Ashly CLX-52 User Manual 2

CLX-52

Compressor/Limiter

Operating Manual

Ashly Audio Inc.

847 Holt Road, Webster, NY 14580-9103

Toll Free [phone], Telephone [phone], FAX [phone]

www.ashly.com

All Trademarks referred to herein, are the property of their respective owners. R-042707

All Rights Reserved

Page - 2 Operator Manual – CLX-52 Compressor/Limiter

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Copyright© 2006 – Ashly Audio Inc.

Operator Manual – CLX-52 Compressor/Limiter Page - 3

L
p

Important Safety Instructions

Consignes de sécurité à lire attentivement

Safety Instructions – 3

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Physical Description - 6

Installation – 7

The lightning flash with arrowhead symbol, within an equilateral triangle, is
intended to alert the user to the presence of uninsulated "dangerous voltage"
within the product's enclosure that may be of sufficient magnitude to constitute a
risk of electric shock to persons. The exclamation point within an equilateral
triangle is intended to alert the user to the presence of important operating and
maintenance instructions in the literature accompanying the device.

1. Read these instructions.
Keep these instructions.

2.
Heed all warnings.

3.
Follow all instructions.

4.
To reduce the risk of fire or electric shock, do not expose

5.
this apparatus to rain or moisture.
Do not use this apparatus near water.

6.
Clean only with dry cloth.

7.
Do not block any ventilation openings. Install in

8.
accordance with the manufacturer’s instructions.
Do not install near any heat sources such as radiators, heat

9.
registers, stoves, or other apparatus (including amplifiers)
that produce heat.
Do not defeat the safety purpose of the polarized or

10.
grounding-type plug. A polarized plug has two blades
with one wider than the other. A grounding type plug has
two blades and a third grounding prong. The wide blade
or the third prong are provided for your safety. If the
provided plug does not fit into your outlet, consult an
electrician for replacement of the obsolete outlet.
Protect the power cord from being walked on or pinched

11.
particularly at plugs, convenience receptacles, and the
point where they exit from the apparatus.
Only use attachments/accessories specified by the

12.
manufacturer.
Use only with the cart, stand, tripod, bracket, or table

13.
specified by the manufacturer, or sold with the
apparatus. When a cart is used, use caution when
moving the cart/apparatus combination to avoid injury
from tip-over.
Unplug this apparatus during lightning storms or when

14.
unused for long periods of time.
Refer all servicing to qualified service personnel.

15.
Servicing is required when the apparatus has been

e symbole de la flèche dans un triangle équilateral symbolisant la foudre est

révu pour sensibiliser l’utilisateur à la présence de tension de voltage non isolée
à l’intérieur de l’appareil. Elle pourrait constituer un danger de risque de
décharge électrique pour les utilisateurs. Le point d’exclamation dans le triangle
équilatérale alerte l’utilisateur de la présence de consignes qu’il doit d’abord
consulter avant d’utiliser l’appareil.

Lisez ces instructions.

1.
Conservez ces instructions.

2.
Observez les avertissements.

3.
Suivez ces instructions.

4.
Pour réduire le risque de feu ou la décharge électrique,

5.
ne pas exposer cet appareil pour pleuvoir ou l'humidité.
Ne pas utiliser l’appareil près de l’eau.

6.
Le nettoyer à l’aide d’un tissus sec.

7.
Ne pas bloquer les ouvertures de ventilation, installer

8.
selon les consignes du fabricant.
Eloigner des sources de chaleur tel: radiateurs,

9.
fourneaux ou autres appareils qui produisent de la
chaleur.
Ne pas modifier ou amputer le système de la mise à

10.
terre. Une prise avec mise à terre comprend deux lames
dont une plus large ainsi qu’une mise à terre: ne pas la
couper ou la modifier. Si la prise murale n’accepte pas
la fiche, consulter un électricien pour qu’il remplace la
prise désuète.
Protéger le cordon de secteur contre tous bris ou

11.
pincement qui pourraient l’endommager, soit à la fiche
murale ou à l’appareil.
N’employer que les accessoires recommandés par le

12.
fabricant.
N’utiliser qu’avec les systèmes de fixation,chariots,

13.
trépied ou autres, approuvés par le fabricant ou vendus
avec l’appareil.
Débrancher l’appareil lors des orages électriques ou si

14.
inutilisé pendant une longue période de temps.
Un entretient effectué par un centre de service accrédité

15.
est exigé si l’appareil a été endommagé de quelque
façon: si il a été exposé à la pluie,, l’humidité ou s’il ne
fonctionne pas normalement ou qu’il a été échappé.

