SONY: TA-N77ES amplifier – Specifications

High End Audio For The Passionates write:

The Sony TA-N77ES is Japan's greatest power amplifier of all time. It's a 55-pound behemoth with huge meters that sounds and measures extremely well. The TA-N77ES was Sony's last effort at pushing the envelope of serious power amplifiers at the end of Hi-Fi's glory days. No one will admit to this and I can't tell you it either, but Sony cleverly sold the design to Accuphase in 1989, who still sells it today in their model P-4100.

The Accuphase P-4100 uses the same isolated power supply for the drivers ("Spontaneous Twin Drive"), the same triple-parallel bipolar output stage, the same idle-power draw, and even the same speaker, meter, input and attenuator controls — and of course the same wonderful huge meters. Accuphase reduced the P-4100's output power for economic reasons to only 90 WPC, and of course raised the price by ten times over what Sony asked for this landmark TA-N77ES. Such is niche marketing...

Inputs 30k Ω, 1 Volt.
Two pairs of gold-colored RCA jacks.
Input Sensitivity 1V for unspecified output.
Rated Power Output
200 watts per channel into 8 Ω from 20 - 20,000 Hz at less than 0.004% THD, both channels driven, from 250mW output to 200W.
230 watts per channel into 6 Ω from 20 - 20,000 Hz at less than 0.005% THD, both channels driven, from 250mW output to 200W.
270 watts per channel into 4 Ω from 20 - 20,000 Hz at less than 0.006% THD, both channels driven, from 250mW output to 200W.
Dynamic Power
300 W at 8 Ω.
370 W at 6 Ω.
520 W at 4 Ω.
800 W at 2 Ω.
660 W at 1 Ω.
Power Bandwidth (IHF) 10 ~ 100,000 Hz, 8 Ω or 4 Ω at 0.02% THD.
Dynamic Headroom (IHF 1978)
1.8 dB at 8 Ω.
2.8 dB at 4 Ω.
THD at 10 Watts
0.0018% at 8 Ω.
0.003% at 6 Ω.
0.004% at 4 Ω.
SMPTE IMD at Rated Output
0.004% at 8 Ω.
0.005% at 6 Ω.
0.006% at 4 Ω.
Damping Factor (8 Ω, 1 kHz)
0.004% at 8 Ω.
0.005% at 6 Ω.
0.006% at 4 Ω.
Slew Rate
150 V/µS.
(300 V/µS inside before the signal hits the output series inductors.)
Output Noise
< 35 µV, A-weighted.
SNR (IHF 1978) 120 dB, A-weighted.
Frequency Response 1 ~ 200,000 Hz, +0, -3 dB.
Power Input & Consumption Varies by market.

Oddly rated 380 watts consumption for USA, even though rated to produce more than 400 watts continuous output. It draws zero power when turned off because it has a real power switch. It's not like modern equipment that never really turns off and consumes power and remains a fire hazard any time its plugged in. The TA-N77ES is completely disconnected when switched off. When switched-on, there is a 9.0 second mute during which it draws 30 watts. Even if ON, the meters are dark for those first 9 seconds.

The meter bulbs are rated a total of 7.2W (1.2W x 6 bulbs).
Actual measured power drain is:
Cold, idle
37.5w, meters off.
46.0w, meters on.
Warm, idle
43.5w meters off.
52.0w maters on.
1 W output, both channels
69.5w meters on.
61.7w meters off.
10 W Output, both channels
138w meters off.
147w meters on.
180 W output, both channels
597 W, meters on (0.859 V audio input, 115.6V from wall).
Warm Idle, if power supply rails at full voltage:
54.4w, meters on
47.7w, meters off.
Size Overall: 7-3/8 x 18-5/8 x 17-3/8 inches HWD.
If you take off the fake wood side panels, what's left is standard 17" wide, but with nothing covering the sides! Unlike other Sony items with fake wood side panels, there is no metal case underneath on the sides.
Weight 55.125 pounds (25 kg).

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