Drifts vs. what? The internal clock, an external clock that Montage is synced to (because you use external clock vs. internal clock), or vs. an external device that is not using a shared central clock?

Internal clock.. how do i make my arps stay in the groove in "100%" after playing with Unit Multiply is my question..

I think what you're experiencing is that unit multiply is always in sync with the clock and you wish the internal clock would somehow "reset" the clock pulse to match where the "downbeat" is with unit multiply in effect after you change unit multiply back to 100%.

Unit multiply doesn't change the clock -- it's formulaic based on the clock. So snapping between different unit multiplies will do what it does (reinterpretation of the underlying clock). I wouldn't consider this "drift".

oh i see.. so what i am looking for is something equivalent to a "key reset" on the Unit Multiply..

Sort of - two different domains of timing. But loosely the general idea.

I imagine the "real deal" you're trying to accomplish is to change actual clock (slow it down, speed it up, put it back to some previous clock). You can't so you use unit multiply to approximate this. But unit multiply doesn't change the clock at all - the "fundamental" time is always chugging along at the initial rate.

Here's a visual of what I think you are experiencing.

I think it's just important to know what you're dealing with so you are aware of the limitations. Ultimately, I don't think unit multiply is the tool for the job if you need unit multiply to switch between beats of the fundamental. I only illustrated one of the two types of switches ("faster" unit multiply clock vs. "slower" fundamental).

The main point here is to illustrate that there is a difference between having direct control of the fundamental tempo and superimposing an interpretation of the fundamental as a "virtual" tempo (unit multiply). And how drawing false equivalencies can get you in trouble (real world is different than assumptions).

so here's my problem.. when i play live with "Unit Multiply" to make certain arps go faster or slower and then bring it back to "100 percent" I feel like it doesn't go back to the original groove to when it began.. i set the "Sync Quantize" to the largest value 480 or quarter note.. am I missing something? i hear sometimes hits the mark but then it drifts..

The best practice way to adjust the "UNIT MULTIPLY" timing... and how it changes how a phrase references the current tempo, is to use the (blue) SCENE buttons to memorize how you want the ARP phrases to reference the current Tempo. Doing so will allow the change to be synchronized with the ARP Phrase start.

From the HOME screen touch "Scene"
On the MEMORY line activate (green) the ON switch above "ARP/MS FX1"
Then touch "ARP/MS FX1" to view the ARP Play FX parameters: Swing, Unit, Gate Time, Velocity

Set [SCENE 1] so that it recalls the initial conditions you want when you recall the program. So 100% for UNIT (Multiply) means the phrase will play at the current tempo.
Set [SCENE 2] as you desire for your first change... 50% means the phrase plays in half the amount of time, still referencing the current Tempo... musician's call this "double time".

Point being, the change will occur when the phrase begins. This removes the guesswork. As long as you press the SCENE button within the ARP SYNC QUANTIZE - the parameter that controls changing of ARP Phrases.

Without this "snapshot" type memory recall, you would have to complete the accurate change by turning the Knob precisely at the right moment. If you're early or late or you cross a bar line while turning the knob, the tempo with Shift anyway at that next beat... the only practical way to ensure accurate change is using the SCENE 'snapshot' memory, and set your Arpeggio phrases to change at "Change Timing = Measure" and the Arp Sync Quantize" value to your comfort.

If you have the ARPs set to change at the top of the measure, and Arp Sync Quantize set to 480 (Quarter Note)... then you only need to press the [SCENE] button within a beat of when you want it to change... and you will never lose sync again.

this is awesome BadMister and Jason.. thank you so much for these tips..