ART Pro Audio TubeOpto 8 - Eight Ch. Mic Preamp with ADAT - Manual (Page 5)

CONTROLS and JACKS
FRONT PANEL
Instrument Input
The 1/4” TS jack on the front panel provides a high impedance unbalanced input, and when used,
automatically switches off the mic pre-amp section. (The rear combo jack’s 1/4” TRS balanced input is lower
impedance and is part of the mic pre-amp. The rear jack is not intended to be used with high impedance
microphones or instruments.) NOTE: The PAD switch is disabled and DOES NOT affect gain when using the
Instrument input.
Gain Control
This control adjusts both the mic pre-amp gain as well as the instrument input gain. The gain markings apply
to the mic pre-amp without the Pad switch depressed. (The instrument input gain is lower than the markings.)
Please refer to the HARDWARE OPERATION section to learn how to optimize the gain control for low noise
operation.
Pad Switch
This switch reduces the mic pre-amp gain to prevent clipping when high-level microphone or line level signals
are applied to the rear panel XLR / 1/4” TRS combo jack input. This switch does NOT affect the instrument
input.
FIGURE 1 - Input Channel
2