Pendulum Audio ES-8 User manual
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InputOutput
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Pendulum Audio
Off
Max Off
Max Off
Max
Off
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6386
METER
THRESHOLD OUTPUT
INPUT
METERTHRESHOLDINPUT OUTPUT
Variable Mu Tube Limiter
ES-8
Vacuum Tube Limiter
ES-8
Remote Cutoff Tube Limiter
Operating Manual
Pendulum Audio, Inc.
PO Box 339, Gillette, NJ 07933
TEL: (908) 665-9333
Web: http://www.pendulumaudio.com
email: info@pendulumaudio.com
Pendulum Audio
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Manual
Gain Reduction
Input Output
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Pendulum Audio
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6386
METER
THRESHOLD OUTPUT
INPUT
METERTHRESHOLDINPUT OUTPUT
Variable Mu Tube Limiter
INPUT
120V/60Hz 30W
POWER
ON
1A
OUTPUT
2 1 2 1
SIDECHAIN
INSERT
1
2
6386 Vacuum Tube Limiter
Pendulum Audio, Inc.
Designed By Greg Gualtieri
Serial No.
WARNING: To reduce the risk of fire or electrical
shock, DO NOT expose to rain or moisture. DO NOT
remove covers. Refer servicing to qualified personnel.
For proper operation, be sure to provide adequate
ventilation. Made in USA.
Date Code
ES-8 Condensed Operating Instructions
The Input attenuator controls the signal level to the input trans-
former. Use it to prevent overload of the transformer and gain
control tube. The optimum operating level is 0VU =+4dBu.
The Threshold control determines the amount of gain reduction
applied to the source material. Up to 12dB of gain reduction is
possible.
The Output control is used to increase the signal level after gain
reduction. Up to +20dB of gain make-up is available.
The VU meter can indicate input level, output level, or gain reduc-
tion. Input and output levels are referred to 0VU = +4dBu. The trim
for zero gain reduction is located below the selector switch.
'Hard' bypass switches for comparing the processed sound directly
with the original source.
Links the two channels for stereo operation. When linked, the
Threshold and dynamics processing (fast, preset and manual
modes) are controlled entirely by Channel 1. The Input and Output
controls for the two channels should be set to the same values.
Input Selects the three sidechain operating modes for dynamic control:
Fast: The ES-8 gain control tube is capable of very fast
operation. In this mode, the attack and release times are
0.5ms and 50ms respectively.
Presets: These six attack/release time settings are identical to the
presets on the classic Fairchild 670 limiter. Presets 5 and 6
are program-dependent.
Manual: The attack and release times are continuously variable
from 1-100ms and 0.1-2s respectively.
TRS 1/4" jacks for inserting an outboard EQ into the sidechain.
Use for frequency-dependent compression or de-essing. Tip is send,
and Ring is return. In Link mode, only the channel 1 insert is active.
The XLR and 1/4" connectors for each channel are wired in parallel.
Pin 2 (Tip) is positive phase and Pin 3 (Ring) is negative phase. Input
impedance is 10k!, transformer-balanced. Output impedance is
600!, active-balanced.
