I was taking a look at MODX's documentation and noticed the Parameter manual is at rev C0. The last Montage version I have is A0 - so I was curious if the Montage download page also had an update. It does. The new document is not model-specific. The new generic name is "synthesizer_en_pm_c0.pdf" (for the English version) instead of "montage_en_pm..." This same file is shared with MODX.

So, what's new (comparing A0 with C0 - skipping any intermediate version)?

1) "Typo" type fix: the Vocoder does not have its own section in effects - it is now grouped with "Misc" to match the effect category Vocoder is classified as.
2) ... nothing until page 62 (pages from start to 61 are identical except for table of contents and title page with different date)
3) Rev C0 Page 62 adds "Rotary Speaker 1" and "Rotary Speaker 2" effects as there was an update to Montage firmware to add an amp simulator to the rotary speaker for a more "dirty" organ sound.
4) Rev C0 Page 63 adds "Uni Comp Down" compression type along with a diagram to visually show how this compression works (a knee at the threshold and 1.0 ratio meaning no volume lowering - higher ratios meaning more volume lowering)
5) ... not going to list pages anymore - C0 adds "Uni Comp Up" compression type with diagram to visually how this compression works.
6) C0 adds "Parallel Comp" - NOTE: Parallel compression means a compressed signal is mixed with the original dry signal so highly compressed passages (loud) are passed through as the original signal and quiet passages will receive a boost due to summing (mixing) of the original signal plus the compressed signal side. It's worth looking more into the applications of this using online sources/literature.
7) C0 adds the 4 Spiralizer effects under the "Tech" category
8) C0 adds the "Presence" effect under the "Misc" category
9) C0 adds "Clipper", "Clipper Source", "Compression" definitions to the effects "C" section (as in glossary terms starting with "C" )
10) C0 adds to the definition for "Direction" details applicable to the new spiralizer effect
11) C0 adds the redundant definition for "Dry/Wet" - which is the same as the existing "Dry/Wet Balance"
12) C0 adds definition for "Gain Limit"
13) C0 adds definitions for "Horn Fast", "Horn Slow", "Horn Slow/Fast" - new documented parameters for the rotating speaker
14) C0 adds "Knee" to the definitions. Incidentally, the only "K" in this list.
15) C0 adds "Make Up Gain" to the definitions. Part of compression.
16) C0 adds "Offset" which is related to pitch, "Ofs Transition" which is time after offset.C
17) C0 adds "Post-comp HPF", a compression effect term
... you get the point, there are new terms defined ... skipping to the MIDI section Rev C0 page 82 --- through the remainder of the document, these pages are "identical" to the rev A0 version.