elysia mpressor - Manual (Page 24)

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Technical Data
Frequency response: <10 Hz – 33 kHz (-3.0 dB)
THD+N @ 0 dBu, 20 Hz - 22 kHz: 0.04 %
THD+N @ +10 dBu, 20 Hz - 22 kHz: 0.33 %
Noise floor, 20 Hz - 20 kHz (A-weighted): -84.0 dBu
Dynamic range, 20 Hz - 22 kHz: 109 dB
Maximum input level: +25 dBu
Maximum output level: +27 dBu
Input impedance: 10 kOhm
Output impedance: 68 Ohm
Input pin assignment: 1. Ground
2. Positive
3. Negative
Output pin assignment: 1. Ground
2. Positive
3. With 68 Ohm to Ground
Power consumption: 50 W max
Fuse type: 230 VAC 0.8 A Slo-Blo
115 VAC 1.6 A Slo-Blo
Dimensions (W x H x D): 483 mm x 89 mm x 377 mm
19 “ x 3.5” (2 U) x 14.8”
Weight: 8 kg / 18 lb
Level Problems
No Signal
This problem can eventually be caused by balanced wiring. If the signal almost drops completely when the
mpressor is activated, a pin of the XLR connector at the input is probably not connected. As the input stages
behave like transformers do, both pins have to be connected. The classic example for this problem is a bal-
anced XLR cable that is connected to an unbalanced output which only uses ground and pin 2 – connecting
pin 3 to ground should solve the trouble.
Level Jump
In some audio processors the output stage is designed in a way that the level will always stay the same – no
matter if they are connected with a balanced or an unbalanced cable. If pin 3 is connected to ground, for ex-
ample, the level at pin 2 will automatically become twice as loud as before. This kind of output stage is usu-
ally unproblematic. But there are also stages which cannot compensate that. Then the level at pin 2 stays as
it is, even if pin 3 is connected to ground. If the mpressor is placed between a device with that kind of output
stage and a device with unbalanced inputs with pin 3 connected to ground, it is possible that the level will
jump up by 6 dB when the compressor is activated. As a general rule, balanced input stages are always the
best choice. In case they are not available, the first attempt to solve this problem should be to disconnect
pin 3 at the XLR inputs of the mpressor and then connect it to ground. This generates an unbalanced signal
that should not shift levels anymore.
APPENDIX