Mode
Threshold
In/Bypass
Link/Split
Output
Meter
Inputs and
Outputs
Sidechain
Inserts
ES-8
ES-8
100 100
ES-8 Front Panel Templates
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RELEASE
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MODE
Zero
IN BYPASS
2s
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2s1ms 40ms
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MANUAL
RELEASE
20ms
ATTACK
MODE
Presets
Manual
PRESETS
PRESETS
Zero
Gain Reduction
Output
Input
2s
Fast
Presets
Manual
Gain Reduction
Input Output
20
10 7532012
3
1
20
10 7532012
3
1
Pendulum Audio
Off
Max Off
Max Off
Max
Off
Max Off
Max Off
Max
6386
METER
THRESHOLD OUTPUT
INPUT
METERTHRESHOLDINPUT OUTPUT
Variable Mu Tube Limiter
ES-8
100100
Session: _____________________ Date: _____________ Source: _________________________ Notes: ________________________
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Manual
PRESETS
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Zero
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Output
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Manual
Gain Reduction
Input Output
20
10 7532012
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10 7532012
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1
Pendulum Audio
Off
Max Off
Max Off
Max
Off
Max Off
Max Off
Max
6386
METER
THRESHOLD OUTPUT
INPUT
METERTHRESHOLDINPUT OUTPUT
Variable Mu Tube Limiter
ES-8
100100
Session: _____________________ Date: _____________ Source: _________________________ Notes: ________________________
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ON
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2s1ms 40ms
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MANUAL
RELEASE
20ms
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MODE
Zero
IN BYPASS
2s
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2s1ms 40ms
1s
MANUAL
RELEASE
20ms
ATTACK
MODE
Presets
Manual
PRESETS
PRESETS
Zero
Gain Reduction
Output
Input
2s
Fast
Presets
Manual
Gain Reduction
Input Output
20
10 7532012
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20
10 7532012
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Pendulum Audio
Off
Max Off
Max Off
Max
Off
Max Off
Max Off
Max
6386
METER
THRESHOLD OUTPUT
INPUT
METERTHRESHOLDINPUT OUTPUT
Variable Mu Tube Limiter
ES-8
100100
Session: _____________________ Date: _____________ Source: _________________________ Notes: ________________________
ES-8 Remote Cutoff Tube Limiter
Features
•Classic feedback compression with the same compression profile as the Fairchild 660 and 670
•Modern class A, solid-state gain make-up stage for wide bandwidth and low distortion
•Soft-knee design with smooth transition from compression to limiting
•Fast attack (0.5ms) and release times ideal for tight program compression or tracking
•Low noise and superior transient response
•Three sidechain operating modes: Fast, Presets and Manual
•Two completely independent channels with stereo linking
•Tubes calibrated for precise stereo balance
•Hard bypass switches for each channel
•Sidechain inserts for frequency-dependent compression and de-essing
•Transformerless balanced output stage capable of delivering +27dBu
•Soft-start warm-up with outputs bypassed until all voltages are stabilized
•Gold-plated relay contacts, I/O connectors and tube sockets
•Fully regulated high voltage (250V), filament and bipolar power supplies
•Custom toroidal power transformer with shield for minimum hum
•Polypropylene capacitors and metal film resistors
Introduction
Thank you for purchasing the Pendulum ES-8, a modern two channel tube limiter designed to have
the compression characteristics of a vintage unit, but with a higher level of sonic accuracy. Rather
than trying to recreate the past, we decided to taken an entirely different approach. The ES-8 uses a
remote-cutoff gain control tube with the same compression characteristics as the vintage Fairchild
limiters to provide the classic feedback response unique to the characteristics of this tube. Subsequent
amplification is accomplished with a Class A, balanced transformerless solid-state line amp, rather
than the push-pull transformer output stage used on vintage variable-mu units. The result is a limiter
that possesses the 'dynamic signature' of a classic tube compressor, but with a more accurate, less
colored signal path.
The soft-knee design used in the ES-8 offers effortless dynamic control with a smooth transition
from compression to limiting. In addition, both channels can be operated independently, or linked
with the flip of a switch. When linked, the threshold and attack/release parameters are controlled
entirely by channel 1, assuring precise stereo balance over the entire range of gain reduction.
For maximum versatility, the ES-8 incorporates a solid-state sidechain to provide a wide range of
control with three modes of processing: In the FAST mode, the limiter works extremely fast (0.5ms
attack time), and is remarkably free of the 'pumping' artifacts normally encountered with slow
variable-mu compressors. It's the ideal choice for invisible dynamics processing, either for tracking or
tight program compression.
The PRESET mode consists of six classic attack/release time settings (identical to the Fairchild
670), that are optimized for program compression, including two settings with program-dependent
release times.
The MANUAL mode offers total control over the attack and release times, which is particularly
useful for creative compression effects or for processing bass guitar.
Most important, the hard bypass switches on the front panel conveniently allow a quick
determination of exactly what the ES-8 is, or in most cases, isn't doing to your signal.
