Audio Database

Image of DA-P7
Commentary

Feature series preamp.

Since it is designed with sufficient care for the separation between channels, it has been improved by about 10 dB compared the conventional product.

The tone circuit uses a current mirror circuit with high voltage amplification, symmetric drive and low distortion, and the filter circuit uses an inverted Darlington emitter-follower circuit to achieve low distortion.

The first stage differential amplifier of the equalizer amplifier employs an ultra-low noise transistor developed by low-concentration diffusion technology of Diatone.

The tone control circuit uses a variable resistor with a unique switch, and the time constant circuit is completely disconnected in the flat position to obtain a flat frequency characteristic.

22-contact full-scale attenuator is used. The gang error is within 1 dB at each attenuation of 28 dB and within 1.5 dB at each attenuation of 30 dB or more.

The remote control allows direct speaker switching of Feature series power amplifiers.

-20dB audio muting.

18 Hz, 12dB/oct low-cut filter.

9 kHz, 6dB/oct high-cut filter.

Two tape monitors.

Independently available duplicate switch.

It can be docked with Feature series power amplifiers.

Model Rating
Type Preamplifier
Input Sensitivity / Input Impedance
Phono1, 2 : 2.2mV/50k Ω
Tuner: 150mV/60k Ω
AUX: 150mV/60k Ω
Play1, 2 : 150mV/60k Ω
Phono maximum allowable input 270 mv (at 2.2 mv, 1 khz, harmonic distortion rate 0.1%)
Output Voltage / Output Impedance
Pre Out (50k Ω load) : Rated 1V/600 Ω
Maximum 9V/600 Ω
Head Phone (8 Ω load) : Rated 50 mv
(at Pre Out 150 mv)
Rec: 150mV/680 Ω
Harmonic distortion factor (20 Hz to 20 kHz) 0.02% or less at 1 V output
At 9 v output : 0.05% or less
Frequency characteristic
Phono (RIAA deviation) : 30 Hz to 15 kHz ± 0.2 dB
Tuner, AUX, Play 10 Hz to 70 kHz 0 dB to 0.5 dB
Tone control Bass : ± 10 dB (100 Hz)
Treble : ± 10 dB (10 kHz)
Filter Low : 18 Hz, 12dB/oct.
High : 9 kHz, 6dB/oct.
Input reduced noise
(IHF, A-network, input short)
Phono: -126dB
Tuner, AUX, Play : -106dB
Number of semiconductors used FET:2
Transistor : 26
Diode : 5
LED:1
Pwer AC100V 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law) 8W
External dimensions Width 425x Height 169x Depth 204 mm
Weight 5.3kg