This page is provided as a reference only.

The original Ventilator™ is no longer manufactured.  We do not have any of the original Ventilators for sale, nor do we expect to get any more of them in the future.  A replacement product is planned for sometime in 2Q/2014.

We can still perform the upgrades -- Stereo Bypass Mod, ST Barker Mod, DSP software update -- on existing Vents.

V i n t a g e
M o d e l i n g

a t  i t s  B e s t  ...



"Another Leslie simulator?" you say.  Yeah, there have been a lot of them over the years.  This one's different.  Most rotary sims are something of an afterthought, even on a Hammond Organ clone.  The Ventilator dedicates as much DSP processing power to the rotating effect as many keyboards devote to their entire sound system.


  Individually Adjustable Rotors

The Speed knob adjusts the two rotorsí velocities, and the Acceleration knob determines the acceleration and deceleration times.  As on the original, the bass and treble rotors run out of sync at slightly different speeds. Acceleration and deceleration times also differ, with the bass rotor taking much longer to speed up and slow down.  The Balance knob adjusts the relative levels of the two rotary speakers.

Tube Simulation

The Drive section is another awesome sound-sculpting tool in Ventilatorís kit. Donít expect the buzz-saw rasp of a transistor-powered fuzz; it delivers all the warmth of tube-flavored overdrive.  The Drive knob dials in everything from a touch of grit to a real rock roar, all of which can be controlled extremely dynamically via an organís volume pedal.  The Distance knob lets you, move the virtual microphones closer for lots of amplitude modulation with an intense stereo effect, or further out for a more diffuse, 'room-like' sound with gentle modulation.

  Versatile Input & Outputs

VENTILATOR comes with a mono input and a stereo output.  The Lo / Hi switch matches input gain to the signal source.  You can insert VENTILATOR between your instrument and an amp or mixing console as well as into an effects loop.

Remote Control

VENTILATOR is a stompbox by design, but you can set it on an organ or keyboard for easier access to the knobs.  Switching speeds is simple enough, either directly via the Slow / Fast stomp-switch on the device, or remotely via a half-moon or external footswitch.  If you are controlling the device remotely, you can also use a kill switch to stop the rotors.  One LED each indicates the respective rotorís current speed.

  Speaker Simulation

An elaborate filter circuit emulates the frequency response of a tube-driven cabinet with exacting precision. When using a guitar amp, simply set the switch to GIT to defeat the speaker simulation and obtain practically linear frequency response.

True Bypass

VENTILATOR comes with a true bypass designed especially for use with guitar.  This relay circuit patches the input signal directly through to the two outputs with absolutely no loss of tone or level.


Why should you buy your Ventilator from ???

  • The owner of Ashby Solutions has been using Hammond Organs and Leslie speakers for over 30 years.  He can help you dial in any sound you are looking for, from showroom clean to 'these go to 11' grunge.

  • Each Ventilator sold by Ashby Solutions is well tested prior to shipping, so you know it will work right out of the box.

  • We provide a quick-start guide in the box, showing what each of the knobs and switches does, and providing wiring charts for the most common player setups.

  • We can provide the Stereo Bypass Option at the time of sale. ( Most dealers will not perform this modification, meaning you have to take the back off the Ventilator and solder.)

  • We are the only source in North America for the ST Barker Mod.

  • can pair your Ventilator with a Dual Foot Pedal, a Halfmoon Switch or MIDI Solutions Relay for remote control.

  • We stock all the necessary options: Y-cables, spare power supplies and power cords.  Get all of your Ventilator accessories in one place.


Still not convinced?

View the   Owner's Manual or our   Quick Start Guide

Read Premier Guitar's review of the Ventilator


H E A R   T H E   V E N T I L A T O R   I N   A C T I O N

Jim Alfredson's excellent YouTube review ...


And of course, the famous Dr. Lonnie Smith demo ...


The Stereo Bypass option explained:
This mod may be necessary if you have a keyboard like the Nord Electro or Roland VR-760, or a full stereo guitar rig, and plan to bypass the Ventilator sometimes during performances.  The Ventilator still uses a mono signal -- in this case, the left/tip connection -- to create the rotary effect in stereo.  It will not create a stereo effect on the bypassed signal.

Mono Ventilator -- A mono input creates a stereo output of a mic'ed Leslie Speaker.  When in Bypass Mode, the mono input is fed to both L + R outputs.

Stereo Ventilator -- Requires a Y-cable to work properly with most keyboards (available here).  The L input creates a stereo output of a mic'ed Leslie Speaker.  When in Bypass Mode, the L + R inputs are fed to their respective outputs.

If a mono plug is used for the Input, the Ventilator works exactly the same when in Ventilator Mode; in Bypass mode, the R output will be muted.  A Stereo Mod Ventilator can still be used with a mono keyboard/guitar and amplifier.

Please note that there are two kinds of 'Y-cables' available at your local music/electronics store:  'sharing' and 'splitting' styles.  Sharing Y-cables are used to connect two headphones together, etc. and each split plug/jack gets a copy of the same signal.  All the pieces will usually be of the same color, whith no 'L' or 'R' markings.  This type of Y-cable will not work as an audio input to the Stereo Mod Ventilator.

Splitting Y-cables send the Tip and Ring to two different plugs, and the mono (TS) plugs are usually color-coded or otherwise marked to tell them apart.  A splitting style cable is needed for a Stereo Mod Ventilator.

The ST Barker™ Mod explained:
Ashby Solutions, in conjunction with NEO Instruments, has developed a Ventilator modification specifically for guitar players who use lower output pickups.