Typical Applications - 8

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

This manual uses a

Perpetual Table Of
Contents. Each page

has a copy of the
manual’s contents in a
gray box just like this
one. The section you are
in will always be bold
with the other sections
“grayed out.” The feature
allows you to jump
directly to another
section without having to
return to a Table Of
Contents page.

damaged in any way, such as power-supply cord or plug
is damaged, liquid has been spilled or objects have fallen
into the apparatus, the apparatus has been exposed to
rain or moisture, does not operate normally, or has been
dropped.

All Rights Reserved

Page - 4 Operator Manual – CLX-52 Compressor/Limiter

Safety Instructions – 3

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Physical Description - 6

Installation – 7

Typical Applications - 8

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

Introduction

Congratulations on your purchase of the Ashly CLX-52 Peak Compressor/ Limiter. The
CLX-52 was designed to meet the need for universal peak-sensitive automatic gain control
(AGC) devices with exceptional audio performance and rugged durability. The CLX-52 has
the following key features:

 Threshold control
 Input/output meter with select switch
 Balanced XLR connectors
 A single TRS patch point detector loop
 Premium components throughout
 Quality construction through computerized, automated assembly

We are confident that you will be pleased with the high performance, superb sound quality,
and reliability that Ashly is known for.

About Ashly

Ashly Audio was founded in 1974 by a group of recording engineers, sound professionals,
and electronics designers. The first products were custom consoles for friends and
associates, but business quickly grew. The philosophy established from the very beginning
holds true today: to offer only the highest quality audio tools at an affordable cost to the
professional user – ensuring reliability and long life. More than thirty years later, Ashly
remains committed to these principles.

What Compressors And Limiters Do

Limiting – All musical programs have constant changes in loudness. It is the job of a
limiter to detect when the volume has exceeded a predetermined maximum safe level, and
to then turn down the volume. When the incoming signal returns to its original level, the
limiter should respond by restoring the gain to normal. Thus, when the level is within a
specified “safe” range, the limiter has no effect. When an occasional peak occurs, the
limiter responds.

Compression - A significant difference in dynamic range is achieved simply by changing
the relationship between nominal signal level and threshold, as a result of either increasing
the GAIN and/or decreasing the THRESHOLD control. The most interesting effect to be
noted, however, is seen by comparing the original input signal with the output signal. The
quietest portions of the original signal will be effectively increased in volume while the
loudest portions of the original signal will be decreased. In effect, both ends of the
dynamic spectrum will be pushed toward the “middle”. More than anything else, it is this
double-ended effect, which distinguishes compression from limiting.

Copyright© 2006 – Ashly Audio Inc.

Operator Manual – CLX-52 Compressor/Limiter Page - 5

Safety Instructions – 3

CLX-52 Compressor/Limiter

A great deal of time was spent developing a wide-bandwidth, ultra-low-distortion, low noise
VCA (voltage controlled amplifier). The result is the CLX-52, a versatile and highly
listenable compressor/limiter suitable for use in professional sound reinforcement, recording
and broadcasting.

The CLX-52 has three different connector types:

 1/4” inch stereo TRS jacks
 Three pin XLR type connectors
 Euroblocks

These three connectors facilitate interfacing to most professional audio products. Both
inputs and outputs can be used balanced or unbalanced.

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Grounding

Physical Description - 6

Installation – 7

Typical Applications - 8

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

Connectors & Cables

Your CLX-52 Compressor/Limiter is provided with three different connector types:

1. 1/4 inch stereo phone jacks (TRS)

2. Three pin XLR type connectors

3. Euroblock Connector
When possible, balanced connections are recommend between all components in your
system, as this eliminates ground-loop induced hum and noise.

CLX Connector Polarities

Unbalanced Connections and Grounding

If you must use unbalanced connectors, the negative lead of the connector should be tied to
the ground lead. Using unbalanced connections could result in chassis ground-loop noise.
Altering the signal/chassis ground relationship in equipment connected to your CLX unit
may eliminate the noise.

All Rights Reserved

Page - 6 Operator Manual – CLX-52 Compressor/Limiter

A

Safety Instructions – 3

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Physical Description - 6

Front Panel
Rear Panel

Installation – 7

Typical Applications - 8

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

Physical Description

The CLX-52 is 1RU, and weighs 8 pounds

CLX-52 Front Panel

1. Gain - The Gain control adjusts incoming signal
level to the VCA circuit. It is always active, so
switching out the limiter function has no effect
on this control. This control should normally be
left at "0" to achieve accurate Threshold
calibration.

