You'll probably laugh...

I selected an LFO, chose square waveform for it, then set the LFO destination to ChannelVol in the ModMatrix with the amount set to +63 (so it cycles between silence and max volumes).

Then I cranked up my soundcard recording frequency to 192KHz @ 24bits (to avoid any beating of waveforms beyond Nyquist freq's, and to limit further aliasing) and played a high pitch note on the Virus so I can easily visually see the envelope of the LFO (when recorded). Then I raised the LFO rate to 127.

Recorded several seconds of it into Wavelab, then, er, manually counted the pulses that occured within 1 second (in otherwords an "x" number of Hz), lol. Turned out there were 93 pulses in 1 second, therefore the speed of the LFO was 93Hz.

They'd be the perfect accompaniment. :) Might require some serious DSP for user definable waves at audible rates though.

Very clever. Was thinking something within the same lines, but thought there might be a shorter way to do it. Wouldn't think of raising the sample rate myself, but it's a very clever move.

About the fact the LFOS tend to alias at extreme settings, like you said, why do you think that happens? Something to do with aliasing?

http://www.youtube.com/watch?v=ByfAuQPbv6k

look at this simple sound with the korg ms 20, sounds amazing even when the LFO's rate goes way fast... It's one of the things analogue does better indeed... And what usually happens, not only on the virus, but overall all things digital, is that it seems that you loose the high frequencies a bit, right? (I'm thinking like the sound on the video, a self oscillating filter, the analogue if we're speaking virus here, modulated by the lfo, say with a triangle wave, real fast, there's a point where you feel that it's struggling to cope with what you're doing, almost like a frontier). Would it be better if I raised the sample rate to record such a thing? Never tried it...

Also, the Blofeld for example has LFOs that go into the audio range, and it would be cool if someone here could do the test and see if there's some stepping noticeable enough to ear, by modulating the rate of it with a slow evolving envelope, for example... 'Cause it makes sense.

EDIT would have to be adjusted manually to notice the midi steps, so maybe record both and post here would be cool (come on blofeld owners out there!!)

About that, I always like to record my digital synths in audio whenever possible, I always feel like automation recorded gets some of the natural feel away, an effect within the same lines here...But for software, while I'm at it, that runs inside the daw, does it also translate everything to 127 positions? Or does it happen only when using midi?

Sorry for all the questions eheh

Cool stuff, Timo!
The DSI Prophet 12's midi specs are not posted anywhere I can find and perhaps oscillator knows this from DSI Forum, however DSI website does not have really ANY tech specs posted other than general product info and a few videos we mostly have all seen.
Speaking of LFO's and Dave Smith---the Evolver Series only have a handful of midi transmit/rec'v parameters, with overwhelming majority being totally sysex and wanted to post this fact as I look at the DSI mono evolver keyboard's paper manual in front of me, (you can download the Evolver Keyboard Manual--applies to whole series aside from obviously a different manual for PolyEvolver because it has the added "combo-mode", yet the specs for LFO's and such remain same in entire evolver series http://davesmithinstruments.com/down...Manual_1.3.pdf
Hope this link works for the up to date manual I am looking at. (my studio is inbetween a state of decontruction/construction as came up with better ergonomic set-up or would oblidge the "come on Blofeld Owners for related test with lfo's)
On page 49 and 50 of evolver keyboard manual, parameter 40 thru 47 relate to the LFO's. Dave Smith elsewhere in manual states sysex was used rather than standard midi for majority of parameter because he NEEDED higher range than 0-127 in order to AVOID any stepping in parameter changes real-time. On page 49 you see parameter 40 for LFO, he used Range of 0-150 for UNsynced lfo freq and 151-160 for sync'd up to 16 cycles PER STEP. LFO Amount on both lfo 1 and 2 a range of 0-200, with amounts over 100 repeats with Key Sync On.

Those examples alone wanted to share for now because since the DSI Prophet 12 is a hybrid of best of Evolver, Tempest, Pro 08, and new developments, am actually wondering if indeed it will be ALL midi-able 100% send/rec'v. By the way, the Evolver parameters of course remain the same regardless if having original encoder version or the newer PE version for keyboard models and parameter values are same with the Desktop Evolver as well.
It must be in Anu Kirk's "Definitive Guide to The Evolver" where I read about why sysex was used for extended values needed as to ensure pretty much everything is able to be modulated with/by anything, without having zipper noises whilst changing parameters.
Thought you might find this interesting!
Great "synth-Sleuthing" Timo, on the Virus' LFO's and shall we assume your findings are same thoughout the Virus A,B,C range, since relatively same engine, except for the Ti Series?
Will try to get my equipment and set-up done thru weekend and may be up to Wed of coming week as have a KILLER root canal gone bad and cannot get into Dentist until Feb 5...it's seriously imposed on my creativity as it's pain to close to the BRAIN!! EEEK!

