So this is why the VL1 had two engines

Virtual Acoustic physical modeling synthesis mathematically simulates the sound and characteristics of acoustic instruments in real-time. This forum covers the VL1, VL7 and VL-70 as well as the PLG100-VL and PLG150-VL plug in boards.

Moderator: parametric

2ManyKeys
Member
Member
Posts: 46
Joined: Thu Feb 15, 2018 3:13 am
United States of America

So this is why the VL1 had two engines

Unread post by 2ManyKeys » Thu Apr 19, 2018 12:49 pm

yamaha_vl1.png
Yamaha VL1
Interesting series of pages about physical modeling on the Nord Modular. The writer often l makes references to the approach used by Yamaha VL1 and does so in detail. The writer appears to have a deep understanding of physical modeling right down to why wind instrument models tend to go flat in the upper registers. Good stuff.

It appears that Yamaha included two engines on the VL1 specifically to better handle note transitions on legato phrasing not really for the polyphony.

http://electro-music.com/pm_tutorial/Pipe-Legato.htm

This could be accomplished manually in a sequencer using two VL70's or PLG cards through tedious crossfade editing in post. A possible performance approach might be too use two PLG's setup as different parts / on different channels and feed them with the same single note being played. Then a mod wheel or expression pedal could be used to fade from one engine to the other on each new solo note better emulating the standing wave transition that is taking place in the pipe during note changes. This is much like the crossfading that all the modern sample libraries do.

Then again, is my MU-2000 actually doing this for me by treating the two PLG150-VL cards as a single part and allocating voices? I probably need to record a legato performance and play with various setups.

Lots of other interesting physical modeling info here as well.
http://electro-music.com/pm_tutorial/Index.htm
User avatar
javelin276
Member
Member
Posts: 123
Joined: Wed Oct 12, 2016 6:00 pm
Contact:
United States of America

Re: So this is why the VL1 had two engines

Unread post by javelin276 » Thu Apr 19, 2018 10:19 pm

You really are digging for data, aren't you. I think the VL engine already does the cross fading you mentioned when you play legato notes. There is a more interesting parameter in the VL engine where you can over-blow a flute (or whichever instrument you choose) and cause it to transition to higher frequency harmonics. The Trumpet does this quite nicely. Have you ran across that feature yet? The Shakuhachi voice is particularly good at this, if you use the right controllers. The demo VL midi files contain a couple of examples of this effect to study and learn from, if you listen for it in the songs. I love the transients the VL cards are capable of.
2ManyKeys
Member
Member
Posts: 46
Joined: Thu Feb 15, 2018 3:13 am
United States of America

Re: So this is why the VL1 had two engines

Unread post by 2ManyKeys » Fri Apr 20, 2018 4:27 am

Hey, I'm an engineer. That's what we do. :-)

Yeah I have found some of the trumpets that traverse various oscillation modes and do those trumpet rips. Very cool. The shakuhachi is excellent!
2ManyKeys
Member
Member
Posts: 46
Joined: Thu Feb 15, 2018 3:13 am
United States of America

Re: So this is why the VL1 had two engines

Unread post by 2ManyKeys » Fri Apr 20, 2018 4:30 am

I haven't tried playing those files yet. Will do that soon.
User avatar
SysExJohn
Global Moderator
Global Moderator
Posts: 595
Joined: Tue Dec 02, 2008 1:00 am
Contact:
Uganda

Re: So this is why the VL1 had two engines

Unread post by SysExJohn » Fri Apr 20, 2018 9:42 am

javelin276 wrote:
Thu Apr 19, 2018 10:19 pm
You really are digging for data, aren't you.
Hey, I'm an engineer. That's what we do.
:lol: ((i))
Yup! Too true. Been there, still doing that!
It appears that Yamaha included two engines on the VL1 specifically to better handle note transitions on legato phrasing not really for the polyphony.
Fascinating stuff. I never thought of that.
I rather suspect that there must be some special circuitry (or code) in the VL1 that recognises note overlap (MIDI legato phrasing) and alternates automatically between the two tone generators. I suspect if one wants to emulate that, one would have to arrange the sequence to use the two VL tone generators alternately by cutting up the phrase across two channels, or some such mechanism. The amount of note overlap might be quite critical.

I do wonder whether the effects are so subtle that it's almost unnoticeable to anyone but a purist (or engineer looking at the waveforms on a scope)!

When using legato phrasing, in almost every sequence I create (sometimes I feel just too bl**dy lazy ;-) ), I switch the channel into monophonic mode (usually accomplished by turning cc#68 on) and overlap the first note over the start of the second, 2nd over the 3rd and so on. Then pull the note on velocity of the 2nd and subsequent notes in the phrase down very low to get rid of any "attack" artefacts as required. Playing a phrase on e.g. a violin creates a different change over sound than e.g. an oboe or a trumpet, etc.
LegatoPhrase.JPG
An incomplete sequence, no dynamics added, etc.
MIDI Tutor forum at http://midi-tutor.proboards.com/index.cgi.
UW500; 2xMU1000 + PLGs AN, DX, VL, VH & PF; SC8850; EWI4000s + VL70m; Samson Graphite 49.
AN1x, Novation X-Station 25. E-MU 02 cardbus + 1616m x 2. Sonar 7 PE. XGworks ST. & SQ01.
Garritan GPO4, COMB2, JABB3, IO, Organs, Steinway, World, Harps + GPO5 ... and now CFX lite.
2ManyKeys
Member
Member
Posts: 46
Joined: Thu Feb 15, 2018 3:13 am
United States of America