2. Threshold - The Threshold control has a range
of -40 to +22 dB, allowing applications from low
level compression to high level limiting. The
Threshold control determines the audio level
above which Gain Reduction occurs. When the
signal peaks exceed the selected threshold, the
LED comes on and gain reduction is occurring.

3. Ratio - This control determines the ratio of
change in output level to changes in input level
for signals above threshold. The numbers
printed around the Ratio control are calibrated
in db and indicate the increase in input (above
threshold) required to produce a 1db increase
in output. This can be expressed conveniently
as a ratio. If the output remains constant no
matter how high the input level, we have an
infinite () input/output ratio. It should be
remembered that the Ratio control has no
effect on signals which are below threshold.

4. Attack Time - The response of the
compressor/limiter to signal levels above
threshold is further defined by the Attack Time
control. Attack time is the amount of time that
the unit takes to attenuate the output level after
threshold has been reached. This unit provides
continuously variable attack times from 200
microseconds to 20 milliseconds.

5. Release Time - Release time, is the time
required to restore system gain to normal after
the input signal has fallen below threshold
level. Proper release time will depend on the
type of program material being processed and
the way in which the limiter is being used.

6. Output Level - Output Level control is provided
to fully cut or restore up to 18 dB of system
gain. For unity gain, set the control to 0.

7. In/Out Switch - This switch enables you to
quickly hear the CLX compressor/limiter in or
out of the audio chain. When the switch is in
the OUT position, all limiting and compression
controls and functions are bypassed, with the
exception of the Gain and Output controls,
which continue to function.

8. Stereo Tie Switch - This switch allows for Gain
Reduction on a stereo signal with no
degradation of the stereo image. When pressed
in, the Stereo Tie Switch combines each
channel's internal detector outputs so that the
channel with the loudest signal will determine
the action applied to both channels. Leave this
switch out for normal operation.

9. Threshold/Gain Reduction Display - As soon
as the threshold level is reached, the yellow
LED illuminates. Depending on how far the
input level rises above threshold, successive
red LED’s will illuminate, indicating gain
reduction. Gain Reduction can best be
described as the difference between input level
and the resulting change to output level. For
signals above threshold, output level will
increase only to the extent that the ratio control
allows.

10. Input/Output Meter Select - While the Gain
Reduction display accurately represents the
action of the limiter, comparing input to output
levels in real time is somewhat more intuitive,
and is made simple using the Input/ Output
Meter Select switch. The Input meter takes its
signal just after the Gain control, and will
indicate input signal level regardless of CLX
output levels or limiter settings. The output
meter display takes its signal from the actual
output of the unit, so every control that affects
the output will also have an effect on output
meters. Used in conjunction with the gain
reduction meters, Input/Output meters prove to
be an extremely useful diagnostic tool when
working with system dynamics and level
control.

unique feature of Ashly Compressor/ Limiters is the incorporation of a double release-time constant. When a
conventional compressor/limiter is adjusted for slow release times, transients such as mic “pops” may cause a severe
reduction in gain followed by a slow fadeup, making the action of the limiter very obvious. With the double time constant,
release from gain reduction after a brief transient is always fast, with a slower release after a sustained overdrive.

Copyright© 2006 – Ashly Audio Inc.

Operator Manual – CLX-52 Compressor/Limiter Page - 7

CLX-52 Rear Panel

1. Inputs and Outputs - Your CLX
Compressor/Limiter is provided with three
different connector types. 1/4" TRS (tip-ring­sleeve) jacks, XLR connectors and Euroblocks.
Inputs are 20K active balanced using 1%
metal film resistors, outputs are 132 servo­balanced.

2. Detector Loop – Ducking - The CLX
Compressor/Limiters have a TRS Insert
DETECTOR PATCH point which can be used
as a "ducking" input, or in conjunction with an
equalizer to produce frequency-sensitive
limiting. Various uses of the detector patch are
discussed under Typical Applications.

3. Power – Switches the unit power on or off.

Installation

Use four screws and washers when rack mounting the unit. For mobile use, the unit should
be further secured as appropriate.

General Requirements

The CLX-52 has specific physical, electrical and signal requirements for proper operation.
These requirements will vary depending on your specific application, setup, and the
settings on the unit. When setting up and testing your system, please take special care to
double check all connections and settings. Please refer to the specifications section of this
manual for specific input, output and other figures.

Safety Instructions – 3

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Physical Description - 6

Front Panel
Rear Panel

Installation – 7

General Requirements
AC Power

Typical Applications - 8

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

AC Power

Your CLX-52 equalizer should be connected to a standard 3-wire grounded electrical
outlet supplying 100-240 Volts, 50-60 Hz. To reduce the risk of ground loop hum, connect
all audio equipment to the same electrical power source. Removal of the ground pin is both
unlawful and dangerous, as a potential shock hazard could result.

