When Joe Walsh approached Dr. Z for a new amp to use on the latest Eagles’ tour, he harkened back to the legendary recordings with the James Gang, where Joe was using small, single ended Tweed combos. Never one to be satisfied with rehashing old designs, Dr. Z and Joe Walsh upped the ante by looking to hi-fi audio amplifiers; from this the Z-PLUS was born.
The Z-PLUS is a parallel, single-end amplifier in true Class A configuration, which yields a rich clean tone that smoothly overdrives into gritty, harmonic-laden distortion. Single-ended, Class A operation produces full even-order harmonics which are typically cancelled in traditional push-pull, Class A/B tube amp designs. The result is sparkling and satisfying tone with the full range of 2nd and 4th order harmonics with clarity akin to an full bodied, acoustic guitar. While typically class A designs are limited by lower clean headroom, the Z-PLUS utilizes two 6V6 power tubes in parallel which increases clean headroom, per Joe Walsh’s request.
For the best of both worlds, the inclusion of a half-power switch drops the second 6V6 out of operation, rewarding you with touch responsive drive, dynamic compression, and lowered headroom. All of the typical Dr. Z features are included: full EQ with master volume and cut, hi and lo sensitivity inputs, an effects loop, a rich reverb circuit, and our variable boost footswitch. The output transformer is a special design for this amp, constructed with the highest grade M-6 stacked laminates, coupled with our custom all-aluminum chassis, and built like a tank to UL-60065 specifications. These Z-PLUS combos are in their standard Ultra-Lite 1×12 combo configuration with a Celestion Alnico Blue Speaker.