Audio Database

Image of A-505
Commentary

This is a stereo pre-main amplifier that combines convenience and digital sound quality.

The power supply section uses a large 230 VA power transformer and a 12,000 μ Fx2 electrolytic capacitor.

To bring out the quality of digital sound, it is equipped with a CD direct switch that connects the CD output directly to the power amplifier.
In addition, by adopting the REC selector with OFF position, deterioration factors can be forcibly eliminated.

It employs a non-switching circuit TypeII to further expand the 0 switching distortion range and further increase the bandwidth. At the same time, thermal distortion caused by the drift of idle current and non-linear distortion of the output stage are greatly improved, and sound quality degradation is prevented and distortion free sound is pursued.

It is designed to be completely non-magnetic and vibration-proof, and uses an extra-thick power cord with polarity display that improves conductivity and reduces nonlinear distortion.
In addition, nickel phosphorus is used for the electrodes and the end of the power plug is made non-magnetic. In addition, parts such as oxygen-free copper wires, copper-plated screws that are effective in absorbing vibrations, and non-magnetic cap audio fuses are used for the speaker terminals of the vise type, large polycarbonate insulators with high rigidity and high vibration damping rate, gold-plated input terminals, and all cords for the signal and power systems.

Model Rating
Type Stereo pre-main amplifier
Rated output
(Both channel drive, 20 Hz to 20 kHz)
100W + 100W (6 Ω, 0.015%)
85W + 85W (8 Ω, 0.01%)
Output terminal Speaker (6 Ω ~ 16 Ω) : A, B, A + B
Damping factor 65 (8 Ω, 1 kHz)
Input Sensitivity / Impedance Phono MM : 2.5mV/50k Ω
Phono MC : 0.2mV/100 Ω
CD, Tuner, AUX, Tape Play : 150mV/33k Ω
Maximum Allowable Input (1 kHz, 0.008%) Phono MM:150mV
Phono MC:12mV
Frequency characteristic Phono MM : 20 Hz to 20 kHz ± 0.3 dB
Phono MC : 20 Hz to 20 kHz ± 0.5 dB
CD, Tuner, AUX, Tape Play : 5 hz to 100 khz + 0 to 3 db
S/N ratio (IHF, A-network
Short circuit)
Phono MM:87dB
Phono MC:69dB
Line system : 100 dB
CD Direct : 105 dB
Tone control Bass : 100 Hz, ± 8 dB
Treble : 10 kHz, ± 8 dB
Subsonic filter 15 Hz, 6dB/oct.
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law) 180W
External dimensions Width 420x Height 122x Depth 346 mm
Weight 8.7kg