1) The audio outputs on Montage are balanced stereo with exception of the PHONES (headphone) jack - which is a single TRS stereo (unbalanced). If you are sitting in front of the keyboard, facing the keys - then reach around to the back of the keyboard, then from left to right:

1st pair of jacks are A/D inputs. Far left is the A/D Input LEFT (Mono) and next is A/D Input RIGHT. When the documentation says "Mono" for the left channel - it is simply saying that if you have a single channel for Mono - then use the Left channel.

Going further right, the 3rd jack is not a pair - but a single connector for headphones. This is an unbalanced stereo connection with 1/4" TRS.

Keep going right, the 4th and 5th jacks are a pair called "OUTPUT (BALANCED) L/MONO, R". This is your main stereo output. Both jacks are balanced. The left-most jack in this pair is the LEFT channel of the stereo pair and the right most is the RIGHT channel of the stereo pair. You can use either a TRS cable for balanced connectivity or you can use a TS cable (aka TS phone plug) which will be compatible but result in an unbalanced connection. Neither of these TRS connections support stereo over a single TRS cable. Stereo requires both connectors (L and R) together.

The next two connectors (6th and 7th) are called "ASSIGNABLE OUTPUT (BALANCED) L, R". These outputs allow routing audio (metronome click, or any PART including A/D input, or any Drum Part key) to these as an option. Assignable outputs strip out the System and Master effects - one use of assignable outputs is for using external effects. Both assignable output connectors are balanced and, like the main outputs described before, require both connectors for stereo (left and right) and also accept TS connectors for unbalanced outputs.

This completes all of the analog audio connectors.

2) The Montage is an audio interface. The USB to HOST connector is used to connect between the Montage and a PC or Mac. Audio can route FROM the PC TO Montage on 6 channels. Audio can route FROM Montage TO a PC along 32 channels (32 Mono, 16 Stereo Pairs, or different combinations of each). You can send any PART to a different digital channel if you want. The A/D input also has any digital (USB) channel it can be routed to.

3) If you connect Montage to a PC with the USB to HOST connector - then using Montage as an audio interface for the Montage tone generator plus the A/D input(s) for a microphone is possible.

4) The USB to Host connector is not the right shape to accept a USB flash drive. The shape of the USB to Host connector is a "Type B" USB connector - which is the same type used in printers. You use a USB 2.0 Type-B to USB Type-A cable to connect Montage to a PC. This type of cable is also referred to as USB 2.0 printer cable. The USB to Device connector is used to plug in a flash drive. This port's primary uses are either to upgrade your firmware or for external storage. External storage is necessary if you are to record using the built-in "Performance Recorder" to record audio. You can use external storage (a flash drive connected to the USB to Device Port) to save your user, library, or "ALL" (backup) files. You can use external storage to load sound libraries you purchase or download when free promotional material is available.

Wow ! Very clear, thanks !

Still have one question for something still unclear to me: you said that the montage can be used as an audio interface meaning it could send samples to my computer right (on 16 stereo channels). Is the USB host connection also capable of MIDI or is it a different connection ? When you say 16 stereo channels, are we talking about samples or MIDI channels ? In other words, when I plug my montage to my computer, does it become a MIDI controller, an audio interface or both depending on what I want to do ?

There are 32 mono digital channels FROM Montage TO the PC using USB.

There are 6 mono digital channels FROM the PC TO Montage using USB.

All of this concurrent with two "ports" of MIDI activity over USB. One Port (Montage-1) accesses the Montage local MIDI activity such as pressing piano keys and turning knobs on the Montage itself. The other Port (Montage-3) accesses devices which are connected to the Montage's 5-pin legacy MIDI-DIN connectors. These are connected to Montage using what is often referred to as a "MIDI cable". This cable is different than any USB cable and is circular rather than square like USB cables.

With respect to the PC connection - there is just a single USB cable from the Montage to the PC or Mac using a USB 2.0 Type "B" to Type "A" cable. This single cable carries MIDI audio in both directions and all at the same time. A DAW can be used to fully manage the configuration of audio and MIDI data flow between Montage and a computer. The DAW leverages a driver and often the DAW provides access to the configuration setting(s) of the driver such as buffer size.