There are phaser pedals, and then there is the Small Stone. While every manufacturer eventually releases a four-stage phase shifter and every guitarist eventually buys one, the EHX Small Stone staked a claim so early and so definitively that its bloodline runs through some of the most iconic guitar sounds in rock history — from the slow, spacious sweep on Radiohead’s “Paranoid Android” to the thick, woozy shimmer that defined the post-punk era. The Small Stone Nano doesn’t reinvent any of that. It doesn’t need to. It packages five decades of analog phasing philosophy into a pedalboard-friendly nano enclosure and hands you two controls to explore the whole landscape.
This guide covers what the Small Stone Nano is, where it came from, how it sounds, and where it fits in your signal chain — with honest assessments of which artists actually used it versus those who used the vintage ancestors it inherited its circuit from.
Where the Small Stone Came From
Electro-Harmonix founder Mike Matthews introduced the original Small Stone sometime around 1974 — making it one of the earliest dedicated phaser stompboxes on the market. Phase shifting as a studio effect already existed in the early 1970s, accomplished through laborious manipulation of tape machines, but the Small Stone democratized the effect in the same way the Big Muff Pi democratized sustain: cheap, immediate, and surprisingly musical.
The original Small Stone went through several distinct versions across its life. The V1 (roughly 1974–76) was hand-wired, noisy by modern standards, and is now a collector’s item. The V2 (1977–78) is widely regarded as the benchmark — it’s the version Jonny Greenwood of Radiohead has documented using across Radiohead’s most celebrated material, and the sound most people imagine when they think “Small Stone.” A V3 “Black Russian” Sovtek-era version followed in the 1990s (different tone character, lower production quality), and a V4 continued through the 2000s.
The Nano chassis version — officially the Small Stone Nano — arrived around 2006, transplanting the V4 circuit into EHX’s compact die-cast nano enclosure. The circuit architecture is the same: a four-stage all-pass filter network driven by a low-frequency oscillator, with the characteristic Color switch that toggles feedback into the phase network. What changed was size, portability, and street price. The Nano made the Small Stone’s tone affordable and board-friendly in a way the large-format version never quite managed.
This V1 Nano has since been discontinued and replaced by the Small Stone EH4800 Phase Shifter V2 — but used examples remain widely available, and many players consider the V1 Nano the sweet spot in the Small Stone lineage for practical pedalboard use.
What the Small Stone Nano Actually Is
Strip away the history and you’re dealing with a remarkably simple pedal. Two controls. One footswitch. An analog 4-stage phase shifter built around a network of all-pass filter stages tuned to produce a characteristic sweeping comb-filter effect on your signal.
The Rate knob controls sweep speed — the pace at which the LFO moves the phase shift through its range. At minimum (fully counterclockwise), the sweep is so slow it barely registers as movement; at maximum (fully clockwise), it tips into fast Leslie-style rotation and even metallic ring-modulator territory. The sweet spot for most musical applications lives in the left-center range of the knob.
The Color toggle switch is where the Small Stone Nano distinguishes itself from simpler phasers. In its DOWN position, Color gives you a milder, fuller phasing — analog in character, smooth in sweep, reminiscent of the MXR Phase 90 in its subtlety though not quite as warm-sounding. MusicRadar’s Trevor Curwen, reviewing the Nano, described the Color-down voice as delivering “milder phasing similar to the Phase 90, though not quite as warm sounding.” In the UP position, the switch introduces feedback into the circuit, deepening the resonance and pushing the sweep into more dramatic territory: what Curwen called “a vowelly ‘wow’ once the rate knob gets to 12 o’clock and beyond,” building to “a classic ‘underwater’ sound” at full rate.
This two-voice architecture gives the Small Stone Nano a range that many single-knob phasers can’t touch. You have the subtle shimmer (Color down, rate slow), the classic mid-tempo sweep (Color down, rate at 9–10 o’clock), the dramatic Radiohead-style whoosh (Color up, rate at 10–11 o’clock), and the full alien-spacecraft zone (Color up, rate at max). MusicRadar’s verdict: “Phasing writ large for those who like an obvious effect.”
One important note on bypass: the Small Stone Nano uses what Equipboard describes as a “pseudo true bypass” system, where the output is directly connected to the input signal in bypass mode, minimizing signal loss. This is not a mechanical true bypass but is designed to keep the signal clean when the effect is disengaged. On a complex pedalboard, it behaves predictably.
