Luther Grosvenor Guitars & Gear: Spooky Tooth's Ariel Bender Complete Rig Guide

Background

Luther Grosvenor was born on December 23, 1949, in Evesham, Worcestershire — the kind of small English market town that in the late 1950s and early 1960s was a long way, culturally if not geographically, from the blues records coming out of Chess and Sun. He taught himself guitar as a teenager, absorbing the British beat groups and the American rock’n’roll and blues that filtered through to provincial England via pirate radio and the occasional London expedition.

By 1967 he had joined Spooky Tooth, the band that would define his early career. Spooky Tooth was a remarkable group — keyboardist Gary Wright and vocalist Mike Harrison gave the band a gospel-inflected, soulful quality that set it apart from most contemporary British rock acts, while Grosvenor’s guitar provided the hard, electric counterweight that kept everything from drifting into MOR territory. The debut album It’s All About (1968) announced the combination; Spooky Two (1969) perfected it. The production on Spooky Two — handled by Jimmy Miller, the producer also responsible for the Rolling Stones’ Beggars Banquet and Let It Bleed — captured Grosvenor’s guitar with an enormous, three-dimensional quality that remains a reference point for anyone interested in early British hard rock production.

Grosvenor left Spooky Tooth in 1970, went through various projects including Stealers Wheel and Widowmaker, and joined Mott the Hoople in 1973 as replacement for Mick Ralphs, who had left to form Bad Company. He adopted the stage name Ariel Bender — Ian Hunter’s suggestion, reportedly — and appeared on The Hoople (1974) and the live album Live (1974). The Mott tenure was brief but incandescent; Grosvenor played with the kind of unconstrained, charismatic energy that the band’s theatrical, rock’n’roll-as-spectacle approach demanded.

Post-Mott, he formed Widowmaker with bassist Steve Ellis and drummer Bobby Harrison, releasing two albums in 1976–1977 before the band dissolved. He largely withdrew from active recording through the 1980s and 1990s but has remained active in interviews and occasional live appearances, and his reputation among serious students of early British hard rock and progressive rock has grown considerably as the revisionist history of the early 1970s British scene has proceeded.

The Rig: Luther Grosvenor’s Guitars, Amps, and Effects

Gibson Les Paul Standard (1958–1960, “burst” era)

Gibson SG Standard (1961–1965)

Gibson ES-335TD (1960–1964)

Fender Stratocaster (pre-CBS, 1963–1964)

Guitars

Gibson Les Paul Standard (1958–1960, “burst” era)

Grosvenor’s primary instrument during the Spooky Tooth and early Mott the Hoople period was a late-1950s/early-1960s Gibson Les Paul Standard — the legendary “sunburst” configuration that has become the single most coveted instrument in the history of the electric guitar. These instruments, built between 1958 and 1960 in the Kalamazoo factory, featured a one- or two-piece Honduras mahogany body with a hand-carved, book-matched AAA-grade figured maple top, a mahogany neck with a rounded “baseball bat” profile (1958) transitioning to a slimmer “slim taper” profile (1960), and a rosewood fretboard with trapezoid inlays. The critical tonal component is the pair of Seth Lover-designed Patent Applied For (PAF) humbucking pickups — wound on a double-coil bobbin to between 7.5k and 9.0k ohms DC resistance (varying considerably between individual units due to the hand-winding process), using Alnico II rod magnets (more common in earlier examples) or Alnico V (more common in later examples), with a plain enamel-coated wire that gives a slightly softer, more rounded high-frequency response than the later plain wire PAF production. The combination of mahogany/maple construction and PAF humbuckers produces the tone that defines a generation of British hard rock: warm, thick, and sustaining on the neck pickup; aggressive, bright, and harmonically complex on the bridge; and everything in between from the middle position. Grosvenor’s Les Paul is the sound of Spooky Two — that enormous, enveloping guitar tone that seems to occupy the entire frequency spectrum without ever becoming harsh or congested.

