There are three types of volume adjustments, with the [GAIN] control (TRIM), the channel faders and the [MAIN VOL] control (MASTER LEVEL). What is the difference between them?

[GAIN] control: This adjusts the audio level input to the respective decks. Depending on the position of the [MAIN VOL] control, sound may be output even when the [GAIN] control is turned all the way down.

Channel faders: These adjust the audio level output from the respective decks for mixing.

[MAIN VOL] control: This adjusts the audio level output externally from the DDJ-T1.