History · Fender-style

The Tremolux line

The Tremolux is the amplifier Fender built to carry a tremolo. It arrives in 1955 as a narrow-panel tweed combo — a 6V6 pair on a 12AY7 front end, with a tremolo circuit and the Depth and Speed controls that go with it — and runs through three tweed revisions in five years, the last of which quietly rebuilds the amplifier around fixed bias and a long-tailed-pair inverter. In 1961 the line moves to a blonde piggyback cabinet and roughly doubles its power, and in 1963 it joins the blackface generation before being dropped in 1966. Tweed-era dating is approximate — Fender did not date-stamp early circuits — so the sub-circuit ranges below are the defensible spans a published source gives, not hard boundaries. No derivation edge is asserted between the rows: this file records the sequence the factory shipped, which is a chronology and not, by itself, a claim about which circuit was drawn from which.

1955–1966 5 models 1 documented 4 history-tier

Era timeline — each bar spans a model's production years; the chain from top to bottom is the line's succession.

Verified circuit — operating point checked against a published chart Draft circuit — drawn and sourced, verification not complete History entry — placed & sourced, circuit not drawn yet Succession within the line

The models

Designation	Years	Watts	Output stage	Key change	Circuit
5E9	1955–1955	18 W	push-pull 2x6V6GT	The first Tremolux, and the first Fender amplifier built around a tremolo. A 12AY7 front end into a cathode-biased 6V6GT pair on a 5Y3GT rectifier, in the narrow-panel tweed cabinet, with Depth and Speed on the panel alongside the volume and tone controls. Speaker and tremolo-footswitch jacks sit on the bottom of the chassis. Sources for 5E9 (1) Mojotone/Ampwares Fender field guide, 'Fender Narrow Panel Tweed Tremolux' — the line 1955-1960 at 18 W with tremolo; schematics listed as 5E9 (55), 5E9-A (55-56) and 5G9 (57-60); 12AY7 preamp and two 6V6GT throughout, with the 5E9 cathode-biased on a 5Y3GT — mojotone.com	history entry Open requests for 5E9 ↗ Suggest research for 5E9 ↗
5E9-A	1955–1956	18 W	push-pull 2x6V6GT	Still cathode-biased, but the rectifier steps up from the 5Y3GT to a 5U4GA — a higher-current bottle and a stiffer supply. The 5G9 drawing that follows carries a note reading "Late 5E9-A models are similar to this model", which makes this revision the one that shades into its successor; it is a resemblance the factory itself recorded, and not a merger of the two designations. Sources for 5E9-A (2) Mojotone/Ampwares Fender field guide, 'Fender Narrow Panel Tweed Tremolux' — 5E9-A dated 55-56, cathode biased, 5U4GA rectifier — mojotone.com Fender 'Tremolux' Model 5E9-A schematic archived at Schematic Heaven (designation-indexed anchor; the drawing is a separate published sheet from the 5G9's and is not reproduced or read here) — schematicheaven.net	history entry Open requests for 5E9-A ↗ Suggest research for 5E9-A ↗
5G9	1957–1960	18 W	push-pull 2x6V6GT	The last tweed Tremolux, and a rebuild rather than a revision. Cathode bias gives way to a fixed −28 V supply from its own rectifier, the cathodyne inverter to a 12AX7 long-tailed pair, and the rectifier to a 5U4GB; a choke arrives in the supply, the output tubes get their own screen resistors, and the tremolo becomes a phase-shift oscillator direct-coupled to a cathode follower, driving a Depth control that sits in the bias line itself. Most of what the brown-Tolex amplifiers would be known for is already here, in a tweed cabinet, and without a negative-feedback loop. Sources for 5G9 (2) Mojotone/Ampwares Fender field guide, 'Fender Narrow Panel Tweed Tremolux' — 5G9 dated 57-60, 18 W, fixed non-adjustable bias, 5U4GB rectifier — mojotone.com Fender 'Tremolux' Model 5G9 drawing (B-EI), schematic and layout — every component value and printed voltage in this corpus's 5G9 entry was read from this published sheet; the drawing is not reproduced — schematicheaven.net	5G9 draft ↗
6G9 / 6G9-A / 6G9-B	1961–1963	30 W	push-pull 2x6BQ5 (6G9), then 2x6L6GC	The Tremolux leaves the combo cabinet for a blonde-Tolex piggyback head and roughly doubles its output. The 6G9 runs a pair of 6BQ5; the 6G9-A and 6G9-B move to 6L6GC. Fixed non-adjustable bias and a GZ34 rectifier throughout, a 7025 front end, and a two-channel Normal / Bright panel with treble and bass on each — the tweed line's single tone control does not survive the move. The speaker cabinet goes from one 10-inch to a sealed pair. One row covers all three 6G9 revisions, so its years span the whole blonde-piggyback run and its wattage is the low end of the field guide's 30-35 W range. Sources for 6G9 / 6G9-A / 6G9-B (1) Mojotone/Ampwares Fender field guide, 'Fender Blonde Tremolux' — 1961-1963, 30-35 W, piggyback; schematics 6G9, 6G9-A and 6G9-B; 7025 preamp, 6G9 with two 6BQ5 and the 6G9-A/B with two 6L6GC; fixed non-adjustable bias, GZ34 rectifier; Normal and Bright channels each with volume, treble and bass — mojotone.com	history entry Open requests for 6G9 / 6G9-A / 6G9-B ↗ Suggest research for 6G9 / 6G9-A / 6G9-B ↗
AA763	1963–1966	35 W	push-pull 2x6L6GC	The blackface generation, on the AA763 circuit: 35 W from a 6L6GC pair, a Normal channel and a vibrato channel each with a bright switch and a treble/bass stack, and a standby switch on the back panel. The model is dropped in 1966, and the Tremolux line ends with it. Sources for AA763 (1) Mojotone/Ampwares Fender field guide, 'Fender Blackface Tremolux' — 1963-1966, 35 W, piggyback, schematic AA763, 7025 preamp, two 6L6GC, fixed bias; Normal and Vibrato channels with bright switches, standby on the back panel — mojotone.com	history entry Open requests for AA763 ↗ Suggest research for AA763 ↗

The circuit column says how far this model has been documented, in three states. A circuit ↗ badge links a verified circuit: redrawn schematic, parts list, and a simulated operating point held against the published voltage chart under a maintainer's sign-off. A draft ↗ badge links a circuit that is drawn, sourced and published, but has not completed that chain — its own page states what is unresolved. A history entry is placed, dated and sourced here, but its circuit isn't drawn at all yet.

Dating & notes

Tweed-era sub-circuit dating is approximate: the field guide brackets the whole narrow-panel run to 1955-1960 and dates the three drawings 55, 55-56 and 57-60 without firm boundaries, so those ranges are defensible spans rather than hard dates. The 18 W figure is the field guide's rating for the narrow-panel line and is a factory-era number, not a measured output. Only the 5G9 is a documented circuit here; the other rows are history-tier entries. A 5E9-A entry, if one is ever added, belongs to its own published drawing — the 5G9 sheet's note that late 5E9-A models are similar is the factory's remark about a neighbouring revision, not a licence to document one designation from the other's drawing.

Sources

Each model's own citations are listed in its row above, under “Sources for …”. The complete data behind this line — every model's fields as stored, including those the page doesn't print — is in history/families/tremolux.yaml.

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