Interesting. I think the Virus probably works within the same lines, here. That's one of the reasons I don't like to rely on midi automation much, and always go for live recording of tweaking instead, whenever possible. Also, there's MIDI with better resolution then the good old 8 bit with just 127 steps, there's the evolution of that with 14 bit range - and I think most modern MIDI controllers have that.

So I'm willing to bet it wouldn't be a problem to have such a huge range on the LFO :twisted:

EDIT - it would mean 16384 steps with 14bit MIDI.

And I think (not sure though) that something like Automap (the protocol for software control, of course) is capable of even more steps then that (can't test right now), I'm saying that because I have changed the number of points many times, to get the knobs responding with the speed I need - quite handy, while not changing the resolution, you can actually do that and it smooths it out nicely, this is definitely the thing I like best about this controllers...

https://www.youtube.com/watch?v=BE_34BptS7w

found this on the recommended for you list on youtube.

Dave Smith IS THE MAN!~! He actually has the same humble persona as I had seen in many Robert Moog interviews and colloquiems...he absolutely has a PASSION for what he does and it shows! I am still quite amazed every time I turn-on the MEK; it BEGS you to turn knobs and create the still yet uncreated! My cat seems to be quite fascinated by the massive LED light show of the sequencer in-action!
Thanks for sharing that! That Prophet 600 Dave mentioned as the FIRST midi-capable synth from his then-company Sequential Circuits, was my first polyphonic synth after learning synthesis on MS20 and wish I had kept that thing!

Yeah, in a way you're lucky you got to learn with such great stuff... I learned mostly with stuff like Rob Papen's Albino eheh.

You're lucky you're going to get the Korg back

However, realize that for QUITE a while, my keyboard playing was limited while active duty officer in military, to a real wooden acoustic piano simply because of where different places stationed. Of course, that real piano is my roots so-to-speak, so that was my recreational "release" spending many hours in the piano room when not lifting weights and swimming.
There's been ALOT of new methods of modulation and various matrices that admitedly am still learning as I go as far as "playing catch-up". Told myself WHEN surviving and ultimately medically retired military disability pension--that I would build-up a synth-based studio for many therapeutic benefits;keeping mind active, and literally physical and mental therapy to fight PTSD....and now it's a reality and have everything kind of taken apart now, with a final plan of effectively connecting everything, using midi extensively--however, I will be recording primarily audio only.
So as you mentioned once, it's "full-circle" because I may have a bit more hardware experience, but it certainly also means i have alot to learn from the likes of you on many levels. Good forums facilitate this without all the ego and crap that you definitely find on some of the other so-called "pro forums".
Dave Smith said something interesting in that clip about how it's not usually an interface's problem with midi--it's moreso the way in which a given manufacturer IMPLIMENTS midi protocol and makes use of available bandwidth---do I hear a cat-call towards Access and Virus Control? LOL!

Good to see discussion is still flowing here.

Timo is that 93 in herz or samples? What I mean is do count one LFO movement as cycle or two? Frequency should be only half of the LFO movements.

Either way I find the LFO works well for the faster stuff at the value of 122, do you know if there is a way to raise the speed less than one step? Kinda tempo dependend.

Access could just allow one of the oscillators to act as an LFO, that way there would be no issues with compatibility. And it could modulate as fast as you wanted. This is of course already possible if you want to modulate phase.

I must try your trick of using the LFO as a source for the filter decay, at that rate it should still be good for pluck sounds. It would be interesting to compare the virus to some other synths. If someone knows a really accurate audio analyzer/FFT for the job, that would be great. And one last thing, is there a way to delay the start of the filter decay by couple ms, like in some analog synths?

Changing the subject a little from the way the C vs. the Snow sounds, can someone tell me how total polyphony compares between the two? I've seen spec sheets that say the C upgraded the B's total polyphony from 24 to 32, then when you look for similar specs on the Snow, consensus seems to be "20-50 depending on patch".

I know the snow has more features, and some of those features could potentially use more DSP resources, but what I am looking for is an understanding of how the raw processing power between the two compares, for example for a patch on the C will you get the same, more, or (yikes) less playable notes if you load same on the Snow?

Thanks for any input.