Gibson SG Standard (1961–1965)

The Gibson SG Standard — introduced in 1961 as the revised Les Paul and retaining that name until 1963 when Les Paul demanded removal of his name — appears in Grosvenor’s live setup alongside the Les Paul. The SG Standard’s specification in the early-to-mid 1960s: double-cutaway mahogany body (no maple cap, purely mahogany), slim mahogany neck joining the body at the 22nd fret for extreme upper register access, rosewood fretboard with crown inlays, and a pair of Patent Applied For or transitional Patent Number humbuckers. The all-mahogany construction gives the SG a distinctly different tonal character from the Les Paul — more midrange focused, less warm low-end weight, with a slightly more aggressive attack and faster note decay. The SG’s lighter weight (typically 6–7 lbs versus the Les Paul’s 8–9 lbs) also makes it more physically comfortable for energetic live performance, which suited Grosvenor’s stage presence. He used the SG for material that benefited from its more aggressive, cutting character — the bridge pickup SG tone through a cranked Marshall is one of the most recognisable sounds in British hard rock.

Gibson ES-335TD (1960–1964)

Grosvenor used Gibson’s semi-hollow ES-335 — introduced in 1958 as the world’s first production thinline semi-hollow electric — during certain recording and live periods. The ES-335TD (“Twin pickups, Double cutaway”) specification of the early 1960s: laminated maple top, back, and sides with a solid maple centre block running the full length of the body, bound f-holes, a rounded Florentine cutaway profile, rosewood fretboard with dot inlays (switched to block inlays in 1962), and PAF humbuckers. The solid centre block provides feedback resistance and sustain while the hollow wings contribute acoustic warmth and note bloom. The result is a tone with more air and complexity than a solid-body Gibson but more control and sustain than a full hollow body — ideally suited to the more melodic, prog-influenced passages in Spooky Tooth’s catalogue.

Fender Stratocaster (pre-CBS, 1963–1964)

Pre-CBS Stratocasters — specifically examples from 1963–1964 with the transitional round-lam rosewood fretboard and the original Fender synchronized tremolo with cast saddles — appear in Grosvenor’s documented setup. The pre-CBS Strat pickup configuration: three Alnico V staggered-pole single-coil pickups with a DC resistance of approximately 5.6k–6.2k ohms, a 3-way selector switch (in the pre-CBS era, before the 5-way switch became standard), and a single volume plus two tone control layout. The brightness and transparency of the Strat’s single-coil pickups contrasted with his Gibson tones, giving Grosvenor a wider tonal palette for different material.

Gibson Flying V (1967 reissue)

The Gibson Flying V — originally produced in 1958 as part of the “Modernist” series alongside the Explorer and Moderne, discontinued after poor sales, and reissued from 1966 onward — appears in documentation of Grosvenor’s live performance during the Mott the Hoople period. The 1967 reissue Flying V specification: korina wood body (on original 1958 examples; the reissue used mahogany), mahogany neck, rosewood fretboard, and a pair of Patent Number humbuckers (the production successor to the PAF, using a similar wind and Alnico magnet structure but with a patent number stamped on the base plate rather than “Patent Applied For”). The Flying V’s visual drama suited the theatrical excesses of the Mott the Hoople stage presentation, and its tone — brighter and more aggressive than a Les Paul due to the V-shaped body’s different resonant characteristics — gave Grosvenor an additional tonal colour for live work.

Strings

Grosvenor used medium-gauge strings — most likely .010–.046 or .011–.048, consistent with the approach of virtually all British hard rock players of the era. These gauges gave sufficient mass for expressive bending and vibrato while remaining manageable across the long touring schedules that characterised the British rock circuit in the early 1970s. Ernie Ball Regular Slinky (.010–.046) or Gibson Sonomatic strings (the factory standard on new Gibsons of the period) are the historically appropriate choices.

