Ssl XLogic G Series User manual

XLogic G Series Compressor
Owner’s Manual

Solid State Logic
Super-Analogue™ Outboard
Owner’s Manual
82S6XL050C
G SERIES
COMPRESSOR

XLogic G Series Compressor Owner’s Manual
As research and development is a continual process, Solid State Logic reserves the right
to change the features and specifications described herein without notice or obligation
E&OE
Revision 0A, September 2003
Revision 0B, January 2004
Revision 0C, June 2004
Minor changes, November 2004
Minor changes, June 2005
Solid State Logic
Begbroke, Oxford, England, OX5 1RU • [phone]
320 West 46th Street, 2nd Floor, New York, NY 10036, USA • [phone]
Suite 401, 5757 Wilshire Blvd, Los Angeles, CA 90036, USA • [phone]
3-55-14 Sendagaya, Shibuya-Ku, Tokyo 151-0051, Japan • [phone]
7 bis, rue de la Victoire, le Blanc Mesnil, Paris 93150, France • [phone]
Via Timavo 34, 20124 Milano, Italy • [phone]
Visit SSL at URL: http://www.solid-state-logic.com
© Solid State Logic
All Rights reserved under International and Pan-American Copyright Conventions
Solid State Logic, SSL and XLogic are trademarks of Solid State Logic
All other product names and trademarks are the property of their respective owners
No part of this publication may be reproduced in any form or
by any means, whether mechanical or electronic, without the
written permission of Solid State Logic, Oxford, England

Page 1
XLogic G Series Compressor
Definitions
‘Maintenance’
All maintenance must be carried out by fully trained personnel. Note: it is advisable to
observe suitable ESD precautions when maintenance to any part is undertaken.
‘Non-User Adjustments’
Adjustments or alterations to the equipment may affect the performance such that safety
and/or international compliance standards may no longer be met. Any such adjustments
must therefore only be carried out by fully trained personnel.
‘Users’
This equipment is designed for use solely by engineers and competent operators skilled in
the use of professional audio equipment.
‘Environment’
This product is a class A product intended to form an integrated component part of a
professional audio recording, mixing, TV, radio broadcast or similar studio wherein it will
perform to specification providing that it is installed according to professional practice.

XLogic G Series Compressor Owner’s Manual
Page 2
A TTA CK - six switchable ranges - 0.1,
0.3, 1, 3, 10, and 30 mSec.
THRESHOLD - continuously
variable from -15dB to +15dB RELEASE - five switchable ranges - 0.1,
0.3, 0.6, 1.2 Sec., and 'Auto' - (Release Time
dependant upon the duration of the signal
peak)
AUTOFADE facility with
RATE continuously variable
from 1 to 60 Sec.
Front Panel Meter shows gain
reduction
Compressor and Side-
Chain IN/OUT
XLR INPUTand OUTPUTconnectors for left
and right channel audio signals
Earth lift switch
Compression RATIO - three
switchable ranges - 2:1, 4:1,
and 10:1
REMOTE connector allows
connection of external meter and
Autofade switch
Gain MAKE-UP to compensate
for compressor action -
continuously variable from -5dB
to +15dB
KEY INPUT
(External side-chain
audio) connector
Power Input Module

