Questions for paraphonic strings synth experts

[RD9]

Ok, so I'm doing some research on the development of early strings synths to possibly try to recreate some sounds on a VA and I have a couple of noob questions about paraphonic synths.

I know there are monophonic, paraphonic, and 2/4/6/8 voice polyphonic synths. Now, I understand envelope trigger/retrigger and note priority factors with monophonic synths. I also understand the general behavior of polyphonic synths. But when it comes to paraphonic synths, Question 1: I'm not clear if there are variations or if some are better than others in terms of envelope/trigger behavior. It seems there's at least one.

I know a little bit about the concept of divide-down, but not that much. I know there's at least one synth with interesting architecture (Crumar Trilogy). I've also tried the RS-09 and know how odd the retrigger on that can be, and I have a Poly-800 and I know how that behaves too. But as for the others I don't know.

I'm mainly interested in better envelope/trigger behavior in the more common and/or affordable ones like Korg/Yamaha/Roland, but other synths are interesting as well. Question 2: I want to know in terms of envelope/trigger behavior, if there is something better than an RS-09, but maybe older than a Poly-800. Are there specific synths that fall in between these two? I'm looking for the oldest best progenitor of true polysynths.

Is it any of these?

• ARP Omni
• ARP Quartet
• Korg Delta
• Korg Lambda (multiple envelopes)
• Roland RS-202
• Roland RS-505 (multiple envelopes?)
• Roland VP-330
• Yamaha SK15
• Yamaha SS30

Update: for Roland, it's looking like maybe the RS-505 was the last in the line of paraphonics before the Jupiter polyphonics completely took over from '79 on (eventually Junos in '82). The VSE RS-505 profile mentions nothing of envelopes though.

[madtheory]

Gordon Reid in Sound On Sound magazine wrote about this very issue in the past, but I can't find the article. I suggest you go through all his articles, he's very knowledgeable, a good writer, actually owns the synths he talks about, and in many cases has interviewed the designer.

[RD9]

Thanks! I found a nice compiled index when I searched for Gordon Reid. I've read his Polyphony to Digital Synths article before, but unfortunately it doesn't cover Rolands/Korgs/Yamahas. I see a few others though. Checking it out...

[nathanscribe]

They're a bit mixed I think. I have a Roland RS-101, which is basically the 202 but without control over the chorus (it's always on) and a couple of minor changes. There are features like keyboard split to think about, how many sounds you get and whether they can be layered, whether there are not only envelopes for every key but how the filters are arranged... the RS-101, for example, has a simple attack/release envelope for each key, a split point 2 octs from the bottom, and only brass/strings/strings2, selectable per side of the split. Filtering is basically a tone control for each of brass and strings. It's a lovely, thick, doomy sound.

I also have the Korg Lambda, which again has attack/release per key (release only for percussives), but no split and the patches are divided into percussive (piano, clav, etc) and ensemble (brass, choir, strings...). There are simple low-pass filters for each batch of sounds, and a brass cutoff frequency. The brass is interesting as it has its own filter apart from the general 'ensemble' tone control, though it really is paraphonic in that if you hold a chord and then press another key, the filter envelope retriggers across all held notes.

The advantage of the Lambda over the RS is flexibility - more sounds, detunes on the three (divide-down) oscs, pitch bend, chorus phase control... but the RS wins hands-down for thick, very very 70s stringer sound and that alone.

I believe the RS-101 was 1975 (mine is, anyway) and the Lambda was about '79 to '82, according to Pete Forrest, whose A-Z isn't always accurate.


The other thing is, are you looking for a stringer, or something more like a polysynth? That is, something with three presets and full poly, or something with six or s dozen presets, some tweaking of parameters, maybe a paraphonic synth section..? From memory, if you want something closest to a full synth, you'd be bloody lucky to find a Korg PS-3100, never mind a 3200 or (ye gods) a 3300, though I have seen the occasional Trident for sale. I don't know of anything else off the top of my head that would act remotely as flexible as a regular synth.

[tom Cadillac]

I'v got an rs101 and agree with its quality of sound.
I'v also got a delta and a Yamaha SK20. But I'm no technical expert.

You can rule the SK20 out for good triggers though - it has a wierd first note priority. I remember someone complaining about this once. Its got some nice features though.

