**
This review was written over the summer, was originally intended for publication in a Gear E-Mag, and is written in a style appropriate for that use... so it may seem a little hokey here on TB... but I feel that there are enough people who this amp may appeal to that I'm just gonna go ahead and post it here in its original form. Enjoy!
July 18, 2010
Krank Dirty Valve D-800 Amplifier & Basszilla Cabinet 
These days, it seems many manufacturers vie for the crown of the “Everything to Everyone” bass amplifier. Shiny, 4lb amps with better than a dozen controls and multi-function footswitches seem to be the order of the day for the modern working bassist. Then, every once in a while, a company produces a product designed to appeal to only a very few out of the crowd. Krank Amplifiers, one of the most visible newcomers to the world of high-gain guitar amplifiers, has made a bold stroke with their first entry into the Electric Bass market - The Dirty Valve D-800 - A bass-specific hybrid amplifier shamelessly labeled as “An amp for the rock and metal guys”. Amen. But of what variety is this amp? High-tech Class-D featherweight? Old-school turret-board tubester? A closer look reveals that the D-800 and its companion cabinet, affectionately titled “Basszilla”, may be slightly harder to classify....
Approaching the D-800 takes a bit of caution. The first thing you’ll notice is the black “go-faster” splatter paint graphics on the 3RU, brushed aluminum chassis. Although I’ve never been a fan of flame graphics splashed across the front of a 70's Camaro, the garish garb of the Dirty Valve did invoke a certain boyish excitement, especially when closer inspection revealed tiny, bright red skulls take the place of the white position markers past the 12 o’clock point on the Volume and Master knobs. The overall effect is that of an Aguilar DB750 dressed in scary-clown makeup for Halloween.... Krank isn’t kidding when they call this a rockers-only rig, if only in that no self respecting Gospel player would be caught dead lugging this thru the door at the local megachurch....
For all the faceplate flair, the D-800's controls are plainly laid out.
Volume or gain controls the input signal from either of the amp’s inputs, labeled for passive or active pickups (-20db).
Treble,
Midrange &
Bass controls are arranged in that order left to right, guitar amp style. Next comes Krank’s Proprietary “
Sweep” control, flanked on both sides by bright red push-buttons marked
Girth and
Midpunch. Next up is the
Fat Growl knob, a Dirty-Valve exclusive, and final push-button marked
Brite bookend the amp’s Master Volume control. Grinning red skulls and all.
Popping off the amp’s well secured cover revealed a mixture of 70's muscle and ultra-modern tech. Attached directly to the faceplate potentiometers and secured to the chassis at all four corners is a single, very thick, two-sided PCB with two JJ 12AT7 tubes mounted vertically at either end. When asked about the choice of the lower-gain 12AT7 instead of the more popular 12AX7, Krank stated that, due to the very high-gain nature of the circuit, they found the 12AT7 to have a smoother and more controllable overdrive characteristic in testing.** I was pleased (and surprised) to find both tubes sitting atop high quality ceramic sockets. The rest of the PCB was sparsely populated, save a few large resistors and an two gigantic power supply filter capacitors, rated at 10,000 uF each. These, when viewed next to what may be the largest toroidal power supply transformer I think I’ve ever seen in an integrated bass amp, promised huge performance, but this is where the old-school stops and the new school begins. Nestled in a rear corner were two very smallish, very new-school looking Hypex branded class-D power output modules. The tiny, surface-mount chipsets and Tungsten blue heat sinks looked distinctly out of place in the amp’s otherwise sparse and muscular looking interior. This is a rare, although not unheard of combination of linear power supply and Class-D output boards. The now famous Aguilar AG500 won over an army of Class-D converts in just this fashion. The two output units are bridged together and wired to two parallel Neutrik combination Speakon and 1/4 outputs. Another small PCB mounted to the rear of the amp holds a transformer balanced DI out, tapped directly from the preamp (post-EQ of course!), and possessing its own rotary level out control. Another very nice touch.
