Neo Ventilator II Leslie Simulator
Update 06-26-2025
As a happy owner of a Hammond Porta-B
and Leslie
760 since I was eighteen years old, I'm a tough customer on
Leslie simulators. I switched to the more compact "clonewheel"
Hammond-Suzuki
XK-3 and XK-3/XLK-3 years ago, they are the best B-3 hardware
emulations I have heard to date. For years I have been happy
with my compact 8 pound rackmount 1U Dynacord CLS-222 for gigs
where I am not playing enough Hammond to justify hauling the
760. I had moved to a new job new town
and had started playing in my school buddy's band. Some venues
have stages that are so small that there wasn't room for either the
760 or my rack with the CLS-222. So my hand was forced to buy
the floor pedal format Ventilator. It had been getting a lot
of good feedback from Hammond players (we're a much harder sell on
Leslie simulators than guitar players). They had been out of
stock for some time, but when I was in the market I happened to be
in the window when a batch were made so I acquired one (good
timing).
While the CLS is designed to emulate the 760, the Vent is designed
to emulate the 122. The Leslie 122 is >the< classic
Leslie to own and it has a different sound from the 760. I
never personally owned a 122, but I have played through them and
they do have their own sound. The 122 is a furniture grade
model targeted to worship and home markets, but that didn't stop
jazz/rock/prog players from gigging them (thus imparting "road
karma" on that poor furniture finish). While the 122 is the
most popular Leslie model for gigging, it only has a 40 watt vacuum
tube amplifier thus it is hard to hear over drums and guitar amps
without micing the 122 (the 760 has 90 watt solid state amplifiers
which are louder). Plenty of owners have souped up their 122
with beefier drivers and amplifiers, albeit at the expense of
tone. Pick your poison... Leslie 122s also need handles
and wheels for gigging, and really good friends to help you move
them in amd out of your vehicle (or up stairs to the gig...
shudder). But for rock and prog players, the vacuum tube
amplifier in the 122 could be driven to distortion which could sound
pretty raunchy (imagine the look of horror on congregation members
or your Aunt Gertrude).
The verdict: the Neo Ventilator II delivers. The firmware of
my unit is v2r0. Guido Kirsch, who designed the Access Virus
synthesizer, built the Vent out of frustration with other simulators
(I told you Hammond players were tough customers). I
definitely hear that warm tone of the 122, but not quite the cabinet
resonance that gives the B-3 percussion its lovely woody
"thunk". Still, Neo delivers the complex mix of phase
shifting, pitch modulation, amplitude modulation, and frequency
shifting; the balance of modulations has to be just right, and the
depth of modulation changes between chorale (slow) and tremolo
(fast) speeds. This is not an easy juggling act, but it is the
spatial movement that defines the "Leslie sound" to Hammond
players. The lower rotor is solely phase modulation -
restricted to the shorter wavelengths of the lower mid frequencies -
and even Neo got this right, as did the CLS.
The Vent has some features that the CLS doesn't have - simulated
power tube distortion, variable acceleration, mic distance from the
rotors, plus some. The CLS is 100% analog while the Vent is
100% DSP. Both have stereo outputs and provide control over
rotor balance and rotor frequency, as well as remote control from a
footswitch. Between these controls, you can dial in your
preferred simulation. The Vent can "disable" the lower rotor
(it remains stationary) for that "Memphis style" Leslie sound.
While the Vent emulates the 122, it wasn't hard for me to emulate
the 760. The CLS has three fixed stereo pan options (plus
mono), while the stereo outputs of the Vent are hard L/R leaving the
musician to set the desired stereo balance at their mixer. You
can use just one output for mono operation. The factory
settings out of the box and suggested settings in the manual weren't
authentic to my experienced ears but with some tweaking you can get
closer to "your sound". Output modes offer flat response for
direct send to a stage monitor or mixer or PA, or "scooped" mids
response for send to guitar or bass amps. A "LO/HI" switch
changes the gain and input impedance for low level instruments like
guitars or electric pianos.
There are five recessed knobs on the panel, and they have dual
functions. You hold two footswitches (printed on the panel) to
toggle between "level 1" and "level 2" functions. The knobs
are always live. Since the Vent doesn't store any user
settings, write down your knob settings as they can be disturbed
with manual handling.
I can't verify the authenticity of the power tube overdive of the
122, but it has that pleasant grungy distortion of power tube
overdrive (I'm a guitar player who knows tube guitar amps) that
sounds much better than the ratty solid state distortion of most
"overdrive" emulations in other simulators. Power tube
overdrive is a different animal than the usual preamp tube
overdrive, one of the few misses in my XK-3/XK-3c. To get the
best tube overdrive emulation, pay attention to the owner's manual
on setting the optimum signal level of your organ.
One of the reasons many Leslie simulators miss the mark is that the
Leslie is not a flat frequency device - its drivers were chosen for
optimal sound with an electric organ (if you try to use your Leslie
as a stereo to play CDs through, it will sound like poop).
This is especially true for the upper rotor, whose Jensen V21 driver
has long been critical to the sound. Another is the diffuser
in the upper rotor horn, which improves the dispersion and timbre
modulation as it rotates. Both the Vent and the CLS got this
right.
The guitar pedal case is rugged enough to place on the floor, and
compact enough to place on top of your keyboard. The
stop/slow/fast footswitch are heavy to push using the hand, a remote
footswitch is a better option. The Vent offers remote switch
configurations to work with a half moon switch (3rd party option
from Trek II), the optional Neo footswitch, or any generic latching
or non-latching footswitch. You can also use a CV pedal to
control rotor speed. Bypass switch can be hard bypass or (new
in version 2r0) soft bypass.
My only beef is the wallwart, they're fine in the studio but I was
never a fan of them on the stage. I will be looking into a
wallwart eliminator that is more rugged. The one thing that no
simulator will emulate is the three dimensional sound of a rotating
speaker in a room - you have to hear the real thing in a room to
understand.
Bottom line, Hammond players can't go wrong with a Vent whether
you're using the vintage Hammond or a clonewheel. I'm keeping
my CLS in my stage racks where everything is pre-wired and ready,
and the Vent serves its purpose very well when I am playing small
stages or showcases, or I don't need my racks. There's a
smaller Mini Vent model with fewer functions and no knobs, sold in
two versions 1) that is targeted to guitar players 2) the other
targeted to Hammond players.
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