The Delta is similar to the lambada I think. It has a yummy filter with a prominant slider for the cutoff, though generally limited conrol. Though I remember reading its got the same basics as the MS20 filter. ?? Though obviously not so much control over it.

Generally I think there's a big leap between true polysynths and the instruments we're talking about.
I don't understand the tech, but it kind of makes sense that manufactors wanted to provide organ/piano type keyboards affordably. And the compromise with getting full polyphony was limited control over the sound.

And once they managed to get up to enough polyphony with full control then all the above mentioned instruments were 'obsolete'. So I think there're in a seperate class of their own with no overlap. Unlike the transition from analog to digital where you have the DW8000 etc bridging the gap.

I find them incredibly useful though. And the SK20 for instance is still used a lot.

[goom]

IIRC, the strings on the RS505 had a separate envelope (maybe AR?) for the synth section. The bass was simply on/off, or maybe tied in with the strings env...I don't remember. It's been years since I played one.

The synth section has a filter ADSR which affects ALL voices simultaneously, and it can be set to single or multiple trigger. Single trigger requires you to release all keys before the ADSR will initiate again (on the next note played, of course). Multiple trigger will initiate the ADSR if any note is newly pressed, regardless of if other keys are already being played. I believe this is where the Paraphonic title comes from.

That's how my fuzzy brain cells remember it, but I could be wrong on some points. Can anyone else verify?

[RD9]

Thanks all. This is very helpful.

The Gordon Reid article/s that madtheory pointed me to (part 20 specifically) confirms that there was a definite limit to paraphonic development because of cost issues, which makes sense.

It's sounding though, like the RS-101/505 and Lambda are better than the RS-09 as far as envelopes are concerned, so I think that answers my question. Arps, Korg Delta, Yamahas, I'm still not sure. Korg PS-series also sounds like a candidate, but probably going to be well out of reach and I may not ever get to play with one anyway.

Now I just have to find an RS- or Lambda and confirm if they have their own distinct envelope/trigger sound compared to the later true polyphonic synths like the Juno/Jupiter/Polysix period. This will help define this "early synth period" sound that I'm after.

[nathanscribe]

Now I just have to find an RS- or Lambda and confirm if they have their own distinct envelope/trigger sound compared to the later true polyphonic synths like the Juno/Jupiter/Polysix period. This will help define this "early synth period" sound that I'm after.

I can do a demo if you like.

On the RS, the envelope for each key is entirely separate. There's no envelope shaping of filters etc., only amplitude.

On the Lambda, only the Brass is affected by the limitations of single envelope for the resonant brass filter, as I explained above - otherwise, there's no envelope control of anything but amplitude and that's separate for each key.

So yes, they're both different to the other 'normal' limited-voice polysynths you mentioned.

[RD9]

Now I just have to find an RS- or Lambda and confirm if they have their own distinct envelope/trigger sound compared to the later true polyphonic synths like the Juno/Jupiter/Polysix period. This will help define this "early synth period" sound that I'm after.

I can do a demo if you like.

On the RS, the envelope for each key is entirely separate. There's no envelope shaping of filters etc., only amplitude.

On the Lambda, only the Brass is affected by the limitations of single envelope for the resonant brass filter, as I explained above - otherwise, there's no envelope control of anything but amplitude and that's separate for each key.

So yes, they're both different to the other 'normal' limited-voice polysynths you mentioned.

Oooh. Yes please. I can never turn down a good demo. And if you don't mind, I'm most interested in hearing unique idiosyncrasies that aren't present on later polysynths. The weirder the better.

Of course it's possible to sometimes hide idiosyncrasies, such as on the RS-09, if you always keep at least one note held down and constantly overlap notes, it's possible to hide the envelope retrigger. But of course this totally influences the playing style, which I find very interesting.

[ImperatorDX]

I also have the Korg Lambda, which again has attack/release per key (release only for percussives), but no split and the patches are divided into percussive (piano, clav, etc) and ensemble (brass, choir, strings...). There are simple low-pass filters for each batch of sounds, and a brass cutoff frequency. The brass is interesting as it has its own filter apart from the general 'ensemble' tone control, though it really is paraphonic in that if you hold a chord and then press another key, the filter envelope retriggers across all held notes.

