Ashly CL-52 User Manual
CL-50E
CL-52E
o
-------
ABMt-V
Compressor/Limiters
Cu /\krtar
1«- '“ti '•an 't, 90- 0*1 in** -t* ^ -ao ^ »o-
lOuc »- ->■ ^ '» P
^ In i' _ V '•
(dB) ^ (rr61
>K-
—[Opl
i-tt-« m <3 o*3<«>a«ao
model CL-50E
model CL-52E
Five-Year Worry-
Free Warranty
Z 9 9 9 %
-------
I shly's Compressor/Limiters are
used to place a ceiling on the
peak levels of program materi
al. When peaks exceed this
ceiling, gain is reduced to keep
A
peaks \«ithin specified limits.
I The amount of gain reduction,
attack and release times, and the output
gain matching are all precise and inde
pendent adjustments. This makes the CL50E and the CL-52E extremely useful for
such diverse applications as loudspeaker
protection, broadcast limiting or compres
sion, recording, tape-to-disc transfer, spe
cial effects, vocal level control, and
musical instrument sustain.
The two important components of any
limiter are the VGA (Voltage Controlled
Amplifier), which actually performs the
function of reducing gain, and the detec
tor, which essentially tells the VGA what to
do. i.e. when to reduce reduce the gain
and by how much. On the surface, it might
seem like the VGA is the most critical
component, since audio actually passes
through it while the detector merely pro
vides it with a DC control voltage, but
experience has shown us that both are
crucial to the overall sound.
The VGA in Ashly’s Compressor/
Limiters represents a new generation of
integrated circuits that offer exceptionally
low noise and distortion figures, flat fre
quency response, freedom from thermal
drift and excellent reliability. Audio signals
passing through the VGA emerge clean
and uncolored.
The detector has the task of monitoring
incoming audio levels and changing the
gain of the VGA as determined by the set
tings of the front panel controls. The
detector in Ashly's Compressor/Limiters is
a fully symmetrical peak responding type,
and includes a ’send-return' loop which
allows frequency selective limiting and
other effects.
The detector must constantly adjust the
gain of the audio path in a manner which
keeps the level under control while still
sounding acceptable to the listener. This
constantly changing gain is a dynamic
action, while conventional audio measure
ments like noise and distortion checks are
static (constant level). This led us to use a
purely subjective approach in the design
of the detector; we did a lot of listening to
determine what sounded good and what
didn't. As a result of this research, we
designed the detector to allow the attack
and release times to speed up as more
and more limiting occurs (the compression
ratio also increases), and we utilized a
double-release time constant to minimize
'pumping' and 'breathing'. The result is a
natural-sounding compressor/limiter that
responds very well to a wide variety of
audio applications.
The CL-50E is Ashly's single channel
compressor/limiter. The CL-52E is essen
tially two CL-50E's in one rack space, but
it offers improved metering and switching.
The CL-52E can be used as a stereo
compressor/limiter or as two separate
mono units. Ten-level meters are provided
on each channel to indicate gain-reduc
tion and output level.
The CL-50E and CL-52E compressor/
limiters, like all Ashly products, are now
fully covered by Ashly's exclusive fiveyear worry-free warranty.
Extremely Low Noise
and Distortion
Detector Patch Points
for Frequency-Selective
Limiting
Gain Reduction Meters
In-Out Bypass
Switching
Inputs and Outputs May
Be Used Balanced or
Unbalanced
Unusually Wide
Control Range on Ail
Parameters
Output Level Meters
and Clipping Indicators
(CL-52E)
Front Panel Stereo
Tie Switch (CL-52E)
Specifications
CONTROLS
stereo tie switch
defeat switch
gain:
ratio:
attack time:
release time:
output:
Detector Patch Point:
(CL-52E ONLY)
±30dB
2:1-<»
200mS. - 20mS.
lOOmS - 2Sec.
-40dBV - +20dBV
allows the connection of an EQ for
frequency selective limiting
Maximum Input/Output Level:
Input Impedance:
Output Impedance:
Frequency Response:
Distortion:
+20dBm
lOkQ balanced bridging
50ii term, w/ 600£2 or more
±.2dB 20Hz - 20kHz
<•015% THD, OdBV 20 Hz • 20kHz, no limiting
<•15% +i8dBV worst case
Hum and Noise:
Power Requirements:
Size:
Shipping Weight:
-95dBV unity gain
120 VAC, 50-60HZ, 5W
19" L X 1 3/4"H X 6"D
8lbs
Block Diagram
Many interesting and productive effects can be
achieved by combining the CL-50E or the CL-52E with
Ashly’s SG-33E or SG-35E Noise Gates.
Architect’s Specification
The unit shall be a single (CL'50E) or dual (CLr
52E) channel compressor/limlter with indepen
dent attack, release and ratio adjustments. It
shall have detector patch points which allow con
nection of an external equalizer in the detector
loop to produce frequency selective limiting. It
shall have front panel mounted switches for
engaging/ defeating the compressor/llmiter func
tions. Performance specifications of a typical
production unit shall meet or exceed the follow
ing: Gain control shall be +30dB. The ratio shall
be adjustable from 2:1 to «. The attack time shall
be adjustable from 200^iS to 20mS. The release
time shall be adjustable from lOOmS to 2 sec
onds. The output shall be adjustable from -40dBV
to ■i-20dBV. The maximum in-out level shall be
+20dBm, The input impedance shall be lOkii bal
anced bridging. The output impedance shall he
50£2 terminated with 60011 or more. The frequen
cy response shall be 20Hz to 20kHz l.ZdB.
Distortion shall be <.015% THD @ OdBV from
20Hz to 20kHz with no limiting, <.15% @4^1SdBV
worst case. Hum and noise shall not exceed 90dBV @ unity gain. The unit shall operate at
115VAC ±5%. 50-60HZ. The unit shall be
designed for mounting in a standard ElA 19'' rack
(19'"L X 1.75"H X 6"D) and shall have a shipping
weight of 8 lbs. The imit shall be either a model
CL-50E (single channel) or a CL-52E (dual chan
nel) Compressor/Limiter manufactured by Ashly
Audio Inc. No other unit shall be acceptable
unless submitted data from an independent
research lab verifies that the above slze/performance specs are met.
Ashly Audio Inc.
ASHLY
Since 1972
© 1990 Ashly Audio
Loading...