General Description
Page 3
1. General Description
The XLogic G Series Compressor is a stand-alone unit which provides high quality stereo
compression, giving the operator critical control over the dynamic range of audio signals. It is
designed to combine the features of SSL G Series Consoles in such a way as to allow interfacing and
use in a wide range of different applications. The unit is packaged in a 1U high 19" rack-mounted case.
The depth of the case (excluding rear panel connectors) is 325mm (13").
Input and Output connections are all made via XLR Connectors on the rear panel.
Power requirement for the unit is 100, 120, or 230V ac., connection being via the rear panel Power
Input Module. Section 3 of this manual describes the procedure for setting the Power Input Module
for different operating voltages.
The main controls and facilities of the XLogic G Series Compressor are summarised and shown
opposite.
Front panel switches allow the compressor and external side-chain signals to be switched IN or out of
circuit. The AUTOFADE switch enables an automatic fade out of a duration set by the RATE control.
When the AUTOFADE switch is released, the stereo signal will fade back up over the set time.
The XLogic G Series Compressor is supplied with the following accessories:
• IEC Mains Cable
• Owner's Manual
Warranty
The warranty period for this unit is 12 months from date of purchase.
In Warranty Repairs
In the event of a fault during the warranty period the unit must be returned to your local distributor
who will arrange for it to be shipped to Solid State Logic for repair. All units should be shipped to
Solid State Logic in their original packaging. Solid State Logic can not be held responsible for any
damage caused by shipping units in other packaging. In such cases Solid State Logic will return the
unit in a suitable box, which you will be charged for. Please do not send manuals, power leads or any
other cables - Solid State Logic can not guarantee to return them to you. Please also note that warranty
returns will only be accepted as such if accompanied by a copy of the receipt or other proof of
purchase.
Out of Warranty Repairs
In the event of a fault after the warranty period has expired, return the unit in its original packaging to
your local distributor for shipment to Solid State Logic. You will be charged for the time spent on the
repair (at Solid State Logic's current repair rate) plus the cost of parts and shipping.
IMPORTANT
Before powering up the unit, check that the correct fuse is fitted and that the voltage
selection setting corresponds to the available Mains Supply. Adjust if necessary, following
the procedure described in Section 3 of this manual.

XLogic G Series Compressor Owner’s Manual
Page 4
Audio
Input
(Left)
Audio
Output
(Left)
KEY
Audio
Input
Audio
Input
(Right)
Audio
Output
(Right)
Rectification
and Peak
Detection
circuitry
MAIN VCA CONTROL VOLTAGE
SIDECHAIN VCA CONTROL VOLTAGE
Simplified Block Diagram of the XLogic G-Series Compressor

Specification
Page 5
2. Specifications
Input Impedance: 20KΩ Electronically balanced
Output Impedance: < 40Ω Electronically balanced
Frequency Response: 20Hz to 20kHz ± 0.2dB
Max. Output: +24dBu Above 0 dBu, at onset of
clipping. (0.1 % THD)
Noise: < –85dBu (-90dBu typical) R.M.S. 20Hz to 22kHz
measured at output, input
terminated with 50 Ohm
resistor.
THD + N: < 0.004 % RMS 20Hz to 22kHz At +6 dBu, 1 kHz.
Crosstalk: < –95dB Below +20 dBu. (at 20 kHz.)
Measured at output of
undriven channel, input
terminated with 50 Ohm
resistor.
Key Input Impedance: 20KΩ XLR Electronically balanced
RATIO: 1:2, 1:4, 1:10
ATTACK: 0.1, 0.3, 1, 3, 10, 30 mSec.
RELEASE: 0.1, 0.3, 0.6, 1.2 Sec., plus AUTO
THRESHOLD: –15 to +15dB
MAKE-UP: –5 to +15dB
AUTOFADE: 1 to 60 Sec.
Compression Meter: Moving Coil, 0 - 20 dB gain reduction
REMOTE Connector: Autofade switch, external gain reduction meter
Note: 0dBu corresponds to a signal level of 0.775V rms.