Specifications
| Parameter | Specification |
|---|---|
| Controls | Rate (knob) + Color (toggle switch) + Footswitch |
| Circuit | Analog, 4-stage phase shifter |
| Bypass | Pseudo true bypass |
| Audio | Mono (1x Input, 1x Output) |
| Power | 9V battery included; optional 9.6VDC-200mA adapter NOT included |
| Current Draw | 10mA |
| Dimensions | 4.5″ × 2.75″ × 2.1″ (nano enclosure) |
| Weight | 0.55 lbs |
| Input Impedance | 100 kΩ |
| Year Released | ~2006 |
| Status | Discontinued (V1); succeeded by Small Stone EH4800 V2 |
| Street Price (used, 2026) | ~$55–80 |
| Made In | USA |
Famous Players — Honest Assessment
The Small Stone Nano sits in an awkward historical position for artist credentialing: the pedal that made the Small Stone circuit famous is the vintage Large Stone and V2 from the late 1970s, not the Nano compact version. The artists most associated with the Small Stone sound used the original hardware. The Nano brings that circuit forward in time, so the lineage is real — but “X uses the Small Stone” and “X uses the Small Stone Nano” are not always the same claim. Here is what the primary sources actually support:
Jonny Greenwood (Radiohead)
Jonny Greenwood is the artist most associated with the Small Stone sound in rock music, and the documentation of his use is primary-source solid — but it is the vintage Small Stone, not the Nano chassis. According to the fan documentation site thekingofgear.com, Greenwood used a Small Stone V2 (1977–78 version) from the early Radiohead years through the 2003 tour, then transitioned to a V4, which he used through the subsequent decade. Songs confirmed to feature his Small Stone include “Planet Telex” (from The Bends, 1995), “Paranoid Android” (OK Computer, 1997) — particularly the verse section — and “Subterranean Homesick Alien.”
The Small Stone Nano does appear on Equipboard’s listing for Greenwood, but the primary documentation points to vintage hardware. The honest framing: the Nano Chassis is the compact modern version of exactly the circuit Greenwood made iconic, and it produces the same fundamental phasing character. If you are chasing “Paranoid Android” phaser tones, the Nano is a legitimate path — but Greenwood himself was using large-format originals.
Ed O’Brien (Radiohead)
Ed O’Brien’s pedalboard across Radiohead’s career has been one of the most documented and elaborately phase-shifted in rock. O’Brien is a known Small Stone user in the broader Radiohead universe, with the instrument’s sweeping phaser character woven into the band’s layered guitar textures throughout the OK Computer and Kid A era. His specific vintage vs. Nano situation mirrors Greenwood’s — the primary documentation covers vintage hardware — but the Small Stone circuit runs throughout Radiohead’s guitar tones.
Jim Root (Slipknot)
Multiple secondary sources, including Equipboard, list Jim Root as a Small Stone Nano user with an attributed quote describing his use: “add a little bit of color to octave parts…or harmonies.” This framing — subtle phasing as a tone texturizer rather than a featured effect — is consistent with how a metal guitarist would deploy a phaser. However, Premier Guitar’s 2015 Slipknot Rig Rundown, which photographed Root’s complete pedalboard, documented a Maxon PT-9 Pro+ Phase Shifter rather than a Small Stone Nano in his effects chain at that time. It is plausible that Root has used the Small Stone Nano at different points in his career, and the quote carries the flavor of firsthand experience — but this connection falls in the “Equipboard secondary, not primary-source confirmed” category. The connection is real enough to mention, but requires honest caveats.
Andy Summers (The Police)
No confirmed Small Stone connection — Andy Summers built his signature phasing around the Roland Jazz Chorus built-in chorus and the MXR Phase 90, not the Small Stone. Mentioned here as context: The Police era established what “phaser in a clean, bell-toned guitar context” could sound like, and the Small Stone Nano operates in a similar register with a different tonal character. If you are chasing Police-adjacent tones, the Phase 90 is the more documented reference, but the Small Stone Nano with Color switch down and slow Rate gets you to comparable territory.
The Color Switch: What It Actually Does to Your Circuit
Understanding the Color switch requires a brief look at how a four-stage all-pass phaser works. The all-pass filters don’t cut frequencies — they shift the phase of different frequencies by different amounts. When that phase-shifted signal is mixed back with the original, some frequencies arrive in phase (and reinforce) while others arrive out of phase (and cancel). The LFO continuously moves which frequencies cancel and which reinforce, creating the characteristic sweeping effect.
