Universal Audio 6176 Manual&Nbsp;

6
610B Operating Instructions
The 610B is a vacuum-tube microphone/instrument/line preamplifier. The main circuit
has two gain stages that utilize a dual-triode tube operating in a class A single-ended
configuration. Variable negative feedback is applied to both of these stages to control
gain, distortion, and frequency response. Balanced inputs and outputs are transformer
coupled.
610B Front Panel (left side)
The front panel has Input Select, Gain, Level, EQ, Pad and Polarity controls as well as a
Hi-Z Input. The center section contains (Figure 2) the power ON/OFF switch, pilot light,
JOIN-SPLIT switch and a 48 V phantom power ON/OFF switch. Each control is
discussed in the following sections.
LOW
HIGH
GAIN
10
9
8
7
6
5
4
3
2
1
0
LEVEL
Hi-Z
4.5K
7K
10K
-15 dB
PAD
0
-5
-10 +10
+5
Line
2.0K
500
2.2M
47K
Mic
Hi-Z
70
200
100
0
+1.5
+3
+4.5
+6
+9
-1.5
-3
-6
-9
-4.5
ø
IN
0
+1.5
+3
+4.5
+6
+9
-1.5
-3
-6
-9
-4.5
ø
OUT
GAIN
PAD HIGH BOOST/CUT
LOW BOOST/CUT
LOW FREQUENCYINSTRUMENT INPUT
INPUT SELECT
POLARITY
LEVEL
HIGH FREQUENCY
Figure 1: 610B Front Panel

Universal Audio 6176 Specifications

General

Type	Channel Strip
Channels	1
Preamp Type	Tube
Polarity Reverse	Yes
Preamp Section	610 Preamplifier
Compressor Section	1176 Compressor
Frequency Response	20Hz - 20kHz
Controls	Gain, Output
Power Requirements	100-240V, 50-60Hz
Inputs	Mic, Line
Outputs	1 x XLR, 1 x 1/4"
Phantom Power	Yes
610 Preamplifier	Yes
1176 Compressor	Yes
High Pass Filter	80Hz
Tube Type	12AX7
Voltage	100-240V