Amps

Marshall 1959 Super Lead 100W (circa 1969–1972)

The Marshall 1959 Super Lead — Marshall’s flagship 100-watt head, introduced in 1965 and refined through the late 1960s into the configuration that defined British hard rock — was Grosvenor’s primary amplification throughout the Spooky Tooth and Mott the Hoople periods. The 1959 Super Lead specification: four Mullard EL34 (or GEC KT77, depending on availability) output tubes in push-pull configuration producing approximately 100 watts RMS, three ECC83 (12AX7) preamp tubes, an ECC83 phase inverter, a long-tailed pair phase inverter topology (changed from the earlier cathodyne design), four inputs (two channels, two inputs per channel), a single-gang master volume (absent on very early examples), and a passive tone stack with bass, middle, and treble controls. The 1959’s circuit produces a characteristic “Plexi” tone — named for the Perspex (plexiglass) front panel used from 1965 to 1969 — that is warmer and less compressed than the later JMP metal-panel versions. Grosvenor ran his 1959 into Marshall 1960A or 1960B 4×12 cabinets loaded with Celestion G12M “Greenback” 25-watt speakers — the 20oz ceramic-magnet Greenback produces a characteristic compressed, harmonically complex breakup that is inseparable from the sound of British hard rock of the period. The combination of a Les Paul’s PAF humbuckers and a cranked 1959 Plexi through Greenbacks is, unambiguously, the sound of Spooky Two.

Marshall JTM45/100 (Super Bass, early period)

Grosvenor also used Marshall’s higher-powered JTM45/100 — the 100-watt version of the original JTM45 circuit, using KT66 output tubes rather than EL34s and producing a different tonal character: slightly warmer, less aggressive in the midrange, with a more gradual compression characteristic. Some players of the era used the Super Bass version of this circuit — nominally designed for bass guitar but beloved by guitarists for its extended low-frequency response and slightly cleaner, more open tone at moderate volumes. The KT66 tube (made by GEC in the UK) has a distinctly different sonic character from the EL34 — rounder, less spiky in the upper midrange, with a more prominent low-end extension.

Hiwatt DR103 (100W Custom 100)

Hiwatt’s DR103 — designed by Dave Reeves and built to an extraordinarily high standard compared to contemporary British amplifiers — appears in documentation of Grosvenor’s studio and live setup. The DR103 specification: four EL34 output tubes producing 100 watts RMS, two ECC83 preamp tubes plus an ECC83 phase inverter and a cathode follower tone stage, a long-tailed pair phase inverter, and Partridge transformers (considered by many to be the finest output transformers fitted to any production British amplifier, contributing significantly to the Hiwatt’s characteristic punch, clarity, and headroom). The Hiwatt has considerably more clean headroom than the Marshall 1959 — it requires more volume before natural overdrive occurs — and its tone is tighter, more transparent, and less coloured than the Marshall, giving a different flavour for certain material. Grosvenor used the Hiwatt for cleaner, more dynamic passages where the Marshall’s natural compression would have been counterproductive.

Effects

Dallas Arbiter Fuzz Face (germanium, NKT275 transistors, circa 1967–1969)

The original round, chrome-faced Dallas Arbiter Fuzz Face — using a pair of NKT275 PNP germanium transistors in a two-transistor series feedback fuzz topology — was a standard component of Grosvenor’s lead tone during the Spooky Tooth period. The NKT275 transistor is characterised by a relatively low leakage current (compared to other germanium devices), which gives the Fuzz Face circuit a more controlled, musical fuzz character than hotter-leaking transistors. The NKT275-based Fuzz Face’s tonal character: warm, harmonically rich sustain with a characteristic “vowel” quality in the attack that is immediately identifiable, and the ability to clean up significantly when the guitar volume is reduced — a crucial characteristic for a blues-influenced player who uses the guitar volume as a dynamic control. The original Fuzz Face circuit board uses hand-selected matched transistors with specific leakage (ICBO) values for optimal performance, and the quality variation between individual units makes the best original examples significantly more musical than average specimens.

