Akai AA-39
The Akai AA-39 is an integrated stereo receiver from the 1990s.
The amplifier section is fully discrete, featuring 2SK117 FET transistors at the input stage and 2SC3854 and 2SA1490 transistors in the output stage. The power supply is supported by 5600µF filter capacitors, while speaker protection is handled by a relay.
This receiver is equipped with a remote control. The volume potentiometer is motorized, and inputs are switched via the LC7821 electronic switch circuit. Tone controls and Loudness are manual and cannot be controlled via the remote.
The soundstage is neutral, and overall performance is decent, although it lacks the classic vintage charm.
Manufacturer: Akai
Status: Defunct company
Source: Wikipedia (Akai)
General Specifications
Maximum power (8Ω): 45WFrequency response (-3dB): 10Hz-60kHz
THD+N: 0.008%
Signal to noise ratio (Line): 99dB
Signal to noise ratio (Phono): 81dB
Residual noise: 0.1mV
Input sensitivity (Line): 150mV
Input sensitivity (Phono): 2mV
Chanel separation (Line): 65dB
Crosstalk (Line): 90dB
Damping factor: 65
Speaker load impedance: 4Ω-16Ω
Dimensions (WHD): 425×156×370mm
Weight: 11.3kg
Produced: 1995-1996
Measured Values
Maximum power (8Ω): 40WFrequency response (20Hz-20kHz): <0.3dB
Channel imbalance: <0.6dB
THD (1kHz, 1W): 0.0032%
THD+N (1kHz, 1W): 0.015%
THD (1kHz, 20W): 0.0062%
THD+N (1kHz, 20W): 0.0093%
IMD (70Hz, 5kHz, 1W): 0.017%
Noise: -71.1dB
Amplification: 123.3
DC offset L: -6.0mV
DC offset R: -4.0mV
Factory Specification Sheet
Factory specification images are sourced directly from the device's original service manual or user manual. These documents are produced by the manufacturer and provide authoritative information on the product's specifications.
Maximum Power
Maximum power is measured using 8Ω resistors on both channels. A 1kHz sine wave input signal is applied and gradually increased until higher harmonics rise significantly. Typically, this is the point at which output clipping occurs.
Frequency Response
Frequency response is measured using several equilizer settings. 'Flat' indicates the tone controls are either turned off or set to their neutral position. 'Max' and 'Min' refer to the maximum and minimum tone control positions, respectively. In the phono section, the expected response follows the RIAA equalization curve.
Residual Noise
These graphs display the noise levels at various volume positions. To eliminate any interference from the input signal, the input lines are shorted during the measurement. Generally, the noise is highest at the mid-point of the volume range (50%)
Distorsion
Total harmonic distortion (THD) is measured using a 1kHz sine wave input, with the output level adjusted to meet different conditions. Intermodulation distortion (IMD) is measured using 'two sine' input signal. THD versus voltage is measured with a 1kHz sine wave input, while THD versus frequency is measured at various output levels.
