Tube Reverb

"Old school, tube-driven, spring reverb rack effect"



The Tube Reverb rack effect module is an old-school, all-tube spring reverb, similar to those found in vintage Fender amps.  Use it like any other rack effect module, or get it without switching for studio use.  Choose your reverb tank.



The Tube Reverb is an all-tube reverb similar to the vintage reverbs of the 60's, and those still found in some current tube amps.  It is not a copy of any particular vintage reverb.  It is similar in some ways to the Fender Twin Reverb or '63 Fender Reverb, particularly if using a Type 4 tank, but it is still not the same as either of those.  It fills an entire 3U Enclosure and requires both 120V AC wall power and our standard 18V DC module power.  It connects into your signal chain and GT switching just like other GT effect modules.  It also has the same footswitch override option so you can have it always on without using a footswitch.

When the effect is not engaged, it is completely bypassed, just like our other modules.  However when it is engaged, there is also a manual reverb switch on the front.  You get reverb when that switch is on Reverb.  Otherwise the switch is on Buffer and your signal will still pass through a tube buffer.  Turning the switch to Buffer will immediately stop all reverb, including "tails".

There is also an included footswitch that is intended primarily for use if the reverb is purchased without the GT switching, as a standalone rack reverb (contact us to discuss if you are interested in that).  That footswitch turns off reverb - your signal will still pass through a tube buffer.  However, when you switch the reverb off with that footswitch, you will get "tails", as the reverb will continue until it fades out.  You can use this footswitch either with or without the usual switching footswitch.  If you use the footswitch override to keep it always on, then the extra footswitch will change the effect between reverb and a tube buffer (with tails).  If you don't care about tails or tube buffering, you can leave the switch on Reverb and just turn the effect on/off with the footswitch.  Or leave it always on with the footswitch override.  Like the normal GT footswitches, the Tube Reverb footswitch is used only for switching.  Your audio signal does not go to the footswitch.

This unit is wired old-school style with terminal strips.  Shielded cabling is used.  Modern versions of vintage style caps are used.  Carbon comp resistors are used, but can be replaced with metal film on request.  It is a pretty quiet unit, so it sounds OK without the quieter metal film resistors.  If you want specific types of caps like Sozo or something, choose the Custom Components option and let us know.  If we can get them we'll put them in there.  There may be some additional cost, depending on what you choose.

The reverb unit hangs from springs inside the reverb tank.  Be careful when moving the unit that you don't bounce it off the springs.  If you do, you'll have to remove the tank and hook them up again.  Although the reverb unit is suspended by springs to absorb shock, you can still pick up unwanted noise from vibration.  Do not place the Tube Reverb on top of a speaker or other source of vibration.

By default you will get a 9AB3C1B tank.  Any 9ABxC1B or 4ABxC1B tank should work, where x is 1, 2, or 3.  The "x" value determines the decay time of the tank. Short (1) is 1.2 - 2.0 seconds.  Medium (2) is 1.75 - 3.0 seconds.  Long (3) is 2.75 - 4.0 seconds.  The Long decay time is recommended for guitars, the shorter ones for other instruments or vocals.  The difference between the "9" and "4" series is the number of springs.  The "9" uses six springs and the "4" uses four springs.  Fender Twin Reverb amps use type 4, as a reference point.  The more springs, the richer and fuller the reverb.

There are four tubes in the circuit.  V1, V3, and V4 are 12AX7 tubes.  V2 is a 12AT7.  JJ brand tubes are used by default.  You can always swap tubes, just like in a tube amp.  Just be sure to use tubes compatible with what is expected in each position.  Like a good tube amp, this unit can take a little while to "break in".  During that time the components are adjusting to each other and reaching their stable points.  The tone can change quite a lot during that process.  They can sound bland to crappy at first, but even just one hour of playing can make a big difference.  After several hours of playing, the break-in will be largely complete and it should sound great after that.  So play it for a few days to let it break-in properly.  Also do that if you swap tubes.  Give it some time to adjust.

There aren't many options.  You get Dwell, Tone, and Reverb controls, as well as the Reverb/Buffer switch and the "tails" footswitch.

Also note that due to the use of AC power and old-style construction, there are no user-serviceable parts other than tubes and the fuse.  We can perform repairs if you need them, as can any good tube-amp repair shop.  We can supply parts if you choose a local repair shop.  Contact us for details.

WARNING - There is an issue you should be aware of when considering our Tube Reverb module.  The module is not inspected or certified by any third party for safety.  While we certainly wouldn't knowingly sell something that would in any way harm or endanger our customers or anyone else, it would be irresponsible of us to lead you to believe that we have any kind of safety certification.  We are not listed by Underwriter Laboratories (UL) or any other third party.  If you do use our Tube Reverb module, you do so at your own risk knowing that a malfunction could injure or kill you or others.  We believe that is always possible with electric products, but with reputable third party certifications you can expect the chance of that to be very low.  We have not had any such reviews or certifications, so we cannot make any factual claim about how dangerous or deadly this module could be.  In the years we've been building and using them we have never had any malfunction of any kind, but that may not be a reliable indication that the module is safe to use.  We want to be very clear about our lack of a safety certification so you can make an informed decision about using this particular module.



  • Tube Reverb - compares to vintage tube-driven spring reverbs



You can have a tube buffer on when the reverb is off, but it is switchable.



  • Tank - You can select from the following reverb tanks. 

4AB1C1B - 4 springs, short decay

4AB2C1B - 4 springs, medium decay

4AB3C1B - 4 springs, long decay (recommended)

9AB1C1B - 6 springs, short decay

9AB2C1B - 6 springs, medium decay

9AB3C1B - 6 springs, long decay (recommended, default)

  • Custom Tubes - If you prefer something other than JJ tubes, choose this option. 
  • No Tubes - If you have tubes you prefer to use, select this option and we won't include any tubes.
  • Custom Components - Select this if you want to customize the resistors or capacitors to use particular brands


Front Panel

  • Dwell
  • Tone
  • Reverb
  • Reverb/Buffer switch
  • Footswitch jack
  • Main Power


Rear Panel

  • Audio In
  • Audio Out
  • On/Off Footswitch
  • On/Off Override
  • DC Power
  • DC Power LED
  • 120V AC Power
  • Fuse


Module Width

The module uses the full 17" of the 3U enclosure and includes both left and right wing on the front panel


Power Consumption (aprox)

7 - 15mA


Base Configurations

Part # Description List Price
MOD-TREV Tube Reverb module $699



Part # Description List Price
MOPT-TREV-CC Component Changes $TBD



No user-serviceable parts other than tubes - contact us for details.