Hammond B-3 · Volume 8
Hammond B-3 — Vol 08: Reference & Cheatsheet
This volume consolidates the values established across Vols 01–07 into a single
bench reference: the three spec tables (B-3 console, Leslie 122, Trek II String
Bass), a drawbar registration chart, a tonewheel frequency reference, a terse
quick-reference card, and a de-duplicated bibliography of every source cited in
the deep dive. It introduces no new measurements; every consolidated value is
traceable to the volume it came from, cited as “(Vol N)” alongside the original
source where useful. Where two volumes appeared to state a value differently, the
apparent difference is reconciled inline with a > **Note:**.
Note: Values carried here marked (est.) or (not published) were already flagged as approximate or unconfirmed in their origin volume; they are repeated with the same flag rather than hardened into specifications. Drawbar registrations are written in the conventional nine-digit form grouped
00 0000 000, read left to right as the physical bar order 16′ 5⅓′ 8′ 4′ 2⅔′ 2′ 1⅗′ 1⅓′ 1′ (Vol 03 §“The drawbars”).
Specifications
B-3 console
| Parameter | Value | Source |
|---|---|---|
| Manuals | Two 61-note manuals (upper “Swell,” lower “Great”) | Vol 01 §“What the B-3 is”; Hammond B-3/C-3 Service Manual |
| Pedalboard | 25-note, low C → middle C (two octaves), radiating/flat | Vol 01; Vol 05 §“The 25-note pedalboard” |
| Tonewheels | 96 total / 91 active sound sources / 5 blank balance wheels | Vol 01 §“Spotting a genuine console”; Vol 02 §“Wheels, gears, and grouping”; dairiki.org Tone Generator |
| Manual drawbars | 9 per manual, 9 positions each (0 = off … 8 = full) | Vol 02 §“Additive synthesis”; Vol 03 §“The drawbars” |
| Pedal drawbars | 2 (16′ + 8′) | Vol 05 §“Pedal tone generation” |
| Footage order (L→R) | 16′ 5⅓′ 8′ 4′ 2⅔′ 2′ 1⅗′ 1⅓′ 1′ | Vol 02 §“Additive synthesis”; Vol 03 §“The drawbars” |
| Key contacts | 9 per key (one per footage), wiping 9 busbars per manual | Vol 02 §“The key-contact matrix” |
| Harmonic Percussion | 2nd/3rd harmonic; Soft/Normal; Fast/Slow; upper manual, B (adjust) preset only | Vol 03 §“Harmonic Percussion” |
| Vibrato/chorus | Scanner: 6 positions V1–V3 / C1–C3; ~412 RPM, ≈ 7 Hz (≈ 6.9 Hz est.) | Vol 03 §“Vibrato & chorus” |
| Tuning reference | A = 440.0 Hz exact (only exactly-tempered pitch; rest approximate ET) | Vol 02 §“Frequency derivation” / §“Tuning” |
| Drive motor | Mains-locked synchronous run motor: 1200 RPM @ 60 Hz, 1500 RPM @ 50 Hz | Vol 02 §“The synchronous motor” |
| Run-motor field coils | ≈ 180 Ω each | Vol 02 §“The synchronous motor”; bentonelectronics.com |
| Start motor | Shaded-pole induction, pinion-clutch run-up; hold Start ≈ 8 s | Vol 02 §“The synchronous motor”; Vol 03 §“Start/Run” |
| Preamp | AO-28 tube preamplifier (adjustable drive) | Vol 02 §“From generator to output” |
| Output | Balanced line, ≈ 3–4 V RMS (≈ +12 to +14 dBu, est. conversion); no internal power amp or speaker | Vol 02; Vol 04 §“The 6-pin balanced connection”; Vol 07 §“Levels & impedance” |
| Output connector | 6-pin Amphenol (to Leslie) | Vol 01 §“What the B-3 is”; Vol 04 |
| Expression pedal | Post-preamp swell on the whole signal; ~logarithmic taper | Vol 03 §“Expression pedal” |
| Weight | Console ≈ 310 lb (140 kg); full rig with bench + pedalboard (packed) ≈ 425 lb (193 kg) | dairiki.org WhatDoesAHammondWeigh |
| Dimensions | ≈ 48½ in W × 38¼ in H × ~24–29 in D (console body ~24–25 in deep; ~29 in incl. pedalboard) | b3sforsale.com; dairiki.org |
Note (output level — reconciliation): Vol 02 §“From generator to output” deliberately left the AO-28 → Leslie hand-off as “balanced line level, voltage/impedance unconfirmed.” Vol 04 §“The 6-pin balanced connection” then resolved it to ≈ 3–4 V RMS, balanced (organforum.com), and Vol 07 converted that to ≈ +12 to +14 dBu (est.). These are not contradictory figures — Vol 04 closes the flag Vol 02 opened. The vintage 122’s exact input impedance remains unspecified in the period literature; the modern Heritage 122H reference point is 10 kΩ / ≈ 100 mV (−18 dBu) (Vol 04; hammondsuzuki.com).
