From Kenny Balys Sent Tue, Jan 9th 2018, 11:34
From Kenny Balys Sent Tue, Jan 9th 2018, 11:34
Thank you so much, this article is going in my lab binder. I have an Elkorus V3, a Hohner String Performer and a Crumar Multiman-S. None of these facts makes me an expert in chorus. I must not post to AH before my first coffee. On 09.01.18 10:38 , Oakley Sound wrote: > For Kenny :-) > > In my mind there are two basic string ensemble topologies, which I > simply sum up as the Solina and the Roland. > > The Solina method uses three sound sources all modulated with a common > LFO (or LFOs) but with each sound source frequency modulated +/-120 > degrees out of phase with the other. It's almost always mono, but I > think the later Solinas were designed for stereo output. The three sound > sources are typically fed with a simple sawtooth from the keyboard > electronics and then each sound source is created with its own BBD and > it associating clock driver. Examples; ARP Solina, Korg Polysix ensemble > mode, Yamaha SK20 et al. However, I think the best sounding example of > this genre is the Logan String Melody II. > > The Roland method uses four sound sources each one modulated by either > one LFO or a combination of two LFOs; one low frequency triangle wave, > and another faster sine wave. Roland used four delay lines with a pair > for each side of the stereo channel. Examples: VP-330, RS-09, RS-505. > Note their two earlier stringers, RS-101 & RS-202, used different systems. > > The Korg Lambda and PE2000 use a variation on the Solina method, but > unlike the Solina and Korg's own Polysix, they use three sets of high > frequency VCOs (and the usual organ divide down technology) with each > chain modulated with two LFOs with the usual 120 degrees phase shift > between them. This works out to be the most complex of all but generates > the least amount of unwanted hiss and noise. Unfortunately, the Lambda's > VCOs were placed so close to each other on the circuit board they lock > together and the rich ensemble effect can only be heard if you use a > large amount of detune or introduce vibrato. > > The later Roland method tends to produce thinner sounding strings but > they do seem to sound better, perhaps more realistic, to my ears at > least, when playing monophonic lines. > > Roland did also use a single LFO in one case, the RS-101, which was then > sent to a divider chain to produce half, quarter and an eighth > frequencies to drive each of the four BBD lines. It has a mono output > but sounds closer to the Solina rather than the later Rolands. > > The ARP Omni falls into its own category I think. This is simply three > separate BBD lines each modulated with its own LFO. The actual ensemble > circuit board module allows for the dry signal to be mixed in with the > effected signal but this has been left unused in all the production > versions I have seen. > > There are also some very effective string machines that use just two > BBDs with the Elka Rhapsody surely being the finest example. > > Then, of course, there is the daddy of them all, the Freeman. It's > probably closer to the Korg Lambda with it's three (or two) divide down > chains. As to what modulates them I have no idea. But from the pictures > online of the insides of the two channel version it seems to suggest > that they have no top octave generator (TOG) but individual high > frequency VCOs like the PS3100 and other older organs. That should make > it sound marvellous. > > Tony >