Recording - January 2015 - 34

Chandler Limited REDD.47

Moving left to right, here are the unit's
controls and functions:
~ 1/4" instrument DI and mic/DI switch
~ Voltage Gain Control: This 7-position
stepped switch is an updated variant of
the one found on the original REDD.47
module. Where the original had only the
three settings mentioned above, the
Chandler version has seven: 16, 22, 28,
34, 40, 46 and 52 dB.
~ Pad switch: -20 dB of attenuation, a
feature not present on the original
~ Rumble Filter (high pass/low cut): This
is a unique highpass filter with 9 stepped
positions of out, 30, 45, 60, 70, 90,
110, 130, 180 Hz (see the sidebar)
~ Output Control: Think of this as the output fader; it only attenuates, and has a
throw of -10 up to 0 dB

~ Pole switch (phase): 180 degree polarity flip
~ Fine Gain Set: This is akin to the
recessed Fine Gain setting on the original, but greatly expanded. Here it offers
±5 dB of gain in 1 dB stepped increments
and also greater tonal benefits beyond
the original (see the sidebar)
~ 48V phantom power switch
~ Power switch and a red jewel power
indicator.
One thing to note is that all the front
panel switches for Pad, Pole, and
Phantom Power are all on when in the
down position, backwards from most
modern boxes where up is on.
Around back, the unit has only an XLR
input, XLR output, and a 3-prong IEC
power cable socket. Unlike Chandler

units of old, the REDD.47 is internally
powered, so no external power supply
needs to be purchased.
Internally the REDD.47 is a deceptively
simple circuit. It is transformer-balanced
with said transformers custom wound to
the original specs. It uses an EF86 tube
on the input stage and an E88CC on the
output. It has a maximum gain of 57 dB
and, like the original, it has a 200 ohm
input and output impedance.
Sound and use
I was sent one of the first available
REDD.47 units in production-serial number 5, in fact.
My first day with it was a round of guitar
tracking for the Madison, WI based heavy
prog band the Mood Manual. Matt, their
guitarist, uses a very simple guitar setup: a
custom-built Les Paul copy, a delay pedal, a
100W Marshall tube head, and a 4x12
slant cabinet, switchable to 2x12.
To capture his rig I used a Shure SM57
into the REDD.47, a Royer R-121 or AEA
N22 into a Chandler TG-2 preamp, and
an AEA N8 (also reviewed in this issue) as
a room mic, also into a channel of TG-2.

Q&A: Chandler's Wade Goeke on the REDD.47
Wade, you've been making the Abbey Road TG Series gear
for over a decade now. What made you move to the
REDD/RS Tube side?
Wade Goeke: When I first started showing designs to [Abbey
Road head engineer] Pete Cobbin, he mentioned that the
REDD.47 was his favorite preamp. That was ten years ago and
I've wanted to do it ever since, but all good things take time!
How faithful is the REDD.47 to the original?
Since Abbey Road had to approve it... it's very close!
What things did you add or alter from the original? Any
Chandler-only additions or improvements?
The most significant were the expanded Fine Gain and the
Rumble Filter. On the original units, the Fine Gain was a small
adjustment for matching the console channels. I gave it much
more range, not simply for more gain, but to expand the tonal
selection. The Fine gain at -5 is much cleaner than an original
REDD module in both distortion and noise floor. Fine Gain at +5
is much "dirtier" than the original, with more harmonic distortion
to make it easier to overdrive the unit. Also, in my opinion, the
preamp sounds thicker with the Fine Gain set high.
And what about the Rumble Filter?
34

RECORDING January 2015

The Rumble Filter is a unique design that uses the input transformer as its lowcut circuit. On the console it was a single setting that required connecting a jumper on the module. It was not
easily accessible and to me it seemed almost like an afterthought. In proper early EMI fashion the documentation even
recommends against using it because it adds distortion to the
signal. Because it is such an interesting sound and design, I
wanted to make it a more significant part of the unit, and I greatly expanded the frequency selection so you can easily tune it in.
Anything else you would like to share should about the
design of the new REDD.47?
Distortion! The REDD.47 will distort like the old units... even more
when combined with a high setting on the Fine Gain. But! You still
have to distort it the way it was done on the classic songs, which is
by driving high gain into it. The distortion comes from overdriving
the input stage, not by cranking the Voltage Gain! At Abbey Road
they ran one module into another to accomplish this. You can also
use another preamp, or a line-level track coming out of your DAW.
Anything else?
Yes, the DI. The DI jacks right into the tube circuit like it does
on a guitar amp. It is virtually identical to plugging into an amp
that uses an EF86 input tube, like an AC15 or vintage Selmer.

Recording - January 2015

Table of Contents for the Digital Edition of Recording - January 2015