The ST Barker Mod adjusts the input gain to allow the instrument to better drive the Vent's tube amp simulator to its fullest capabilities.  While many guitars have 'hot' enough output to allow the Vent to create any tone from '50s clean to overdriven rock, some single coil pickups do not.  In particular, vintage Stratocaster® and Rickenbacker® 'toaster' pickups can't really drive into that "frying eggs" zone that many players are looking for.  (For an example, think of the guitar intro to Ringo Starr's It Don't Come Easy.)

This mod is not recommended if you use a variety of guitars with humbucking and single coil pickups.  In that case, adding 6-8dB of clean gain ahead of the Ventilator when using your single coil guitar is probably a better option.  But if you are a dedicated Strat player who doesn't want more pedals in the chain, this mod is just the ticket!

For guitarists, here's Ryan Fleming's really excellent demo of the Ventilator's features ...

[Thanks, Ryan!]

And here's another guitar demo of the famous Leslie® Grind ... without a Leslie!

[Thanks to Sean T. for his efforts!]

This demo also shows off the ST Barker Mod.  Without the mod, you'll likely need some spare clean gain ahead of the Vent to get that kind of growl out of a stock Strat or a vintage Ric.  (P.S.  The Drive knob changes thoughout the video.)


Ventilator switches explained:
The Ventilator has two foot switches on the case, and can support two more in a remote pedal or Halfmoon Switch.  However, not all functions are available in both places.  There are also two push switches on the side of the Ventilator that affect how it performs.

Function Description Vent Foot Sw Remote Sw Push Switches
Fast/Slow Rotary speed (when not bypassed) Yes Yes No
Stop Rotary effect stopped, amp and cabinet sims working No Yes No
Bypass All effects off, input passed directly to output Yes No No
Guitar Mode Bypasses cabinet sim, amp sim is still active No No Yes
High Gain Changes input(s) and outputs to guitar levels No No Yes


Remote Switch Choices
Ashby Solutions sells a variety of remote controls for the Ventilator.  Which one is right for you?  It all depends on your performance needs.  Here is an overview of their features and relative costs.

Model Type S/F
Stop 760
Ventilator Remote Foot * * * * * * * * *
C/O/T Halfmoon Switch Hand * *
C/T Halfmoon Switch Hand *  
AS 122 Style Dual Foot * *   *         *
AS 760 Style Dual Foot * * *           *
AS Single Foot *               *
AS 122 Momentary Foot   *     * *     *
AS Single Momentary Foot         *       *
AS Dual Momentary Foot         *   *   *
VENT-11 n/a * *
* *

Can the Ventilator support two remotes -- typically, a Halfmoon Switch and a floor pedal?  The general answer is, no. Some combinations of foot and hand control settings will work, but others will not.

The more tech-y answer is:  You can connect two remotes (with a 'sharing' Y cable or Y adapter), but the one that you are currently not using has to be in the Stop/Off position.  So, if you're mid-song using the Halfmoon Switch, and suddenly realize that both hands are busy and reach for the foot control, it may not work properly.  However, you could choose either switch for a particular song beforehand, and make sure that the other switch is in the Stop/Off position before starting.  And it kind of goes without saying that remotes like the C/T Halfmoon and the Ashby Solutions single footswitch won't work:  they have no Stop/Off position.

Remember that the switches on the Ventilator itself still work, regardless of what position the remote is in.  So, if the Ventilator is left on the floor as a 'stomp box,' two methods of controlling speed (the remote and the Ventilator itself) are always supported.


K O R G   B X 3 / C X 3   D E M O S

All organ demos used a digital Korg BX3 with PreAmp amp sim setting and all EQs set to '0.'  For the CX3 v1 simulations, the drawbar type was changed from Mellow to Bright, which returns to the CX3 v1 drawbar curves.  A samll amount of Dark reverb was added through the BX3.  All recordings are direct-to-disk, with no external processing or EQ.  The first half of each clip was played with drawbar setting 88 8000 000 and 3rd harmonic percussion; the second half was played with drawbar setting 88 8884 448.

  BX3/CX3 v2 Clean
Knobs at Speed = 12:00, Acceleration = 1:30, Balance = 12:00, Drive = 0, Distance = 1:30

  BX3/CX3 v2 Overdriven
Knobs at Speed = 12:00, Acceleration = 1:30, Balance = 12:00, Drive = 2:00, Distance = 1:30

  CX3 v1 Clean
Knobs at Speed = 12:00, Acceleration = 1:30, Balance = 12:00, Drive = 0, Distance = 1:30

  CX3 v1 Overdriven
Knobs at Speed = 12:00, Acceleration = 1:30, Balance = 12:00, Drive = 2:00, Distance = 1:30


G U I T A R   D E M O S

All demos used an Agile Harm 1 with Vintage Vibe P-90s, set the the middle pickup position.  The Vox AC30 used the Top Boost channel, with Treble and Bass at the 1:30 position, with a small amount of dark reverb.  No additional effects or processing were used.

  Direct Recorded Stereo
Drive and Distance at 1:30
  Vox AC30 w/Alnico Golds
Guitar setting, no Drive, Distance at 1:30
  Direct Recorded on Guitar setting
Play this one through your guitar amp to see how it will sound

Not responsible for typographical errors.  Ashby Solutions,, the Ashby Solutions logo, and ST Barker are trademarks of Ashby Solutions.  All other trademarks and registered trademarks are the property of their respective owners.

Copyright © 2001-2014 by Bruce Wahler.  If you have suggestions, please send them to