Unpacking
The unit was carefully packed at the factory to protect against damage in transit. Nevertheless, be
sure to inspect the unit and shipping carton for any signs of damage that may have occurred during
shipment. If there is any damage, notify us immediately for further instructions. It’s also a good idea
to save the carton and packing materials should you ever need to return the unit for repair. The
shipping carton should contain the following items: the ES-8 Vacuum Tube Limiter, a 3 prong IEC
power cord, and this operating manual.
Mounting
The ES-8 uses two EIA-standard rack spaces, and can be mounted in any standard 19 inch (483mm)
equipment rack. If the ES-8 is mounted in a mobile rack or road case, it is important that the rear of
the chassis is supported to prevent possible damage from mechanical shock and vibration. Excessive
shock and vibration can cause damage or premature failure of the vacuum tubes, or cause them to
shaken loose from their sockets. Please avoid rough handling.
Ventilation
For proper operation, it is very important that adequate ventilation is provided. Vacuum tubes
produce a significant amount of heat that must be removed from inside the chassis. The side panel
vent holes and top panel slit vents should never be blocked in any way. Never mount the ES-8 below
a rack unit with a depth greater than 7 inches (178mm). Do not mount the ES-8 near other heat-
producing equipment such as power amplifiers or other vacuum tube products. If possible, leave open
at least one rack space above the unit, and use a rack spacer with a ventilation grille. Never operate the
ES-8 inside a road case where the side panels are cushioned in foam.
Preventing Ground Loop Hum
One of the reasons the ES-8 sounds so good is that it uses an active-balanced output stage rather
than an a push-pull output transformer. However, it does not benefit from the galvanic isolation
provided by an output transformer. For this reason, a few precautions are necessary to insure hum-free
operation:
• Isolate the front panel from the rack rails. Use plastic shoulder washers to prevent electrical contact
between the rack ears of the ES-8 and the metal rails of the equipment rack.
• Isolate the ES-8 from units mounted above or below it in the rack. Make sure the front panels are
not in electrical contact and that the top or bottom cover screws of the ES-8 are not touching those
of any other units.
• Connect the 3 prong IEC power cord to the single-point star grounded electrical source for your
facility.
The idea here is to make sure the ES-8 seeks ground at only one point. For safety reasons, do not
lift the ground at the IEC power cord. Keep in mind that in a properly grounded hookup, the ES-8
does not hum. Please, take the time to do this right, and you will be rewarded with hum-free
operation. Call us if you have any questions. Please note that pin 2 is hot.
Power Requirements
The ES-8 is equipped with a 3-prong IEC power connector and detachable cord. Never operate the
ES-8 with the ground on the power cord defeated. Unless otherwise stated, this unit operates from
120V/60 Hz at 30W. The ac fuse is accessible from the rear panel and is rated at 1A/250V (3AG)
SLO-BLO. To check or replace the fuse, make sure the unit is unplugged. Operation at 240V/50Hz is
available as an option. Please contact us for more information.
Servicing
Other than changing the tubes, the user should not attempt to service the ES-8 beyond that
described in this manual. Never remove the covers or attempt to replace the tubes until the unit has
been disconnected from the ac power source, and all circuits inside have been allowed to discharge for a
period of at least 30 minutes. The vacuum tubes become very hot once the unit has been turned on,
and they should not be touched until they have cooled to room temperature. To reduce the risk of fire
or electrical shock, do not expose to rain or moisture, or operate it where it is exposed to water. Since
potentially lethal voltages are present inside the unit, it should only be opened by qualified service
personnel. Refer all servicing, or any questions about servicing, to Pendulum Audio, Inc.
Operation
While the operation of the ES-8 may appear to be rather straightforward, there are a few features
which may differ from what you’re accustomed to seeing on other vacuum tube compressors. You
may find it useful to refer to the Condensed Operating Instructions at the beginning of this manual to
quickly identify the operation of the front panel controls. However, we suggest you read through this
section to take advantage of all its features, and to make sure you are operating the ES-8 in the way
most appropriate for the type of dynamics processing you’re doing.
