User manual
39
July/August 2014 resolution
MODULAR PROCESSING SUPPLEMENT KNOW HOW
Thermionic Culture
The Nightingale is the second of Thermionic Culture’s half-rack 4U
format units, the rst being the Freebird 3-channel value EQ. It is
an all-valve aair with two ECC832 for mic amp/EQ, 6AQ8, 5965,
and 5726 in the compressor section. Two mic amps with a useful
valve EQ have their own outputs (XLR unbalanced) which can give
+20dBu. These can be combined or taken individually into a vari-
mu compressor-based on The Phoenix stereo valve compressor,
but with a little more ‘attitude’. The compressor section has its own input (balanced XLR) which can
be selected instead of a feed from the mic amps, also an XLR balanced output capable of +25dBu.
www.thermionicculture.com
Standard Audio
The Standard Audio Stretch multiband compression unit is inspired by 70s and 80s tape noise
reduction units. The input signal is split into LF (20-110Hz), MF (110Hz-3kHz), HF3 (3-20kHz), and
HF9 (9-20kHz) frequency bands and then individually compressed with ratio, attack, and release
settings tailored to each frequency band. The Input control allows the user to set the gain structure
through the unit so that the desired amount of compression occurs while a post-mix circuit Output
level control allows the engineer to set the output level to DAW/tape without altering the mix
blend. A Filter/Compression pushbutton lets the user cycle continuously through seven dierent
lter combinations.
www.standard-audio.com
JLM Audio
The BA500 mic preamp module uses a discrete 99V Op-Amp for 60dB of gain
and an impedance control range from 200Hz-3kHz. It has a large white LED-
backlit 34mm VU meter for output level. The TG500 mic preamp module is a
two-FET, six-transistor Class-A design providing 75dB of gain. It is based on
early Neve, BBC, and EMI equipment with simple transistor stages that have
been redesigned to include additional features. The LA500 compressor is a
redesign of the LA-3A/LA-2A-type compressor with additional features, including 5:1 and 10:1 ratios
(in addition to 3:1) and sidechain HPF switching between at, 100Hz, and 200Hz, so the low end can
be compressed or removed from the sidechain. A make-up level pot varies between 0-20dB of gain.
The FC500 Enhanced FET Compressor is a redesign of the 1176LN-type compressor with a fully
variable Ratio control (from 3:1 to 20:1) and sidechain HPF (from 10-100Hz). Compression linking is
possible with two or more FC500s using the link switch. The HPM500 is a six-channel headphone
mixer module that ts in the spare space next to the API Lunchbox power supply so no 500 slots
are wasted in the Lunchbox itself. Since there are 12 wires to solder to the back plane output XLRs,
an IDC plug that has to be removed from the power supply to the mixer car, and a short extension
cable plugged from the mixer to the power supply, it is recommended that the HPM500 is installed
by a technician.
www.jlmaudio.com
Avedis Audio Electronics
The E27 is a 3-band equaliser module with nine
selectable frequencies per band. The all-discrete
design also boasts +/-16dB boost and cut using a continuously
variable potentiometer, pushbutton shelving option for low and high frequencies,
high headroom, and low noise. Jensen transformers couple the input and output. Custom machined
aluminium knobs adorn Gold-plated rotary switches. Avedis Audio also manufactures the R52, a dual
rack compatible with select Series-500 modules. It features an internally regulated power supply
with phantom power, a Link switch for connecting channels, and an LED power supply indicator.
www.avedisaudio.com
JCF Audio
Aimed fairly and squarely at the front end of the recording chain, where broad
strokes of sound adjustment need to be made quickly, the JCF Audio More
‘n’ Less is a channel amplier with mic (congurable as front only or front and
rear) and line (rear only) inputs. No switching is needed between these inputs.
It has an Output level control, single knob compression and simultaneous
make up gain function, a static boost equaliser — Top or Bottom and a
dynamic loss equaliser. A Cinemag steel 1:2 output transformer is used for oating output, isolation,
and drive, while a four-position pad optimises drive of the Cinemag mic input transformer.
www.jcfaudio.com
JMK Audio
The JM-115C is a transformer-coupled VCA-based compressor using true RMS detection similar to
the dbx 160VU. Compression ratio starts at 1.25:1, rising to 20:1. The JM-120 is a dual Hi-Z input DI
preamp with one common (Jensen) transformer-balanced output. The Guitar input is specically
designed for guitar input impedance, gain structure (maximum 48dB), bandwidth all optimised to
produce a clean and quiet signal. The Bass/Keyboard input is designed for the higher output of a
bass guitar or keyboard and optimised for bass.
www.jmkaudio.com
T
he 500 series is a modular system that enables the user to bring
together preamps, equalisers, dynamics and effects and combine
them to create unique sounds and push creativity during the
recording process. Each module fits inside one or two slots — two
slots being stereo — and then these are connected on the rear panel of
the power rack using standard XLR cables. The general intent is that the
modules work at +4dB line levels to facilitate inter-module connectivity.
Today’s 500 series format is a grandfathered ‘standard’ that originated
with several companies, including API, Aphex, and DBX. Over the years
API stuck with the format and more recently there has been enormous
growth in the number of manufacturers producing 500 series modules
and the racks to power them from. The enduring attraction of this modular
processing package is that it is compact, portable and allows the user to mix
and match modules and to be able to sample premium brand products in an
affordable way.
Lots of manufacturers make 500 racks, what operating
principles are they basing their racks on?
It seems that most companies that offer racks are offering variations on
the original API spec. In other words, they make a box with a bunch of
slots and then provide power via a 15-pin card edge connector following
the pin configuration that was originally set out by API. EDAC tends to be
the connector of choice as these have two conductive sides for improved
connectivity.
The powering of the racks seem to range from about 100 milliamps per
slot and up. As API set out the standard at 130 milliamps, this seems to be
the predominant format. The power supplies provide a shared pool of current
from which the user then determines which modules can be used.
With the advent of power hungry tube devices and the demand for
vintage solid state devices to be moved into the 500 series format, it seems
that more power is beneficial as many of these devices were designed with
greater power availability than the original 500 series format.
How did Radial do what is has with its 500 racks?
Radial started with the idea that a power rack could do a lot more if the
modules could be mixed and matched in series or in parallel. This prompted
us to incorporate a mixer in the Workhorse. We also thought that replacing
patch cables with feed switches could simplify setups and keep the rear patch
panel clear. We then took the position that the rear panel could actually work
as a patchbay if ¼-inch TRS cables could be incorporated. Finally, because
API had left a couple of pins free in its latest designs, we adopted them for the
Onmniport jack. This ‘module specific’ port enables a manufacturer to add
a feature such as an insert, key, instrument input or whatever, as an extra
function to their module without changing the original spec.
Once we got things going, we then quickly discovered many ‘home-built’
modules are not necessarily built properly. During testing, in some cases,
they actually caught fire. So we added safety fuses that basically shut down
the racks should a fault occur. This not only protects the Radial Workhorse
power rack, but also protects modules and your home!
After the Workhorse was completed, we then added various other rack
formats to suit different customer needs for 3, 6 and 10 spaces.
Inside and
behind the rack
Not all modules and racks are created equal.
We talk to Radial Engineering president
PETER JANIS about the ins and the outs.