Apollo x8p Hardware Manual
Front Panel
13
(3) Hi-Z Inputs 1 & 2
The Hi-Z (high impedance) JFET direct inputs are for connecting low-level passive
devices such as electric guitar and bass instruments into channels 1 & 2 for A/D
conversion. Hi-Z input gain levels are adjusted with the Preamp control for the
associated channel.
The Hi-Z inputs have a default input impedance of 1M Ohms. The input impedance may
vary when Unison plug-ins are inserted on the channel within the Console application.
For details, see the Unison chapter in the
Apollo Software Manual
.
Important:
Connect only ¼” unbalanced TS mono phone plugs to the Hi-Z inputs.
TRS stereo plugs cannot be used.
Automatic Input Detection
Hi-Z inputs 1 & 2 use the same A/D converter channels as the corresponding Mic 1 &
2 and Line 1 & 2 inputs. When a device is plugged into a Hi-Z input, the Mic and Line
inputs for the channel are overridden, the Mic/Line switch for the channel has no effect,
and the stereo link is severed (if active).
Important:
To use Mic or Line inputs 1 or 2, its corresponding Hi-Z input must be
disconnected.
(4) Preamp Gain & Channel Select Knob
This rotary encoder with integrated switch has three functions:
Rotate – Rotating the knob adjusts the preamp gain for the selected input channel.
Press – Pressing the knob selects which preamp channel (1 – 8) is adjusted by the
front panel preamp controls.
Press+Hold – When a Unison plug-in is active in the channel’s dedicated Unison
insert within the Console application, pressing and holding the knob for two seconds
enters/exits Unison Gain Stage Mode.
Each of these three functions above is explained in greater detail below.
Preamp Gain
The preamp gain of analog inputs 1 – 8 is adjusted with the rotary control. The preamp
channel to be adjusted is set with the Channel Select (press) function. The input to be
adjusted (Mic, Line, or Hi-Z) is determined by the state of the channel’s Mic/Line input
switch (#6) or Hi-Z input (if connected).
Rotating the knob clockwise increases the preamp gain for the selected channel. The
available gain range for the preamp channels is 10 dB to 65 dB for the Mic, Line, and
Hi-Z inputs.
More than one full revolution of the knob is needed to move through the available range.
This feature increases the control resolution for more precise preamp gain adjustments.
Tip: To adjust signal levels for inputs 9 – 18, use the output level controls of
devices connected to those inputs.
