EMS VCS3 emu gets FS overhaul

[k brown]

Just finished giving this very old SM build a good FS brush-up. Got the envelope a bit closer to how the hardware worked, but still not quite there. The 'Putney'/Synthi envelope was pretty weird by today's standards.
Here's how it's supposed to work - notice that the 'On' (Hold) segment doesn't begin till the Gate goes off.
So the graphic shows the env staying at full as long a key is held down, then upon release of the key, the Hold stage begins and lasts for the time set by the 'On' (Hold) panel control. Anyone know how to get an env to do this?

VCS3 eg.png (18.93 KiB) Viewed 17808 times

I included the oscillator and velocity functions of the DK keyboard (underneath the pin matrix).

The PUTNIE_os copy.jpg (193.36 KiB) Viewed 17808 times

The PUTNIE os_v1.02.fsm

(1.55 MiB) Downloaded 1008 times

[Spogg]

Brilliant Kevin, I love it!

The envelope generator you described seems well weird.
I’m not sure what advantage it would offer to a player over a conventional one. Maybe you could explain if/why EMS thought it’s better…?

Cheers

Spogg

[trogluddite]

I’m not sure what advantage it would offer to a player over a conventional one. Maybe you could explain if/why EMS thought it’s better…?

Note how k brown's diagram has an OFF period of zero output at the end; a timed "silent" stage - and the control for OFF has a "manual" label at the of its travel. On the original synth, unless OFF is set to 'manual', the envelope restarts at the end of the OFF period, so you end up with a modulator generating a series of trapezoid pulses with control over the mark/space ratio and slopes. When set to 'manual' the continuous looping stops and the envelope has to be restarted with a trigger (the original had a red button next to the joystick for doing this.) So you get the choice of using it as an envelope or an LFO - albeit of a rather unusual kind in both cases.

As for why. I don't know what specific reasoning EMS used; but at the time the VC3 was released, synths were so new that no-one was blinkered by any conventions about how they should be played - as standard, there was no keyboard, even though it's a self-contained set of modules. Bob Moog thought likewise, and was famously totally against the MiniMoog when his development team presented it to him, as he thought that keyboards were an abomination which limited player's imagination for how synths might be played. It didn't help that the VC3's oscillators had such notoriously unstable tuning that playing them from a keyboard was somewhat "Les Dawsonesque". If you listen to Brian Eno's VC3 solos on Roxy Music songs, you'll get the idea!

To emulate it fully in FS, you'd really need two envelopes, so that when the "envelope looping" mode is being used, there's also a "one-shot" envelope to tell FS when a voice can be discarded.

[Spogg]

To emulate it fully in FS, you'd really need two envelopes, so that when the "envelope looping" mode is being used, there's also a "one-shot" envelope to tell FS when a voice can be discarded.

Thanks for that trog.
I'm wondering if the whole thing could be done in blue, since it's all monophonic anyway. That would eliminate the need for the complexities of voice creation and killing...

I found and I've attached the pdf which contains more detail, and where I believe Kevin sourced his images.

Cheers

Spogg

[k brown]

You know your synth history, Trog, but you have one thing a bit off. Moog had keyboards almost from the beginning, and long before the mini. Moog's very first gear didn't include keyboards not because he thought they were 'an abomination', but because pretty much the only electronic music being made at the time was of the non-chromatic, experimental type - being born out the 'tape music' world. During the development of Moog's first (modular) synth gear one of his main collaborators/consultants was Herb Deutsch, and it was at his suggestion that Moog developed a keyboard; Moog's response was more like "sure, why not?" You may be mixing Bob up with Don Buchla, whose attitude towards keyboards was much as you describe - so called 'West Coast' synthesis was very much about experimental music and not keyboard playing. 'East Coast' was more open to other ways of using synths. What Moog was resistant to was an integrated, internally hard-wired synth and was only interested in modular. The mini was 'knocked together' by others at the company while Bob was off trying get investors to save his then-struggling company as sales of the modular gear had slumped badly. Upon returning and finding the mini project well along, after some initial anger he quickly came solidly on-board and realized it was the best chance they had to save the company (though he thought it was more of a 'Hail Mary' than others did). And, boy did it save the company (for awhile anyway )

Yes, Spogg I was just going to post that. To recreate this eg you have to pay careful attention to the footnotes as well. It seems that rotating the Off control to anything other than the Manual position automatically sets the repeat mode running, so when moved off full CW the knob would need to generate a trigger?

[Spogg]

It seems that rotating the Off control to anything other than the Manual position automatically sets the repeat mode running, so when moved off full CW the knob would need to generate a trigger?

Yes, that's how I read it too.

I'll have a think about it, but I think blue is the way to go...

Cheers

Spogg

[trogluddite]

You may be mixing Bob up with Don Buchla, whose attitude towards keyboards was much as you describe

Thankyou for the correction, and for reminding me that I really should double-check things now that my memory isn't what it used to be! You're quite right, of course, Moog wasn't so much anti-keyboard as pro-diversity in control methods.

I'll have a think about it, but I think blue is the way to go...

Yes, I agree, that would be the only way to emulate the envelope accurately- though note on/off could be used as a simple gate to determine when the synth is sounding I suppose, which might be convenient as an option at least, and could potentially work in poly.

[k brown]

Whoa ! - Trog and Spogg are on the case!

@Trog - you can tell I'm a little obsessed with early synth history. I'm old enough to have vivid memories of the first time I heard Emerson Lake and Palmer's "Tank" and "Lucky Man"- it was in my town's top HiFi shop and was played on their best system at top volume - there's still a dent in their floor from the impact of my jaw
Very soon after I had a chance to fiddle with a friend's Roland SH-2 - and the die was cast.

[k brown]

I just realized the typo in the subject line - Trog must have blood stains on his rug from biting his tongue
Any way to edit a thread's title?

[trogluddite]

Trog must have blood stains on his rug from biting his tongue

More of a niggling feeling that something was off, but I couldn't quite work out what - so I copied your typo into my post, too!

Any way to edit a thread's title?

The topic title can be edited for any post when posting or editing - it propagates from the previous post rather than the top post unless edited (as I've done here.) I'll do a moderator edit on the top post, as I can't remember whether there's a time/post limit on the edit button being available (it's always available for moderators.)

Very soon after I had a chance to fiddle with a friend's Roland SH-2 - and the die was cast.

I've always wanted a play on a proper modular set up. I only ever had "baby" analogue synths; a Korg MS10, and later, a beaten up Teisco 60F passed to me by a friend for fixing which he never got around to taking back. I loved playing with both of them, and I regret getting carried away when Steinberg invented VST and I sacrificed my hardware for what was peanuts compared to today's prices for analogue.