Block Diagram
14
Summit Audio, Inc.
Block Diagram
The Impedance control of the 2BA-221 sets the input
impedance of the microphone input. The Pad reduces the
input level by -20 dB. The microphone input is next amplified
by the solid-state preamp before being summed together
with the Hi-Z input, line level input and the stacking input.
The polarity switch can invert the signal if desired.
Mic
Input
Stack
Input
Stack
Output
Line
Input
(rear)
Line/Inst.
Gain
Hi-Z
Input
(front)
Peak
Meters
Variable
Mic
Impedance
ø
Polarity
-20
Pad
Mic
Preamp
Insert
In/Out
1/4"
Output
XLR
Output
HP Filter
In/Out
Summing
Amp
Filter Freq.
Output Level
+
-
Tube
Output
Stage