Universal Audio 4-710d Four-Channel Tone-Blending - Manual (Page 9)

9
Front Panel Descriptions
Analog Controls
(1) Hi-Z Inputs - Connect a high impedance signal from an instrument such as electric guitar or bass
to these standard unbalanced 1/4" phone jack connectors. The 4-710d’s jack detection circuitry
automatically switches from the selected rear panel MIC or LINE input to the channel’s front panel Hi–
Z input whenever a plug is inserted into this jack. The Hi-Z input impedance is 2.2MΩ for all four
inputs. These JFET direct inputs provide maximum fidelity with no high-end loss.
(2) Gain - Adjusts the gain of the channel’s input stage. Turning this knob clockwise raises the
amount of gain applied to the input signal. This control also determines the level sent to the
compressor if the compression circuit ( #13 on page 11) is engaged.
(3) Blend (“∞”) - This unique control sets the relative contribution from the solid-state and vacuum
tube preamplifier circuits. When in the fully counterclockwise (TRANS) position, only signal from the
solid-state preamplifier is heard. When in the fully clockwise (TUBE) position, only the signal from the
tube preamplifier is heard. At the twelve o’clock position, signal from both the solid-state and tube
preamplifiers is heard at equal amounts.
 Making a connection to the 4-710d’s front panel Hi-Z input jack automatically disconnects
any signal arriving at the rear panel mic and line input.
 The controls for channels 1-4 are identical, so each control is only described once.