Hookup
Please refer to the rear panel layout (see the Condensed Operating Instructions) for the location of
the inputs, outputs, and ac power. Make all connections to the ES-8 before applying power.
Inputs
On the right hand side of the rear panel are the transformer-balanced inputs for channels 1 and 2.
The female XLR connectors on top are 3 pin balanced inputs with Pin 1 = ground, Pin 2 = positive
phase input (+), and Pin 3 = negative phase input (-).Use them for connecting the ES-8 to +4dBu
transformer-balanced or active-balanced sources. If you encounter ground loop hum when connecting
to balanced sources, lift the shield from Pin 1 on the input end of the cable.
The two 1/4” jacks below the XLR connectors are unbalanced input connectors, wired in parallel to
the XLR inputs, with Tip = Pin 2, Ring = Pin 3, and Sleeve = Pin 1. Use them for connecting the
ES-8 to unbalanced sources. Do not attempt to use the XLR and 1/4” inputs simultaneously.
Outputs
To the left of the input jacks are the active-balanced output jacks for channels 1 and 2. The male
XLR connectors on top are 3 pin balanced outputs, with Pin 1= ground, Pin 2 = positive phase
output (+), and Pin 3 = negative phase output (-). Connect these outputs to XLR- or TRS-balanced
line-level inputs. If you encounter ground loop hum when connecting to balanced inputs, lift the
shield from Pin 1 on the input end of the cable.
The two 1/4” jacks below the XLR connectors are unbalanced output connectors, wired in parallel
to the XLR outputs, with Tip = Pin 2, Sleeve = Pin 1. Use them for connecting the ES-8 to
unbalanced inputs or mixer inserts.
AC Power
On the left side of the rear panel is the IEC input socket. Connect to a 120V/60Hz receptacle with
the 3 prong IEC power cable supplied with the ES-8. For safety reasons, do not lift the ground on the
power plug by using a 3-to-2 ground lift adapter.
Turn on the power to the unit using the ac power switch located above the power inlet socket.
Although it might seem a bit awkward to put the ac power switch on the rear panel of the ES-8, there
is a very good reason for it. By keeping the ac away from the front panel, hum induced by the ac line
into the front panel circuitry can be virtually eliminated.
If necessary, replace the 1A/250v 3AG SLO-BLO fuse only with the same type and rating.
Power-up Sequence
To prolong tube life, the ES-8 goes through a soft-start sequence for gently applying power to the
tubes and stabilizing the circuit before engaging the outputs. When the power switch is turned on, the
outputs remain in BYPASS and the dc voltage on the tube filaments is ramped up to 12.6Vdc. Next,
the high voltage supply is slowly increased to 250V and the circuit is allowed to stabilize for about 2
minutes. Finally, the IN/BYPASS switches are activated and the blue ‘on’ led on the front panel is
illuminated. For best results, please allow the ES-8 to warm up for 10 minutes or longer before use.
TO PROLONG TUBE LIFE, TURN OFF THE ES-8 WHEN NOT IN USE.
ES-8 Front Panel Controls
Please refer to the front panel layout (see the Condensed Operating Instructions) for the location of
all switches and controls discussed below. The operation of both channels is identical, unless the two
channels are linked. All toggle and rotary switch contacts are gold-plated for high reliability. All panel
rotary controls are long-life conductive plastic potentiometers.
Input: Off to Max
The INPUT control is actually a passive balanced attenuator positioned between the input
connector and the input transformer. It controls the input level to the input transformer, and
consequently, the input level to the ES-8 gain control tube. In normal operation the INPUT control
should be set fully clockwise to MAX, since the ES-8 is designed to operate with +4dBu input levels.
On occasion, it will be necessary to reduce the input level to the ES-8 to prevent overload of the input
transformer or the tube gain stage. Monitor the input level with the VU meter to determine if input
attenuation is required. Unlike most other tube compressors, the input control is located in the
primary circuit of the input transformer, and does not affect the balance of the gain control stage.
Threshold: Off to Max
The THRESHOLD control determines how much gain reduction is applied to the source material.
