Cuter than a pit bull pup, this shiny and dangerous mini-stack is also an appealing living room rig for anyone who loves wonderfully compressed shred tones with plenty of low end that cut like a saber saw yet won’t shatter windows. The amp also has a useful and articulate clean channel, though, at a recent rehearsal, a veteran bassist accused this setting of sounding a tad shallow. I reminded him that the trunk on a 911 Carrera is shallow too, but you don’t buy a Porsche for cargo space. I wanted to show this critic what the amp is really for by kicking the Krank channel into high gear with an authoritative stomp of my foot and then “screeching my tires” with an asphalt-melting sequence of speed metal power chords. Unfortunately, the Rev JR doesn’t actually have a footswitch—which is surprising for a two-channel amp retailing in the quadruple digits. (To change modes, press the front-panel channel-select switch.) Tip: To get the most lava out of the lead channel’s two 12AX7 preamp tubes, be sure to engage the Boost switch and the tube-driven effects loop, even when nothing’s in the loop. Then dime the loop level knob, and the amp will erupt with thoroughly saturated Darrell Abbot-approved mosh metal mayhem. Sick!

My only qualms with the Rev JR result from some simple design oversights. For instance, while the aesthetically pleasing chromed-out speaker grills are attached only by Velcro (to give you quick access to the front-mounted speakers), they can’t be yanked out without first removing two of the solid poplar cabinet’s metal corner protectors. Also, the two PCB-mounted 6L6 power tubes are installed so close together you can hardly get a Fender Heavy between them. This suggests less than optimal heat dissipation and a small risk of broken glass if the amp ever takes a nasty knock (though Krank has already shipped hundreds of JRs with zero reports of cracked tubes). Also, because the poplar cab is so small, the tubes can’t be removed and replaced without first removing the entire amp chassis.

Unraveling the mystery of this perplexingly inconvenient tube setup was as easy as calling Krank’s Arizona headquarters. The amp, a Krank designer admitted freely, was originally designed for shorter, narrower, easily yank-able 6V6s, but the company later opted for 6L6s to more closely match the tone and reliability of their 6L6-powered Revolution heads. Krank’s spirit of full disclosure—a rarity in the manufacturing industry—is refreshing. It suggests that like the ambitious and adaptable young company that designed it, the Rev JR will see improvement with each new “rev.”

Kudos Monstrous metal tones, miniature stack. Decent clean channel. Cute.

Concerns No footswitch. Poor power tube access.

Contact  Krank Amplification, (888) 572-6548, krankamps.com