[A6] Who's getting busy with their Andromeda

[Michael E. Caloroso]

 >>> I'll throw my hat in the ring:  I want to emulate the sound
 >>> of the ARP Pro-Soloist, specifically the sounds used by Tony Banks.
 >>
 >> I have a Pro/DGX. Considering that it is a 1-oscillator mono synth,
 >> you would think that emulating its sound should be an easy task. But
 >> I think there was some clever programming of the presets going beyond
 >> the simple VCO-VCF-VCA archichecture. The ARP filter has a very
 >> special sound wich I have failed to emulate with the A6 until now.
 >
> It's the multiple filtration that's the doozy.  The signal can run through
> any of 10 fixed resonator filters, along with a highpass filter on one of
> several fixed settings, in addition to the more-or-less conventional lowpass
> VCF.
> 
> Plus, it's not a "true" 1-oscillator architecture.  There are separate
> sawtooth and pulse waves (always hardsynced to each other) which can be
> routed through different sets of filters before being summed.  Oh, and the
> "sawtooth" isn't a true sawtooth -- it's a sum of 5 synced square waves,
> resulting in a 64-stepped ramp.  No kidding!
> 
> It's truly a unique beast, and it's uniqueness both tweaks and irks me.  I
> love its one-trick pony sound (though it's got 30 presets they all REEK of
> "Pro-Soloist") but I don't feel like dragging it to sessions and gigs!

For a one VCO monophonic synth, some of those ProSoloist sounds remain 
elusive to my programming attempts.  The Fuzz Guitar presets amaze me. 
And the bassoon and oboe presets are just haunting.

Yes, emulating the fixed resonators would be tough in the A6.  Some very 
fine presets in the PS indeed due to the resonators.  The service manual 
shows the signal flow for each of the presets, but they're still hard to 
nail on any other synth.

Part of the PS's sound is its 4034 filter, 99% identical to the 4035 
filter in early black/gold Odysseys and Axxes.  It's an infringed Moog 
ladder lowpass VC filter with some improvements.  Moog found out and 
sent out the legal beagles.  The Pro/DGX used the 4075, but doesn't 
sound as good.  When I was first checking out my PS for purchase, there 
was something about the sound I liked despite being a preset monophonic 
single VCO synth; it was later I learned of the 4034.

And the VCO is indeed interesting.  It's a traditional charged cap VCO 
core, but running at a high frequency that is divided down into pulse 
waves, which are strategically summed together to produce a ramp, and 
also varying pulse waves.  The VCO already has a VC input via LFO 
modulation.  A shame they did not add CV & trigger I/O jacks, this thing 
begs for a pitch bend wheel or ribbon.  One of the most expressive 
synths I have played.

And how they implemented the preset programming... forgeddabouddit!!!

MC