Accuphase A-45 (2006)

Name: Accuphase A-45
Brand: Accuphase

Pure class A stereo power amplifier released in November 2006, featuring fully balanced signal paths and MCS+ topology.

Overview

The Accuphase A-45 is a pure class A stereo power amplifier developed using design technology from models A-60 and A-30, positioned between them in the product lineup. It was released in November 2006 and manufactured in Japan under the NICOLOGY standard. The amplifier features fully balanced signal paths from input to output stage, uses power MOS-FET devices in a six-parallel push-pull configuration per channel, and can be bridge-connected for monaural operation. It includes 4-stage gain control and an analog power meter with OFF and sensitivity switching functions.

Specifications

Amplifier Class	A (NICOLOGY)
Rated Output (Stereo, 8 Ω)	45W + 45W
Rated Output (Monaural, 8 Ω, bridge)	180W
Total Harmonic Distortion (Stereo, 4–16 Ω)	0.03%
Frequency Response (rated output)	20 Hz – 20 kHz ±0.2 dB
Gain	28.0 dB (max)
Input Sensitivity (8 Ω, stereo, max gain)	0.76 V
Input Impedance (Balanced)	40 kΩ
Input Impedance (Unbalanced)	20 kΩ
S/N Ratio (A-weighted, max gain)	115 dB
Damping Factor	200
Power Consumption (no signal)	235 W
Dimensions (W×H×D)	465 × 211 × 464 mm
Weight	30.9 kg
Power Supply	100 VAC, 50/60 Hz

Design

The A-45 uses a fully balanced instrumentation amplifier design with MCS+ and current feedback circuits, extending parallel operation to the A-class drive stage. The signal path is fully balanced from input to output, with gold-plated copper foil on PCBs. Each channel uses six parallel push-pull power MOS-FETs. The power supply features a 600 VA toroidal transformer and 47,000 μF×2 smoothing capacitors. The amplifier supports stereo, dual mono, and bridge modes via a mode selector switch and includes balanced XLR and unbalanced RCA inputs. Speaker terminals accommodate Y lugs or banana plugs.

Context

The A-45 sits between the A-60 and A-30 in Accuphase’s lineup, offering 50% more power than the A-30 while costing half as much as the A-60. It shares the brand’s signature champagne/gold faceplate and dual analog power meters.

Market

The original price was ¥570,000. Used units have listed at $4,200 USD, €4,900, and NT$120,000. Original documentation has sold for up to €8, and catalog listings have received bids up to ¥1,100.

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