3. Checking Operating Voltage and Fuse
Note: Before attempting to apply power to the unit, check that the correct fuse has been installed and that the
operating voltage setting is correct. If necessary, adjust as described below.
Fuse Selection and Replacement
The XLogic G Series Compressor is supplied configured for single-fuse ('Live/Line' only) operation.
The appropriate fuse must be fitted – 1A for 100/120V operation, 0.5A for 230V operation.
Operating Voltage Selection
The XLogic G Series Compressor is not fitted with an auto-ranging power supply and the input setting
must be confirmed before applying power. The input module can be configured to be one of 4 voltage
settings. The setting is indicated by a plastic pin protruding through the appropriate hole in the fuse
panel.
The setting is altered by a small vertical PCB which can be fitted in 4 positions.
To change the setting:
i) Switch off and remove the IEC lead.
ii) Using a small flat-bladed screwdriver, lever open the fuse panel to the right of the connector.
iii) At the right hand side is a vertical PCB with a plastic key which indicates the setting. Using
pliers, pull out the PCB.
iv) The PCB has to be rotated until the desired voltage is shown along the edge which plugs into
the module. The plastic key (and this bit is quite fiddly) must also be rotated so that it points out
of the module and so that the round pin aligns with the appropriate hole in the cover panel;
(refer to the diagrams below).
v) Re-insert the PCB and replace the fuse panel. The plastic pin should project through the
appropriate hole.
240
120
100
240
230
120
100
240
230
120
100
240
230
100
100V Setting
(Use for 90-105V)
120V Setting
(Use for 105-125V)
230V Setting
(Do not use)
240V Setting
(Use for 220-240V)
Mains Input Programming PCB
These diagrams show the PCB arrangements for the different voltage settings.
Note that if the mains voltage is a nominal 230V, the ‘240V Setting’ should be used – not the ‘230V Setting’!
XLogic G Series Compressor Owner’s Manual
Page 6
100V
120V
230V
240V
Mains Input Module

Features
Page 7
4. Features
4.1 Earth Lift Switch
This switch is located on the rear panel. It isolates the circuit 0V from the Earth cable of the Mains
Input Connector. The case and the lid are always connected to the Earth cable. If the unit is to be
connected to an installation with a Mains Earth, then it may be necessary to operate the switch in
order to eliminate hum caused by earth loops.
4.2 Remote Connector
The rear panel REMOTE Connector allows the connection of an external gain reduction meter and
Autofade switch and lamp. The diagram below shows the required connections.
REMOTE
Remote
Autofade Switch
(Latching)
Remote
Autofade
Lamp
(24 V.)
Remote Meter -
SSL Part No.
42MDD7FR
5 4 3 2 1
9 8 7 6
+
-

XLogic G Series Compressor Owner’s Manual
Page 8
5. Connection Details
The picture below identifies the PCBs and shows the locations of the various connectors which are
referred to in this section.
5.1 Connections from 82E345 Card to Front/Rear Panel
The rear panel REMOTE connector allows the use of an external meter and/or AUTOFADE switch
(see Page 5). The connector is a 9-way 'D'-type; at the PCB end is a 10-way ribbon connector, PL1. The
meter connector, PL3, is a 5-way Molex type. Designations for each connector are as follows:
PL4
PL1
PL5
PL2
PL3
82E345
82E346
Position
of Safety
Cover
82E347
PL1: 82E345 Main Card to REMOTE Connector on Rear Panel
PL1 Pin Function 'REMOTE' Connector Pin
1 External Meter +ve 1
2 External Meter -ve 6
3 Ext. AUTO FADE Switch - A 2
4 Ext. AUTO FADE Switch - B 7
5 Ext. AUTO FADE Lamp - A 3
6 Ext. AUTO FADE Lamp - B 8
7 n/c –
8 n/c –
9 n/c –
10 n/c –

