Octal-equipped Excellence for the One-and-only Joe Walsh
Marking the latest amplifier collaboration between Dr. Z and the legendary Joe Walsh, the Octal Six head is a testament to the good Doctor’s ceaseless aim of elevating the art of tube amplification. This 30-watt head wears a fairly traditional tube amp configuration on the outside, sporting a simple single-channel design and a flexible 3-band EQ. However, a peak under the hood reveals this amp’s idiosyncratic arrangement of tubes, including 6SL7 and 6SN7 octal tubes in the preamp section. Fueling the power amp is a pair of 7591 power tubes. This distinct variety of valves comes together to deliver a tone that captures all the harmonic-rich density of a classic tweed-style amplifier, only with enhanced definition and clarity. Furthermore, you get Dr. Z’s super post-phase-inverter Master Volume to achieve saturated sounds at home-appropriate volume levels. Wrap it all up with a Zero-Loss FX loop to integrate your stompboxes, and the Octal Six represents an innovative new addition to Dr. Z’s top-tier tube amp lineup.
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Octal-powered preamp section
What is an octal tube, anyway? The truth is that most guitarists are likely already familiar with octal tubes already, even if they didn’t know the family by name — 6v6s, 6L6s, EL34s, and most other power tubes are, in fact, “octal,” sporting 8-pin bases. However, octal tubes are a rare sight in the preamp section of a modern guitar amplifier, as they’ve been all but replaced in that application by smaller 9-pin tubes like the 12AX7.
The Dr. Z Octal Six represents a return to the octal preamp tradition. It boasts large bottle 6SL7 and 6SN7 tubes in the preamp section — tubes you’d likely run into on old projectors, televisions, and all sorts of mid-century electronics. These tubes are supplied with their own independent DC heater supply, which results in exceptionally noise-free operation in relation to the gain they dish out. Moreover, they supply an overdriven character that sings with smooth compression and harmonic-rich overtones.
Distinctive 7591 power tubes
While Joe originally suggested driving the Octal Six’s power amp section with time-tested 6V6s, Dr. Z took a different route with less-common 7591 power tubes. Why? Dr. Z relays to Sweetwater that the 7591 was one of the tube world’s very last power tube designs, representing a so-called “perfected” variation of the 6L6. Indeed, 7591 tubes are revered for their remarkably high-sensitivity input, which grants your superior playing dynamics with a crisp, powerful, and detailed output. And while they were often utilized on high-fidelity amplifiers of the past, the 7591s can be found on scores of classic guitar amplifiers from the vintage era — especially the guitar amp models from an iconic New Jersey-based builder best known for the bass amps.
Time-tested Dr. Z utility features
In addition to the Octal Six’s superb set of tubes, this single-channel, vintage-inspired amp features a much-welcomed duo of modern Dr. Z appointments. First up, the Octal Six comes equipped with a post-phase-inverter Master Volume control, allowing you to tame this beast’s 30-watt roar into bedroom-appropriate levels without compromising an inch on tonal complexity. Plus, you also get the Doctor’s Zero-Loss FX loop to cleanly integrate time-based and modulation effects without coloring your octal-powered preamp’s tone.
Dr. Z Octal Six Head Features:
- 30W, single-channel tube combo amplifier, marking Dr. Z’s latest amplifier collaboration with Joe Walsh
- All-octal tube design, including a 6SL7 and 6SN7 in the preamp, in addition to 7591 power tubes
- Simple and straightforward control setup, with a 3-band EQ, Volume, and Master Volume controls to shape your sound
- Delivers clear, harmonic-rich cleans, along with a compression-rich overdriven saturation that recalls the roar of vintage-era tweed-style amplifiers
- Post-phase-inverter Master Volume control allows you to capture high-octane breakup tones at respectable volume levels
- Zero-Loss FX loop makes it a breeze to integrate your stompbox collection’s time-based and modulation pedals without coloring the preamp
- Paper-wound, vintage-spec Heyboer output transformer