Rangemaster Treble Booster (Dallas Electronics, OC44 transistor, circa 1966)

The Dallas Electronics Rangemaster Treble Booster — a single-transistor germanium booster using a PNP OC44 transistor (manufactured by Mullard) in a common-emitter configuration — was present in Grosvenor’s signal chain, used ahead of the Marshall to push the front end harder and add harmonic density. The OC44’s specific characteristics — a transition frequency of approximately 1MHz, collector-base leakage of 20–80µA in typical examples, and forward current gain (hFE) of 70–150 — produce a frequency-selective boost that emphasises the upper midrange and treble while providing a degree of harmonic saturation. The Rangemaster’s input impedance is approximately 470k ohms, which loads the guitar’s pickup slightly differently than a standard buffer, contributing to the characteristic tonal interaction between the guitar and the booster. Germanium transistors are temperature-sensitive, and the OC44’s sonic character changes slightly with ambient temperature — a characteristic that early users simply accepted as part of the device’s personality.

Vox V846 Wah-Wah (Fasel inductor, circa 1967–1969)

The Vox V846 wah pedal — using a Fasel inductor (a hand-wound, single-layer coil with a ferrite core, manufactured in Italy) in a variable bandpass filter circuit, a 100k audio-taper potentiometer for sweep control, and a BC109 silicon transistor — was Grosvenor’s primary wah unit. The Fasel inductor’s resonant characteristics give the V846 a broader, warmer sweep range than wah pedals using inductors with different specifications — the peak frequency ranges from approximately 450Hz (toe back) to 1.6kHz (toe forward), producing the characteristic “cocked wah” sweet spot that many blues-rock players found optimal for rhythm playing. The V846 circuit’s relatively low-gain transistor stage preserves the dynamics of the input signal, making it more responsive to pick attack variation than higher-gain wah designs.

Coloursound Overdriver (Sola Sound, circa 1972)

The Sola Sound Coloursound Overdriver — distinct from the Tonebender fuzz — is a germanium transistor overdrive/boost pedal using OC75 transistors in a relatively low-gain configuration that produces a warm, transparent overdrive rather than heavy fuzz saturation. Simmonds used this type of device for adding definition and midrange emphasis to his rhythm sound without the more extreme tonal transformation of a fuzz pedal. The Overdriver’s circuit uses a single transistor in a common-emitter configuration with a limited clipping stage, producing a characteristically warm, musical overdrive that preserves the fundamental tonal character of the guitar and amplifier.

Univox Uni-Vibe (circa 1969–1971)

The Univox Uni-Vibe — developed by Shin-ei in Japan and marketed by Univox in the US — is a phase/chorus effect using four light-dependent resistors (LDRs) driven by a single incandescent lamp in a rotating configuration, producing a modulated phase shift that approximates (but does not precisely replicate) the sound of a Leslie rotating speaker cabinet. The Uni-Vibe’s LDR-based circuit produces a characteristically warm, slightly asymmetric modulation that has a distinctly organic quality compared to later transistor-based chorus and phaser designs. Grosvenor used the Uni-Vibe for adding movement and texture to sustained passages and for specific atmospheric effects, particularly in the more psychedelic-leaning material of the later Spooky Tooth period.

Maestro Echoplex EP-3 (tape echo, early 1970s)

The Maestro Echoplex EP-3 — the transistorised successor to the earlier EP-2 tube model, using a solid-state preamp but retaining the 1/4-inch tape loop mechanism for echo generation — provided Grosvenor with warm, saturated tape echo for both live and studio use. The EP-3’s delay time ranges from approximately 80ms to 800ms, controlled by moving the playback head along the tape path. The tape-based echo mechanism introduces a subtle pitch modulation (wow and flutter from the tape mechanism) and a gentle high-frequency roll-off with each repeat, giving the echoed signal an increasingly warm, degraded quality that digital delay cannot replicate. The EP-3’s preamp stage, even in bypass, adds a subtle colouration to the signal — a characteristic that many players considered a feature rather than a flaw.