The Color switch introduces a feedback loop into this network. With Color OFF (DOWN), the phase-shifted signal goes straight to the output — clean sweep, predictable, musical. With Color ON (UP), a portion of the output is fed back into the input of the phase network. This regeneration deepens the notches in the comb-filter, makes the cancellation and reinforcement more dramatic, and gives the sweep that hollowed-out, resonant quality that makes the Small Stone sound more “aggressive” than competitors using similar stage counts.
The practical result: Color DOWN is the working guitarist’s setting — subtle, supportive, adds motion without dominating. Color UP is the character setting — obvious, dramatic, very much in the foreground of the mix. One pedal, two distinct personalities. Both are analog, both are musical, and neither requires deep thinking to use effectively.
MusicRadar noted one important nuance compared to vintage hardware: “Next to our 70s vintage Small Stone, the Nano can duplicate some of the sounds but gets much brighter in one segment of the sweep, so the dark-to-bright nature of its sweep sounds more intense and is especially notable at slower rate settings.” This brightness at the top of the sweep is a character of the Nano’s circuit tuning — some players prefer it, some prefer the vintage warmth. It is not a defect; it is the Nano’s own voice within the Small Stone family.
Tone Recipes and Settings
Subtle Vibey Motion (Indie/Folk/Country)
Color switch: DOWN. Rate: 8–9 o’clock. This produces a barely perceptible shimmer — enough to add three-dimensionality to a clean Telecaster through a Fender Deluxe Reverb without the effect being identifiable as a phaser. Works beautifully on arpeggiated chord progressions and single-note lines alike. The foundation setting for players who want the pedal invisible when it works and noticed only when absent.
Classic Small Stone Sweep (Rock/Psych)
Color switch: DOWN. Rate: 10–11 o’clock. The comfortable mid-tempo sweep that defined the Small Stone’s reputation in 1970s rock contexts. Add a clean amp with modest reverb and a Stratocaster, and you have three decades of analog phaser character in a single setting. This is the setting for sustained chord work — the sweep gives notes room to breathe and decay through multiple phase cycles.
Radiohead Paranoid Android Verse Phaser
Color switch: UP. Rate: 10 o’clock. Jonny Greenwood’s V2 Small Stone produced the famous verse phasing on “Paranoid Android” with the Color function engaged and a slow-to-moderate rate. On the Nano, this combination produces that same hollowed-out, vowelly sweep — though the Nano will be slightly brighter at the top of the sweep than the vintage hardware. A Les Paul or a guitar with humbuckers will darken the character slightly and push it closer to vintage territory. The Radiohead verse is about motion in sustaining notes, not obvious modulation of picked attacks.
Fast Leslie/Rotary Speaker Simulation
Color switch: DOWN. Rate: 2–3 o’clock. At this speed, the sweep starts to lose its “slow movement” character and becomes a fast shimmer that approximates the sound of a rotary speaker or Leslie cabinet in its slower “chorale” mode. Useful behind a clean, open-voiced chord voicing. Not as convincing as a dedicated rotary simulator, but musically effective in a mix where the effect doesn’t need to stand up to direct comparison.
Full Submersion (Experimental/Shoegaze)
Color switch: UP. Rate: 3 o’clock to maximum. This is the Small Stone at its most theatrical — the regeneration deepens the sweep to the point where the effect is inescapable, and at full rate it tips into what MusicRadar described as “a classic ‘underwater’ sound.” At the absolute maximum rate with Color ON, the phasing transitions toward a metallic ring-modulator quality. Not a subtle setting by any measure, but in a wall-of-sound context or a track built around textural layers, it is exactly what the Small Stone Nano was built to deliver.
Jim Root Octave-Color Texturizer
Color switch: DOWN. Rate: 8–9 o’clock. Chain: Guitar → Octave (EHX Pitch Fork or POG) → Small Stone Nano → Amp. This is the use case Jim Root described: adding “a little bit of color” to octave harmonics and stacked parts. A slow, subtle phase shift softens the artificial character of digital octave doubling and gives harmonized parts a slight organic wobble. Not a featured effect — a production technique for thickening heavy riffs without muddying them.
The Small Stone Nano’s two-control architecture makes settings descriptions simple and reproducible. All positions are described relative to the knob face, where 7 o’clock is fully counterclockwise and 5 o’clock is fully clockwise.