The interesting thing in Lambda is the amplitude envelope for the ensemble section and how it uses its 3 oscillators. When I have at least one sound engaged in the Percussive section, it means that one osc is generating that sound and the remaining two play the Ens sounds. In such a scenario, I get a totally polyphonic style envelopes on all sounds. However when I turn off all the tabs in the Perc section, the Ensemble sounds become a bit thicker but the newly added oscillator does not follow the same envelope as the other two and the sound retriggers in a paraphonic way.

Is that the same in your Lambda or is it some fault in mine? Do the strings envelopes behave in the same way with the pecussive tabs turned on and off, especially with long attack and release times? I always keep at least one Perc sound switched on and the Perc volume slider all the way down if I want to play just the strings in a true polyphonic manner.

[Automatic Gainsay]

What defines a paraphonic synthesizer is when there is one VCA, one ENV, and one VCF for all of the voices of the synth.

The Korg Lambda is divide-down, but it has individual VCAs and ENVs for the keys (and, if I'm not mistaken, a couple of each per key), which means it is only half paraphonic... and then not really even that. The only sound which uses a VCF is the brass sound. The rest of the sounds lack any sort of voltage control on the filter (if they have any filter at all). Without dynamic aspect of voltage control on the filter, it's impossible to tell whether is it one filter or many.

So, the Lambda is only fractionally paraphonic.

[nathanscribe]

Oooh. Yes please. I can never turn down a good demo.

OK, give me a day or so to get round to it. If I have time tonight I'll do it then. Won't be anything spectacular, mind, but will give some idea of the way things work.

The interesting thing in Lambda is the amplitude envelope for the ensemble section and how it uses its 3 oscillators. When I have at least one sound engaged in the Percussive section, it means that one osc is generating that sound and the remaining two play the Ens sounds. In such a scenario, I get a totally polyphonic style envelopes on all sounds. However when I turn off all the tabs in the Perc section, the Ensemble sounds become a bit thicker but the newly added oscillator does not follow the same envelope as the other two and the sound retriggers in a paraphonic way.

Is that the same in your Lambda or is it some fault in mine? Do the strings envelopes behave in the same way with the pecussive tabs turned on and off, especially with long attack and release times? I always keep at least one Perc sound switched on and the Perc volume slider all the way down if I want to play just the strings in a true polyphonic manner.

Sounds like a fault to me. I have two Lambdas, both faulty in different ways... they don't seem to be the most reliable things.

Regarding the oscillators:

The Lambda has three master oscillators, and three sets of divide-down ICs. These ICs provide square waves to the sound-shaping circuits at all times, no matter which presets are enabled. All sounds are built from combinations of square waves at different frequencies, so the Brass, for example, which sounds like a sawtooth, is actually a pseudo-sawtooth made from 1 whole-amplutide square at base frequency, half-amplitude at twice frequency, etc. Effectively it's a stepped sawtooth, if you can imagine that. All the presets have their own sound-shaping circuits and they are all supplied continuously from the dividers at four octave-apart frequencies, so the same outputs that are feeding the Brass input are feeding the strings and the piano, etc.

Now, what I suspect happens (but this is a guess based on how it's structured) is that there's some phase cancellation when using multiple presets as they all use the same source waves; maybe that accounts for a perceived drop in either volume or 'weight' when engaging particular sounds together.

The envelopes of each of the two sections are separate, so you should not get any crossover between the action of one set and the other.

The Percussive section uses only the main oscillator. The Ensemble use a mixture of either two or three oscs, depending which sound you're talking about.

[nathanscribe]

(if they have any filter at all)

The difference between the tonality of the strings, chorus and strings II, for example, is entirely down to them having their own filters. All the notes go through a single filter per preset; the filters are fixed and non-user-adjustable.

You do get a tone control but that's about it except the Brass, which I've already described.

[Automatic Gainsay]

The difference between the tonality of the strings, chorus and strings II, for example, is entirely down to them having their own filters. All the notes go through a single filter per preset; the filters are fixed and non-user-adjustable.

Yes, my point was merely that without a voltage-controlled dynamic alteration, the term "paraphonic" becomes irrelevant. (The "if at all" was only in reference to my memory that at least one or several of the presets didn't seem to have any filtering at all-)

[calyx93]

Just to add to the early non-paraphonics, the early 70's Elka Rhapsody 490 & 610 and Freeman String Symphonizer all had individual envelopes too.