Note (weight/dimensions): No weight or dimension figure is stated in Vols 01–07. The values above are common-knowledge approximations marked (est.) and are flagged for the accuracy-review pass to source or strike; they are not relied upon elsewhere in the deep dive.
Leslie 122
| Parameter | Value | Source |
|---|---|---|
| Type | Rotary tone cabinet; two independent rotating sources | Vol 04 §“Why a rotating speaker” |
| Power amplifier | Single-channel push-pull tube amp, ≈ 40 W | Vol 04 §“The amplifier & power supply” |
| Output tubes | Matched pair 6550A | Vol 04 |
| Driver / phase splitter | One 12AU7A dual triode (balanced input) | Vol 04 |
| Voltage regulator | One OC3 gas-discharge, regulated rail ≈ +310 VDC | Vol 04 |
| Rectification | Solid-state bridge (rectifier tube on earliest units) | Vol 04 |
| B+ rail | ≈ +430 VDC at rectifier, ≈ +415 VDC at the 6550A plates | Vol 04; Vol 06 §“Safety” |
| Crossover | Passive, transition at 800 Hz | Vol 04 §“The 800 Hz crossover” |
| Treble | Stationary compression driver → rotating two-horn casting (one live horn + one sealed dummy counterweight) | Vol 04 §“Horn & drum rotors” |
| Bass | Down-firing 15″ woofer, 16 Ω → rotating drum/scoop baffle | Vol 04 §“Horn & drum rotors” / §“The 800 Hz crossover” |
| Horn speed — tremolo (fast) | ≈ 400 RPM (≈ 6.7 Hz) | Vol 04 §“Fast/slow” |
| Horn speed — chorale (slow) | ≈ 40–50 RPM (est.) (≈ 0.7–0.8 Hz) | Vol 04 §“Fast/slow” |
| Drum speed — tremolo (fast) | ≈ 340 RPM (≈ 5.7 Hz) | Vol 04 §“Fast/slow” |
| Drum speed — chorale (slow) | ≈ 40 RPM (est.) (≈ 0.67 Hz) | Vol 04 §“Fast/slow” |
| Speed select | Half-moon switch on organ → changeover relay in cabinet (DC riding the balanced pair) | Vol 04 §“Fast/slow” / §“The 6-pin balanced connection” |
| Connection | Balanced audio on a 6-pin Hammond (“6H”) connector (the 147/145 use a 6-pin “6W” unbalanced wiring — same pin count, not interchangeable) | Vol 04 §“The 6-pin balanced connection” |
| Drive belts | Upper (horn) ≈ 25.5 in rubber; lower (drum) ≈ 31 in polyurethane | Vol 06 §“Belts” |
| Weight | ≈ 147–150 lb (≈ 67 kg) | hammondorganco.com / b3world.com Leslie specs |
Leslie 122 6-pin pinout (Vol 04 §“The 6-pin balanced connection”; captain-foldback.com):
| Pin | Wire colour | Function |
|---|---|---|
| 1 | Black | Balanced audio (one leg) |
| 2 | Yellow | Signal / DC ground (reference for switching DC) |
| 3 | Gray | AC mains in |
| 4 | Blue | AC mains in |
| 5 | Brown | B+ feed, ≈ 300 VDC |
| 6 | Red | Balanced audio (other leg) |
Warn: The 6-pin cable carries AC mains (pins 3, 4) and a high-voltage DC feed (≈ 300 VDC, pin 5) alongside the audio. It is not a signal patch cord — mate/de-mate only with the whole system powered down; never probe or hot-plug it (Vol 04; Vol 06 §“Safety”; Vol 07 §“Levels & impedance”).
