Audio Database


A500 series control amplifier kit.

All stages are push-pull circuits using left and right independent power supplies for all amplifier circuits.
In addition, a duo-beta circuit is mounted to improve sound quality with an appropriate amount of NFB and DC servo.

The equalizer is a dual equalizer configuration with dedicated equalizer circuits for MC and MM. The MC equalizer is capable of 3 levels of sensitivity switching, making it possible to best match with cartridges.

A fully direct connection is used from the cartridge input to the output to the power amplifier, eliminating the coloring of sound by the condenser.

Equipped with phono straight function, input selector, REC selector, mode, Attenuator, and balancer can be separated by one switch to make a circuit with only equalizer and flat section.

Uses a 3 mm thick front panel.

The A502Limited is a kit with the same circuit structure and luxurious parts. It uses a glass epoxy 70 μ m copper-foil substrate, copper-foil Styrol capacitor, audio electrolytic capacitor with sound quality measures, and oxygen-free copper wire / AC cord.

There was a CR part set for A502Limited for A502.

Model Rating
Type Control amplifier kit
Output voltage Rated 1 v
15 v max.
Output impedance Pre out : 100 Ω
Rec out : 100 Ω
Total harmonic distortion factor 0.005% or Less (3 V, 20 Hz to 20 kHz)
Frequency characteristic 20 Hz to 20 kHz ± 0.2 dB (pre out)
Input sensitivity Phono MC : 0.12 mv, 0.2 mv, 0.07 mv
Phono MM:2mV
Tunre, Aux and Monitor : 140 mv
Input impedance Phono MC : 100 Ω, 10 Ω
Phono MM : 47k Ω
Tuner, Aux, Monitor : 100k Ω
Signal-to-noise ratio (IHF-A) Phono MC : 70 dB or more
Phono MM : 80 dB or more
Tuner, Aux, Monitor : 100 dB or higher
Phono maximum allowable input (1 kHz, RMS, standard) MC:16mV
Tone control NF Type, Variation Max ± 8 dB
Low-range bending point frequency : 150 Hz, 300 Hz, 600 Hz
High bending point frequency : 1.5 kHz, 3 kHz, 6 kHz
Attachment Attenuator (-20dB, normal, signal off)
Rec Selectors (Phono, Tuner, Aux, Tape1 → 2/2 → 1)
Tone switch (in/defeat)
Subsonic (in/defeat, 15 hz, -6dB/oct)
DC-configuration headphone amplifier (8 Ω, 100 mWmax)
Mode switch (reverse, normal, mono)
Power consumption 25W
External dimensions Width 438x Height 98x Depth 336 mm
Weight 5.5kg
Sold Separately A502 Limited Kit CR502L (¥ 56,000)