Hands-On Review:Randall RM100M Head

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Randall RM100M Head

Choose between 18 tube preamps, three at a time!

By Mikey Lank


Randall RM100M

Randall's RM100M means you no longer have to sacrifice one great tone to get another. It provides something no other amp maker has ever approached--all tube analog re-creations of the preamp sections of the world's greatest guitar amps combined with a user-maintainable all-tube power section. The preamps are hot-swappable independent modules and there are 18 available in all. The RM100 holds three at a time and each operates as an independent channel. For premium tube amp versatility, it's in a league of its own.

Modeling schmodeling

Digital technology has come a long way toward making lots of different classic guitar tones available to the average player. But to my ear all those amp models sound like cartoon caricatures of the originals. They have recognizable elements of the original amp's tone, but the real heart and soul is missing. So throughout the digital age I've stuck with my trusty old tube amps. They may not sound like other amps, but they always sound good.


With the RM100M, guys like me can have the best of both worlds. I can have the real tube ambience of a classic Blackface, the searing scream of a stack, and the rich distortion of a Boogie all in the same head, all analog, and all tube! Essentially it is amp modeling, but it's physical amp modeling--using the same types of capacitors and circuitry as the original amps--including a pair of 12AX7s--to duplicate sonic characteristics without losing the essential organic analog warmth that made these amps great in the first place.

Boutique features

The RM100M is not just a 100W tube docking station for these smokin' little preamps. In fact, its features far surpass even very high-end boutique amps. On the front, an effects wet-and-dry knob controls the parallel effects loop, which features dedicated tubes to warm up the signal from brittle digital effects before it goes to the power section. Discrete signal paths send wet and dry signals into the power amp separately, so you can keep the in-your-face dry sound and mix in the precise level of effects you want. There's also a serial effects loop, which is good for overall conditioning effects such as compressors and noise gates.


The front-panel presence knob lends brilliant three-dimensionality to the vintage-style modules and makes the more modern modules really sparkle on the high end. The density control knob controls the overall bass. Together, the presence and density knobs operate similar to a two-band EQ. There are also a master volume, standby switch, and power switch on the front.


On the back, the RM100M really comes through as a player's amp. Each of the Ruby EL34 power tubes is accompanied by its own LED, fuse, test point, and easily accessible bias control. If a tube goes out, it will automatically be bypassed without interrupting your performance and its LED will light up to alert you. Then you simply pull out the tube and plug in a new one. Using a standard voltmeter, you measure its bias from the handy test point and adjust with the bias control. This easy biasing means you don't need matched tubes. You can simply adjust the bias and match them up yourself. Finally, you don't have to be a tech to keep your amp tiptop. Yes!


Other goodies around back include a universal voltage selector so you can take the RM100M anywhere in the world, MIDI in and through, and a slave line out for recording or sending to the mains. The included RF3 MIDI footswitch not only selects between preamps but also lets you couple external effects with each channel via the MIDI through jack. I've never played another amp with such powerful accessibility and flexibility for a working musician.

Mondo modules

Rest assured, Randall's module system is no hollow gimmick. These preamps are radically different from one another. It's obvious just looking at the modules that each has its own unique circuitry. When you plug them in, their gain levels are very different and their responses to knob tweaks vary greatly. The impact when I first switched between them was a heavy cognitive dissonance. It was almost eerie that such widely divergent tones could come out of the same amp.


The modules I checked out were all first-rate interpretations of the amps they were modeled after: Brown--I felt the spirit of Eddie flowing through my fingers as I tapped my way through a badly butchered rendition of "Eruption." My hands weren't up to the task, but this emulation of a hot-rodded Plexi with awesome midrange sustain certainly was. The Brown will definitely be a favorite of grungy folk as well. Recto--thick, rich distortion with great definition and hair-trigger responsiveness came pouring out of this module. Designed after the Mesa/Boogie Dual Rectifier, it is a scary likeness. SL+--Punchier and a bit more high-gain than the Marshall Super Lead it's designed after, this module really made me feel like a stadium crowd slayer. You metal fiends will definitely dig this one, but it's big, bold sound is also great for rockin' blues from Eric to Billy G. Blackface--this one is so closely designed after its Fender classic namesake that I couldn't hear the difference in a side-by-side test. The knob response was slightly different, but I had no trouble dialing in my favorite tones--from glassy clean tones to gritty, bluesey overdrive.


Every player is different, but it looks to me like Randall has created the ultimate amp--every amp you ever wanted with super-high-quality real tube circuitry. How can you go wrong with that?

Features & Specs:



  • Holds any 3 of Randall's preamp modules
  • 100 Watts
  • EL34 Ruby Power tubes
  • MIDI in/thru
  • Master Volume, Presence, Density controls
  • Parallel loop with front panel mix control
  • Series loop
  • Individual tube biasing controls and test points
  • Individual tube status LEDs
  • Individual tube fuses
  • Slave out
  • 3-button MIDI footswitch included
  • Slotted grille front

Available Randall preamp modules:

  • Ultra
  • Modern
  • Brown
  • Clean
  • Recto
  • SL+
  • Plexi
  • JTM
  • Top Boost
  • Tweed
  • Blackface
  • DLX
  • XTC
  • 1086
  • Mr. Scary
  • Grail
  • Brahma
  • Super V