Trek II String Bass (model SB-2500B)
| Parameter | Value | Source |
|---|---|---|
| Function | Separate synthesized string-bass voice generator, keyed from the pedals, retaining the original Hammond pedal tones | Vol 05 §“The Trek II bass expander”; trekii.com; dairiki.org |
| Voices | 16′ and 8′ string-bass footages | Vol 05; trekii.com |
| Notes | 25 (matches the pedalboard) | Vol 05; trekii.com |
| Keying | Monophonic (“desirable for faster playing”) | Vol 05 §“The Trek II bass expander” |
| Pedal drawbars after install | Four: 16′/8′ Hammond + 16′/8′ Trek II — select Hammond only, Trek II only, or any blend | Vol 05; dairiki.org |
| Controls | Sustain (note-ring length), Pluck (attack transient), quartz-referenced tuning | Vol 05 §“The Trek II bass expander”; trekii.com |
| Console control mount | Underside of the front wooden rail; Molex to the main board | Vol 05; dannychesnut.com |
| Install | Taps the pedal contacts (not the audio bus): contact strip on the pedal support, 19 wires to the board via a DB25; main board mounts anywhere in the console; power transformer sited away from the organ motor | Vol 05 §“The Trek II bass expander”; dannychesnut.com |
| Sustain time range (s) | Not published (est.; not asserted) | Vol 05 §“Warn (unconfirmed specifics)“ |
| Output level / impedance | Separate output(s) exist; level/Z not published (est.; not asserted) | Vol 05 |
| Internal supply voltages | Not published (est.; not asserted) | Vol 05 |
Note: The SB-2500B adds a string-bass voice and adjustable sustain, not a true 32′ sub-octave. A genuine 32′ pedal-solo division is an RT-2/RT-3/D-100 feature, absent on the stock B-3 (Vol 05 §“What the B-3 has”).
Drawbar registration chart
Registrations below are widely-published starting points; players vary them
freely, and named voicings differ slightly between sources. Footage order is the
Vol 03 physical order 16′ 5⅓′ 8′ 4′ 2⅔′ 2′ 1⅗′ 1⅓′ 1′, grouped 88 8888 888.
Sources: hammondwiki.org (StandardPresets); Hammond B-3 Owner’s Playing Manual;
common Hammond drawbar charts. Entries cross-referenced to Vol 03 are traceable to
this deep dive directly.
| Name / use | Registration | One-line description |
|---|---|---|
| Full organ | 88 8888 888 | All nine drawbars out — the fullest, most “pipe-organ” stack (Vol 02 §“Additive synthesis”) |
| Classic jazz / Jimmy Smith (comp) | 88 8000 000 | 16′ + 5⅓′ + 8′ only — fat, fundamental-heavy with quint body; the Vol 03 §“Driving it” worked example |
| Jimmy Smith (lead/solo) | 88 8800 000 | Adds the 4′ octave for cut on a single-line solo |
| Blues / rock | 88 8000 008 | Smith-style base plus the 1′ for sparkle/edge into a driven Leslie |
| Bright “full flutes” | 00 8888 000 | The bright upper-octave voicing named in Vol 03 §“Driving it” (Tip) |
| Soft flute (8′ + 4′) | 00 8400 000 | Mellow two-footage flute; cf. the “Flutes 8′ & 4′” preset 00 5403 000 (Vol 03) |
| String (Salicional) | 00 4544 222 | Thin, reedy string voice — identical to the Vol 03 E-key Salicional preset |
| Gospel pad | 88 8800 008 | Wide body plus 1′ shimmer for sustained, swelling chords |
| Theatre / tibia | 80 8808 008 | Full tibia flute voice (16′ 8′ 4′ 2′ 1′) for theatre/gospel |
Note: Two of these are directly traceable to Vol 03: the jazz
88 8000 000(the §“Driving it” example) and the string00 4544 222(the E-key Salicional preset, Vol 03 §“Preset keys”). The remainder are standard published registrations and are flagged for the accuracy-review pass as starting points rather than canonical single-source values.
The factory upper-manual preset registrations (recalled by the reverse-colour keys, not the drawbars) are tabulated in Vol 03 §“Preset keys” and not repeated here; B♭ is Cancel (manual silent) and B is Adjust (live drawbars, and the percussion source).
Tonewheel frequency reference
Pitch is geometric: f = (N/60) × T × R on a 1200 RPM (20 rev/s) shaft, tuned so
A = 440.0 Hz exactly (Vol 02 §“Frequency derivation”). Equal-tempered
reference values for the lowest octave and the A440 anchor are below; these match
the anchors used in Vol 02 (A = 55.000 / 440.000 Hz; low C ≈ 32.7 Hz) and the
pedal frequencies of Vol 05 (C1 32.70, F1 43.65, C2 65.41, G2 98.00, C3 130.81 Hz).
