Z-80

“After 6 years of development, this is the amp I can rest my legacy on.” – Dr. Z

Specifications

General Information

In 2017 Brad Paisley found himself in possession of a vintage unicorn: a real-deal Vox AC80, at the time the most powerful amp the company had ever built, and also the rarest, numbering under 300 built. The first generation of these amps were built for the Beatles to use on their US stadium tours in the mid-60s in an attempt to elevate the Liverpudlian Lads’ sound over the throngs of screaming fans. While in Cleveland on tour, Brad excitedly invited Dr. Z to hear the amp, both being die-hard Beatles fans, and Brad having a piece of both musical and amplifier history. That meeting ended with a question that would become an obsession over the next 6 years: “Could you build me another one, Z?”

The uncanny magic of the original Vox design was also it’s Achilles’ heel. The AC80 had 4 individually cathode-biased EL34 power tubes, pushed to the brink of meltdown in order to achieve 80+ watts from the output section. The original cabinets were practically ovens for the tubes, providing poor ventilation and often going thermal while being pushed night after night. This caused Vox to rethink the design and supply the power section with a more reliable fixed-biased circuit in the second generation AC100 in the late 60s, but this design lost some of the harmonic response of the original, causing the company to shelve the amp soon after. Dr. Z set out to make his iteration firstly, and most-importantly, reliable enough to stand up to the rigors of Paisley’s robust tour schedule. Starting with a stouter power transformer custom-spec’ed from Heyboer Transformers, he also reined the cathode values in, relieving the punishing voltages the EL34 tubes were under in the vintage design, and designed his own aluminum-welded chassis and head cabinet to allow for proper ventilation. Seeking to retain the unique vibe and distinct tone of the original cathode-biased design, but insuring it was bullet-proof, the amp now dubbed the Z-80 has been on Paisley’s stage for 5+ years on the road, and has also found its way to numerous other Z artists’ backline as a test of real-world reliability.

Dr. Z has never been satisfied to simply copy a design; the aim is always to bring a vintage tone into the present, meeting the demands and needs of today’s player. Beyond improved reliability, refinement of the circuit was in order: a post-phase inverter master volume was tuned to control the brutal 80+ watts of crystalline, chiming power on tap. A Metro “Zero Loss” FX loop was added, allowing the player to dial up the grit and grind, but retain the clarity of their time-based effects and modulation. While the original Vox design was intended for bass guitar, Dr. Z massaged the Z-80’s preamp to include a midrange control to dial in the range most important for guitar instead of the original’s fixed resistor value, and ironed out some of the quirks in the tone stack by increasing gain and expanding frequency bandwidth.

Six years of relentless evolution has gone into the Z-80, having been built-up, then torn down to the tacks over half a dozen times; a testament to considerations taken for an amp Dr. Z considers a touchstone in his company’s legacy. The Z-80 retains the original AC80’s quad of individually cathode-biased EL34s, two 12AX7 preamp and one 12AU7 phase inverter, includes both a custom power transformer that exceeds the original’s requirements and reliability, and is fitted with a replica output transformer designed around the original AC80 schematics, manufactured exclusively for Dr. Z by Heyboer Transformers. Hand-wired meticulously by Dr. Z himself, the Z-80 outperforms the original design requirements, has undergone the crucible of the road, and provides a dynamic, unmatched playing experience one can only achieve by buckling up and plugging into 80 watts of British Invasion-inspired power.

Magazine Reviews

The Z-80 was reviewed and awarded an Editors’ Pick in the May ’24 edition of Guitar Player Magazine.