The Test Drive-
With all controls set flat, the D-800 had a very even, very tubey tone, while being slightly shy in the treble region. The tone controls, being all tube driven, were subtle and somewhat interactive in that cutting
Mid made
Bass adjustments seem more dramatic. This behavior will be familiar to those who’ve spent time with tube guitar heads. Moving east on the control panel we are confronted with some less familiar goodies....
Girth does just what you think it should, and shunts in a wide, mild boost in the lowest frequencies. “
Sweep” is Krank’s proprietary passive midrange tweak-tool.... found on all Krank models. Running it through the range, I get the impression of a wave running horizontally left to right across the frequency spectrum... boosting a wide band of frequencies and cutting a narrower band behind it as it travels. This control can give you a bunch of really nifty, punchy sounds, and a few bad ones... “
Sweep” alters the EQ curve so dramatically that, if your Midrange settings are too high, certain settings can sound downright tinny and obnoxious. This is a very powerful control and should be used with caution. Krank describes their
Midpunch button as re-voicing the stack for a classic dirty overdriven tone. This is an understatement. Functionally the
Midpunch has the effect of turning the “Presence” knob on a tube amp from off to full-on in a split second. Here again the interactive nature of the circuit becomes apparent... With
Midpunch selected,
Sweep set anywhere from 1-5 and
Mid adjusted tastefully, you get a slightly gritty, grand piano ring, great for cutting through dense guitars.
Sweep set anywhere between 5 and 7 its SVT-city. Anywhere past 7, and its gets unpleasantly clangy. “
Fat-Growl”, another Dirty Valve exclusive, provides an adjustable range of the sweetest, furriest Bass Guitar overdrive I’ve every heard. Overdrive is an intensely personal matter, with many types and sounds having just as many devotees as detractors... Krank walks the tightrope skillfully here. The tones range only from slight tubbiness to subtle fur and into true grind only at extreme settings. When running
Fat Growl thru its paces, midrange overtones become more present, but the overdrive never gets shrill, almost as though only the tastiest frequencies get placed in the overdrive side-circuit. Even with the control dimed, true distortion is unavailable, but what you do get is thick, meaty, overdrive sirloin. Again, the circuit is so interactive that, with
Fat Growl in use, each control on the amp can dramatically alter the overdrive characteristic, especially Volume. Engage the
Midpunch with this knob up and you have growl and grit enough to slice through even the loudest guitar shred, engage the
Girth control,
Midpunch out and set the Sweep just about anywhere, and you have a thundering steam-shovel. Pure Rock bassist heaven. Like most of the other controls on the D-800,
Brite does what it should, and tastefully. And it’s loud. I mean really, really loud. And why shouldn’t it be? Are we not men?
The Basszilla enclosure was manufactured specifically to mate with the Dirty Valve. Krank looked to Chris Catero, Director of New Product Development & Artist Relations (and the only Bass Player at Krank’s Tempe, AZ headquarters) for inspiration. Having been a touring bassist with several rock and metal acts for over a decade, Chris used his own live rig as a starting point - “I’ve pretty much always used an 810 and a 412 live. It was the only way for me to get enough low-end punch and hi-mid cut for me to really fill out the mix live.” The Basszilla is basically one half of Chris’s live rig, a 410 and a 212 loaded into two separate, sealed chambers. The first thing I noticed was how closely the Basszilla resembled an SVT-810E in dimensions and stack-ability. Two edge-mount top handles take the place of the towel bar often seen on large cabs, along with edge-mount heavy-duty caters. The second thing I noticed was the lack of side or rear handles, which made it a bear to get out of touring endorser and NY Hardcore legend
BRICK BY BRICK’S trailer. “Yeah, it sucks getting the thing in and out, but the sound makes it totally worth it.... and that’s coming from a guitar player!!” chuckled Mike Valente, BRICK BY BRICK’S founding member and outspoken Krank free-agent and general tout “We’ve all used Mesa for 15 years or so. Now we all use Krank, if that tells you anything....” A steel kickplate is provided but, alas, no skid rails.... a potentially serious problem for those of us not lucky enough to have a load-in crew! Popping the control plate off revealed a high-quality plywood shell, with thick, sound dampening acoustic stuffing placed liberally in each chamber. For the drivers, Krank chose USA Eminence, connected with very heavy wire and mounted to the solid-maple baffle with largish T-nuts. “In testing prototypes, we found the solid maple baffle gave a brighter sound to the cab overall, so we went with it!” Stated Catero in a phone interview. “We don’t really delve too deeply into the science of it.... we try a bunch of things, keep what works, and employ the best materials and parts available.” Everything about the cab’s construction screamed quality, with the stamped steel grill adding the finishing touch.
