note pressure sensitivity – provided your synth is capable of interpreting it – but takes away the traditional performance controls of a synth keyboard: the good old pitch bend and modulation wheels we have seen as our goddamn right as keyboard players ever since they were introduced with the Minimoog.

So I decided to build my own simple Launchpad Companion Controller, based on an Arduino.

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