This unit will perform normally within the AC voltage range specified above. Voltages
less than this, as found in “brown-out” conditions, may reduce performance. In the event of
a blown fuse, replace only with same type fuse. No user serviceable parts are inside the
chassis. Overall power consumption is less than 5 watts.

NOTE: The power switch does NOT isolate the appliance from mains. Make sure the mains
power socket or an alternative disconnect device is near by and easily accessible. When the
product is connected to mains, the line-filter and the input of the fuse are energized.

All Rights Reserved

Page - 8 Operator Manual – CLX-52 Compressor/Limiter

Safety Instructions – 3

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Physical Description - 6

Installation – 7

Typical Applications - 8

Protective Device
Recording
De-Essing
Instrument Texture
Ducking
Stereo Operation

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

Typical Applications

The applications of the Ashly CLX-52 can be divided into two basic categories, limiting and
compressing. When used as a protective device it is functioning as a Limiter. It may also be
used to reduce the dynamic range of a signal, creating a fuller sounding signal without
increasing the loudness peaks, in which case it is functioning as a compressor.

The CLX-52 As A Protective Device

The CLX-52 provides fast and accurate gain control for the prevention of sound system
overload due to unexpected transients. Sustained distortion caused by amplifiers running
out of power or occasional, one-shot high level overload (a microphone falling onto a
hardwood floor) can damage speakers and other system components. The CLX-52 can be
installed in several locations in a sound system to achieve specific goals:

CLX-52 Signal Path Location Effect

After the mixer and before the
crossover and amplifier(s)
After an active crossover and
before the amplifier(s)

After a parametric EQ and
before the amplifier(s)

Compression and Limiting acts on the entire signal, preventing crossover and amplifier
overload and maximizing the dynamic performance of both
Compression and Limiting acts on each segment of the signal (to which a CLX-25
channel is connected) coming from the crossover allowing for different settings in each
segment
This setup is typically used to control feedback. By using the parametric EQ as a multi­point notch-filter on the feedback frequencies and the CLX-52 to limit those
frequencies, an accurate and automatic feedback control can be imposed on a system.

Recording

The CLX-52 limiter can be used to prevent input overload (clipping/distortion) in a live
recording environment. To prevent distortion while preserving dynamic range set the
CLX-52 as follows: Gain = 0, Threshold = 2-3 dB below recorder input max, Ratio = 10,
Attack = 2 mS, Release = .2 Sec, Output = 0. Every situation is different, so
experimentation before final recording is always a good idea.

De-Essing

A special type of saturation problem often encountered in recording is the sibilant (Ssss)
sound of the human voice. The solution is frequency-dependent limiting, which is easily
accomplished with the CLX unit. By inserting an equalizer into the Detector Patch point
and boosting the equalizer at high frequencies in the vicinity of the sibilant, the limiter’s
detector circuit becomes more sensitive to this particular range of frequencies, and so will
limit the bothersome sibilants more than other frequencies.

Altering Instrument Texture

Compressoion can be used to help bring out a lead vocal or instrumental solo in a cluttered
mix. The compressor is also a great corrective tool when working with singers whose own
dynamic control is less than perfect. Experimentation is highly recommended.

Voice-Over Compression (Ducking)

The CLX-52 can be used to reduce music to a background level when an announcer is
speaking. The detector is connected to respond only to an announcer’s voice.

Stereo Operation

On the CLX-52, pressing the Stereo Tie switch combines the detector outputs so that the
loudest channel controls the limiter action of the other channel. This allows true stereo
imaging to be preserved regardless of which channel is in gain reduction.

Copyright© 2006 – Ashly Audio Inc.

Operator Manual – CLX-52 Compressor/Limiter Page - 9

Safety Instructions – 3

Troubleshooting

Situation Action

No Audio Output Check AC Power. Is the power switch on? Check input and output connections - are they

reversed? Are you sure you have an input signal?

Controls Have No Effect Is the Limiter In/Out switch In? Perhaps the Ratio control is set too low to produce an audible

effect or the input level is below threshold. Is the Threshold LED lighting up? If not, lower the
threshold setting or increase the gain. Do not expect to hear any effect when the input level

is below threshold, since the unit is simply a linear amplifier at those levels.
When Using Heavy
Compression,
Background Noise Is
Noticeable During Quiet
Sections Of The Program
Excessive Hum Or Noise Hum is often caused by a “ground loop” between components. Try using the suggested

Note: Unshielded cables, improperly wired connections, and cable with broken strands
(shorts, etc.) are the most common problems. Make sure you use good quality cable with
connectors soldered firmly on the correct pin. When in doubt, get in touch with your Ashly
dealer.

