This is a long one.

[Tony Allgood]

Hi all,

Since I have finished my monosynth, I have had a few enquiries about what
useful things I found out in the construction. In a switched linked synth
the number of routing permutations will be limited by the number of switches
and pots. No patch leads here. But I have ended up with 40 switches and 54
pots. The basic architecture of one channel is two VCOs feeding one VCF
feeding one VCA. Two ADSR generators are used to control the VCF and VCA.
The synth contains two channels. Both channels can work in parallel on
separate MIDI channels, i.e.. two separate synths. Or, one MIDI channel can
operate both, i.e.. a two VCF, four VCO synth. The VCFs can work in parallel
on all four VCOs or separately.

So what do I really think are essential things to include? FM and AM for one
of the pair of VCOs; this is good. FM of the filter cut off, this is great.
Hard sync is essential, but even more so if you get the sync'd VCO to sweep
with the ADSR. Don't bother with negative going sweeps. The hard sync on the
CEM VCOs is actually quite good. Multi mode filters with HP as well as LP.
The Moog ladder is there as well for those mellow moments. Pulse width
modulation controlled by ADSR, I love this one. Delayed LFO is great for
vibrato, but a waste for the VCF's LFO. Be sure to include fine tuning, I
didn't and have tune pots that span two and half octaves... ouch. White
noise I generated with a shift register, I could not get noisy sources to
work at all well. Alternate noise source which is a clone of the cymbal unit
in an early Roland drumbox, this is great for high-hat wickedness. This
feeds straight into each of the VCFs. Don't bother with keyboard tracking
for the ADSRs... its not worth it, unless you've got a load of CEM3310s.
Velocity drive on the filter cut-off, yes. Full and half wave on the VCO on
the triangle outputs is great too.

And what about the front panel.... 6mm MDF and painted black with
plasticote. No labels since I built the thing and know what each one does.
Low cost collet knobs, colour coded. I would recommend the miniature toggle
switches from Farnell, pt no. 958-906 SPDT.