TRIO 700M

Commentary

This is a stereo power amplifier of the Supreme Series.

The 700M is fully equipped with bare characteristics for all responses without NFB, and with appropriate NFB applied on top of that, stable operation is always realized even in high signal level, fluctuation of impedance and distortion.

A large-capacity transformer of 600 VA or more is adopted for the power transformer, and a cut core with less leakage flux is realized by using flux density, a cut core with less leakage flux is realized.
In addition, a rectifier using a large-capacity industrial semiconductor 12B20 and a large-capacity electrolytic capacitor of 36,000 μ F/80WV are combined to realize a power supply with good regulation.

The cooling mechanism has four large heat sinks of 78mmx143mmx170mm arranged in a configuration with good air flow, ensuring high power with long continuous operation without attaching auxiliary parts such as cooling fans.

In the final stage of the amplifier circuit, a triple push-pull connection with a buffer stage is adopted. Even at high output, three transistors are operated only within the range of high hFE and good linearity to reduce hFE distortion. In addition, by placing a buffer stage between the first stage and class A drive stage, distortion and phase shift are eliminated.
In the drive stage, the bootstrap circuit is eliminated in order to enhance the bare characteristics, and the distortion due to the low-frequency time constant is also shut out. This greatly improves out-of-band characteristics, dynamic characteristics, minimum signal characteristics, and other characteristics that do not appear in normal measurement.

The protection circuit consists of three components : ASO detection, DC detection and rush current prevention.
The transistors are protected by the limiter method using ASO detection, the speakers are protected by the DC detection relay method, and the power switch circuit is equipped with a surge prevention circuit to suppress the rush current until all circuits are fully operational.

Equipped with a large power meter.
It is a 4-step range switching type of -20dB, -10dB, 0 db and OFF so that it can be read easily even at small output level.

The subsonic filter uses a Darlington 2-power supply type active filter that is resistant to external noise and less distorted.

Speaker jacks are provided in the Route 3.

A highly stable rotary switch is used for input level control. The input level can be reduced to -20dB in 2 dB steps.

Equipped with two input terminals.

The wood case was sold separately as an option.

Model Rating

Type	Stereo power amplifier
Band-guaranteed effective output (20 Hz to 20 kHz)	170W + 170W (8 Ω continuous operation, THD0.1%)
Total harmonic distortion factor	0.1% (8 Ω, 20 Hz to 20 kHz, at Rated Output) 0.05% (8 Ω at 1/2 Rated Output)
Signal-to-noise ratio	100 dB (8 Ω) 115 dB (8 Ω, IHF-A curve)
Residual noise	0.5 mv (8 Ω)
Input sensitivity	1 v (170W output, 8 Ω)
Input impedance	50k Ω
Damping factor	40 (8 Ω)
Rated load impedance	4 ~ 16 Ω
Frequency characteristic	20 Hz ~ 20 kHz + 0 -0.5 dB
Subsonic filter	12dB/oct(fc:18Hz)
AC outlet	Switched : 2 lines Unswitched : 2 lines
Pwer	100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law)	350W
External dimensions	Width 440x Height 200x Depth 360 mm
Weight	27kg
Sold Separately	Wood Case SR-700M (¥ 18,000)