Since the ES-8 is a ‘soft-knee’ feedback compressor, it does not have a strictly-defined ‘threshold’, like
VCA-based units that uses feedforward detection. A maximum of 12dB of gain reduction is available
from the ES-8 gain control tube. The range of the THRESHOLD control is off to -20dB, which
permits a steady-state input level as low as -8dBu to achieve the full 12 dB of gain reduction.
Output: Off to Max
Use the OUTPUT control to increase the signal level after compression. Up to 15dB above the
level of the input signal is possible. The unity-gain setting (0dB) is 12:00. The OUTPUT control on
is a 20% audio taper potentiometer, which permits finer adjustment of output level in the critical 0-
15dB range.
Meter: Input/Gain Reduction/Output
The illuminated ANSI VU meters are electronically isolated from the signal path, and can be
switched to measure input, output or gain reduction. Keep in mind that a VU meter is a mechanical
device, designed in accordance with a with a well-accepted ballistic standard, to indicate an average
loudness level. On the other hand, the led meters on your mixer or digital recorder are reading a peak
program level, and faithfully register all those short transient spikes that add little to the perceived
loudness of the program material. The ratio of the peak to average levels can be 20dB or greater
depending on the source (e.g. drums). So, if you’re wondering why the led meters on your recorder are
flashing near zero, but the input and output levels on the VU meters of the ES-8 are hovering at or
below -10, you’re simply seeing the difference between the peak and average program level.
Input
When the METER switch is in the INPUT position, the VU meter indicates the signal level at the
XLR and 1/4” input connectors. The meter is calibrated to 0dB = +4dBu (1.23vrms). Use this setting
to monitor the average program level into the input transformer and compression tube of the ES-8. To
minimize control voltage artifacts in the signal path (especially when using the FAST mode), the
input level should be in the range of -5 to 0VU.
Gain Reduction
When the METER switch is in the GAIN REDUCTION position, the VU meter indicates the
amount of gain reduction applied to the input source. Keep in mind that the meter is indicating an
average gain reduction, and does not reflect how the ES-8 is responding to peaks faster than the
meter’s response time. When the peak to average ratio is high (e.g. drums), trust your ears to be the
ultimate judge.
Zero
A screwdriver - adjustable trim control, located below the METER switch, is used for zeroing the
meter when it is set to read GAIN REDUCTION. Use a small, flat-bladed screwdriver, and adjust the
meter to indicate 0VU with the THRESHOLD control set to OFF. Gain Reduction is measured
directly from sidechain control voltage, so very little drift of the meter should occur. Let the unit
warm up for at least 20 minutes before making any adjustment.
Output
When the METER switch is in the OUTPUT position, the VU meter indicates the signal level at
the XLR balanced output connectors. The meter is calibrated to 0dB = +4dBu (1.23vrms). Use this
setting to monitor the average program level sent to a tape machine, mixer input or channel insert.
Mode: Fast/Presets/Manual
The ES-8 incorporates a solid-state sidechain circuit to provide a wide range of dynamic control.
For maximum versatility, there are three distinctly different modes of operation.
Fast
In the FAST mode, the gain control tube operates with very fast attack and release times (0.5ms
and 50ms respectively). This mode is remarkably free of pumping artifacts even at high compression
levels. It's the ideal choice for tracking or tight program compression. Use it whenever you don’t want
to hear the ES-8 working, particularly on vocal tracks.
Presets
The PRESETS mode consists of six attack/release settings which are ideal for program
compression. These presets are identical to those found on the classic Fairchild 670 Limiter. The first
four presets offer a selection of fixed attack and release times, with the release times indicated on the
dial markings. Presets 5 and 6 are program-dependent release times, where there is initially a quick
release, followed by a longer decay time to zero gain reduction. Think of these settings as a ‘gated’
release time, where the compressor operates more rapidly at the average program level, but takes much
longer to return back to zero gain reduction. In other words, the compressor does not immediately
‘suck back to zero’ when there is a brief pause in the program (e.g. between words in a vocal track).
