It may be a glitch or it may be programming.

If you want to have a fun treasure hunt, you can go into the effect parameters.  I don't know if chorus in this Performance is an insertion effect or a system effect.

For insertion effects you can go into those parameters and write them all down before changing anything.  Then go to the modulation control menu and tab through all of the assignments looking for that insertion effect as a destination and write down all of those settings.  This is all when chorus isn't working for you. 

Then after you get it working (switcheroo) write down the parameters again.  Both places.  See what differences there are - if any.

Often a "source" of confusion may be a controller that is assigned to control the insertion effect wet/dry or some other parameter that would essentially disable the effect.  And that the controller at its default  position isn't allowing the effect to happen.  You may need to discover how that is setup and turn a knob (assignable, super, wheels, etc), or press a button or touch the ribbon or after touch or ....  Or delete the assignments if you want and set the chorus like you want without any controllers offsetting the parameters.

If chorus is an system effect then (variation, for example) then you would look at those parameters and mod control and also send/return settings.  The sends/returns may be offset too by controllers.

If you've already eliminated all of that then maybe you're on to something.  

I don't have an M but the previous generation has that Performance and it's probably similar so I could look at it that way.  If you haven't already dug into the Performance more deeply then it would be a good excersice.

Guess it's worth mentioning that for something like this you can also play the audition and listen for chorus.  If you hear chorus turn on then keep repeating the audition and look at the lights and secondary screen which may tell you what's activating the chorus faster than menu diving.

Welcome to the forum!

Looks like you are working on getting up to speed with what that beast of an instrument is capable of.

Based on what you posted you have a pretty good approach to make it up the, sometimes steep, learning curve.

1. Pick something simple

2. Try things and see what they do. 

3. Ask for comments if you're not sure why the results you get aren't what you expect

There is no point in beating your head against the wall if there is a chance someone else may be able help you go 'around' that wall.

As far as we can tell what you are experiencing is NOT a bug but is a direct result of the change to the chorus effect that you made when you tried to diagnosis the 'not working' impression you had.

Your starting point should always be: bugs/glitches aside, whatever the synth does it is doing because it was programmed to do it.

I realised that when I select a voice in my Montage M7 say, Full Tine, the chorus effect is not working until I manually switch the effect to and forth (G Chorus to Symphony chorus and back) then the Chorus effect start working.

That 'switch the effect to and forth' is actually changing the original chorus effect programming.

1. Load 'Full Tine 2' performance - 2 parts and each has a 'G Chorus' effect using the 'Basic' template' as Ins B

2. That effect has been ALTERED from its default values by the sound designer that created the performance

3. You hear it is 'not working' and switch to Symphony chorus and then back to 'G Chorus'

4. When you switched back you replaced the original effect programming with the default parameter values

5. Unknown to you some parameters got changed

LFO speed - .25 to .21

Dry/Wet - D63>W to D12>W

EQ Low Gain - -1db to 0db

EQ High Gain - 0db to +2db

You can see these changes very easily without having to write anything down:

1. Load 'Full Tine 2' performance

2. Edit part 1 and navigate to the 'Effect->Ins B' screen

3. Put your cursor on the effect 'Type' box at the top of the screen

4. Change the effect to 'Symphony' and then back to 'G Chorus'

5. Use the front panel buttons under the sliders to switch back and forth from part 1 to part 2 

6. Notice which param values change on the screen as you switch back and forth

Of course it is always possible that your particular instrument has a bug but your part 2 has chorus but part 1 doesn't it is likely just the programming. 

HINT #1: when analyzing components of a part (elements, operators, effects, sequences, control assignments) it can be much more efficient to COPY that component to a 'dummy' or 'test' part. Then you can use the front panel 'part' buttons to quickly switch back and forth to see the same screen for both parts. That makes comparing things MUCH easier.

HINT #2: You never need to actually copy things from the screen. You can take screen snapshots that are saved to a USB stick:

In the Motif XF, Full Tine has chorus as what's now called the variation system effect.  And initially the send for this chorus is zero which means you will hear no chorus.  And AF2 (assignable function switch 2 also called A.SW2 now) is what offsets the chorus's send to system effects.  It adds about 40.  And you can hear the chorus when the AF2 button is lit.

I doubt anything is wrong and more likely a misunderstanding of how this Performance has been programmed.  Maybe the demo turns on chorus and if it matches the Motif XF then you should see the audition turns on A.SW2 at some point and this is when you should hear chorus engage.

Of course if.you don't like how this works you can edit the preset Performance and [STORE] your changes to a User Performance.

Hi to complete the good answer provide by Jason, here is the ESP screen capture of the variation send for Full Tine 1, it's 0 as you can see on the join picture

And at part level, the use Assign Switch 2 is done to increase the variation send.

Since the 'Full Tine' performance doesn't exist on the Montage M models we found, and reviewed, the 'Full Tine 1' and 'Full Tine 2' perfs. 

We don't have access to a Motif XF but as far as we could tell the 'Full Tine 1' appeared likely to be the equivalent of the single voice 'Full Tine' from the Motif XF imported as 'Full Tine 1' and thus having 1 part.

The single part uses VCM EQ 501 'Flat' and Pitch Change 'Detune' insert effects and Chorus G for variation as described.  

We ruled that perf out based on OPs reported issue:

the chorus effect is not working until I manually switch the effect to and forth (G Chorus to Symphony chorus and back) then the Chorus effect start working.

The Var effect in Full Tine 1 uses default programming so changing from 'G Chorus to Symphony chorus and back' won't change that and it also won't change the position of assign switch 2.

