3
X2.5 Owner’s Manual
The preamplifier has four sets of input connections, both single-
ended and balanced output connections, a tape loop and a full
function remote control that mirrors the front panel functions.
It also has a 5-way binding post that is used for remote amplifier
turn-on. The preamplifier’s voltage and current rating are indicated
by affixed tag on the bottom of the preamplifier. It will indicate
either 240 volts, 220 volts, 120 volts, or 100 volts. A 0.5 amp 3AG
slow blow fuse is provided with 100-120 volt units, and a 0.25 amp
slow blow fuse is provided with 220-240 volt units. The frequency
rating of the power supply is 50 to 60 Hz. The preamplifier
typically draws 30 watts during operation. Please verify that the
indicated voltage requirement of this preamplifier is consistant with
the voltage at your location.
We have provided a standard IEC AC power cord that fits into
the IEC line receptacle at the rear of the preamplifier chassis.
The preamplifier is equipped for operation with an earth ground
provided by the users AC outlet. Do not defeat this ground. The
chassis and circuit ground of the preamplifier is connected to earth
through a power thermistor, which gives a ground connection for
safety but helps avoid ground loops.
There are a total of four inputs and a separate tape loop. Two
of the four inputs can be used single-ended or balanced. The
other two inputs are single-ended only. The tape loop has both
single-ended and balanced inputs and outputs. Balanced inputs
and outputs are via XLR connectors. Single-ended inputs and
outputs are via RCA connectors. On the XLR connectors, pin 1
is grounded, pin 2 is the positive signal, and pin 3 is the negative
signal. Left channel RCA connectors are marked with “L” from
below. Right channel RCA connectors are marked with “R” from
below. Balanced XLR inputs and outputs are marked with “L” for
left and “R” for right channel.
If your signal source is unbalanced, input will occur through the
RCA input connector, which is in parallel with the XLR connections
1 and 2. When single-ended inputs are used on input 1 and input
2, a shorting plug is provided between pins 1 and 3 of the XLR
connection, shorting the negative input to ground, and providing
optimal performance.
The unbalanced input impedance of the preamplifier is 33 kOhms.
In balanced mode, the input impedance is higher, with a differential
impedance of at least 66 kOhms.
Setup