Manual
The MANUAL mode offers total control over the attack and release times. The range of the attack
and release controls is 1ms to 100ms and 0.1s to 2s respectively. Manual control is particularly useful
for creative compression effects or for processing bass guitar. Quite often, a greater level of
compression can be applied to program material if a very long attack time and a short release time are
used. In this instance, the compressor is responding to the average program level, does not ‘over-
compress’ on short peaks, and recovers quickly. In other words, it doesn’t ‘pump’ as much!
Sidechain Inserts
On the rear panel are two TRS 1/4" jacks (one for each channel) for inserting an outboard EQ into
the sidechain detector circuit. This is useful for frequency-dependent compression or de-essing. The Tip
is Send, and Ring is Return.
Link/Split
When this switch is set to SPLIT, the two channels of the ES-8 operate independently. In LINK,
the sidechain circuits for the two channels are coupled for stereo operation. The THRESHOLD,
dynamics processing (fast, preset and manual modes) and IN/BYPASS functions are controlled entirely
by Channel 1. The INPUT and OUTPUT controls for the two channels should be set to the same
values.
Although linking the two channels will keep the stereo image centered, it may tend to collapse the
stereo spread a bit too much on some program material. In this case, run the two channels of the ES-8
SPLIT, and set all the controls for both channels to the same values. Listen carefully to verify that
the degree of image shift that occurs is acceptable.
In/Bypass
These are 'hard' bypass switches for comparing the processed sound directly with the original
source. IN connects the output of the ES-8 line stage directly to the output connectors. BYPASS
connects the input source directly to the output. When linked, and channel 2 is set to IN, the
IN/BYPASS switch for channel 1 conveniently controls both channels at once.
Other Issues
Internal Adjustments
There are three adjustments to the ES-8 that are only accessible by removing the top cover:
• Calibration of the meter when measuring gain reduction
• Stereo balance of the gain control tubes in LINK mode.
• Push-pull balance of each gain control tube for control voltage rejection.
These adjustments are required only if one of the tubes are replaced, or if they drift out of
calibration with age. Since these adjustments must be made with the ac power on, and potentially
lethal voltages are present inside the chassis, we recommend that they be made only by qualified
service personnel who are familiar with working around high voltage tube circuitry.
For your safety, we strongly recommend that you contact us for servicing. On request, detailed
instructions for performing these procedures will be provided to qualified service personnel.
Options
There ES-8 is available with transformer-balanced outputs using high-quality Jensen transformers.
However, we do not recommend this unless absolutely necessary, since the transformers will color the
sound. If at all possible, try to make it work without them. See the section entitled ‘Preventing
Ground Loop Hum’ for more information.
Replacing the Tubes
TO PROLONG TUBE LIFE, TURN THE ES-8 LIMITER OFF WHEN NOT IN USE!
All vacuum tubes have a limited life due to filament failure, reduced electron emission from
the oxide coating on the cathode and/or a buildup of impurity gases is the bulb. The gain
control tubes in the ES-8 are expected to give many years of service. If you notice the sound
quality deteriorating - higher distortion, muddiness, poor compressor response, or excessive
microphonic behavior - it’s time to change the tubes. We recommend changing only the tube
that is defective. If you are uncomfortable with replacing the tubes yourself, please have it
done by qualified service personnel. Replacement tubes are available directly from us.
1. Unplug the ES-8 and wait at least 30 minutes for the high voltage in the unit to
discharge and for the tubes to cool to room temperature.
2. Remove the top cover by removing the nine #6-32 Phillips-head screws.
DO NOT remove the bottom cover.
3. Note the position of the two tubes (V1 and V2) in the porcelain sockets.
The gain control tubes are 6ES8 or ECC189 Remote-Cutoff Triodes.
NOTE: THERE ARE NO SUBSTITUTES FOR THESE TUBES!
ONLY THE EXACT REPLACEMENTS WILL WORK!
