Value in this archive is a reading with a basis attached, never a number pulled out of the air. Where a sold-price sample exists it is published as a sold reading; where only asking prices or old auction guides exist, the figure says so.
| Class | Years | Market data | What drives it |
|---|---|---|---|
| Valve power amplifiers (McIntosh MC-series, Quad II, Dynaco ST-70) | 1953–1971 | Sold samples on the British and American icons; estimates elsewhere | Output transformers, originality, matched valve sets |
| Valve preamps and control units (Quad 22, Marantz 7, McIntosh C-series) | 1954–1965 | Mixed: sold samples plus dealer asking prices | Phono stage condition, original case, service history |
| Early transistor amplifiers and receivers | 1965–1980 | Dealer and forum asking prices | Serviceability, original output devices, cosmetic condition |
| Turntables (Garrard 301/401, Thorens TD-124, Dual) | 1953–1975 | Sold samples on the idler-drive icons | Bearing type, plinth, original arm, platter condition |
| Tape machines (Revox A77, B77, G36) | 1966–1989 | Dealer asking prices | Head wear and remaining life, motor condition, version |
| Kit equipment (Heathkit, EICO, Knight) | 1947–1972 | Thin: asking prices only | Quality of the original assembly, which is hard to inspect remotely |