than trying to recreate vintage tube gear, Pendulum Audio designs
tube processors that incorporate modern, extended-bandwidth,
Class-A circuit designs. Both the MDP-1 tube preamp ($2,495)
and the ES-8 tube limiter ($3,495) are 2U, dual-channel units
that feature transformerless outputs, low noise and a frequency
response from below 20 Hz out to 65 kHz (75 kHz for the ES-8).
Classy aesthetics, impeccable front panel screening, positive-action
knobs and switches, gold-plated I/O connectors, and large, illuminated
ANSI VU meters suggest the rigorous attention to quality that
lurks below the hood. There you'll find gold-plated switch/relay
contacts and tube sockets, polypropylene caps, metal film resistors
and custom toroidal power transformers with hum-blocking shields.
On both units, the chassis is ventilated through the top and
ES-8 Variable Mu Tube Limiter
The ES-8 is basically the same device as the Pendulum 6386 Tube
Limiter, except that the ES-8 employs two 6ES8 tubes (one per
channel) for gain control in lieu of 6386 tubes, which are in
increasingly short supply. The dual-channel ES-8 offers the same
compression curves as the Fairchild 660 and 670, but the ES-8
departs from those vintage designs in that a Class-A, solid-state
makeup gain stage is used to drive its transformerless balanced
outputs. Fast and Manual modes complement the six 'Fairchild'
Inputs are via balanced XLR and 1/4-inch TRS phone jacks,
wired in parallel. Outputs are via balanced XLR and unbalanced
1/4-inch phone jacks, also wired in parallel. A sidechain insert
is provided for each channel on 1/4-inch TRS jacks (tip is send,
ring is return), enabling frequency-sensitive processing applications
such as de-essing. A Power switch (serving a soft-start warm-up
circuit) and detachable three-prong AC cord round out the unit's
As one would expect from a tube limiter, the ES-8 does not
offer a ratio control. The compression characteristic is soft
knee, with a smooth transition from compression to limiting as
you hit the device harder. The ES-8 can provide up to 12 dB of
Continuously variable rotary knobs provide control over input
attenuation, output gain boost/cut and threshold. The unit is
optimized for +4dBu nominal levels. Maximum makeup gain is set
at 12 dB at the factory, but you can adjust trims inside the
chassis to increase the output control's maximum boost to
A three-way rotary switch lets you choose between three compression
modes for each channel: Fast, Presets or Manual. Fast mode features
fixed 0.5ms attack and 50ms release times.
The Presets mode activates a six-position rotary switch that
implements different "Fairchild" presets. The first
four presets offer release times of 0.1 second, 0.3 second, 1
second and 2 seconds, respectively. Presets 5 and 6 provide program-dependent,
two-stage release times ranging between 1 to 4 seconds for preset
5 and 5 to 20 seconds for preset 6. In both presets 5 and 6,
an initially quick release time is followed by a longer decay
back to zero gain reduction. Attack times range from 1 to 4 ms
for all six Fairchild presets.
Switching the ES-8 to Manual mode activates continuously variable
attack and release rotary control knobs that are provided for
each channel. Manual attack times range from 1 to 100 ms. Manual
release times range between 0.1 and 2 seconds.
Separate rotary controls for each channel switch the VU meters
to show input, output or gain reduction levels. Independent hard
bypass switches are also provided for each channel. The ES-8's
two channels can be operated independently or linked via a front
panel switch. When linked, channel 1's settings control thresholds,
all dynamics processing (modes and attack and release times)
and bypass switching for both channels. Only the input, output
and meter mode controls remain independent when the channels
are linked, a logical arrangement.
My first test of the ES-8 was on arpeggiated
acoustic guitar, played with a flat pick. Switched to Fast mode,
the ES-8 sounded outstanding. The processed track was utterly
devoid of audible amplitude modulation artifacts with 3 dB of
gain reduction showing on the meters. (Peak gain reduction levels
were obviously higher than what the VU meters showed.) The ES-8
produced a smoother timbre than most compressors I've heard in
this application. Even with 7 dB of gain reduction, amplitude
modulation artifacts were barely audible.
Fast and Manual modes provided great
dynamics control for lead vocals. And pushing the ES-8 hard in
Manual mode, I co-axed wonderfully warm, dense and crunchy tones
out of my '62 Strat. The ES-8 also performed well on kick and
snare drums, although a tube limiter is too slow to give you
explosive UREI 1176LN-type snare sounds. Disappointingly,
the ES-8 lent a tone to electric bass that was a little too soft--almost
cottony--for my tastes.
The program-dependent Fairchild presets
worked best for stereo bus compression. The ES-8's dynamics processing
was laudably transparent. The unit lent a slightly euphonic,
softer sound to the mix, while perfectly preserving spectral
balance. The harder you hit the ES-8, the creamier it sounds.
Purists might bark at me, but 8 to 10 dB of gain reduction on
a stereo mix sounded great.
The only big beef I have with the ES-8 is that its inputs
lack headroom. Pumping +26dBu mixes into the unit from my 02R's
analog outputs, I had to lower the input levels about 8 dB down
from unity to avoid audible distortion. [DESIGNER'S NOTE:
This is EXACTLY what the input attenuator is for! You can, in
fact use the input control to change the texture of the sound,
by controlling how hard the input transformer and input tube
are driven. If you routinely work with +26dBu input levels and
use large amounts of gain reduction, the range of the Output
level can be internally adjusted for up to +30dB of makeup gain.
The output stage can drive up to +32dBu without distortion].
I should also note that the ES-8's +4dBu gain structure does
not accommodate -10dBV levels very well, as the input control
is strictly an attenuator. For most pro tracking applications,
these issues should not be a problem.
The ES-8 is a clean, transparent tube
limiter that performs admirably on the acid test for compressor/limiters--percussive,
broadband program material. The unit is not heavily colored,
lending more of a soft sound, rather than bursting with overtones.
Its only weaknesses are its limited headroom at input and practical
incompatibility with -10dBV systems. Boasting
a plethora of features and elegant looks that more than justify
the $3,495 price, the ES-8 is bound to find a home in many pro
Pendulum Audio, PO Box 339, Gillette, NJ 07933; 908/665-9333;
Michael Cooper is a Mix contributing editor and owner of Michael
Recording in beautiful Sisters, Ore.