Where It Fits in a Signal Chain
Phasers work in most signal chain positions, and the Small Stone Nano is flexible enough to operate effectively at multiple points. The conventional placement is after drives and distortions but before delay and reverb — this puts the phaser’s sweep through the downstream modulation effects rather than the other way around, which tends to sound more natural and controlled. Drive → Small Stone Nano → Delay → Reverb is the baseline.
Placing the Small Stone Nano before a drive pedal produces a different character: the phased signal gets distorted, which bakes the sweep into the distortion texture rather than adding it as a surface effect. This approach tends to make the phasing less obviously audible but more present in the overall tone — the drive “smears” the phase notches in a way that many players describe as more organic. The vintage blues-psych approach. Try Nano → overdrive for this effect.
The 10mA current draw is low by any standard — a single isolated output on almost any pedalboard power supply handles it easily. The included 9V battery provides a useful backup if your supply fails during a gig, though the optional 9.6VDC-200mA adapter sold separately will outlast any battery in extended use.
The pseudo-true-bypass system keeps the dry signal clean when disengaged. In a long true-bypass chain, the absence of a buffer can cause high-frequency loss — but at 10mA the Nano is light enough that pairing it with a buffered pedal elsewhere in the chain (a Boss tuner, any Boss drive) solves this completely.
Comparisons: Small Stone Nano vs. The Competition
vs. MXR Phase 90
The Phase 90 is the Small Stone Nano’s most direct competitor and most meaningful comparison. The Phase 90 is also an analog four-stage phaser, also around $100 new, also beloved by classic-rock players. The differences are real: the Phase 90 is warmer and more uniform in its sweep, with a rounder top-of-cycle characteristic. The Small Stone Nano with Color OFF is similar but “not quite as warm,” per MusicRadar — it brightens more dramatically at the top of the sweep. The Phase 90 has one knob (Speed); the Small Stone Nano adds the Color switch for a second distinct voice. If you want one classic phaser with the most refined, reliable single character: Phase 90. If you want two distinct phasing personalities and a slightly wider range: Small Stone Nano.
vs. EHX Small Stone (Large Format)
Same circuit, different size. The large-format Small Stone uses a bigger enclosure and has been available in various versions since the 1970s. The Nano’s compact size is its advantage; the large-format version’s advantage is component spacing and, in some vintage examples, circuit characteristics that evolved over production runs. For practical pedalboard use, the Nano wins without contest. For collectors or players specifically chasing Jonny Greenwood’s V2-era tone, the large-format vintage hardware is the reference.
vs. Boss PH-3
The PH-3 is digital, offers multiple modes (four-stage through ten-stage phasing, filter mode, rise/fall modes), and provides significantly more control over the effect character. The Small Stone Nano is purely analog — warmer, simpler, more limited. Players who know exactly what they want from a phaser (the classic four-stage sweep with Color switch options) should choose the Nano; players who want to explore multiple phasing modes and digital precision should consider the PH-3. These are different tools for different priorities, not a straight upgrade path.
vs. EHX Bad Stone (Discontinued)
The Bad Stone was EHX’s more elaborate phaser, offering manual sweep control and a polarity switch in addition to the standard rate and color controls. The added manual control made it useful for static comb-filter tones (like the Electric Mistress Filter Matrix) and slow manual sweeps. The Bad Stone is now out of production; used examples command a premium. The Small Stone Nano is the practical, accessible option within the EHX phaser family — less complex but more immediately useful for standard phasing applications. For the EHX Electric Mistress’s comb-filter territory, the Filter Matrix switch on the Mistress is a better tool than either phaser.
Buying Guide: V1 Nano vs. V2 EH4800
The V1 Small Stone Nano (the pedal this article covers) is discontinued and available only on the used market. The successor, the Small Stone EH4800 Phase Shifter V2, is the current-production equivalent — same basic architecture, updated features. When buying used, the V1 Nano is a reliable, well-characterized pedal with a long track record; street prices run roughly $55–80 for units in good condition.
Equipboard community notes that post-2020 production runs feature a black-and-orange swirl logo rather than the silver reissue aesthetic, and there is community debate about whether circuit changes occurred. The general consensus is that the core circuit character remains consistent, though the newer production runs may sound slightly different in A/B tests against earlier examples.