Re: So this is why the VL1 had two engines

Unread post by 2ManyKeys » Fri Apr 20, 2018 2:42 pm

I gather that technique works well for you. Like I said, I need to cook up some legato test sequences and test with one or both VL engines on the MU-2000 to see how that is handled. Those MIDI files included with the PLG would likely illustrate any differences even better than I can.
User avatar
SysExJohn
Global Moderator
Global Moderator
Posts: 595
Joined: Tue Dec 02, 2008 1:00 am
Contact:
Uganda

Re: So this is why the VL1 had two engines

Unread post by SysExJohn » Fri Apr 20, 2018 3:05 pm

Yes, I had a browse through a few of the VL files you posted.
I didn't see anything "magical" I must say.

As an example I took a look at the "Bizet-Carmen_Habanera.mid" and found track 1 devoted to a VL flute in C.

The Vl instrument is put into monophonic mode by issuing an XG sysex command:
F0 43 10 4C 08 00 05 00 F7
Right at the start of the file.
Thereafter overlaps occur from time to time as can be seen here in measures 15 and 16:
LegatoHabanera01.JPG
Examining the MIDI file in detail shows no extra controls other cc#11 etc.
So I expect any swapping occurs within the VL1.
MIDI Tutor forum at http://midi-tutor.proboards.com/index.cgi.
UW500; 2xMU1000 + PLGs AN, DX, VL, VH & PF; SC8850; EWI4000s + VL70m; Samson Graphite 49.
AN1x, Novation X-Station 25. E-MU 02 cardbus + 1616m x 2. Sonar 7 PE. XGworks ST. & SQ01.
Garritan GPO4, COMB2, JABB3, IO, Organs, Steinway, World, Harps + GPO5 ... and now CFX lite.
DrSynth
Member
Member
Posts: 49
Joined: Sat Jul 30, 2011 7:58 pm
United States of America

Re: So this is why the VL1 had two engines

Unread post by DrSynth » Sat Apr 28, 2018 7:15 pm

The two engines - the Elements - on the VL1 are completely independent. There is no internal 'crossfading' as described going on. Legato behaviors/transitions are inherent in the model itself. The voices play exactly(*) the same on a VL1 or VL7 (single engine/Element version). And of course, the VL70M (which IIRC is what the chipset is on the PLG board) is a Single Element and plays legato notes just fine.

Now, there are a few 'split' voices we did where we used one engine/Element for the lower register and the other for the upper register of the sound. The Bassoon was one IIRC, and you can actually hear a slight 'glitch' or 'interruption' in the sound when playing legato across the split point between the two.

There is no 'reason' per se for having 2 engines in the VL1. It was just a 'feature' decision to allow for layering complimentary sonic elements which is necessary to better emulate some sounds -- IIRC the Shakuhachi is one of this approach -- as well as to allow for duophonic playing, which is very useful for wind/brass.

Your 2 PLG boards are similarly fully independent. Two are not needed for legato playing.

(*) Obvously, any component voiced layered sounds from the VL1 will be different on the VL7 as it will have the primary Element only

Manny

PS I read the online article mentioned and I think the description is far too simplified and the use of the term "pipes" in his example allows for an easy misunderstanding -- they're not sonic elements i.e physical "pipes" that have to be replicated. It's more the way old data and calculations are retained in the model when new data is introduced for calculation. There is a specific parameter in the VL that controls the "slew" or "lag" (to use old analog synth terms) for the model to recalculate new data.

*edit* re-reading that linked article, using a pipe organ as a modeling example for the VL is actually incorrect. A woodwind is a single "pipe" for all notes played, not separate pipes for each note as in his pipe organ example. In other words you don't have 32 different sized Clarinets that you swap in and out of your mouth to play different notes/pitches -- which is what you'd have to be doing to make the pipe organ example representatively accurate. So that analogy is false and sent you looking for things that just don't apply to, or exist in, the VL single reed woodwind model. In a woodwind, the only difference in legato playing is not tonguing new notes. Tonguing is just a new 'burst of air pressure' introduced into the system, which is directly read from the breath controller or a WX controller. Don't get stuck in the keyboard/synth paradigm of what 'legato' means because it's different. That said, VL can be played without a breath or wind controller using a traditional envelope to generate the air pressure input as a replacement for actually blowing into a controller, and legato playing simply changes the pitch withut retriggering the envelope.
Yamaha: SY99's x6 , TG77's x3, Reface DX, VL1, VL70m, FS1r, DX200, DX7II FD E!, DX7II FD, TX802
Kurzweil K2000, Korg Wavestation EX, Kawai K1, Sequential Pro One, Arp Odyssey
What's a Roland ...?
Post Reply

Return to “Yamaha VL1, VL7, VL-70, PLG100-VL and PLG150-VL Forum”