Operating instructions

2
Preamp Operating Instructions
The 2-610 is a two-channel, vacuum-tube microphone/instrument/line preamplifier. Each channel has
two gain stages that each utilizes 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.
2-610 Front Panel
The front panel has two identical channels (figure 1) each with Input Select, Gain, Level, EQ, Pad and
Polarity controls as well as a Hi-Z Input. The center section between the channels (figure 2) has the
Power On/Off switch and light and a 48 V phantom power On/Off switch for each channel. Each control
is discussed in the following sections.
LOW
HIGH
GAI N
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
Mi c
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
GAI N
PAD HI GH BOOST/CUT
LOW BOOST/CUT
LOW FREQUENCYINSTRUMENT INPUT
INPUT SELECT
POLARITY
LEVEL
HIGH FREQUENCY
Figure 1: 2-610 front panel channel controls