Vacuum tube reference & design toolkit
Amperatubes — Vacuum Tube Design Companion: 339 tubes, 286 SPICE models, 54 learning guides
Datasheets, SPICE models, interactive loadline calculators, and 54 learning guides for vacuum tube circuit design.
Six pro tools at your bench
Loadline calculator, AI assistant, recommender, hum-hunting workbench, cathode-follower designer and a clean schematics review board — every tool the site has, on one page.
has a voice.
Drag the Q-point across the plate characteristic curves and watch power, distortion, and gain respond in real time. 286 tubes with full Koren SPICE models ready for simulation.
Every tube
has a voice.
Drag the Q-point across the plate characteristic curves and watch power, distortion, and gain respond in real time. 286 tubes with full Koren SPICE models ready for simulation.
339 vacuum tubes. Full specs, datasheets, Koren SPICE parameters.
Supply voltage, bias, load. SE or push-pull. Class A, AB, or B.
Output power, H2/H3 distortion, gain, impedance. Transfer curves.
Two tubes, every angle covered
Half-day deep-dives with live SPICE, photos, datasheets, NOS-field notes, sound DNA, anatomy, 3D render — the encyclopedia format we wish existed for every flagship tube.
The 12AX7 / ECC83
The most-used tube ever made — and the one most misunderstood.
High-mu twin triode that defined an era of recording, broadcast and guitar amplification. We trace it from RCA 1947 through Mullard, Telefunken, Amperex, RCA red-base, GE, Sylvania, JJ, Sovtek and modern reissues — with three Koren variants, a 3D render and the most precise photographic ID guide on the web.
- 20+ NOS variants documented
- Live SPICE simulator
- Authenticity field guide
- Sound-DNA per maker
Three tracks. Pick yours.
From "what is a tube" to "design my own OTL": 54 guides curated into three depth levels — from a 30-minute primer to a half-day flagship encyclopedia.
The eight houses that built the century
Mullard Blackburn, Telefunken Berlin, RCA Harrison, GE Owensboro — every flagship factory, sortable by era, type, rarity and dissipation.
339 Vacuum Tubes
From octal-base power triodes to miniature noval preamp tubes — each entry includes full electrical specifications, pinout diagrams, sonic character descriptions, operating presets, and SPICE model parameters where available.
One palette. Everything.
Tubes, guides, glossary, topologies, manufacturers — searchable by alias, by filter, by natural language. The fastest way to anything on Ampera.
- 4 corpora indexed: tubes · guides · glossary · topologies
- Semantic ranking — "warm preamp triode" finds 12AX7
- Inline filters: type:triode mu>50 maker:mullard
- Compare basket — pin tubes with ⌘↵, fire /compare
Compare Any
Two Tubes
Overlay plate curves, compare gain structures, and see which tube fits your circuit. Every specification side by side.
Open Comparator →The Story of
Amplification
Fleming Valve
John Ambrose Fleming patents the first thermionic diode — the vacuum tube is born.
Miniature Revolution
Noval-base miniatures replace octals, shrinking amplifiers and enabling hi-fi.
Audiophile Renaissance
New-production tubes from Russia and China reignite demand for valve amplification.
Independent technical companion — always cross-check with official datasheets
Built by Jean-Michel Falligan — independent project, Paris
Start designing.
339 tubes · 286 SPICE models · 54 guides · Free & open