3
FRONT PANEL CONNECTIONS AND CONTROLS
Figure 2 – Front controls
Input Gain control
This control optimizes the input signal level before the tube gain is applied. Both Microphone and
Instrument input gains remain the same and are affected by this adjustment. Input gain can be ad-
justed from 0dB (for line level signals) to 40dB of gain.
The analog meters are used to see the effects of the input gain setting.
Additional gain is available via the Gain switch (+20dB) and the Analog Output control (+10dB) for a
maximum of 70dB total.
The combination of these controls allows the user to adjust the signal level through the tube section,
providing more or less “tube” sound as needed. To obtain more “tube’ sound, increase input gain, use
the +20dB Gain switch, “normal” plate voltage, and less Analog output gain.
Both the microphone and instrument inputs are optimized for their respective sources as far as signal
levels and noise performance. Running most of the gain on the input generally provides the best
performance of the DIGITAL MPA II. Refer to the section titled “Obtaining the best noise performance
