Adcom

Browse Adcom vintage audio equipment in the Vintage Technology Archive.

Amplifiers

• GFA-1 (1979) — Adcom GFA-1 (1979) bridged power amp — four amplifiers in pairs, 200W/ch into 8 ohms, 340W into 4 ohms measured by Hirsch-Houck.
• GFA-1A — Adcom GFA-1A stereo power amplifier, 200 W/ch into 8 ohms, toroidal transformer, balanced bridge topology, successor to the GFA-1.
• GFA-2 — Adcom GFA-2 stereo power amplifier (early 1980s). Known for dual independent power supplies per channel. Little documentation survives; a few period product announcements confirm its 100W rating and a…
• GFA-545 II (1991-94) — Adcom GFA-545 II power amplifier (1991-94). A refinement of the original GFA-545 with a massive power supply and thermal protection.
• GFA-555 II — Adcom GFA-555 II stereo power amplifier, 200W/ch, the refined second-generation version of the legendary GFA-555. Period reviews describe it as a high-value reference amp.

Cd Players

• GCD-300 — Adcom GCD-300 compact disc player — thin documentation, but known specs include 4x oversampling, dual 18-bit DACs, 0.004% THD.
• GCD-575 — Adcom GCD-575 CD player. Features 176.4 kHz sampling, dual DACs, Class A output, low output impedance. Little documented.

Power Amplifier

• 555II — Adcom GFA-555II power amplifier: 200W/ch MOSFET design, legendary budget high-end sound. Specs, history, and buying notes.

Power Amplifiers

• GFA-2535 — Adcom GFA-2535 multi-channel power amplifier, c.1992-1994. Switchable 3/4-channel operation, 200W per channel, award-winning home theater/multi-room amp.
• GFA-535 — Adcom GFA-535 power amplifier, 60 W/ch, praised by Sam Tellig in HiFI-Stereo as best in its price class. This page has production dates.
• GFA-545 — The GFA-545 was the smaller sibling to Adcom’s celebrated GFA-555, sharing the same basic circuit topology at a lower power rating and price.
• GFA-565 (1989 – c. 1992) — Adcom GFA-565 monoblock power amplifier (1989–c.1992). 300W/8Ω, 450W/4Ω, 850W/2Ω at <0.02% THD, >60A output. A GFA-555 evolved; sold in pairs.
• GFA-5802 — Adcom GFA-5802 power amplifier, 300W/ch into 8 ohms, 450W/ch into 4 ohms, Class A front end, XLR and RCA inputs. Documented only through 1997-1998 period advertisements.
• GFA-585 (1990–1997) — Adcom GFA-585 (1990–1997) stereo power amplifier. 200W/ch rated, 1.2 kVA toroidal, dual-mono, Sanken outputs. $800 new, $400–$700 used. A giant killer with known heat and hum issues.
• GFA-7000 — Adcom GFA-7000 five-channel THX power amplifier, 130Wx5 into 8 ohms, documented in 1996-1997 HiFI-Stereo and Audio reviews.
• GFA-7500 — What little is known about the Adcom GFA-7500 comes almost entirely from a pair of period reviews in HiFI-Stereo. It was a THX-certified multichannel
• GFB-800 — Adcom GFB-800 Music Control Center — whole-house audio distributor from c.1990. Little documented; known from Audio magazine ads and specs.

Preamplifiers

• GFP-1 — Adcom GFP-1 preamplifier. Little-documented companion to the GFA-1 power amp. Period reviews note discrete circuitry, stepped attenuator.
• GFP-565 (1989–?) — Adcom GFP-565 stereo preamplifier (1989–?), 5Hz–90kHz, 0.0025% THD, 100-ohm main out. A sub-$1000 purist preamp with a loyal modder following.
• GFP-750 — Adcom GFP-750 stereo preamplifier (1997–?), fully balanced design with Pass Labs Alep P lineage, 102 dB S/N, relay-switched source selection.

Tuners

• GTP-400 — Adcom GTP-400 tuner/preamplifier (1988-1993). A separate-component alternative to receivers, praised in Audio and HiFI-Stereo for signal-to-noise and scan tuning. Little else documented.

Unknown

• 545II — Adcom GFA-545II power amplifier, circa 1991. Little documented beyond period ads in Audio magazine. High-current design with thermal protection and distortion alert.
• AND-100 — Adcom AND-100 integrated tuner/preamplifier with 100 W/ch amplifier, phono and high-level inputs, source lights, and wireless remote — known mainly from 1986-87 magazine coverage.
• NAD-1700 — Adcom NAD-1700 preamp/tuner, nearly undocumented. Only known reference is a May 1991 HiFI-Stereo review listing a NAD Model 1700 at $799 with discrete phono stage, infrasonic filter, and motorized vol…

Other Models

• GFA-5200 — Adcom GFA-5200 power amplifier — 50W into 8 ohms, 80W into 4, MOSFET output stage, 27,000 µF filter bank. The small Adcom that punches well above its rating.
• GFA-5400 — Adcom GFA-5400 two-channel MOSFET power amp — 125W into 8Ω, 200W into 4Ω, in two versions (v2 adds output protection). Known specs and service notes.
• GTP-450 — A stereo tuner preamplifier from Adcom, released in 1993 with a design intended to pair with high-current power amplifiers.
• GTP-502 — A stereo tuner preamplifier from Adcom, noted for clean sound reproduction and integration with high-end audio systems. With full specifications.