Not enough information from your description. Does it do this on all sounds? Or only on certain sounds? Does it ever occur on a Factory Preset... does the same problem occur in headphones as well as your speaker system? Does swapping cables swap the channel with the problem? There can be many causes ... try and eliminate as many as you can yourself. If connected to your computer via USB, use metering as found in most DAWs to help measure your output levels.

You can certainly have it checked but try to trace it to a specific cause ... intermittent problems are the worst kind. Taking it in for repair may or may not catch an intermittent problem. Therefore, attempt to look for things that could possibly be the cause of this. Because it is possible to generate intermittent crackling noises on purpose (certain effect types create crackling noises), and by accident (overloading an Output Bus), you have to try to track down when it occurs specifically. Keep a log, see if it occurs on a specific type of sound, for example, organ or sounds with lots of sine waves.

Imported DX-style FM sounds are often a culprit — because there are so many different sources, some may be significantly louder than others. It is possible to overload and clip devices connected in the audio chain. That is one of the key things you may want to eliminate.

Just FYI — Depending on where you are located your MONTAGE may still be under warranty (it’s 2-years in the USA).

Soon as I turn on the Montage without hitting any Keys you get the popping. I switch TRS audio cables still same issue. It Pops then stops for several second then pops again this is the intermittent I am referring to. It is not effects because nothing being played. Montage is not connected to computer

It Happen on All sound, presets with head phones and speakers system (sound board MPC X) and (Apollo 8 sound board).

Im sorry I mention 2017 the warranty is over I check was purchased in 2016 that 3yrs.

Does sound like I need to have it sent in to a repair shop

Yes. If it does it on all sounds.

There are effects that create Clicks and Pops full time, whether the instrument is being played or not, just FYI... The Turntable (Vinyl) effects make noise all the time - just like records do... music does not have to be sounding for the clicks and pops to sound. However, this effect is used sparingly, and usually the program is named appropriately to hint about the noise — often the words “vinyl” or “turntable” are used in the Performance name. But this is not an Effect you are likely to find on the Acoustic Pianos, for example.

The headphone test (very important) because it eliminates all external possibilities such as cabling, loose connectors on the amplifier or speakers, etc., etc. if you are playing one of the Factory Preset acoustic piano Performances, and you’re hearing clicks and pops in your headphones, that a fairly good way to zero in on the problem. If you are sure you can duplicate this for the repair shop, by all means take it in for a look... worst case you find out it needs repair and you get it fixed. Best case: you get the product cleaned/tested and nothing was seriously wrong.

It is such a strange question, if it is doing something that for three years it didn’t do before... and you’re 100% sure on the headphone test, by all means take it to an authorized service shop.