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When we reviewed the Randall Thrasher in the February 2014 issue of Guitar World, we discovered that Randall was making some fascinating low-wattage high-gain amps as part of its Diavlo Series.
A few weeks later, the new RD5H head and RD112-D cabinet arrived at our studio so we could put them through their paces.
While the Thrasher is a fire-breathing beast for the biggest concert stages, the RD5H Diavlo is designed primarily for the recording studio or practice when you want massive-sounding, highly saturated gain tones but don’t need 130dB to get your point across.
The RD5H is a five-watt all-tube head featuring one 6V6 power amp tube and two 12AX7 preamp tubes. The amp’s selection of controls is about as simple as it gets, consisting of gain, tone and master volume knobs, but an ingenious three-way tone stack shift mini-toggle switch allows the amp to produce a surprisingly wide variety of tones. The RD5H also features an excellent Class A discrete instrument-level effect loop that works particularly well with pedals and instrument-level rack gear. For direct-recording applications, the amp includes a speaker-emulated XLR output with a ground-lift switch.
Randall offers a variety of speaker cabinets that make a great match for the RD5H, but we were drawn to the RD112-D, which has a Randall-designed 50-watt eight-ohm 12-inch speaker. The cabinet itself is much bigger than the average 1x12 cabs designed to go with mini amp heads, and the speaker is protected by a metal diamond-shaped mesh grille like certain classic speaker cabs from the late Eighties. The front baffle is angled to project sound upward and enhance treble response, and the totally sealed closed back and two ports at the lower corners deliver tight, focused bass. Randall also offers the RD112-V30 with a Celestion V30 speaker installed in it.
After plugging into the RD5H and RD112-D rig and turning everything all the way up, I was astonished at just how loud a little five-watt amp driven by a single 6V6 tube can be. The cabinet is the magic part of the equation. I tried it with a few other mini-amp heads I own and was blown away by how much louder and bigger those amps sounded. This is the only 1x12 cab I’ve used in the past 20 years that sounds awfully damn close to a 4x12. The Randall speaker sounds absolutely huge, and it’s hard to imagine a Celestion V30 providing a significant improvement.
The RD5H absolutely excels at high-gain distortion tones. With the master volume turned up all the way, the 6V6 gets pushed to that wonderful balance of crunch and crisp definition. The gain control adds extra layers of harmonic sizzle, but that glorious power-tube distortion remains the dominant force throughout. The tone control provides an impressive sweep, from fat midrange to razor-sharp highs. However, the tone stack shift switch is the best way to instantly dial in the tones you want, as it provides a mid-boost setting (perfect for solos), a “stock” position with even bass, mid and treble response (probably the setting most players will prefer), and a scooped-mid setting that sounds absolutely massive thanks to the RD112-D’s incredibly tight and deep bass response.
I also tried the RD-110D 1x10 cab and one-watt RD1H, which together make a fun and considerably quieter metal rig that’s ideal for apartment dwellers. The RD-110D also paired nicely with the RD5H for fat midrange solo tones, which makes it a useful color to add to one’s palate in the studio. But for the full meal deal, the RD5H and RD112-D are the way to go.
List Price RD5H, $449.99; RD112-D, $374.99
Manufacturer Randall Amplifiers, randallamplifiers.com
The RD5H is a high-gain five-watt head with a versatile three-way tone stack shift switch, speaker-emulated XLR output and effect loop.
The RD112-D 1x12 cabinet contains Randall’s own specially voiced 50-watt, eight-ohm 12-inch speaker in a large cabinet with bass ports and an angled baffle.
The Bottom Line
With its outrageous high-gain tones and pro features, the Randall RD5H is a testament to the saying “good things come in small packages.”