Output configuration
The mono version has an XLR-3-M output; the stereo version is available with either XLR-3-M (unbalanced) or XLR-5-M (impedance- or electrically-balanced) outputs. Three- and four-channel versions have an unbalanced XLR-5-M output.
X-R capsule outputs are inverse polarity. For the standard mono XLR-3-M output amplifier, the capsule signal is round to pin 3 (negative polarity), with an impedance-balanced output on pin 2. Thus, capsule amplifier will yield positive polarity when connected to a balanced input amplifier via a standard XLR microphone cable. When used into an unbalanced input, pin 3 should be connected as the signal lead.
The X-R capsule amplifier is also available with a transformer-coupled (mono only) or electrically-balanced output (mono or stereo). The electrically-balanced output will increase output level by 6dB, and has twice the current draw compared to the impedance-balanced output. The transformer-coupled or electrically-balanced outputs may be useful where a positive polarity output is required into an unbalanced input preamplifier (where phantom power is supplied by an external device), or where the higher output is desired. The transformer-coupled output will also provide the best performance from low-voltage phantom supplies (9V-12V), and may have superior noise rejection compared with the other output options (70dB CMRR for the transformer-coupled output).
A mono X-R capsule amplifier has an optional switchable output, with the following selectable features:
- left switch position – low-cut filter, corner frequency 160Hz, 6dB/octave;
- center switch position – normal output;
- right switch position – -10dB attenuator.
The feature switch is set with a 3mm flathead screwdriver. The switchable output is only available for mono input and either impedance- or electrically-balanced outputs.
For the stereo XLR-3-M version, the left channel is routed to pin 3, and the right channel to pin 2. There is also a stereo noninverted output option, where the output is inverted from the input, yielding positive polarity output from the amplifier for the X-R capsules. For this option, the left channel is pin 2, and the right channel is pin 3. The stereo electrically-balanced or stereo noninverted output options require four amplifier circuits (3.2mA total current draw).
The output pin configurations for XLR-5-M versions are as follows (inverted unless otherwise noted):
XLR output/
TB4M input pin |
2/3 |
3/1 |
4/4 |
5/2 |
stereo (electrically balanced) |
left noninverted |
left inverted |
right noninverted |
right inverted |
stereo (impedance balanced) |
75Ω to ground |
left inverted |
75Ω to ground |
right inverted |
left-center-right (with side encoding) |
center |
left |
side |
right |
2D surround |
center |
left |
back |
right |
3D surround (ambisonic) |
back left down |
front left up |
back right up |
front right down |
Output cables
Custom output cables are available in a range of special formats to support stereo and multichannel output. These cables are configured to route the X-R output pins to pins 3 of the XLR-3-M outputs, with impedance-balancing components on pins 2. This will result in positive polarity when connected to balanced XLR input microphone amplifiers.