Quiet program material is effectively made louder while loud peaks are made quieter. When

the program source is thus raised in volume, its noise floor is also raised in volume by a

proportionate amount. This is not a defect in the Compressor/Limiter, but an unavoidable

side effect of the gain altering process. If the noise becomes a problem, the solutions are to

either decrease noise at the program source, or use less compression.

balanced input and output hookups if the other pieces of equipment used in conjunction with

the CLX unit have balanced inputs and outputs. Noise can also be caused by insufficient

drive levels. Make sure you are sending a nominal 0 dBV line level signal to the unit.

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Physical Description - 6

Installation – 7

Typical Applications - 8

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

Dimensions

In inches

All Rights Reserved

Page - 10 Operator Manual – CLX-52 Compressor/Limiter

A

Safety Instructions – 3

Introduction - 4

CLX-52 – 5

Connectors & Cables – 5

Physical Description - 6

Installation – 7

Typical Applications - 8

Troubleshooting - 9

Dimensions - 9

Specifications - 10

Warranty - 11

Specifications

Specification CLX-52

Gain ±15dB

Ratio

ttack Time

Release Time 100 mS – 3 Sec

Output

Maximum Input Level +23 dBu

Maximum Output Level +23 dBu

Input Impedance

Output Impedance

Frequency Response 20 Hz - 20 kHz, ± 0.2 dB

Distortion

Output Hum & Noise

Power Requirements

Shipping Weight

Dimensions

Note: 0dBu = 0.775 Vrms

100-240 Volts, 50-60 Hz – 30 watts

200 μS - 20 mS

- to +18 dB

20 K balanced

132 servo-balanced

<.01% THD, 0dBu, 1KHz

<0.15% THD, +15dBu,

20Hz-20KHz

19”Lx1.75”Hx8”D

2:1  

-96dBu

8 lbs

Copyright© 2006 – Ashly Audio Inc.

Operator Manual – CLX-52 Compressor/Limiter Page - 11

Introduction - 2

Safety Instructions – 3

Limited Warranty

Warranty service for this unit will be provided by ASHLY AUDIO INC. in accordance with
the following warrant statement.

ASHLY AUDIO INC. warrants to the owner of this product that this product and the
components thereof, will be free from defects in workmanship and materials for a period of
FIVE years from the date of purchase. ASHLY AUDIO INC. (ASHLY AUDIO) will,
without charge, repair or replace, at its option, defective product or component parts upon
prepaid delivery to the factory service department or authorized service center, accompanied
by proof of purchase date in the form of a valid sales receipt. This warranty gives you
specific legal rights, and you may also have other rights which vary from state to state.

EXCLUSIONS: This warranty does not apply in the event of misuse, neglect or as a result of
unauthorized alterations or repairs. This warranty is void if the serial number is altered,
defaced, or removed. ASHLY AUDIO reserves the right to make changes in design or make
additions to or improvements upon this product without any obligation to install the same on
products previously manufactured.

Any implied warranties which may arise under the operation of State law shall be effective
only for FIVE years from the date of purchase of the product. Ashly Audio shall be liable only
to correct defects in the product itself, and not for any damage or injury which may result from
or be incidental to or a consequence of such defect. Some states do not allow either limitations
on how long an implied warranty lasts, or the exclusion or limitation of incidental or
consequential damages, so the above limitations or exclusions may not apply to you.

The PE Series - 3

Introduction - 4

Physical Description - 4

CLX-52 – 5

Installation – 5

Connectors & Cables – 5

Operation – 7

Physical Description - 6

Troubleshooting - 8

Installation – 7

Spec Table - 9

Typical Applications - 8

Measurements - 10

Troubleshooting - 9

Dimensions - 11

Dimensions - 9

Warranty - 12

Specifications - 10

Warranty - 11

Obtaining Warranty Service in the United States
For warranty service in the United States, please follow this procedure:

Return the product to Ashly, freight prepaid, with a written statement describing the defect
and application the product is used in. Ashly Audio will examine the product and perform
any necessary service, including replacement of defective parts, at no further cost to you.

Ship your product to:

Ashly Audio Inc.
Attn: Service Department
847 Holt Road
Webster, NY 14580-9103

For units purchased outside The United States of America, service will be provided by an
authorized distributor of ASHLY AUDIO INC.

Obtaining Warranty Service Outside the United States For units purchased outside The
United States of America, service will be provided by an authorized distributor of ASHLY
AUDIO INC.

All Rights Reserved

Copyright© 2006 – Ashly Audio Inc.