Connections
Page 9
5.2 Inter-Card Connectors.
There are two connectors in this category. PL2 is a 26-way ribbon connector, and interfaces the 82E346
Switch Card to the 82E345 Main Card. PL4, a 16-way ribbon connector, carries all of the audio signals
between the 82E347 XLR Connector Card and the 82E345 Card.
PL2: 82E345 Main Card to 82E346 Switch Card
Pin Function Pin Function
1THRESHOLD Pot CW 14 RATIO Switch Left 1:10
2THRESHOLD Pot Wiper 15 MAKE-UP Pot CW
3THRESHOLD Pot ACW 16 MAKE-UP Pot Wiper
4 Control Voltage In 17 MAKE-UP Pot ACW
5 Control Voltage Out 18 +18V
6 0V 19 –18V
7RATIO Switch Right Wiper 20 Compressor IN Switch/Lamp
8RATIO Switch Right 1:2 21 Ext. Side-Chain IN Switch/Lamp
9RATIO Switch Right 1:4 22 AUTOFADE Switch
10 RATIO Switch Right 1:10 23 AUTOFADE Lamp
11 RATIO Switch Left Wiper 24 AUTOFADE Pot CW
12 RATIO Switch Left 1:2 25 AUTOFADE Pot ACW & Wiper
13 RATIO Switch Left 1:4 26 n/c
PL4: 82E345 Main Card to 82E347 XLR Connector Card
Pin Function Pin Function
1 Right O/P +ve 9 Left I/P –ve
2 Right O/P –ve 10 Left I/P +ve
3 Right I/P –ve 11 0V Left
4 Right I/P +ve 12 0V Left
5 0V Right 13 0V Key
6 0V Right 14 0V Key
7 Left O/P –ve 15 Key I/P –ve
8 Left O/P +ve 16 Key I/P +ve
PL3: 82E345 Main Card to Meter
Pin Function
1 Meter +ve
2 Meter –ve
3 Meter Backlight +ve
4 Meter Backlight –ve
5 n/c

XLogic G Series Compressor Owner’s Manual
Page 10
5.3 Power Connector to 82E345 Card
This connector carries AC power from the transformer secondary to the 82E345 Main Card.
PL5: A.C. to 82E345 Main Card
Pin Function
1 Transformer Secondary - A
2 Transformer Secondary - 0V
3 Transformer Secondary - B
4 Reserved for future use
5 Reserved for future use

Circuit Description
Page 11
6. Circuit Description
Internally, the unit comprises three cards:
• 82E345 Main Card
• 82E346 Switch Card
• 82E347 XLR Connector Card
The Power Supply circuitry is contained on the 82E345 Main Card, and is fed from a transformer
mounted at the rear of the unit.
Circuit descriptions for each of the PCB sub-assemblies follow. Circuit diagrams for each card are
located immediately after the corresponding circuit description.
6.1 The 82E345 Main Card (Drgs. T82345.71-3, T0384G.71)
This card contains (from left to right when viewed from the front of the unit) two identical compressor
stages for right and left channels, control circuitry common to both channels, and the Power Supply
circuitry.
Compressor Circuitry
The two compressor stages are identical, and component references for the right and left hand
channels differ only in the use of an 'R' and 'L' suffix respectively. The diagram below shows the audio
signal path in simplified form.
The balanced input signal passes via input bypass relay RL1 through H1, providing an unbalanced
output. This signal feeds the input of the main VCA, H2, via gain trim preset VR1. The output of H2
drives hybrid H3 to provide a balanced output which feeds via output bypass relay RL2. VR2-3 are
used to set VCA symmetry and output signal balance respectively; these are factory set and should not
require further adjustment.
The sidechain VCA, H4, is fed with an unbalanced audio signal either from H1 (see above) via TR1 or
from the rear panel KEY connector via H5 and TR2, dependent upon the setting of the External Side-
chain IN switch. The output of H4 is buffered by IC1.
Audio
Input
Ext.
Sidechain
Audio
Input
Audio
Output
To RATIO
circuitry (IC2/3)
(see next page)
H1 H3
RL1 RL2
H5 IC1
Sidechain VCA Control
(see next page)
Main VCA Control
(see next page)
IN
H2
H4

