DIATONE DA-A7

Commentary

A power amplifier of the Feature series released by Diatone.

It adopts a differential amplification 2-stage current mirror drive system and is designed with an emphasis on low distortion factor especially for small signals.
By combining a high-gain, low-distortion current mirror circuit and a power transistor with good linearity, the bare characteristics are improved. Moreover, a low distortion factor is realized by sufficient NFB.

High ft transistor and current mirror drive improve pulse rise characteristics.

The power supply section contains one 300 VA power transformer and two 63 V, 18000 μ F electrolytic capacitors.

Effective heat radiation is achieved by placing heat generating components such as a heat sink and power supply transformer outside the chassis.

Using a heat sink of 0.5 ℃ / W per channel, the temperature of the power transistor is kept low enough.

The protection relay is used as it is for changing the speaker.
As a result, the damping factor does not decrease as in conventional speaker switching switches.

It can be docked and remotely controlled with Feature series preamplifiers.

Model Rating

Type	Stereo power amplifier
Output	Double-channel operation, 20 Hz to 20 kHz : 75W + 75W (8 Ω) 110W + 110W (4 Ω) Both channel operation, 1 kHz : 85W + 85W (8 Ω) 120W + 120W (4 Ω) Single-channel operation, 1 kHz : 95W/95W (8 Ω) 140W/140W (4 Ω) Music Power : 200W (8 Ω) 360W (4 Ω) EIAJ (5% strain) : 180W (8 Ω) 280W (4 Ω)
Harmonic distortion factor	0.1% (at rated output) 0.02% (20 Hz to 20 kHz at 1W output) 0.003% (1 khz at rated output of -3dB)
Intermodulation distortion factor (1W, 50 Hz : 7 khz = 4 : 1)	0.03%
Input Sensitivity / Impedance	1V/50k Ω
Frequency Response (0.5W, 0 dB-1 dB)	10 Hz to 50 kHz
Output Bandwidth (0.1% IHF Distortion)	10 Hz to 50 kHz
Damping factor	100
Channel separation	85dB(1kHz) 60dB(20kHz)
Residual noise	0.25mV
Muting time	5 seconds
Adaptive load impedance	4 ~ 16 Ω
Pwer	AC100V 50Hz/60Hz
Power consumption	185W (Electrical Appliance and Material Control Law) 270W at Rated Output (8 Ω)
External dimensions	Width 425x Height 170x Depth 225 mm
Weight	11.5kg