T1 ToneMatch® Audio Engine / Trim Pots
The T1 trim controls for CH 1-3 provide a significant gain increase when you reach the upper limit. This increase in gain is normal operation.
Most sources like typical microphones and piezo pickup systems can provide enough level without the need to add significant gain from the trim control. Certain sources like passive acoustic guitar pickups require additional gain and in these cases it can be necessary to set the trim level to the upper range of the control. When the trim control is set this high you may notice the gain change. This is normal operation. If you want to run the trim control at lower settings we recommend using a preamp or simple stomp box level booster.
The trim for CH 4/5 do not exhibit the same behavior (as the trim controls for Channels 1,2,3) as these inputs are designed for line level sources and do not have the same gain staging as CH 1-3.
For more information see: T1 ToneMatch® Audio Engine