XLogic G Series Compressor Owner’s Manual
Page 12
Compressor Control Circuitry
Most of the control circuitry is common to both right and left hand channels. The diagram below
shows the control signal path in simplified form.
The output from the sidechain VCA buffer IC1 (see previous page) drives the Ratio circuitry based
around IC2-3. This is essentially a precision rectifier circuit whose limits of linear operation may be
altered by switching different voltages (derived from potential divider network R29-35) into the
inverting input of IC3 via the RATIO switch. The output from IC3 is then fed to the Attack/Release
circuitry. The resulting signal is finally buffered by IC53, and is used to drive the meter directly. This
signal is available on the REMOTE connector, allowing a similar external meter to be driven. See
Section 4 for details of a suitable meter.
The Autofade circuitry generates a variable rate voltage change (with a sharper 'knee' characteristic
towards the end). When AUTOFADE is pressed, the output of IC58 goes low, causing the output of
IC63 to go high. C54 thus begins to charge via the AUTOFADE pot and R61, causing the output of
IC63 to gradually fall. This will affect the VCA Control Voltages after D54 is biased on. When C54 is
sufficiently charged, IC63 switches low. Overall Gain Trim is provided by VR50.
IC54-55 act as summing amplifiers to produce the Sidechain and Main VCA Control Voltages
respectively. IC54 sums the signals from IC53 (see above) and the THRESHOLD control, and IC55
sums the signals from IC53, the MAKEUP control, and from the Autofade circuitry output from IC52
(see above). The outputs of IC54-55 drive the control inputs of H2 and H4 respectively (see previous
page). If LK5 is inserted, VR4 can be used to adjust VCA tracking between left and right channels.
Both 'hard' and 'soft' bypass options are available, configuration being via LK1 and LK2. (The required
link positions for either option are clearly identified on the PCB.) In 'hard' bypass mode, when either
the Compressor is not IN or power fails, the audio signal bypasses the compressor via relays RL1-2.
In 'soft' bypass mode, switching the Compressor IN switch off isolates all VCA control voltages and
the external sidechain audio path via TR57-58 and TR3, reducing the unit function to that of a unity-
gain amplifier.
Note: With the compressor in 'soft' bypass, the AUTOFADE facility remains available.
IC55
IC53
IC54
THRESHOLD
Control Sidechain VCA
Control
(see previous page)
Main VCA
Control
(see previous page)
MAKEUP
Control
AUTOFADE
circuitry
IC50/
51/52/63
Meter
Output
RATIO cctry.
IC2/3
ATTACK/
RELEASE
circuitry
From
Sidechain VCA
Buffer (IC1)
(see previous page)

Circuit Description
Page 13
Power Supply
The Power Supply comprises a primary regulator stage which produces +18V and -18V dc. lines, and
secondary regulator stages, fed from these lines, which provide the various circuit voltage supplies.
The nominal 40V ac. from the centre-tapped secondary of T1 is rectified by D61-64. The +ve and -ve
outputs from this bridge rectifier (referenced to the centre tap of T1) feed regulators IC56 and IC57
respectively to produce +18V and –18V lines from which all the circuit voltage supplies are derived.
Briefly, these are as follows:
Regulators IC58 and IC59 are fed by the ±18V lines and provide outputs of ±12V which are used for
the RATIO switch resistor chains. Regulators IC60 and IC61 are also fed by the ±18V lines. These
provide outputs of ±15V which power the VCA circuitry. Supplies of ±18V for the control circuitry are
decoupled from the main ±18V lines by R110-111 and C72-75. A further supply of +11V is derived from
the +18V line via D74 and R112 and constitutes the negative supply for the logic circuitry. The ±18V
analog supplies are decoupled from the main ±18V lines by R113-114 and C84-85.
Details of the transformer and operating voltage selection circuitry are shown on drawing T0384G.71.

Page 14
XLogic G Series Compressor Owner’s Manual
82E345 MAIN
CARD SILK SCREEN
Title
Date 19 FEB 1990
Solid State Logic

Add schematics for T82345 and T0384G in place of
this sheet