The V1 Nano was made in the USA. The build quality is consistent with EHX’s nano-enclosure line — solid die-cast housing, standard EHX footswitch, durable for live use. The main fragility points are the Rate knob (single-gang potentiometer, standard) and the Color toggle (a standard MEC or similar miniature switch that has proven durable across thousands of reported uses).
Ownership Notes
The most common user experience note about the Small Stone Nano is that the Color switch in its UP position can feel “too intense” for some applications — particularly on single-coil guitars where the sweep’s top-of-cycle brightness is more pronounced. If Color UP sounds exaggerated on your Stratocaster, try rolling off the treble at the guitar’s tone knob slightly before the signal hits the Nano. The resulting phasing is darker and more vintage-correct.
The 100kΩ input impedance is relatively low for a phaser — some vintage and boutique phasers run 1MΩ or higher. This means impedance-sensitive pickups (vintage single coils, passive high-output humbuckers) may see a slight high-frequency interaction at the input. In practice this is rarely noticeable in a band mix, but players running a pristine clean signal into recording interfaces may want to use a buffer before the Nano if they hear HF roll-off.
No adapter is included — EHX’s nano-format policy. A 9V battery gets you started, but for any regular gigging use, invest in an isolated output on a quality power supply. The Fender Stratocaster → Small Stone Nano → Fender Deluxe Reverb combination is essentially a genre-defining clean rig — the Small Stone adds motion without covering the Strat’s clarity.
Frequently Asked Questions
Is the Small Stone Nano true bypass?
Not in the standard mechanical sense. The Nano uses what EHX calls “pseudo true bypass” — when disengaged, the output is wired directly to the input, minimizing tone loading and signal loss, but the circuit is not physically disconnected from the signal path. In practice, the bypassed tone is transparent and indistinguishable from true bypass for most applications.
What’s the difference between the Small Stone Nano V1 and the EH4800 V2?
The V1 is the discontinued original Nano chassis version, Made in USA, with the traditional Rate/Color controls. The V2 (EH4800) is the current-production successor with an updated aesthetic (black-and-orange swirl logo) and minor circuit revisions. The core four-stage phasing character is consistent between them, though enthusiasts report subtle tonal differences in A/B tests.
Does Jonny Greenwood use the Small Stone Nano?
Primary documentation of Greenwood’s Small Stone use covers vintage hardware — specifically the V2 (1977–78 era) through the 2003 tour, and a V4 after that. The Nano is the compact version of the same circuit family, and it appears on Equipboard’s listing for Greenwood, but the documented gear is vintage large-format Small Stones. The Nano is the functional equivalent in a smaller package.
Where should I put the Small Stone Nano in my signal chain?
Most players place it after drives and before delay/reverb — the standard modulation position. Placing it before a drive produces a different, more integrated phasing effect where the sweep is baked into the distortion. Both approaches are valid; the conventional chain position is easier to control and more versatile.
Can the Small Stone Nano do slow, subtle phasing or is it always dramatic?
Absolutely. Color switch DOWN with Rate at 8–9 o’clock produces a barely perceptible shimmer — enough to add organic movement to a clean tone without identifying itself as a phaser effect. The “dramatic” reputation comes from the Color UP voice and higher rate settings, but the Nano operates effectively across the full subtlety spectrum.
How does the Color switch compare to a standard resonance control?
The Color switch is a feedback switch, not a continuously variable resonance control. It introduces a fixed amount of regeneration into the phase network — you get two distinct voices (switch down or up) rather than a continuously adjustable resonance parameter. For more surgical control over feedback depth, the EHX Bad Stone (discontinued) or digital phasers offer variable resonance. The Nano’s binary approach is simpler and for most players covers both the territory they need.
Is 10mA current draw power supply friendly?
Very. 10mA is low enough that almost any isolated power supply output handles it easily — you could run multiple Small Stone Nanos from a single Voodoo Lab Pedal Power 2+ without exceeding any output’s capacity. The included 9V battery is a practical backup, and the optional 9.6VDC-200mA adapter gives regulated power if you prefer it.
What guitars pair best with the Small Stone Nano?
Single-coil guitars (Strat, Tele) produce a brighter, more pronounced sweep — especially with Color UP, the top-of-cycle brightness is very evident. Humbuckers (Les Paul, SG, 335) darken the sweep character slightly and push the sound closer to vintage warmth. Neither pairing is wrong; it’s a tonal preference. The Color DOWN setting is more forgiving across pickup types; Color UP rewards darker pickups for vintage Small Stone character.