That is why we reported our results for Full Tine 2 since, as mentioned earlier Full Tine 2 has 2 parts and they each use Chorus G with non-default programming. The Variation effect uses 'Auto Pan'.

Changing either parts 'Chorus G' and then back brings audible chorus into play. For Full Tine 2 the Var Send for each part is also set to 0 and assigned to the Mod Wheel with a ratio of +118 but Var is Auto Pan rather than Chorus G as on Full Tine 1.

No matter which perf OP is using it is likely a programming issue especially since changing away from G Chorus and back manifests the change OP reported. Seems unlikely any 'bug' would act that way.

You have to sympathize with relatively new users that run into this sort of thing because it isn't easy to track down a definitive cause even when you have a pretty good idea where to look.

But hey, that is one of the things that keeps us in business!

"L'effet chorus joue à cache-cache avec moi"

What I'm noticing is that even ESP doesn't have the offset values displayed anywhere.  Really wish Yamaha would add some kind of display that would tell you the offset value of the parameter so you could see what the final result is after moving a knob or push a button that has the parameter as a destination.

Also, the curves shown with the Montage/MODX (of every vintage) series do not have any scale shown.  So it's more difficult to tease out what the result will be unless you spend the time figuring these things out.   The Motif XF had similar curves and labeled each axis with values.  So the more current generation is a bit of a regression in this department.   Even better than labels (or in addition) it would be nice to see instantaneous values.   Even on the curve screens it would be cool to be able to move the source controller and see a dot move on the curve with a box that tells you the input and output values.  This would input/output display would be going beyond the Motif days.

Thank you all for the help. I think I make it easier to understand. Because I don’t have this issue with my MODX7.  Say I choose Full Tines 2 with Chorus G effect or any voice with a insertion effect, when I increase the parameter/intensity of the chorus, there is no change of intensity, until when I change the effect and switch back to Chorus G then I hear the intensity change. With my MODX7, with an increase of intensity of the chorus effect, I immediately hear it without needing to switch to other effects and back. 

Ok, good now it's clear you're talking about full time 2.   I'd have to fire up the Montage (classic) to see what it does since Motif doesn't have this.

But your point is well articulated.  You have Full Tine 2 on your MODX7 and on your Montage M7 and they don't seem to work the same.  That would be a head scratcher for me too.  But you can still mill around both instruments' parameters and offsets and see if there's a difference. 

I get there's a workaround but I would dig more into the preset and try to draw out what is squelching chorus before taking a sledgehammer and doing that effect swap.

With an insertion effect, the primary suspect is going to be Dry/Wet balance.  You want D<W by the max amount (dry smaller than wet) to hear max Chorus.  Also assuming the normal things like the insertion effect is turned on.  I imagine when I fire up the Montage (not M) that what I'd see is going to match your MODX7 (also not M).  So presumably I won't "see" the problem.

You could also dump your SysEx for Full Tine 2.  The easiest way to get this out there is to go to Soundmondo and share your preset Full Tine 2 Performance.

The other thing I can say is if you have your bank set to "All" in Category Search and search (use magnifying glass) for "Full Tine 2" - make sure there's only one Performance listed.  If there's more than 1 then you may have saved a copy with the same name and it might have some problem versus the preset.  I'm not thinking this is likely.  Just something to verify.

Thanks 🙏 

What do you mean by this 'new' info you provided?

Say I choose Full Tines 2 with Chorus G effect or any voice with a insertion effect, when I increase the parameter/intensity of the chorus, there is no change of intensity, until when I change the effect and switch back to Chorus G then I hear the intensity change.

This would be a good example for you to use to learn just how the programming can affect what is happening and why many of the presets need to be modified by the user before they use them.

Help us understand what you are changing.

1. What are you doing to 'increase the parameter/intensity of the chorus' on the Montage M? You didn't mention that before.

2. which part are you changing the chorus effect on? Full Tine 2 has 2 parts and they both use Chorus G as Ins B programmed the same way

Did you look at the effects settings as I suggested?

The programmed Dry/Wet for Chorus G in the Full Tine 2 perf  is 'D63>W' but the default programming is 'D12>W'.

A setting of D63>W is a VERY DRY signal with little or no chorus. When you 'change the effect and switch back to Chorus G' you are replacing that with the default value of 'D12>W' - that is, you decrease the Dry component from 63 to 12.

That is why you 'hear the intensity change'.

With my MODX7, with an increase of intensity of the chorus effect, I immediately hear it without needing to switch to other effects and back.

What, exactly, are you doing to 'increase of intensity of the chorus effect'?

Can't speak directly to the Modx7 but that suggests the programming is different. Maybe Assign Switch 1 is ON on the Modx but OFF on the Montage M. That switch is assigned to 'InsB Dry/Wet' on the Montage M with a ratio of 20 so pressing the switch will alter the D63/W to about D24>W adding quite a bit of chorus (wet) to the mix.

IT'S THE PROGRAMMING - that is the thought to keep uppermost in your mind when something doesn't seem right.

Almost anything you do after loading a performance with change something, somewhere. Even if you accidentally move a knob or mod wheel that can, and often, does change things. 

The consequence is that when you now STORE the performance to save the changes you WANTED to make it will save those accidental changes as well. And you may not even notice it did that until you are in the middle of a gig and press a button.

CAVEAT: you have to be VERY careful when you are creating your performances that you don't, accidentally, include changes like that. You move a slider/knob/ribbon simply to double-check things are ok and hit STORE. Well you just stored that slider/knob/ribbon change you made.

Make sure ALL of your controllers are in the position you want them to be before you store a performance and before you load the next performance.