Every voltage, part value, and tube model in this archive traces back to primary literature — datasheets, tube manuals, and the engineering references of the era. This is that shelf, kept in the open. For how the circuits relate across time, see the family histories and the lineage tree.
Original metrology write-ups from building the corpus — the questions the published data raised, and how we resolved them.
Interactive bench tools and quick references built from the same corpus — decode a part, run the small sums that come up while working on these circuits, or look up a term.
The ten tubes this corpus documents — nine SPICE models; the 6L6G shares the 5881 family model — each with the manufacturer datasheets its model is fitted and cross-checked against. How the models are derived →
Receiving-tube manuals, catalogs, substitution guides, and the tube-amplifier design handbooks — the reference shelf for ratings, base diagrams, and circuit conventions. The tag on each entry records the basis for its copyright status.
Foundational tube theory — amplification factor, plate resistance, mu, and the triode/amplifier math that every later design manual builds on.
(published 1920)
Beginner-level, non-mathematical account of the tube as detector and amplifier — plain-language circuit explanations.
(published 1922)
Vacuum-tube amplifier circuits, transmitting/receiving apparatus design, and general radio measurement technique.
(published 1920)
The earliest Radiotron tube-type catalog — ratings for the 1920s receiving and detector tubes.
(published 1924; also carries a CC Public Domain Mark)
Early-1930s Radiotron tube manual — base diagrams and characteristics for the transition-era tube lineup.
(1932 itself is renewal-dependent; renewal not independently verified)
Base diagrams, ratings, and typical circuits for the late-1930s tube lineup.
(1937 is renewal-dependent; not independently verified)
Post-war receiving-tube manual — ratings and base diagrams for the tube generation feeding the earliest tweed-era amplifiers.
the 1974-75 CCE Books renewal lists (the window for a 1947/48 work) were searched directly and carry no RCA/Radiotron/Receiving Tube Manual renewal. Keyword-based, not a certified negative.
Ratings and base diagrams for early-1960s receiving tubes — covers many of the preamp and driver tubes in blackface-era circuits.
(1961; hosted via bitsavers, freely downloadable)
The last major RCA receiving-tube manual before the 1964+ renewal-certain window begins.
(1963, edge of the window; hosted via bitsavers)
Full receiving-tube manual — ratings and base diagrams for the early-1950s lineup.
(1951; no PD mark; freely hosted)
Full tube manual for the late-1950s lineup — covers many tubes used in blackface-era circuits.
(1959; no PD mark; freely hosted)
Classic tube-amplifier design reference — push-pull output stages, power-supply design, distortion analysis. A direct ancestor of guitar-amp topology.
(1941; no PD mark or renewal evidence found)
The definitive tube-amplifier design bible (1300+ pages) — output- transformer design, push-pull classes, negative feedback, distortion, and resistor/capacitor/potentiometer characteristics. The most-cited reference in guitar-amp design literature.
higher-risk — first published in Australia, so a US copyright could have been restored under URAA regardless of US renewal. Link only; do not treat as clear-PD without specialist review. (This is the full-access scan, not the borrow-only copy.)
Cross-reference of American receiving tubes with industrial and European substitutes.
(1960 is renewal-dependent; not independently verified)
Cross-brand tube substitution guide — useful for finding period-correct alternates for a vintage circuit.
(1950; no PD mark; freely hosted)
First-edition tube substitution cross-reference — direct and near-direct replacements across manufacturers.
(1950; no PD mark; freely hosted)
The primary references behind the non-tube parts — output and power transformers, carbon-composition resistors, paper and electrolytic capacitors, rectifiers, speakers, and the early transistors of the pedal era.
The standard tube-era output/power-transformer design monograph — core materials, winding topology, leakage reactance, interleaving, frequency response.
(hosted unrestricted in the folkscanomy electronics collection)
Foundational transformer theory — magnetics, core loss, leakage reactance, regulation — underlying all later output-transformer design texts.
(1938; unrestricted full download)
Carbon-composition resistor characteristics, capacitor theory, potentiometer/attenuator taper laws, transformer and rectifier reference data — a comprehensive era-correct engineering reference.
(Digital Library of India scan; full open download)
Resistor and capacitor theory (paper and electrolytic), rectifier circuits, transformer design, and volume-control taper curves — the other essential period cross-reference alongside Reference Data for Radio Engineers.
(hosted unrestricted; full download open)
A dedicated monograph on wet/dry electrolytic-capacitor design, manufacture, aging, leakage, and application — a primary source on the behavior of the era's filter capacitors.
(archive description states "Original copyright 1945, copyright not renewed")
Manufacturer trade periodical on paper and electrolytic capacitor construction, application notes, and period characteristics.
(hosted unrestricted; full open download)
Forward-drop and aging characteristics, voltage-multiplier topologies, thermal derating, and replacement data — the definitive period selenium-rectifier reference.
(hosted unrestricted; full open download)
Manufacturer engineering data for the carbon-composition ("hot-molded") resistor line used throughout vintage tube amps — tolerance, temperature and voltage coefficients, long-term drift. Dated 1975 but describes the unchanged formulation used since the 1930s-40s.
(manufacturer literature; linked for access only)
Manufacturer catalog with explicit Alnico-5 magnet weights and specs across the line — Jensen was the principal alnico speaker supplier to guitar-amp makers of the era.
(1965 catalog; status not verified; linked for access only)
Germanium alloy-junction transistor theory and specs (2N43A family) — early-germanium reference for future fuzz/booster pedal research.
(hosted unrestricted; not independently dated)
PNP germanium alloy/alloy-diffused transistor data — squarely in the era of the classic germanium fuzz/booster circuits (Fuzz Face, Tone Bender).
(hosted unrestricted)
Germanium-to-silicon transition-era transistor manual — device data and bias/application notes matching the vintage of the earliest fuzz/booster designs.
(bitsavers mirror, unrestricted)
Copyright tags are this project's good-faith reading of the
evidence, not legal advice — pd-outright (published pre-1931),
non-renewal (renewal window searched, none found),
pd-mark (a Public Domain Mark applied by the archive),
renewal-dependent (status turns on a renewal check we have not
completed), in-copyright (linked for access only). When in doubt we
link rather than rehost.