Accuphase E-306V (1997–2001)
A 20.5 kg integrated amplifier with a 500 VA transformer, two 22,000 µF capacitors, and a rear slot for optional input boards.
Overview
The first thing you notice is the mass. It weighs 20.5 kg in a chassis measuring 475 mm wide, 170 mm tall, and 418 mm deep. That weight isn't ornamental. Inside sits a 500 VA power transformer feeding two 22,000 µF electrolytic capacitors, a power supply sized for serious current delivery.
The E-306V is Accuphase's refined take on the earlier E-306, released in December 1997 and manufactured through 2001 according to hifi-wiki.com. It's a Japanese-built integrated stereo amplifier with a modular layout. The preamplifier and power amplifier sections are built independently, each with its own power supply circuitry, and a SEPARATE switch lets you decouple them entirely. You can use the preamp out to drive something else, or feed the power amp from an external preamp. That kind of flexibility in a one-box design is rare.
Power output is rated at 140 watts per channel into 4 ohms, 120 watts into 6 ohms, and 100 watts into 8 ohms. The amp gains power as impedance drops rather than choking, which says the power supply is doing its job. THD is specified at 0.035% across a 4 to 16 ohm load range, and frequency response from the main amp input holds 20 Hz to 20 kHz within ±0.2 dB at rated output.
Accuphase built this one to be serviced and expanded. An AAB-standard slot on the rear accepts optional boards. The Line-10 at ¥8,000 adds another line input, and the AD-10 Analog Disk Input Board at ¥50,000 adds a phono stage with MM and MC capability. The remote commander (RC-22) handles volume and input switching via infrared pulse and runs on two AA batteries. A remote is handy on a piece of gear this heavy, especially when it's racked low.
Key Features
Current Feedback Topology in Both Stages
Most amplifiers of this era used voltage feedback in their gain stages, which tends to narrow bandwidth as gain increases. The E-306V uses current feedback in both the power amplifier and line amplifier sections. As Accuphase describes it, the benefit is stable frequency response across gain changes, so the amp doesn't change character depending on where the volume sits. Phase shifts in the upper frequencies are minimized, which gives cleaner transient behavior and a more consistent tonal picture from quiet late-night listening to full-tilt playback.
Parallel Push-Pull Output Stage
The power amplifier section uses a parallel push-pull output stage built around high-performance audio transistors on a large heat sink. Running multiple output devices in parallel spreads the current load and keeps each transistor in a more linear region. The heat sink is there to hold thermal stability during sustained high-output passages. The amp draws 385W at rated 8-ohm output, versus just 50W at idle, so the heat sink has real work to do.
Discrete Line Amplifier with Differential Complementary Circuit
The line amplifier is fully discrete, with no op-amps and no integrated circuits in the signal path. It uses a differential pure complementary push-pull circuit with an emitter follower output stage. This is old-school, parts-intensive design, and it's increasingly rare in integrated amplifiers. Gain is 28 dB from the main input to the output and 20 dB from the high-level input to the pre-out. Input sensitivity for high-level and balanced inputs is 113 mV for rated output, with input impedances of 20 kΩ (unbalanced) and 40 kΩ (balanced).
Logic-Controlled Relays with Gold-Plated Crossbar Contacts
Input switching runs through logic-controlled relays with hermetically sealed, gold-plated twin crossbar contacts. These aren't cheap sealed relays. They're the type developed for telecommunications applications, where contact reliability over thousands of cycles is required. The relay layout keeps signal paths short, and the gold plating resists the oxidation that would otherwise degrade contact quality over decades of use.
Summing Active Filter Tone Controls
The bass and treble controls aren't simple shelving networks. They use summing active filters derived from professional graphic equalizer designs - bass ±10 dB at 300 Hz, treble ±10 dB at 3 kHz. When set flat, the signal bypasses the filter network entirely, which preserves signal purity. The loudness compensator adds 6 dB at 200 Hz when the volume is set 30 dB down, for low-level listening when the ear's sensitivity to bass drops off.
Logarithmic Peak Power Meter and Brass Speaker Terminals
The front panel has a logarithmic compression peak power meter with analog display. It's a moving-needle meter that reads actual power output rather than just signal presence. The speaker terminals are solid brass, machined rather than stamped, and accept heavy-gauge cable without complaint. That sort of detail costs real money to implement.
Modular Expansion via Rear Slot
The rear-panel AAB-standard slot accepts optional input boards, so the E-306V can be configured to the user's system rather than fixed at the factory. The Line-10 board adds a line-level input for a CD player, tuner, or DAC. A used E-306V with the AD-10 already installed adds meaningful value.
Historical Context
The E-306V was released in December 1997 as a further refinement of the E-306, which Accuphase had already established as a successful integrated amplifier. The company's own materials describe the V as "a further refined and enhanced instrument for totally faithful music reproduction," drawing on experience gained building separate preamplifier and power amplifier components. Production ran through 2001 according to hifi-wiki.com, though at least one European listing claims a 1996 release. That discrepancy may reflect regional launch timing or a seller's imprecision.
The model shares design lineage with a cluster of Accuphase integrated amplifiers from the same period: the E-305, E-305V, E-307, E-308, E-350, and E-406V, the last of which was rated at 170 watts per channel into 8 ohms with 0.02% THD according to HiFI-Stereo (1999, p.95). The E-306V sits in the middle of that range, more powerful than the E-305 variants and less so than the E-406V, which was rated at 170 watts per channel into 8 ohms. It's recognized as a classic model in the Accuphase lineup, and the company still references the original English-language information folder on its own website.
Collectibility & Value
The E-306V trades regularly on the used market, with listings on Reverb, Audiogon, HifiShark, and various Japanese and European marketplaces. A unit in very good condition was listed for $3,200 approximately five years ago. That's the most concrete price data point available, though it's dated. At the other extreme, a 1997 unit sold on Yahoo Auctions for ¥500 in July 2025, which is almost certainly an outlier: a parts unit, a mislisted item, or a sale where the final price wasn't captured correctly. Treat that figure as an anomaly.
Condition notes on surviving examples typically mention light natural aging with minor scratches and scuffs. One Audiogon seller described their unit as being in "perfect condition" and noted it had been carefully maintained. No common failure points have been documented in available sources, and spare parts availability isn't well-documented either. Accuphase's modular construction and discrete circuitry should make these amps serviceable by any competent technician, with no proprietary ICs to fail and no surface-mount parts to navigate.
When shopping, verify the SEPARATE switch functions correctly, confirm the relay switching works cleanly on all inputs, and check whether the optional boards are included. A unit with the AD-10 phono board installed is significantly more useful than a bare line-stage version. Shipping is a consideration. At 20.5 kg, one seller quoted a flat $80 rate within the contiguous United States including packaging and insurance, which is reasonable for a unit this heavy.
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