Audio Database

Image of DA-P15S
Commentary

A preamplifier aiming at low distortion by reviewing the basics.

The first stage of the equalizer amplifier uses a low-noise FET that is carefully selected from many transistors in terms of noise and performance to minimize the noise generated by the first stage transistor and improve the S/N ratio.
Also, the S/N ratio is improved by lowering the impedance of the RIAA feedback circuit.

As for residual noise, which greatly affects the performance of the tone amplifier, we use a low-noise FET that carefully examines the noise characteristics of the first stage transistor to reduce the noise like the equalizer amplifier.
In addition, the impedance of the feedback circuit is reduced to improve the S/N ratio.

Both the equalizer amplifier and the tone amplifier use a two stage differential amplifier circuit with a current mirror load. This circuit reduces distortion at the time of open loop and further increases the band width to improve bare characteristics sufficiently, and provides stable negative feedback to reduce distortion.
We have also succeeded in reducing the distortion to less than 0.03% (Phono MM) and 0.002% (AUX) near the limit in the 20 Hz to 20 kHz band by spending many days studying the device and circuit configuration with less distortion.

As for the MC head amplifier, from the perspective of reexamining the transistor itself, we adopted a transistor different from conventional ones and devised and adopted a new circuit to reduce noise.

In addition to the signal circuit, it uses a two monaural construction that separates the left and right channels from the power supply to the ground.

It has a tape-duplicate switch.

It has a built-in headphone amplifier.

Built-in tone defeat mechanism.

Equipped with a subsonic filter to cut out ultra-low frequency noise.

Turnover can be switched.

Built-in muting relay when power is ON.

There were 2 types, DA-P15 with a rack-mount carrying handle and DA-P15S without a carrying handle.

Model Rating
Type Preamplifier
Input Sensitivity / Input Impedance Phono1, 2 mm : 2.3mV/50k Ω, 100 pF
Phono2 MC : 0.1mV/10 Ω
Tuner, Aux, Tape1, 2 : 150mV/50k Ω
Output Voltage / Output Impedance Output1, 2 : 1V/600 Ω
Rec out1, 2 : 150mV/600 Ω
Phones : 600mV/15 Ω
Frequency characteristic Phono (RIAA deviation) : 20 Hz to 20 kHz ± 0.2 dB
Tuner, Aux, Tape1, 2 : 10 Hz to 100 kHz + 0 -0.5 dB
Harmonic distortion factor (1 V output
Volume -20dB, 20 Hz to 20 kHz)		 Phono1, 2 mm : 0.003%
Phono2 MC:0.005%
Tuner, Aux, Tape1, 2 : 0.002%
S/N (A Network) Phono1, 2 mm : 84 dB (input terminal short)
Phono2 mc : 77 dB (47 Ω termination at input terminal)
Tuner, Aux, Tape1, 2 : 110 dB (input terminal short)
Channel separation
(Input Terminal Short, 20 kHz)		 Phono:80dB
Tuner, Aux, Tape1, 2 : 105 dB
Tone control
Bass: ± 10 dB (100 Hz, Turnover Frequency 500 Hz)
± 10 dB (50 Hz, turnover frequency 250 Hz)
Treble: ± 10 dB (10 kHz, 2.5 kHz turnover frequency)
± 10 dB (20 kHz, 5 kHz turnover frequency)
External dimensions DA-P15 : Width 480x Height 108x Depth 349 mm
DA-P15S : Width 424x Height 108x Depth 338 mm
Weight DA-P15:7kg
DA-P15S:7kg