In testing, the Basszilla was surprisingly more Boutique than Brute. Mated to a studio mic preamp (positioned slightly off-axis) and Class A/B power amp with all controls set flat, a passive J-bass spoke cleanly and clearly with an even, present midrange and excellent treble response for a tweeterless cab. Resonance was very low and the cabinet seemed carved out of rock, with zero hardware vibration or unwanted mud. Back pickup plucking provided ample burp and buzz, and the 12"s absolutely sang with my late 80's fretless jazz. When paired with the D-800, the Basszilla’s mean side emerged. Responding well to the Dirty-Valve’s wide palette of overdriven and furry sounds, the Basszilla provided ample push in the bass region and really crackled with tube-overdriven life up high. With the D-800's Master Volume set anywhere past 5, this rig is stupidly, insanely loud, with further experimentation into the upper reaches of the Master knob’s range bringing more and more upper midrange bite into the overall sound, while bass response remained largely the same.
While, even at extreme settings, the D-800 / Basszilla rig does not provide gut-loosening Low-Bass, it isn’t meant to. This is a machine built for one purpose; cut through dense guitar. In practical application it does the job better than any single rig I’ve used in this setting, as well as cleaning up the mud often inherent in heavy, down-tuned bands. In rehearsal with a very loud metal band consisting of mic’d up double kicks and two Mesa Boogie Dual Rectifier stacks, the Krank bass rig filled out the holes in the mix in some unexpected ways, and had the uncanny effect of cleaning up the entire mix. Where the rig felt somewhat shy in the sub-80hz pillow region on its own, in a live setting my drummer’s kick drum felt more present and the whole band felt tighter. With the EQ set in neutral and
Sweep about halfway thru the range, each note spoke through the guitar with bite and clarity. With
Girth engaged and
Fat Growl turned up just past 5, the effect was like sweeping away bad frequencies in the guitarists’ tone, and quick, second position runs and hammer-on tags came through in a tight, present fashion I wasn’t used to. Engaging
Midpunch brought a familiar SVT flair to the overall mix, and created a bit of upper midrange clang great for big unison verses. I was pleased to find I didn’t have to dig in as much as with other rigs to get this effect. With the bridge pickup solo’ed on my Brubaker Brute, the Krank brought forward the Jaco buzz naturally, while not being nasal or needing additional bass boost. Blending both pickups gave a deep, ringing Geezer Butler type tone. Perfect.
Krank set out to make a bass rig for Rockers, and in the D-800 and Basszilla, they have succeeded completely. The overall construction and materials used borders on boutique, while still clad in leather and painted black. A cool mixture of old-school mojo and nu-school tech, the Dirty Valve D-800 and Basszilla are singular tools for a singular purpose, and, if Rock or Metal is
your thing, it will make you enjoy getting dirty.
** Krank encourages the end user to experiment with using different tubes in the preamp.
midpunch, fat growl and especially Sweep dramtically alter the gain and "loudness" of the amp. Again it's more like a guitar amp in its setup than a SS bass amp in the way the controls are laid out. There is no "flat" setting so to speak...
