What’s Fat, purple, and loud?
Well, Barney the Dinosaur is one answer, but not the one we’re looking for here. The correct answer is the KJL Dirty 30 amplifier head.
Gearheads know “fat” is a reference to tone (and it’s a good thing… more later), and the purple is for the Dirty 30′s cool tolex cover. Loud is for the dual Electro-Harmonix 6550 power tubes.
Although the KJL looks pretty typical, it does have a couple features that set it apart. The first is the active three-position midrange control that allows a player to select where the mids are cut – 300, 400, or 500 hertz. It, along with the passive treble, mid, and bass controls provide ample control and make the Dirty 30 sound great with single-coils and humbuckers.
Another nice feature is the midrange control’s footswitch jack, which allows the user to bypass the mid control altogether – this is very useful for soloing.
For instance, with a humbucker-loaded Hamer Studio plugged into one of two 4×12″ cabs (a Celestion-equipped Randall and an Alnico-loaded Tone Tubby), the tone remained smooth and fat through both cabinets. We cut back a healthy amount of midrange for regular rhythm chords. Then, using the footswitch, we bypassed the mids as we geared up for a solo, and were quite impressed with how the single notes popped. There was also a slight gain boost, which we liked.
As we cranked it up and the 6550s started to sweat, the 30 produced noticeably more sustain. An overdrive/boost pedal added a bit of drive to the single-coil pickups in a Strat, or if we needed more overdrive at lower volume. In any setup, we found tones reminiscent of a Marshall, but with a more round, full tone covering all frequencies. The tone remained smooth and fat through both cabinets, with the Randall offering a little more high-end response.
Fiddling with the midrange frequency control and the class AB/class A (fixed-/cathode-bias) switch on the back of the amp, we were able to accommodate just about any guitar.
The only nit we’d pick is that the two metal heat vents above each power tube get very hot to the touch. Call it a job hazard…
Nonetheless, KJL’s Dirty 30 is a sweet piece of gear for someone looking for early-Marshall-like tones, with a substantial twist of control and added punch.
KJL Dirty 30
Type of Amp 30-watt all-tube.
Features High-quality construction, all-tube circuitry, dual-EH6550 power section, selectable midrange frequency.
Price $999 (retail).
Contact KJL Amps, 521 Hamilton, Gretna, LA 70053. Phone 504-363-9143, kjlamps.com.
This article originally appeared in VG‘s Dec. ’03 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.