Accuphase E-303 (1983)
High-end integrated stereo amplifier with MOSFET output and direct-coupled phono stages, released in December 1983.
Overview
The Accuphase E-303 is a high-end integrated stereo pre-main amplifier released in December 1983. It was designed with digital sources like PCM and CD in mind, and it uses technology from Accuphase’s high-grade separate components. The preamp section has a balanced, symmetrical circuit. The power amp delivers 150W/ch into 8Ω with exceptionally low distortion. The phono stage is fully discrete and FET-based, for both MM and MC cartridges. MC input impedance is switchable (10Ω, 30Ω, 100Ω), and a dedicated flat amplifier sits before the EQ stage for minimal signal loss.
Specifications
| Power Output (8 Ω) | 150W/ch |
| Total Harmonic Distortion | 0.01% (20Hz–20kHz, >4Ω) |
| Frequency Response | 20Hz–20kHz ±0.2dB (main amp, rated output) |
| Damping Factor | 150 (8Ω, 50Hz) |
| Input Sensitivity / Impedance (MM) | 2.7mV / 47kΩ |
| Input Sensitivity / Impedance (MC) | 0.085mV / 10, 30, 100Ω selectable |
| Preamp Output | 1.4V / 200Ω |
| Tape Rec Output | 170mV / 200Ω |
| Headphone Output | 0.4V, 4–100Ω |
| Tone Controls | 10-step, ±7.5dB in 1.5dB steps (Bass: 200Hz/500Hz, Treble: 2kHz/7kHz) |
| Subsonic Filter | 17Hz, -12dB/octave |
| Power Supply | 100/117/220/240VAC, 50/60Hz |
| Power Consumption | 550W (8Ω rated output) |
| Dimensions | 445 × 160 × 370 mm (W×H×D) |
| Weight | 20.5 kg |
| Original Price | ¥298,000 (Japan, 1983) |
Design
The E-303 uses a triple push-pull output stage with six MOS FETs, giving a 600W PD margin. The entire signal path - from MC head amp to power output - is directly coupled. There are no capacitors in the signal chain, and DC servo circuits prevent drift. The phono preamp is FET-based, with dual FET packages and thermally bonded transistor pairs. The MC input has its dedicated flat amplifier ahead of the EQ stage. The tone control is a precision switch type with 1.5dB steps. Signal routing goes through gold-plated, hermetically sealed crossbar relays placed close to the inputs to keep the signal path short. The illuminated VU meters show logarithmic peak levels referenced to 8Ω.
Context
The E-303 belongs to a lineage that began with the E-202, Accuphase’s first integrated amplifier (1973). It evolved from the E-305 and shares its design approach with other models like the E-302 and E-305V. The E-303X variant has solid aluminum rotary potentiometers instead of the base model’s linear slide pots, which some reviewers prefer for durability and value. Accuphase was founded in late 1972 by former Kenwood engineer Jiro Kasuga. It built its reputation on high-grade separates before refining those designs into integrated units like the E-303.
Market
Current market prices range from €1,800 to €3,499, depending on condition and region. Common problems are dry solder joints, failed mute relays, DC offset drift, and degraded capacitors that need recapping. Some units are advertised as overhauled ("revidiert") or fully recapped. Maintenance often means replacing thermal pads, repairing traces, and servicing connectors damaged by mishandling.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Service Manuals, Schematics & Catalogs
- Schematic — audiocircuit
- Service Manual — audiocircuit
- Service Manual — archive.org