Recording - August 2015 - 26

B Y PA U L V N U K J R .

A-Designs Audio Ventura
A rackmount slice of history gives your tracks a classic console vibe
Designed by Carl Johnson for Peter
Montessi's California-based A-Designs
Audio, the Ventura is a channel strip with
microphone and instrument preamp sections
and a 3-band equalizer. Note that the
Ventura is an update of A-Designs Audio's
older JM-3001, with a new look and nice
added features like the instrument preamp.
It's inspired by the input and EQ section
from a 1970s-era Quad Eight Electronics
Ventura recording desk. Not surprisingly, the
microphone preamp in the Ventura is a single
channel of the one found in the A-Designs
Pacifica 2-channel mic pre, which is also
Quad Eight inspired. In 2014 the Pacifica
celebrated its 10 year anniversary; over the
past decade it has built up quite a following
and a solid reputation as a workhorse preamp for many studios.
A trip to Ventura
The Ventura is a housed in a 1U 19" rackmount enclosure and is finished in the same
off-white creme finish found on the old
Ventura desks, and the Pacifica rackmount.
The knobs are buttery smooth with a great
balance of resistance and glide, all of the
dual-concentric stepped switches offer a
hearty click, and even the toggle switches are
extra firm and solid.
Handmade in the USA, the Ventura is built
around A-Designs' own custom C12X discrete op amp. It runs on ±30V DC rails and
offers high gain, a fast slew rate, and virtually no DC offset. It is capable of driving a
50 ohm load at 50 Hz with extremely low
current draw. The unit has -120 dBm of
Noise (EIN), less than 0.01% distortion, and
600 ohm outputs.

RECORDING August 2015

Found in the mic pre, the instrument pre,
and the EQ section, the C12X op amp is a
key factor in the Ventura's sonic signature. It
is the stacking of op amp into op amp, coupled with the unit's Cinemag input and output
transformers, that gives the Ventura a classic
console sound.
The preamps-mic and instrument
The microphone preamp has its controls on
the unit's right side. It's a 1400 ohm singlestage, solid state transformer-coupled design.
It has 72 dB of gain range via a single variable gain knob with a throw of -62 dBV to
+30 dBV. Just as on the Pacifica, it has a -20
dB pad, +48V Phantom power switch with
LED, and a phase/polarity flip switch.
Moving to the left end of the Ventura, we
find the instrument preamp, with front mounted 1/4" input jack and variable input gain
control. You may be thinking, "Big deal,
almost every mic pre offers a DI input nowadays." This one is different. Many other units
simply buffer the input signal before it hits the
mic preamp stage to bring it in line. In contrast, the Ventura uses a single-stage, singleended, C12X op amp equipped circuit that's
completely independent from the mic preamp. It has a 20 Megohm nominal impedance and an impressive 70 dB gain range.
3-Band EQ and Filters
There are two EQ sections on the Ventura.
The first is a simple set of filters that function
even when the 3-band EQ section is
bypassed. The High Pass Filter's corner frequency is 150 Hz and the Low Pass Filter's is
9 kHz. Both feature a 2nd order slope: 12
dB/octave.

Moving to the EQ section, the Ventura
offers three bands of overlapping EQ controlled by dual concentric stepped switches.
The red outer ring selects the frequency, while
the black inner knob cuts or boosts the frequency in steps of 2, 4, 6, 9 or 12 dB.
Each band offers 11 frequency choices.
Low ranges from 50 to 500 Hz, the Mid
band is 300 Hz to 3 kHz, and the High is
1.5 to 15 kHz.
Unlike many classic channel strip-based
EQs which use a variable Q, on the Ventura
each band can be switched between three Q
settings: S (Sharp 2.4), W (Wide 0.7), and
N (Narrow 7.7). Additionally the Low and
High bands can be toggled between a shelf
or a bell setting. When in shelf mode, the Q
control is bypassed.
The EQ, as mentioned, can be switched in
and out of the circuit. Final controls include a
switch to select between the instrument or
microphone preamps, and a front mounted
power switch equipped with its own LED indicator.
Independence
The last big feature on the Ventura is its simple yet effective routing options, which allow
the EQ and the preamps to be used either in
series or completely independent of each
other.
Around the back are is a balanced XLR mic
input, a balanced XLR mic/instrument output,
a 1/4" TRS EQ input/insert return, and lastly
a balanced XLR main output. With these you
get a choice of preamp only with its own
I/O, EQ only with its own I/O (the EQ input
breaks the master chain), or you can run from
the mic input or the front side instrument input

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