Pass Labs pre-amplifier - Manual (Page 5)

5 X0.2 Owner’s Manual
There are a total of five inputs, a separate tape loop and two outputs
on each of the pre-amplifier chassis. One chassis is exclusively
dedicated to right channel and the other exclusively left channel.
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.
If your signal source is unbalanced, input will occur through
the RCA input connectors, which are in parallel with the XLR
connections. When single-ended inputs are used, a shorting jumper,
which is provided, should be inserted between pins 1 and 3 of the
corresponding XLR connection. The supplied jumpers short the
negative input to ground, and provide for optimal performance. The
X0.2 preamplifier will function without these jumpers, but gain will
be lower and performance will not be optimal.
The unbalanced input impedance of the pre-amplifier is 10K Ohms.
In balanced mode, the input impedance is higher, with a differential
impedance of at least 20K Ohms.
Next to the inputs on the rear panel of the gain stages, the pre-
amplifier offers tape inputs through both XLR and RCA connectors.
This output is a direct connection to inputs 1, 2, 3, 4 and 5 when they
are selected from the front panel. Input 6 (TAPE IN) is deliberately
not available through the tape output connection. Tape input is
designated for use with a tape recorder if you have one, and we have
arranged that it will not place its output on the tape out, which will
prevent you from accidentally creating a feedback connection with
your tape machine.
The main outputs are located left-hand of center (viewed from the
rear) of the rear panel, two male XLR connectors, and two RCA
connectors. The RCA connectors’ ground is in parallel with pin 1
of the XLR outputs, and the RCA hot is fed from an independent
summing junction that maximizes the X circuit benefits. The RCA,
single-ended, outputs are buffered from the balanced outputs.
In an effort to accommodate a wide range of equipment we have
configured this product so that you may use both single ended and
balanced outputs at the same time. On the XLR, pin 1 is ground, pin
2 is positive output, and pin 3 is negative output.