MXR Phase 90 (script logo, circa 1974–1976)

The original MXR Phase 90 — the “script logo” version, using four J-FET transistors in a cascaded all-pass filter configuration — appeared in Grosvenor’s rig during the Mott the Hoople period. The script-logo Phase 90 (distinguished from the later “block logo” version by a hand-drawn MXR script logo and subtly different component values) produces a warmer, slightly less intense phase effect than the later production version, with a characteristic “bloom” to the phase cycle that works particularly well with overdriven valve amplifiers. The Phase 90’s single-knob “Speed” control adjusts the LFO rate from slow, swelling sweeps to fast, warbling modulation.

Playing Style & Tone Philosophy

Luther Grosvenor was a player of enormous, unconstrained energy — the kind of player who sounds like he genuinely doesn’t care whether the next note is technically “correct” by the standards of any particular theory, as long as it feels right and communicates something real. This is not sloppiness; this is a very specific and very difficult thing to achieve. The controlled abandon of a great rock guitarist — the ability to make every note sound inevitable while also sounding spontaneous — requires years of internalised vocabulary and a willingness to commit absolutely to the moment. Grosvenor had both.

His rhythm playing was the bedrock of everything. The Spooky Tooth records succeed in large part because Grosvenor’s rhythm guitar is simultaneously heavy and melodic — he wasn’t playing power chords in the conventional sense, but full voicings with inner voice movement that gave the harmony depth and interest. The combination of a PAF-equipped Les Paul, a cranked Plexi, and Grosvenor’s right-hand attack — medium-heavy pick, moderate angle to the strings, decisive downstrokes on the main beats — produced a rhythm guitar sound of extraordinary authority. It’s the kind of rhythm playing that makes the rest of the band sound better by association.

His lead playing drew from both the blues and the British rock tradition that had transformed the blues into something harder and more aggressive without losing its emotional directness. He used the full range of the neck with confidence, moving between pentatonic vocabulary and more chromatic passages with fluency, and his string bending was precise and expressive — the kind of bending that arrives exactly where it’s meant to arrive, neither sharp nor flat, with vibrato applied from the wrist in the manner of his Chicago blues sources. The Mott the Hoople period showcased a more theatrical, extrovert version of this approach: bigger bends, wider vibrato, more stage movement, more feedback. The Ariel Bender persona was not a mask — it was an amplification of qualities already present in the playing.

Tonally, Grosvenor understood volume as a musical parameter. His ideal tone was the sound of a valve amplifier working at high output — the compression, the harmonic complexity, the three-dimensional quality that only a driven output transformer can produce — and everything in his signal chain served that goal. The treble booster pushed the front end harder. The fuzz supplemented the amp’s own distortion for specific lead passages. The wah added vocal articulation. But the foundation was always the amp itself, running at the edge of its capability, and the guitar’s interaction with that working-hard circuit. This is a tonal philosophy shared by virtually every great British valve amp guitarist of the 1969–1974 period, and Grosvenor embodied it completely.

How to Sound Like Luther Grosvenor

Guitar Approach

A PAF-humbucker-equipped Les Paul is the correct starting point — either a Gibson Les Paul Standard with ’57 Classic or ’57 Classic Plus pickups (the latter has a slightly higher output for the bridge position), a Gibson Custom Shop ’59 Les Paul reissue, or a Paul Reed Smith McCarty 594 (which uses PRS’s 58/15 pickups, voiced to approximate PAF characteristics with approximately 7.7k–8.2k ohms DC resistance and Alnico II magnets). For a more budget-conscious approach, an Epiphone Les Paul Standard with aftermarket PAF-voiced humbuckers — Seymour Duncan Seth Lover SH-55 (bridge and neck), Throbak SLE-101, or Wolfetone Dr. Vintage — will deliver the essential character.

Use a medium-heavy pick — 1.0mm–1.2mm celluloid or Dunlop Tortex — and pick closer to the bridge than the soundhole for rhythm work to maximise attack clarity. For lead work, move toward the neck pickup and let the amp’s gain and the pick’s attack control the sustain rather than relying solely on pedals. Focus on consistent vibrato from the wrist — practice isolating the wrist rotation from finger movement until it becomes second nature.

