So I haven’t been great at keeping up to date with what I’ve been up to. To be honest I’ve been having to much fun playing with my synth to stop and write about it.
I’ve got quite a few more modules finished now – so many in fact they no longer all fit in my makeshift case. The prospect of building a proper case is looming large on the horizon. Perhaps I ought to build two, at the rate I’m building it won’t take me long to fill them!
Talking of cases, I picked up a rather nice old tool case in Hastings while visiting my sister. I paid the bargain price of £10 for it and a thumb piano. It’s a little worn and is going to need a little attention and is also quite shallow so I’m intending to use it for controller modules which aren’t that deep. I think I’m only going to use one side and make the lid detachable. It will make a good place to store cables when I’m playing out.
So, down to the modules.
You may notice I’ve been experimenting with a new technique for panels. I’ve been using some 2mm clear acrylic with paper panels stuck on with double sided sticky tape and covered in sticky back plastic. All done in the finest Blue Peter tradition 🙂
The panel for the SEM VCF went a little wrong as I forgot to mark where the screw holes were and managed to put text just where two came through. The perils of trying to finish things late at night. I’m pretty happy with the results though and they’ll do until I get some proper panels made.
TH X4046 VCO
I’ve had a couple of Motorola 4046 phased locked loops for over 20 years and they have found a home in this excellent oscillator. It can go from sub-audio frequencies to just above the range if hearing meaning that it can be used as an LFO as well as an audio voice.
It produces Sine, Triangle, Saw, PWM and Skewed Saw waveforms and has great Hard Sync – meaning you can feed a signal from another oscillator into it which will keep resetting the oscillator to the beginning of its cycle.
I’ve built two sets of boards but have only panelled one as a test of my layout. I’m currently thinking of not bothering with my own panels for this as there are some very nice aluminium panels available already.
PT Audio Dual Digital Oscillator
Another board offered through Muff’s. This is a different kind of oscillator from the analog TH X4046. At it’s heart it has a microprocessor and is a digital wavetable oscillator. This allows it to create a different pallet of sounds from standard waves to bitcrushed noise. The signals from either oscillator can also be used to modulate each other and the selection of which wave is playing in the selected table can by modulated with a control voltage.
Second TH Controller LFO & MegaOhm VCA Rider
I’ve already written about these in previous posts so wont bother here.
Moogah Oberheim SEM Multimode VCF clone
This is a clone of the classic filter from the Oberheim SEM that one of the members of Muff’s offered with the blessing of Tom Oberheim. In addition to the originals voltage controlled cut-off frequency this circuit Moogah has also added voltage controlled resonance.
It’s a multimode filter meaning it can be used as a High, Band or Low pass filter. It also has a variable output allowing you to sweep from Highpass to Lowpass. Although it doesn’t self resonate it growls and squeals in a most delicious manner.
I haven’t got round to tuning this filter up properly yet as I’ve been enjoying playing with it so much.
Voltage Processing Module
This is a collection of useful control voltage processing tools. It has two circuits which allow you to attenuate, invert, offset and also apply glide (or portamento) to a signal. Very useful for scaling signals from a sequencer to an oscillator without retuning the oscillator among other things.
I’ve also managed to squeeze in two active Multiples. This circuit just takes one input and splits it into three identical outputs. They may not sound very exciting but these circuits are essential tools.
Currently on the breadboard I also have my own take on a Baby 10 sequencer. I’m currently designing circuitry to alternate between two buses allowing me to make longer sequences.