Audio Database

A-3040
Commentary

Tube bulb type control amplifier kit.

All circuits are unified with SRPP outputs. For the equalizer circuit, a twin triode 12AX7 with Takamasu ratio is used for the first stage and the outputs.
The flat amplifier has basically the same circuit configuration as the equalizer circuit using 12AU7. The final stage uses 12AU7 as well as the flat stage. The design is simple with SRPP output.
In addition, the linearity is improved by strictly selecting the constant value, and an output circuit with low distortion factor is constructed.

In the power supply section, the power supply to the equalizer circuit and tone circuit is completely separated, so that distortion and turbidity caused by signal interference between each amplifier.
In addition, in order to prevent distortion caused by mutual interference, each heater circuit is independently stabilized to produce a purer sound.
Another reason for the development concept of completely separating the power supply circuit is to make each amplifier block the highest quality. The amplifier circuit is determined by total tuning including the power supply circuit, and the power supplies for the equalizer stage and the flat stage are separated independently.

It employs a LUX type NF tone control circuit that allows natural and straightforward tone adjustment without unreasonable effort. It also uses a continuously variable detent volume for both low and high tones for ease of use.
The maximum variation is ± 10 dB, and the switchover point is set to 200 Hz for low band and 4 kHz for high band.

Model Rating
Type Tube type control amplifier kit
Output voltage Rating : 2 v
Maximum : 20 V or more
Total harmonic distortion factor 0.05% or Less (1 kHz, 1 V)
Input Sensitivity (Output 1 v) Phono MM:1.8mV
CD, Line, Tuner : 170 mv
Input impedance Phono MM : 50k Ω
CD, Line, Tuner : 100k Ω
Frequency characteristic Phono MM : 20 Hz to 20 kHz ± 0.2 dB or less
CD, Line, Tuner : 5 hz to 100 khz -1dB or less
Signal-to-noise ratio (IHF-A corrected) Phono MM : 81 dB or more
CD, LIne, Tuner : 97 dB or higher
Pwer 100 VAC, 50Hz/60Hz
External dimensions Width 493x Height 142x Depth 403 mm
Weight 11.5kg