Amp Approach

A Marshall Plexi-circuit amplifier is essential. Options range from the original (a vintage 1969–1972 Marshall 1959 Super Lead if budget is not a consideration) through reissues (the Marshall 1959HW or 1959SLP) to quality boutique clones: the Ceriatone 1959 Plexi, the Friedman BE-100 Deluxe (which adds modern conveniences while retaining the Plexi circuit’s essential character), or the Metropoulos Metroplex. Run into a 4×12 cabinet loaded with Celestion G12M Greenback 25-watt speakers — the Heritage Celestion G12M-65 Creamback is an acceptable modern alternative if Greenbacks are unavailable. Add a germanium treble booster (Catalinbread CB30, Analogman Beano Boost, or a DIY Rangemaster clone with a selected OC44 transistor) ahead of the amp.

Control	Setting (0–10)	Notes
Preamp Volume (Input Volume)	8–10	Plexi input volume drives the preamp — crank it for natural valve saturation
Bass	5–6	Warm but controlled — mahogany body + full bass = mud if you’re not careful
Middle	7–8	This is the Spooky Tooth tone — forward mids, present and three-dimensional
Treble	5–7	Higher for SG/bridge pickup clarity; lower for Les Paul neck warmth
Presence	4–6	Moderate — adds edge and definition without harshness
Master Volume (if fitted)	6–8	Push the output stage — natural compression is the target
Treble Booster (pre-amp)	6–7	OC44 Rangemaster-style — harmonic density and upper-mid push
Fuzz (for leads)	Sustain 6–7, Volume unity	Germanium NKT275 Fuzz Face — singing sustain, not gated splat

Add the Uni-Vibe (or a quality clone: Fulltone Mini Deja Vibe, Voodoo Lab Micro Vibe, or Dunlop UV-1FC) set to a slow chorus speed for rhythm playing on the more atmospheric Spooky Tooth material. Tape echo (Fulltone Tube Tape Echo, T-Rex Replicator, or Strymon El Capistan set to tape mode) at 180–300ms, one to two repeats, 20–25% mix, for lead depth without clutter.

Influence & Legacy

Luther Grosvenor occupies a specific and important position in the British hard rock family tree: he is one of the generation of players who took the raw material of the British blues boom and forged it into something heavier, more riff-centred, and more theatrically ambitious. The Spooky Tooth records of 1969–1971 are documents of that transformation in real time — you can hear blues vocabulary being reinvented as hard rock vocabulary, chorus by chorus, riff by riff.

His influence is most clearly felt in the tradition of British hard rock and early heavy metal that followed in the wake of the bands he played with. The combination of PAF-equipped Gibsons, cranked Marshalls, and blues-derived playing that he exemplified in Spooky Tooth was the foundational formula for the entire New Wave of British Heavy Metal generation a decade later — players like Brian Robertson, Scott Gorham, and their contemporaries were working from the same toolkit that Grosvenor helped establish. The Mott the Hoople connection is equally important: Mott’s influence on the glam and hard rock scenes of the mid-1970s, and through them on punk and post-punk, created a lineage that runs in directions Grosvenor himself probably never anticipated.

The comparison with Mick Ralphs — his direct predecessor in Mott the Hoople — is instructive. Both players used similar equipment philosophies (Gibson/Marshall, vintage-circuit tone), but Ralphs was a more controlled, compositionally focused player while Grosvenor was wilder, more theatrical, more willing to sacrifice precision for impact. Together, they bookend a certain kind of British hard rock guitar ideal: the craftsman and the showman, both essential. The connection to Paul Kossoff — another PAF Les Paul/Plexi devotee of the same generation who pushed the emotional limits of the British hard rock template — illuminates the philosophical kinship between players who prioritised feel and tone above all else. And the parallel with Ronnie Montrose — Grosvenor’s American counterpart in the project of building enormous, humbucker-driven hard rock tone — shows how the same sonic priorities produced similar but culturally distinct results on either side of the Atlantic.

Frequently Asked Questions: Luther Grosvenor Guitars & Gear

What guitar did Luther Grosvenor use in Spooky Tooth?

