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Verfügbare Sprachen
Verfügbare Sprachen
CONCEPT
Distributing (splitting) audio signals is one of the general tasks in audio engineering. The
Palmer Delta 28 is simply put, a splitter unit with adjustable inputs and outputs. During
development a great amount of focus was spent on meeting all professional demands on
such a device. For example the galvanic isolation of the line inputs, meaning there is no
need to worry about ground loop hum – one of the central problems in complex audio set-
ups.
The Delta 28 incorporates two "1 in 4" distribution amplifiers in a 19" one unit housing. By
switching into mono mode the Delta 28 can also be used to mix the two inputs together
and split them up into 8 mono outputs.
The input sensitivity and impedance can be switched between microphone and line levels.
A similar adjustment is available for the outputs; The switch next to the outputs on the
rear of the device attenuates the respective output by 20dB, allowing an optimal dynamic
volume control for the outputs. All Inputs and Outputs are equipped with continuous wide-
range volume control pots.
All inputs and outputs have XLR connectors according to standard conventions. Each out-
put is equipped with a so called "ground-lift-switch". When pushed, the shielding on Pin 1
is disconnected and ground loop hum can thus be eliminated/avoided.
The inputs and outputs are all transformer balanced, but you can also connect unbalanced
connectors. In this case make sure that the XLR-Pin 2 is connected to the hot lead and
that the XLR-Pin 3 is connected to the shielding of the unbalanced connector. Should such
a setup lead to hum problems then try bridging XLR-Pin 3 with XLR-Pin 1.
SETUP
This device is intended to be mounted in 19" racks. As mentioned earlier, the Delta 28
implements high quality audio transformers. The device should thus not be installed close
to a strong magnetic field caused by devices such as large mains transformers. This could
result in audible stray pick-ups. If in doubt, test the location on a trial basis.
All input- and output connectors are found on the rear of the Delta 28. The power is sup-
plied by the AC mains voltage. Connect the device via the rear IEC socket. Use high quality
shielded cables for the audio connections. It is advisable to use microphone cables with a
cross section of 2x 0,14mm² or higher.
A switch next to each of the two input-volume pots on the front allows you to individually
switch between microphone and line levels for the inputs A and B. When in mic mode, the
input signal is boosted by 30dB, very strong microphone signals lead to an inconvenient
adjustment range. Should the mic setting result in a small adjustment range of the pot then
switch to line. Use the 5-segment LED meter to monitor the input level. NOTE: The 0dB
LED on the meter lights up at an input level of +6dB. At the output the signal is amplified
by a maximum of 10dB. So an output level of +16dB is produced when the pot is turned
right up.
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PALMER - PRMD28: Users' Manual
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