The full 91-wheel spec is large and is not reproduced here — see goodeveca.net
Hammond Tone Wheel Spec and dairiki.org GearRatio for all 91.
| Note | Equal-tempered f (Hz) | Note | Equal-tempered f (Hz) |
|---|---|---|---|
| C1 | 32.70 | G1 | 49.00 |
| C♯1 | 34.65 | G♯1 | 51.91 |
| D1 | 36.71 | A1 | 55.00 |
| D♯1 | 38.89 | A♯1 | 58.27 |
| E1 | 41.20 | B1 | 61.74 |
| F1 | 43.65 | A4 (ref) | 440.00 |
| F♯1 | 46.25 |
Note (actual wheels vs equal temperament): Per Vol 02 §“Tuning,” only A is exactly equal-tempered; every other wheel is an integer-gear approximation, off by up to ≈ 0.69 cent in the first seven octaves and ≈ 1.93 cents (C♯) in the top octave (192-tooth cap). The Hammond low-C wheel therefore measures ≈ 32.692 Hz (Vol 02), fractionally below the equal-tempered 32.70 Hz tabulated above. The table is the equal-tempered reference; the instrument’s wheels sit a few cents off it by design — the source of the gentle “Hammond beats.”
Quick-reference card
Terse operational reminders, each cross-referenced to its origin volume.
Power-up ritual (Vol 02 §“The synchronous motor”; Vol 03 §“Start/Run”)
- Hold Start ≈ 8 s (induction run-up motor spins the generator to speed).
- With Start still held, throw Run ON (synchronous motor captures and locks to mains).
- Release Start. To shut down, turn Run OFF.
- Pitch follows the mains frequency — an out-of-spec inverter plays sharp/flat.
Leslie speed (Vol 04 §“Fast/slow”; Vol 03 §“Vibrato & chorus” / §“Driving it”)
- Half-moon switch: tremolo (fast, horn ≈ 400 RPM / drum ≈ 340 RPM) vs chorale (slow, ≈ 40–50 RPM); many installs add off/brake.
- The inertia ramp between speeds (a second or more, horn and drum ramping at different rates) is the signature gesture — driven musically during the take.
Percussion 1′-borrow gotcha (Vol 03 §“Harmonic Percussion”)
- Switching Harmonic Percussion ON cuts the upper-manual 1′ drawbar (its tonewheel tap feeds the percussion trigger) — the 1′ goes silent in the mix.
- Normal volume slightly drops the sustained level; percussion works only from the B (adjust) preset, upper manual, and is single-trigger (re-arms only after all keys release — play detached).
Oiling (Vol 06 §“Routine: lubrication”)
- Interval ≈ once per year (catch-up dose if overdue); Hammond tonewheel oil only (low-viscosity, non-detergent mineral oil that wicks the cotton threads).
- Never 3-in-1, detergent, or multigrade oil — it gums the wicks and the bearing runs dry. Do not over-oil (excess migrates onto scanner plates and key contacts). Oil takes a week or more to reach every bearing.
Safety (Vol 06 §“Safety”; Vol 04 §“The amplifier & power supply”)
- Death cap: on any pre-grounded-cord console/Leslie, remove the AC line-to-chassis death cap (≈ 0.047–0.1 µF) and fit a grounded 3-wire cord — a failed death cap puts full mains on the chassis, keybed, and pedals.
- B+ discharge: the AO-28 and Leslie amp hold +400 to +430 VDC (≈ +415 VDC at the 6550A plates) on filter caps after power-off and unplugging. Discharge through a resistor-limited tool and verify 0 V with a meter at every cap section before any contact. Treat “unplugged” as “still charged.”
- 6-pin cable carries mains + HV DC — never hot-plug or probe it.
Bibliography
Consolidated and de-duplicated from the “Sources” of Vols 01–07.
Primary service & owner documentation
- Hammond B-3 / C-3 Service Manual (Hammond Organ Company) — generator, drawbars, key contacts, presets, percussion, matching transformer, preamp, connector, expression, start/run (Vols 01–03).
- Hammond B-3 Owner’s Playing Manual — drawbar colour-coding, registrations (Vol 03).
- Hammond Organ Co. — hammondorganco.com: owner’s manuals, pedalboards (two 16′/8′ pedal drawbars), and /oils tonewheel-oil product (Vols 04–06).
