Envelope follower

If you take a PART and assign its output to either an unused / non-routed output (such as Assign L&R) - or even OFF - the part's output is still available for the envelope follower to use as its source (Part 1-16). Once envelope following a part, you can assign any arpeggio to this part and turn master/part arpeggio switch to ON. Once the arpeggio is triggered - it will start to excite the envelope follower. Depending on the arp's "pattern" - this will have a unique effect on the envelope follower's response.

Once the envelope follower is "jumping around" - in response to a PART's ARP (a part which is not routed to your speaker outputs) - you can use envelope follower as a source and assign a destination and curve (preset or user) to control some other parameter or multiple parameters. Switch to your FM-X PART(s) to assign the source/destinations.

When you expand the list of destinations, you'll see the FM operator parameters available.

Doing this can generate some organic sound shaping as the nature of the follower is not necessarily to have the exact same response at every time offset within the arpeggio due to the ability to amplify error (noise) or ... (further discussion involves some assumptions about the internal signal routing - not sure if assumptions are correct - leaving out the speculation).

Maybe someone else will give a more 1) 2) 3) answer. Still do not have the board setup from the weekend.

Side note: I really dig the "edit" feature on the forum ...

Yes, the Envelope Follower explained in detail in the article with example. Don't limit your thinking, almost anything can be used, some things work better than others. As you experiment, you begin to identify what make a good Envelope shape, and how much or how little you need to apply to get results. The article includes ways to further "shape" the source's Envelope using FEG/AEG.

Thanks for the information. I'm quite familiar with both env followers and env generators. Just wanted to know how it's implemented in Montage.

@ Chris:

Im glad we have these tutorials. Would it be possible to include a bullet point summary of what was discussed in each tutorial?

the titles do that. (Seriously) Montage In Depth Programming Series

@ Phil:

Thanks for the information. I'm quite familiar with both env followers and env generators. Just wanted to know how it's implemented in Montage.

that's what the article attempts to explain. Each Part's OUTPUT routing appears in two places (for convenience):
1) On the PART > Common > Part Settings > General screen
2) On the PART > Common > Effects > Routing screen

On the Effects Routing screen you can see how the signal flows through the 3-band EQ, the two Insert blocks, a 2-band EQ before the Sends to REV and VAR, and how you can turn the PART OUTPUT Off, but still send the audio to the Envelope Follower. This way you can decide if you want to hear the source or just hear its influence through the modified Part.

A picture (from Yamaha) of the envelope follower in general block diagram form is here: or

In more detail - perhaps something like:

Where "A" (input) is routed to the envelope source, output is the AND of "B" and "D" where C7 is adjustable through the "release" parameter (longest release = AND w/VCC instead "D", shortest release = small C7 value, increasing release = larger C7 value). Attack adjusted by C6 value which is the final hysteresis stage. Gain is adjustment of trim part R18. In the schematic above, "C" and "D" are two different styles of a gate for the release. "C" is essentially non gated, "D" gates the release inversely proportional to C7's (capacitor) value.

Since "B" is an analog output, this would route into an ADC to generate values 0-127 which is the fundamental range of just about anything such that it translates within MIDI-land 7-bit data values. This could be where the gain stage is actually implemented. Not entirely important for a high level understanding mixed in with very low level detail.

Note: schematic is not from Yamaha - I just selected it out of what's available online as a means to show something in the ballpark.

Didn't think this was the kind of of info you were after at first.

Some other backup information:

https://www.google.com/patents/US8686276

is a Yamaha patent on implementing an envelope follower in software (of a cellphone) which may provide insight on Yamaha's take of how to build an envelope follower.

Some more internals can be gleaned from: http://sandsoftwaresound.net/swp70-tone-generator/

Although I'm not going to research any further than this to determine where the envelope follower may be. There's another chance that I have the level/kind of detail you're looking for wrong.

Bad Mister and Jason, Thank you very much for your response. I'll check the links you've provided when I get the chance.