Soundtronics MIDI Ultimate DIY Analogue Synth Based on the MFOS Sound Lab Ultimate

Published on Jan 8, 2019 Soundtronics Ltd

Related posts:
2018: Who are Soundtronics? 5U Modular with MFOS Yusynth & more // Synthfest 2018
2016: Soundtronics to Partner with MFOS on Bringing Synth DIY to the Masses & Other Formats

Video description for the above:
"In January 2019, the UK electronics magazine EPE published the first of 6 articles written by Paul Cooper of Soundtronics Ltd on how to build the MIDI Ultimate. The MIDI Ultimate is an analogue synth based on the MFOS Soundlab Ultimate. The soundtrack was produced entirely on the MIDI Ultimate using overdubbing and the Reaper DAW software. Whilst it is not that close to the original Stranger Things theme, a studio full of classic 80's synths was not going to be replaced by one 'home made' synth but it was fun to try!"

Midi Ultimate DIY Synth Demo 2

Published on Feb 24, 2019 Soundtronics Ltd

"At the time of publishing this video, 2 of the 6 installments of the build guide for the MIDI Ultimate synth have been publish in the EPE magazine. So why you are busy with your soldering iron, here is another taster of a track from the 80's using only the synth and the Reaper DAW software for recording the individual sound layers."

MIDI Ultimate Patch 1 - Pulsing Filter

Published on Mar 11, 2019

"We have named this patch the Pulsing Filter and this recording was done in one take using only the MIDI Ultimate and a MIDI keyboard for the key changes. The patch is based on three VCOs tuned to sub octave and sub sub octave. Their square wave outputs feed into the VCF, the VCA is bypassed and onto the echo effects section. The VCF has both LFO and ADSR modulation for the cut-off frequency. The LFO rate is very slow and gives the underlying cyclic sound. The ADSR is triggered from two sources, the sample and hold clock to give the main beat and also from the MIDI keyboard to give emphasis to note changes. During the course of the track, echo is added, then white noise and then lots of filter resonance."

via Soundtronics

"The MIDI Ultimate project is a fully-featured analogue synth with a performance comparable to many commercially available instruments. The MIDI Ultimate is an evolution of the musicfromouterspace.com (MFOS) Sound Lab Ultimate design by the late Ray Wilson who is credited for much of the design which has been reproduced with kind permission of Synthcube.com in the US.

This project will appeal to both those whose primary interest is in electronics and those whose interest is purely making music. This is quite a large build to take on with nearly 700 components (fig 1) and may initially be seen as rather daunting. However, the construction is covered in 6 issues of the EPE magazine with cover dates from February 2019 to July 2019. With care and with our detailed constructional articles, it is quite achievable. The two essential skills needed to undertake this construction are soldering and component identification. If these are new to you then numerous guides and videos can be found online. If you are a first timer or relatively inexperienced in electronics, practice your soldering before starting on this synth. Whilst the component count is high, the PCB is assembled systematically with each individual section tested before moving onto the next.

Synth Features
Three Musically Accurate Voltage Controller Oscillators (VCOs) with sawtooth and variable width pulse wave forms, pulse width modulation, hard-sync, log CV inputs.
Voltage Controlled Low Pass Filter (VCF) 12db/Oct doubles as a sine wave oscillator
Voltage Controlled Amplifier (VCA)with log response
White Noise Generator
Active 8 Channel Mixer for all VCO waveforms, noise and external input
Two Attack, Decay, Sustain & Release Envelope Generators (ADSR)
Two Low Frequency Oscillators (LFO) with square, ramp, triangle and sawtooth waveforms
Repeat Gate Generator that can also double as another square wave LFO)
Sample & Hold (S&H) with variable sample rate and glide
Toggle Switch Patching with potentiometer mixing
Echo Effect Sound Processor
MIDI to CV Interface with 1-16 channel selector switch, responds to all 128 MIDI note keys
Headphones and Line output
Integral +/- 12Vdc Power supply Regulator (needs external 12Vac 500mA plug top adaptor)
DIY Construction with through hole components
Single board design with PCB mounted pots and switches eliminates panel wiring"