Accuphase A-48 Class A Stereo Power Amplifier

The A-48 is a full-fledged "pure class A stereo power amplifier" that has been redesigned based on the design technology developed for the higher-end model, and has been refined to have an attractive sound quality.

The output element uses high-performance audio-grade power MOSFETs, and is driven by 6 parallel push-pull pure class A per channel.

This allows the amplifier output to have a low impedance, and constant voltage drive is possible to support low impedance loads, achieving linear power against the load impedance of 45W/8Ω, 90W/4Ω, 180W/2Ω, and 360W/1Ω (music signal only) per channel.

The input circuit also uses an "instrumentation amplifier" configuration.

This method configures the entire power amplifier, including the signal input stage, as a balanced amplifier, and the signal path from the input terminal to the power amplifier stage is fully balanced.

Thanks to the excellent technology inherited from the higher-end model, a signal-to-noise ratio of 117dB and a damping factor of 800 have been achieved.

Furthermore, by using two A-48s in a bridged connection, you can upgrade the amplifier to a high-output monophonic amplifier of 180 W/8 Ω, 360 W/4 Ω, or 720 W/2 Ω (music signal) per channel.

■Power MOSFET 6-parallel push-pull circuit

■Linear output characteristics to load impedance

■Powerful power supply with large toroidal transformer and large-capacity 60,000μF filter capacitor

■Instrumentation amplifier

■Signal input section with high-gain discrete configuration

■Equipped with dedicated power supply for signal input section

■Equipped with line input terminals and balanced input terminals

■Polarity switching function for balanced input terminals

■Equipped with MCS+ circuit

■Equipped with current feedback amplifier circuit

■Uses MOSFET switch for protection circuit

■High damping factor: 800

■Uses balanced remote sensing

■Equipped with speaker output protection circuit to prevent short circuit accidents

■Equipped with high-sensitivity large power meter

■Equipped with two large speaker terminals

■4-stage gain control function

■Bi-amp connection and bridge connection possible

■Aluminum hairline finish top plate

Rated continuous average output (between 20 and 20,000Hz)

Note: (※) loads are limited to music signals.

In stereo mode (both channels operating simultaneously)

360W/ch 1Ω load (※)

180W/ch 2Ω load

90W/ch 4Ω load

45W/ch 8Ω load

In monophonic mode (bridged connection)

720W 2Ω load (※)

360W 4Ω load

180W 8Ω load

●Total harmonic distortion

In stereo mode (both channels operating simultaneously)

0.05% 2Ω load

0.03% 4-16Ω load

In monophonic mode (bridged connection)

0.05% 4-16Ω load

●IM distortion

0.01%

●Frequency response

At rated continuous average output: 20-20,000Hz +0 -0.2dB

At 1W output: 0.5-160,000Hz +0 -3.0dB

●Gain (gain selector switch at MAX)

28.0dB

(both stereo and monophonic modes)

●Gain selector: Gain (dB)

MAX:28 -3dB:25 -6dB:22 -12dB:16

●Load impedance

Stereo mode 2-16Ω

Monophonic mode 4-16Ω

●Damping factor

800

●Input sensitivity (8Ω load)

Stereo mode 0.76V at rated continuous average output

0.11V at 1W output

Monophonic mode 1.51V at rated continuous average output

(bridged connection) 0.11V at 1W output

●Input impedance

40kΩ balanced

20kΩ line (unbalanced)

●S/N (A weighted, input shorted)

117dB Gain selector switch MA X

122dB　Gain switch　-12dB

At rated continuous average output

●Power meter

Logarithmic compression type, with display off function

-∞ to +3dB (dB/% display)

Hold time: ∞

●Power supply

AC100V　50/60Hz

●Power consumption

180W　At no input

427W　Electrical Appliance and Material Safety Act

272W　At rated output of 8Ω load

●Maximum external dimensions: Width 465mm x Height 211mm x Depth 464mm

●Weight: 33.0kg