Hands-On Review:Back in Rack- Randall Modular Tube System.

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by Eric Kirkland

Digital modeling amps exist for players who want or need a palette of diverse sounds. But what comparable device serves the tube devotees who don't want to sacrifice an ounce of analog tone?

No worries, mates, Randall has the rig for you. Sired by Bruce Egnater, the magician of high-gain and amplifier arts, the all-new Modular Tube System (MTS) makes it possible to enjoy the tones of your favorite amplifiers by simply loading cartridge-like modules into the system's groundbreaking RM4 modular tube preamp. Each module is loaded with two 12AX7 tubes and, for unparalleled realism, contains the actual tone-shaping circuits of the original amps. What's more, Randall has included some exciting new tones in its module lineup, and more modules are slated to come in the near future.

Test System Tour
The MTS consists of the RT2/50 MIDI Switching Tube Amplifier, the RM4 Modular Tube Preamp and the 12 currently available MTS modules. For this review, I tested all 12 modules. From my own equipment, I used two Marshall 4x12s, with vintage Greenbacks and 75-watt Celestions, cable from Cardas Audio, a Relic Strat and a PRS Custom 24.

The dynamic and rich RT2/50 power amp provides more than enough juice and comes with my highest recommendation for tone, features and layout. (Randall also offers a solid-state power amp option, the RP2/200.) This hard-hitting stereo heavyweight is driven by four horizontally mounted 6L6s and three 12AX7s, and pushes 50 watts per side. Channel-specific controls for volume, presence and density give players a tight grip on tone and response, and controls for presence and density let them dial in the desired amount of high-end accentuation and bass, respectively. When employing the RT2/50, I found that these two latter controls were best used for obtaining an optimal level of definition-tightness or looseness-separate from the preamp controls.

In order to accommodate players' many stylistic needs, the RT2/50 accepts a variety of power tubes, including the EL34, 5881 and 6550. And there's good news for anyone who knows how to use a digital volt/ohm meter: Randall's engineers wisely included test points and bias adjustments right on the front panel-wahoo! This feature's placement makes it very easy for players to stay in front of the amp and set the bias for the best possible tone. Alongside the test points sit the main fuses and tube-failure indicator LEDs. The positioning of these features is especially convenient, as it can save time and hassle in an emergency.

Located on the unit's back are MIDI in and thru connections, two speaker outs for each channel, an input for each channel and a mono/stereo mode switch. A MIDI footswitch, included with the RM4 preamp, can be programmed so that one channel of power tubes on the amplifier is activated when you select a specified module. For instance, when you're running the Plexi module you might want to have the footswitch programmed so that it also selects the amplifier channel that utilizes the EL34s. It doesn't get any better than that!

At the core of the MTS is the RM4 Modular Tube Preamp. It provides slots for four modules and takes advantage of many well-engineered features. Its faceplate houses a channel select button, a single instrument input and controls for effects mix and master volume. You can switch from one module to the next by pushing the channel select button or by using the included programmable footswitch. The RM4's backside offers easy access to the unit's three preamp tubes, MIDI footswitch connections and the rocker-type power switch. Also featured are separate parallel and series effects loops with their own send and return jacks, a pre-loop output, two post-loop outputs and a single input (all the jacks are the common 1/4-inch type). Note that bypassing the loop via the pre-loop output creates a slightly tighter and faster response from the amp.

Inside, the RM4 has a single 12AX7 that is common to all modules in the preamp's input stage. In addition, the unit has two tubes to buffer the effects loop for a natural presentation that so many effects lack. This is one of the keys to achieving the superior effects sounds of your favorite guitarists.

Plug and Play Modules
Randall's 12 available modules are Tweed, Blackface, Deluxe, Clean, JTM, Plexi, Brown, SL+, Top Boost, Recto, Modern and Ultra. Each module is chrome-paneled and has identical controls, which include gain, bass, mid, treble, master and a bright switch. To swap one module for another, simply loosen its two thumbscrews and pull. You can then insert another module-two plastic guides assure error-free alignment and precise seating-tighten the thumbscrews and be ready to roll.

Tonal Breakdown
All the modules offer impressive sonic attributes and flexibility. I found that these re-creations of well-known circuits, when coupled with the RT2/50 tube amplifier, were often accurate enough to handily replace the vintage classics. Here's a basic description of each:

Clean is a modern tone, with sparkling clarity that's stiffer and more defined than that of early Fender types. You funk guys will dig this one for its projection and control. The Blackface and Deluxe are very similar, with warmth and organic tones to spare. As expected, the Deluxe has more "give," while the Blackface delivers extra "punch." Turn the gain to about half with either of these and you'll be blown away by the smoky hues of the early, naturally compressing Fenders.

The Tweed module is just plain fun. Dial the gain high and enjoy true-to-life ZZ Top and Buddy Guy tones. Notes swell on singing bends, and chords are nasty and loose, with no buzz. Keep the bright switch off, add an overdrive and you'll have a lead machine that will astound audiences and take your playing to another level. The Top Boost module is incredible with the bright switch engaged, where it re-creates the harmonics and easy play of the Vox amplifier (although there may be a little less gain here than on the original).

If Marshall is your thing, the MTS includes a number of modules that will satisfy you. The Plexi is hard driving and a little smoother than the crunch of the classic amplifier, and sounds best with the loop bypassed. The JTM module will take you on a quick ride to old, stinging Marshall tones. Crank the gain and master on this one and you'll revisit the sounds that made Clapton a legend.

While the Brown module faithfully rendered the basic Van Halen tone that so many admire, I preferred the SL+ module for re-creating EVH sounds. This circuit starts with the Super Lead EQ and adds extra gain, creating a modified flavor that dampens some of the high end, a sound for which the Super Lead is famous. Since the SL+ has plenty of bite on its own, I rarely used the bright switch with this one. If you reduce the density at the power amp for a tight midrange and adjust the presence with regard to your attack, you'll be rewarded with a Seventies Marshall tone that is better than the original in many respects.

For really high gain, there are three choices: Recto, Modern and Ultra. Recto provides you with plenty of Mesa-inspired mayhem, while the all-new Modern circuit takes a Vox EQ and mates it with super distortion. Ultra is also new and obviously the result of Mr. Egnater's insatiable appetite for gain; it features a searing lava flow of distortion that must be played to be appreciated.

The Bottom Line
There's no doubt that by combining the RT2/50 power amp with the RM4 modular preamp and modules you can create an all-tube guitar system capable of eclipsing digital amplifier performance and rivaling the amps it emulates. By providing accurate circuits in an intelligent framework, Randall has raised the bar for all channel-switching amplifiers, rack mount or otherwise. These reasonably priced visionary products offer the sound quality and versatility found in top studios while honoring the aesthetics and tonal heritage of classic tube amplifiers.


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