Accuphase E-306 (1994)
Twenty kilos of champagne-gold integrated amplifier that Accuphase built to embarrass its own separates - and priced at ¥260,000 to make the point.
Overview
Accuphase released the E-306 in December 1994 at ¥260,000. The price and the power rating are not the interesting part. The architecture is. The company designed this as a true integrated pre-main amplifier with the preamplifier and power amplifier sections kept fully independent, electrically and structurally separated to keep interference out of the signal. You get the convenience and small footprint of an integrated, without the compromises that usually come with sharing a chassis and a power supply between the two halves. Accuphase positioned it as an amplifier whose sound quality rivaled top-tier separates. The spec sheet backs up the ambition, though it can't prove the claim.
The power numbers are the conservative sort Accuphase was known for. Contemporary spec listings in HiFi-Stereo (1996, p.61) confirm the E-306 as a 100-W/ch integrated, quoting 100 W × 2 continuous average into 8 ohms from 20-20,000 Hz. Rated continuous average power is 100 watts per channel into 8 ohms, rising to 120 into 6 and 140 into 4, all specified across the full 20 Hz to 20 kHz band with both channels driven. Distortion is quoted at 0.04% into a 4-16 ohm load, with IM distortion at 0.01%. One service-document excerpt floating around lists a 180 W/ch figure at 0.02% THD with no load impedance attached. That doesn't square with the manufacturer's own ratings, so treat it as an unresolved anomaly and not a second spec.
The current-feedback topology is what sets the E-306 apart from a generic mid-nineties integrated. Accuphase fed the output signal back as a current rather than a voltage. That drops the impedance at the feedback input so low that phase rotation becomes unlikely and almost no phase compensation is needed. According to the design literature, the payoff is excellent dynamic behavior - clean start-up and a natural energy response that voltage-feedback designs struggle to match. The power stage uses parallel audio power transistors. The supply is built around a transformer of roughly 500 VA feeding two 22,000 µF filter capacitors.
Key Features
Current-Feedback Circuit, Discrete Throughout
The E-306's amplifier circuit is current-feedback and fully discrete, with no op-amps in the line stage. The line amplifier uses Accuphase's differential-pure complementary push-pull input feeding a single-ended push-pull emitter-follower output stage. The current-feedback approach is the reason the amp feels quick and unflustered on transients rather than soft or rounded. The company applied the same design philosophy across its separates of the period.
Dedicated MM and MC Phono Stages
Instead of one compromise phono input, the E-306 carries separate equalizer circuits tuned to each cartridge type. The MM side is built around FET elements that hold input impedance high across the whole frequency range, so the cartridge isn't loaded down. The MC side uses a low-noise differential input with a reduced-impedance NFB loop to pull clean signal out of very low-output coils. Sensitivity runs 3.9 mV into 47k ohms for MM and 0.11 mV into 100 ohms for MC, with signal-to-noise of 85 dB and 70 dB respectively. Gain from the MC input to the tape output is a hefty 60 dB.
Sealed Gold-Plated Relay Switching
Input selection is handled by a logic-controlled relay scheme rather than a mechanical selector, which keeps the signal path as short and direct as possible. The relays are sealed communications-grade types with gold-plated cross-bar twin contacts. That means low contact resistance, high durability, and no noisy switch contacts to clean twenty years down the line.
Motorized Volume and the RC-14 Remote
The volume control pairs a high-quality attenuator with a small motor and clutch for smooth remote operation, driven by the included RC-14 Remote Commander over infrared pulse. The remote also handles input selection through the logic circuit. It takes two AAA batteries and measures 45 by 136 by 18 mm, 85 grams with batteries. That's modest by modern standards, but it was a genuine convenience feature in 1994.
Preamp and Power Amp, Separable
A selector switch and dedicated input/output terminals let the preamplifier and power amplifier sections be used entirely independently. Owners can run the E-306 as a standalone preamp into a bigger power amp, or feed its power stage from an outboard preamp. Most integrateds never offer that. Combined with the electrical and structural separation of the two halves, it's the clearest expression of the design's separates-rivaling intent.
Logarithmic Peak-Hold Power Meters
The large analog meters use logarithmic compression with a peak-hold function, so a wide dynamic range reads clearly at a glance and fast musical transients don't flash past unregistered. The scale reads directly in dB against an 8-ohm load. The meters are the visual signature of the amp.
Balanced Inputs and Practical Connectivity
Two balanced inputs are provided alongside the single-ended set, with balanced sensitivity of 113 mV into 40k ohms. There are nine inputs in total including the phono and tape connections, a subsonic filter at 25 Hz with a 12 dB/octave slope, and a loudness compensator giving +6 dB at 200 Hz. The speaker terminals are large enough for thick cable and accept banana plugs. Frequency response from the main input is 20 Hz to 20,000 Hz, +0/−0.2 dB. The low-level inputs run +0.2/−0.5 dB over the same band. Headphones from 4 to 100 ohms are accommodated.
Historical Context
Accuphase built the E-306 as a premium alternative to the big American and Japanese names. Dealer literature of the era pitched Accuphase integrateds directly against McIntosh and Luxman, and the E-306 was the model carrying that argument in the mid-nineties. The dating needs a flag. The release is documented as December 1994, but some resale listings describe production as running from 1993 to 1997. The Archive treats December 1994 as the reliable release date and leaves the end of production unconfirmed. A separate model, the E-306V, exists and is a different amplifier. Its specs don't transfer, and the relationship between the two isn't documented in the sources available here.
Collectibility & Value
The E-306 trades in the $2,500 - $2,700 range on the used market, based on recent eBay listings for units described as excellent condition and tested. One of those listings specifies 100 V operation, which is the standard Japanese domestic voltage. Export buyers should confirm whether a step-down transformer is included or required before committing. Pricing guides exist on Audiogon's Bluebook and HifiShark aggregates listings, but no specific benchmark prices were captured from either. The sources available document no pattern of common failures or maintenance headaches. Beyond the usual advice to verify the motorized volume and meter function on any forty-year-old amplifier, buyers are largely on their own.
eBay Listings
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