- Leslie Heritage 122H / 142H Owner’s Manual — hammondsuzuki.com (modern line input 10 kΩ / ≈ 100 mV / −18 dBu reference) (Vol 04, Vol 07).
Books
- Mark Vail, The Hammond Organ: Beauty in the B — company history, cultural arc, model lineage (Vols 01, 03).
Technical wiki & analysis
- HammondWiki / dairiki.org — Tone Generator (96 wheels / 91 active / 5 blank; 24×2×2 = 96; four-octave bin spacing), GearRatio (1200 RPM, frequency formula, twelve gear ratios, A = 440 exact, cent errors), PresetPanel, StandardPresets, Vibrato, Oiling The Hammond, Death Caps, How To Clean Key Contacts, Classical Organists Dislike Most Hammonds, Trek II String Bass with Simultaneous Retention of Hammond Pedal Tones, Leslie Recording Techniques, Leslie hookup-kit part numbers, Hammond Modifications (Vols 01–07).
- electricdruid.net, Technical aspects of the Hammond Organ — frequency formula and A = 440 worked example, drawbar footages → harmonics, nine key contacts / key-click, foldback, lowest pedal tonewheel ≈ 32.7 Hz (Vols 02, 05).
- goodeveca.net, Hammond Tone Wheel Spec — representative frequency table, 91-active count, 192-tooth top-octave cap (Vol 02).
- bentonelectronics.com — Hammond Synchronous Run Motor, Hammond Generator Start Motor, Console Start and Run Switch Wiring, Servicing the Hammond B-3 Type Pre-Amp, Servicing the Leslie 122 Amplifier, Servicing the Leslie Motors, Servicing the Hammond Vibrato Scanner, Oiling Instructions for the Hammond Organ (Vols 02, 04, 06).
- hammondtoday.com — AO-28 schematic and parts list (Vols 02, 03).
- modularsynthesis.com — vibrato scanner mechanism (Vol 03).
- captain-foldback.com — Uncle Harvey’s guide to Leslie pin-outs, Leslie amplifier schematics, Leslie Combo Preamp (Vols 04, 07).
- goodeveca.net, kr-sound.com (death-cap safety), b3world.com, forums.musicplayer.com (Hammond 9 Key Contacts Assigned to Harmonics), narkive alt.music.hammond-organ (dry tonewheel bearings) (Vols 02, 06).
Forums & community references
- organforum.com — B-vs-C electronics, 122 balanced input level (≈ 3–4 V RMS), 6550 replacement, pedal frequency limits, RT-3 pedalboard, MIDI-encoder retrofits (Vols 01, 02, 04–07).
- groupdiy.com — 122 DC speed-switching levels (Vol 04).
- theatreorgans.com — Hammond-Leslie FAQ (start/run, rotary, 800 Hz) (Vols 02, 04).
- gearspace.com, harmonycentral.com — Leslie mic’ing, retrofit threads (Vol 07).
- en.wikipedia.org — Hammond organ (Model A 1935, percussion 1954, B-3/C-3 through early 1975, A-100 1959), Leslie speaker (rotor speeds, 800 Hz, 40 W), Pedal keyboard (25-note range, RT-3 32′ solo) (Vols 01, 04, 05).
Pedalboard, Trek II & accessories
- azurehillsmusic.com — Hammond 25-note pedalboard (C–C range, radiating vs concave, dimensions) (Vol 05).
- trekii.com — Trek II String Bass SB-2500B (25 notes, 16′/8′, monophonic, Sustain/Pluck, quartz tuning), UC-1A combo preamp, OBL-2 line-out (Vols 05, 07).
- dannychesnut.com — Trek II String Bass installation (pedal contact strip, 19 wires / DB25, Molex console control, transformer placement) (Vol 05).
- tonewheelgeneral.com, pianofarm.com, reverb.com, amplifiedparts.com (Leslie belt specs), goffprof.com — restoration parts, oils, combo-preamp and line-out product references, drive belts (Vols 04–07).
Recording
- soundonsound.com (How do you record a Leslie speaker?), shure.com (Miking the Legendary Leslie Tone Cabinet), recordingmag.com (Miking the Hammond and Leslie) (Vol 07).
Cross-references: console electronics and lineage Vol 01; theory, generator, drawbars, foldback Vol 02; controls, presets, percussion, scanner, start/run Vol 03; Leslie 122 anatomy, rotors, 6-pin connection Vol 04; 25-note pedalboard and Trek II bass Vol 05; maintenance, safety, oiling, recapping Vol 06; mic’ing, levels, interfacing Vol 07.