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Operation. Whilst tweakers may salivate at the sight of an exotic tube amp, tweaking is not on the menu. Aside from custom feet and maybe some Walker resonance control discs, the only thing to do is sit back and enjoy the music. There aren't any meters to monitor or bias adjustments to fret over. Operation is extraordinarily simple. The master power switch is on the rear is generally left on. The push-button switch on the front brings the amp out of sleep mode and activates the auto bias. Within seconds you are listening to music. During the entire 10-second process an indicator light first turns red, then green for ready. A second touch of the button shuts the amp down and places it back into sleep mode. If you use the amp regularly, leave the master switch on and merely use the push button. As with all equipment in my system, the Kronzillas were powered from my Equi-Tech 10WQ balanced power system. The Krons reacted especially well to balanced power by reducing their already low noise floor whilst tightening and extending the low end. Balanced power does not change the core character of a component. It does though—-and I'd say rather dramatically—improve many of the aspects of that inherent character.


The warm-up sound change was minimal, with the amp hitting its stride about 30- 60 minutes later. Whilst running in a normally lit room, the only indication of operation is the single green front light. Contrary to the evocation and implication of the Kronzilla name,operation is smooth, benign and thankfully uneventful. The amps under review were review samples and with previous use did not require break-in. According to Eunice, a new pair of DXL typically require 200 hours to sound their best.

Sound. Its SET brethren need to be carefully matched to an appropriate speaker. Not so the DXL. It's got balls. With their relatively high sensitivity, the Wilson Audio Alexandrias were effortlessly driven in my medium/large 6.000cu.ft. room. I was easily able to exceed 100dB without distortion, congestion or compression. The Kronzillas and Alexandrias were an outstanding match. Peter Breuninger evaluated the same review pair in his listening room with his MBL 101E MkII and the exciting new YG Sonja. With a sensitivity of 81dB and nominal impedance of 4Ω, the DXL were not a synergistic match for the bearish MBLs but Peter stated they were "magical" with the 88dB Sonjas.


I previously stated and still believe that no matter the neutrality of our intentions, we all bring a bias to building a system or any audition. An amplifier with a pair of twin triodes no matter how large invokes certain old-style SET prejudices both pro and con. Already the first listen dispelled that notion. The Krons with their twin triode tube towers (try saying that fast) redefined it. The first session was a shockingly good surprise. They sounded spectacular top to bottom. To be frank, the DXL do display certain traditional SET virtues like micro dynamics, the flow from one note to the next, that midrange magic and musical decays. But this is not your typical SET or triode sound since there's also extension, deep bass, low-end grip and PraT for seemingly the best of both worlds – SET strengths without their well-documented weaknesses. No blindfolded listener would ever categorize this as a classic triode sound.

Bass. The bottom end is real and visceral. It might not be the final word for resolution and control compared to the very best transistor amp but you will not find it lacking. The bass on Ray Brown's "Cry Me a River" from Soular Energy [Pure Audiophile] was shocking with a solid grip, deep and redolent without the flabbiness of some tube designs. A good test of your bass response are the drum whacks of Jennifer Warnes' "Way Down Deep" from The Hunter [Cisco Music], mixing a killer combination of deep resonant low bass with Warnes’ unique voice. The balance was just right and I sat enthralled with an unconscious silly grin. While the low bass did not match the Tenor 350s, it was outrageously good for a tube amp and excellent by any standard. Overall the amps tend towards a neutral tonal balance. If forced to characterize the sound, it would fall on the ever so slight side of warm but certainly not overly so and never romantic or syrupy.


Harmonics/resolution. Tubes, especially triodes, tend toward rich harmonics with wonderful decay and air. I remember reading a theory describing a sonic conflict in some tube amps where their naturally long decay 'collide' with incoming transients for a smearing effect that reduces detail. I’m no engineer and cannot scientifically prove or disprove the theory but I do know that only the very best tube amps such as the DXL combine rich harmonics, decay, air and resolution. The Kronzillas successfully walked this thin line between these often contradictory goals.

Instruments appeared physically stable in space, separated and surrounded by well-defined air. Some solid state might give the illusion of greater resolution but sometimes reflects a more skeletal nature of musical outlines where the DXL filled in the outlines in bold rich colors. Some of the highest resolution components clearly delineate instruments but don’t always distinguish between their tonal colors to produce a cool sound. A segment of listeners might enjoy this type of presentation but I on the other hand like my music fully fleshed out which demands harmonic richness. High resolution can produce a precise but flat sound. The DXL is the antithesis and immersive, alive and vivid. Many amps tend to lean to one side or the other. It’s a fine delicate balance to straddle between resolution and correct harmonic structure and the DXL elegantly navigate these tricky waters.

Every amplifier and component has its own unique sound. Whilst each might be enjoyable, they can’t possible all be 'right'. Hence each trades off one type of distortion for another. Some tube amps offer a very euphonic pleasant distortion of warmth which often is low bass distortion and mid-bass blurring. It’s generally even-order distortion and therefore less egregious but distortion nonetheless. The hybrid Kronzillas nicely balance warmth with bass resolution, providing the distinct bass lines and clarity generally associated with transistor amps.

In the world of tube-based power amplifiers, the DXL top-to-bottom resolution is world class and on the level of the best OTL amps I've heard. In absolute terms the Kronzillas’ resolution is elite as good as the best solid state? Tough to say but probably a degree below the most expensive transistor amps. Unless you compared by direct contrast however you won’t find the Kronzillas lacking. The Krons clearly display the microdynamic gradations in music as those tiny delicate shifts which define musical textures moment to moment. It’s the difference between a low and high-resolution digital photo. Low res might convey the picture but tonal variations are chunky and coarse. Small transitional areas are homogenized. Contrast that to high-resolution images with almost infinite smoothness and better gradated image tones. The analogy holds with amplifiers and especially the Kronzillas.