Randall RM 20 B

Randall RM 20 B

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RM 20 B, Tube Combo Guitar Amp from Randall.

2 user reviews
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Randall RM 20 B tech. sheet

  • Manufacturer: Randall
  • Model: RM 20 B
  • Category: Tube Combo Guitar Amps
  • Added in our database on: 02/23/2007

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Randall RM 20 B user reviews

Average Score:4.0( 4/5 based on 2 reviews )
 2 reviews100 %

iamqman's review"Nice little package"

Randall RM 20 B
Randall has really taken a hold on the module industry. Them and Egnater have really grabbed the preamp modules and owned the entire market of this industry. You can basically put any type of preamp sound you can think of in this unit, because there probably is a preamp design out there that will do any sound that you want. Now there are builders strickly just for modules.

With this little unit you can take one of your favorite preamp and insert it into the power shell. If you don't like the preamp voicing or toe then simple take it out and try a different one.

Honestly this has been such a breakthrough design in recent years. Since there is no much musical influence nowadays , many guitars have influences that go from one end of the spectrum to the other. Finding and amp that can do all of that is pretty much impossible. Well until now it has been impossible.

Randall MTS RM20B 15-watt Tube Compo Amplifier Features:

* Single modular channel
* 15 watts
* Ruby EL84 power tubes
* 12" Celestion Greenback speaker
* Master Density and Presence controls
* Footswitchable Tube Boost function
* Boost Gain control for desired distortion
* Boost Level control to adjust the boost volume
* Dual function Standby switch for live and silent mode
* Series effects loop
* XLR Mic Eliminator direct output
* 8/16-ohm extension speaker output
* Slave output
* Rear panel power tube bias test points.
* World voltage AC input selector


Type Tube
Number of Channels 1
Power 15W
Speakers 1 x 12" Celestion Greenback
No Effects
No Reverb
No Amp Modeling
No Preamp Tubes
Power Tubes 2 x EL84
Inputs 1 x Instrument
No Outputs
Footswitch I/O
Effects Loop No Effects Loop


This is really a preamp shell. There are no tones at all in this amp. You must go out and buy from Randall or Egnater the preamp voicings that you want. You have three options to put in the slots provided. Randall has built just about any preamp module you can think of. So it can take come exploring and trial and error to find the right one you want for your sound.

One of my favorite modules is the Mr.Scary from George Lynch. I really love that module a lot. It is thick and fat sounding and turns even the most ordinary guitar into a shredder. If you don't like the preamp module you can always dump it and try something else and a minimal cost. Guys on the internet are always buying and selling modules to find that sweet spot in their guitar rig.


One great thin that is offered in this shell is the depth control. I wish Marshall and other amps would start putting this standard on their amps. So much of time I find trying to nail that low end which can be absent from a lot of guitars. The shell has the density knob which is basically the same thing.

At new these amps come in at around $770, which isn't bad for a shell power amp combo. You can pick up modules for around $200 to $300 depending on which one it is. They are sort of about the price of a good stompbox pedal so I guess you could look at it this way. You generally add pedals to an amps so you are adding preamps t your power amp.
Audiofanzine FR11/04/2008

Audiofanzine FR's review

Randall RM 20 B
(Originally written by Cko74/translated from Audiofanzine FR)

20-watt all-tube amp.
Connections: FX loop, Line Out, Footswitch Boost, External Speaker 8/16 Ohms, Guitar Input and a clever system to allow you to set the tubes bias.
Controls: Gain, Volume, Boost Gain, Boost Level, Presence, Density, Treble, Middle and Bass. 3-way standby selector: Silent, Off, Live (I don't understand the difference between off and silent). On/Off switch.
No effects, only one channel.
This amp works with different preamp stages so you can exchange it in a few seconds. This model has only one module slot.
I own the Ultra Lead module, my guitar is a Custom 77 China Girl CS2 (SG type)


Easy setting: just turn the controls to find your own tone.
It was hard for me to find a "good sound" and I'm not totally satisfied yet. No user's manual was provided with the amp.


The amp suits all styles from hard rock to heavy metal. The amp has no real clean sound even if you turn down the knobs on your guitar. It always has a hint of crunch (which I love ^^) and it is perhaps a bit too "fat" for blues. But I already knew I'd only have one channel when I bought it.
I like the sounds of the preamp stage but would prefer a more bluesy tone.


Very good amp!
Only critic: it's price. It's expensive even without preamp module!

I recommend it if you have the money.

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