XQP 541 Owner's Manual

XQP 541 Optical Compressor
Owner's Guide
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lHRESHOLD
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-2
-3
4
-8
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IN
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MAKEUP
OPTICAL COMPRESSOR
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II{TRODUC1ION
Thank you for purchasing the XQP 541 Optical Compressor. The 541 is a feedback style com-
pressor that uses a Silonex opto-coupler for its grain reduction element. Intentionally simple to
operate, it utilizes only the most basic control set for absolutely no-fuss compression.
We trust that you already knorr that the 541 is a module desigmed to fit into the ApI S00-series
format. It comforms to the stand,ard pinout, including stereo linking on pin 6.
The 541 has received API's1/PR Atliance certification.
PINOUT
1. Chassis
2. + Output
3 .
4. - Output
5. Audio Common
6. Stereo Link
7 .
8. - Input
9.
1 0 . + I n p u t
1 1 .
1 2 . + 1 6V D C
13. PowerGround
1 4 . - 16 V D C
1 5 .
OPERATION
This is easy. After installing the s4I into your Lr:nchbox or other s00-
series rack or console and patching it in as desired, there are only three
steps to follow:
l. Push the IN button. This is a relay bypass when out. It will light up
yellow when the unit is engnged.
2. Rotate theTIIRESHOLD pot cor:nter-clocklyise
until the gain reduc-
tion suits your fancy.*
3. Rotate the MAKEUP pot clockririse (in the time-honored fashion) to
restore the output level.
METER
The 541 employs a l0-segment tED metet to display gain reduction.
Its operation is like marry of the old school mechanical meters used for
this function, and OdB is at the rrery top of the scale in this case. Like the
mechanical counterpart, a DC rroltage feeds the meter driver and causes
it to display OdB when no compression is taking place. one of the three
internal trimmers adjusts this voltage and can be tweaked if needed
(see page 2 for diagram). As the opto-coupler responsible for causing
gain reduction does its thing, a second one reduces the DC voltage
feeding the meter, causing it to register down from OdB. r?re driver chip
used to operate the meter is designed for vU applications, and if you look
at the markings beside it, you will see that each of the top five segments
represents a ldB change, whereas the scale becomes rather logarithmic
after that. T?ris gives you accurasy in the begirming stages of compression
(0 to 6dB or so), and becomes pretty general once you get to the point that
]rou are smashing the daylights out of things. If your input signal is loud
enough and you decide to crank the Threshold control to 40, you may just
witness the disapperance of the -m dB LED. This is an indication that you
have gone off the scaie and are really cooking. Don't be disturbed.
Incidentally, when the r.mit is bypassed, the meter continues to finction.
IINKING
If you wish to link two 541's for stereo operation, there is a single DIp
svuitch on the PC board that can be turned to the ON position (see page 2
for diagram). Do this for both r.rnits. There may or may not be action to
take in making your rack ready for linking.
Some norr have all pin 6's
already wired in parallel, some have the option but mr,rst be soldered.
consult the manual for your particr.rlar rack or console. No resistors are
needed between 541 's; only a wire between the pin 6 connections of the
two slots.
when using two 541 's in link mode, both sets of controls are still active,
Hovyever, the sidechairs of both units mix together egually, so any com-
bination of TIIRESHOLD settings will cause eachunit to react the same.
typically' egtral amounts would be applied from each module. However,
SPECIFICATIONS
lnput impedance:
Ouput impedance:
Frequency responce:
Max.output level:
THD (no gain reduction):
Noise:
Attack time:
Release time:
Compression
ratio:
Current requirement:
43ko balanced
50n balanced
4 - sskHz (-3dB)
22dBu
<4.002o/a @ l kHz
-80dBm, unweighted
30mSec.
200mSec.
3:1
100mA @+/-16v
Specifications subject to change without our knovrledge.