Grosvenor’s primary guitar during the classic Spooky Tooth period was a late-1950s Gibson Les Paul Standard — the “burst” configuration with a sunburst finish, mahogany/maple construction, and a pair of hand-wound Seth Lover PAF humbucking pickups. These pickups, wound to between 7.5k and 9.0k ohms DC resistance with Alnico II or Alnico V rod magnets, produce the warm, thick, harmonically rich tone that defines the Spooky Tooth sound. He also used a Gibson SG Standard and, for specific material, pre-CBS Fender Stratocasters.

What amplifier did Luther Grosvenor use?

The Marshall 1959 Super Lead 100-watt head — the “Plexi” configuration with EL34 output tubes, Perspex front panel (on pre-1969 examples), and the long-tailed pair phase inverter topology — was Grosvenor’s primary amplification in Spooky Tooth and Mott the Hoople. He ran these heads into Marshall 4×12 cabinets loaded with Celestion G12M Greenback 25-watt speakers. He also used Hiwatt DR103 heads for their cleaner, more transparent tone on appropriate material.

Why did Luther Grosvenor use the name Ariel Bender?

The name Ariel Bender was adopted for Grosvenor’s tenure in Mott the Hoople, reportedly at the suggestion of vocalist Ian Hunter. It was a stage name that captured the theatrical, extrovert quality of his playing — Ariel (the spirit from Shakespeare’s The Tempest, associated with freedom and magical energy) and Bender (a string-bending guitarist). It remains one of the more evocative rock pseudonyms of the era, and Grosvenor has used it alongside his own name in subsequent documentation of his career.

What fuzz pedal did Grosvenor use?

Grosvenor used the original Dallas Arbiter Fuzz Face with germanium NKT275 PNP transistors — the two-transistor series feedback fuzz circuit in the original round, chrome housing. The NKT275 transistor gives the circuit a warm, musical character with excellent dynamic response to guitar volume changes. He also used the Sola Sound Coloursound Overdriver for a more transparent overdrive/boost sound, and the treble booster (Rangemaster-type, with OC44 transistor) ahead of the amplifier for harmonic enrichment and additional front-end drive.

What is Spooky Tooth’s Spooky Two and why does it matter for guitar tone?

Spooky Two (Island Records, 1969), produced by Jimmy Miller, is one of the finest British hard rock guitar recordings of its era. The album captures Grosvenor’s PAF Les Paul through a cranked Marshall Plexi in a recording environment that preserved the natural dynamics and three-dimensional quality of the amplifier at volume — something that studio compression and EQ increasingly eliminated from rock recordings as the 1970s progressed. The guitar tone on the record is enormous, warm, and alive in a way that repays attention from anyone interested in how great valve-amp hard rock tone sounds when captured correctly.

How does Grosvenor’s tone differ between Spooky Tooth and Mott the Hoople?

In Spooky Tooth, Grosvenor’s tone is slightly warmer and more blues-oriented — the PAF Les Paul/JTM45-Plexi combination in a recording context where the band’s gospel-influenced arrangements left space for nuance. In Mott the Hoople, the Ariel Bender persona pushed toward a more aggressive, rock-forward tone: higher gain, more front-end drive from the treble booster, and a more theatrical use of feedback and wah in live performance. The core gear philosophy remained constant — vintage Gibsons, cranked Marshalls — but the application was adjusted to fit Mott’s more extrovert, rock-as-spectacle approach.

Did Grosvenor use a Uni-Vibe, and when?

Yes — the Univox Uni-Vibe, using its LDR-based phase/chorus circuit, appeared in Grosvenor’s setup particularly during the later Spooky Tooth period (1969–1970) when the band’s material became more psychedelically influenced. The Uni-Vibe’s characteristic warm, organic modulation — produced by four light-dependent resistors responding to a single rotating lamp — gave sustained notes and chord passages a dimensional quality distinct from both phaser and chorus effects. It’s an effect closely associated with Hendrix and the psychedelic rock era but was used more broadly by British players of the same period.