4. Remove the tube and replace it with the same type.
5. Reinstall the top cover and screws.
Note: In most cases, tube DC and AC rebalancing, gain calibration and L/R balancing will be
required. Although this not a difficult process, it should be performed only by qualified service
personnel that are familiar with servicing vacuum tube equipment. Potentially lethal voltages are
present inside the unit. Detailed instructions for performing these procedures will be provided on
request.
ES-8 Specifications
Circuit Type: remote cutoff gain control tube with balanced class A solid-state
line stage and transformerless output
Input Sensitivity: +4dBu
Input Impedance: 10kΩ(nominal) with 1:1 input transformer
Freq. Response: -1.0dB 15Hz and 75kHz with 600Ωoutput load
Noise: less than -85dB below +4dBu output level
with Output control at unity gain (12:00)
Distortion: less than 0.08% THD+N, 20Hz to 10kHz
Output: +27dBu balanced into 600Ωload
Max. Gain Reduction: 12dB
Threshold: up to 12dB of gain reduction at -8dBu input level
Ratio: 1:1 to limiting, program-dependent
Output: off to +15dB
Modes: fast, preset or manual operation
Fast: 0.5ms attack, 50ms release
Presets: 1ms/0.1s, 1ms/0.3s, 2ms/1.0s, 4ms/2s,
2ms/1 to 4s and 1ms/0.5 to 20s (program dependent)
Manual: attack time varaible from 1.0ms to 100ms
release time varaible from 0.1s to 2s
Meter: selection of input level, gain reduction, or output level
input and output levels are referenced to +4dBu = 0VU
In/Bypass: hard bypass of input signal to output connector
Link/Split: links channel 1 and channel 2 for stereo operation
Polarity: input and output XLR connectors are pin 2 hot
Vacuum Tubes: (2) 6ES8 (US) or ECC189 (European)
Power: 120Vac, 30W (240Vac optional)
Power Supplies: +250Vdc, +12.6Vdc and ±18Vdc, fully regulated
with soft-start warm-up and output bypass
Dimensions: 2U enclosure, 19" x 3.5" x 12.5" (48.2 x 8.8 x 31.8 cm)
Weight: 14lbs (6.4kg)
Limited Warranty
Pendulum Audio, Inc. warrants to the first purchaser of a new Pendulum ES-8 Vacuum
Tube Limiter that the unit is free of manufacturing defects in materials and workmanship for
a period of one (1) year from the date of purchase. Pendulum Audio, Inc.'s sole obligation
under this warranty shall be to provide, without charge, parts and labor necessary to remedy
defects, if any, which appear within one (1) year from the date of purchase. All warranties
expressed or implied made by Pendulum Audio, Inc., including warranties of merchantability
and fitness, are limited to the period of this warranty. Pendulum Audio, Inc. is not
responsible for indirect, incidental or consequential damages arising from the use or failure of
this product, including injury to persons or property.
This warranty does not cover damage due to: misuse, abuse, modification, accident or
negligence. The warranty does not apply if the unit is repaired or altered by persons
unauthorized by Pendulum Audio, Inc. in such a manner as to injure, in Pendulum's sole
judgment, the performance, stability or reliability of the unit. The warranty does not apply if
the unit is connected, installed or used otherwise than in accordance with the instructions
furnished by Pendulum Audio, Inc. There is no warranty on vacuum tubes.
If the equipment requires warranty repair, return authorization must be obtained from
Pendulum Audio, Inc. prior to shipment. Equipment should
not
be shipped to Pendulum
Audio, Inc. until return authorization and the proper shipping address is obtained from us.
The equipment (with all its components parts and connecting cables) must be suitably
packaged, including a note with the owner's name, address, telephone number and a
description of the reason for return. The owner pays two-way shipping (we recommend UPS
or FedEx), and we suggest that the shipment be insured for its full value.
This limited warranty is in lieu of all other warranties, expressed or implied, and no
representative or person is authorized to represent or assume for us any liability in
connection with the sale of our products than set forth herein. This limited warranty gives
you specific legal rights, and you may also have other rights which vary from state to state.
Pendulum Audio, Inc. • P.O. Box 339, Gillette, NJ 07933 • (908) 665-9333 • www.pendulumaudio.com
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