KENWOOD/TRIO L-06M

Commentary

A monaural power amplifier using Σ drive system.

Sigma drive system is adopted, and sigma connection with speakers is possible.
The Σ drive method was devised to prevent distortion caused by the back electromotive voltage generated by the movement of the cone paper (voice coil) of the speaker. The concept of NFB, which had been completed in the amplifier until now, is expanded to the input terminal of the speaker by using four cables. By incorporating both the cable and the input terminal of the speaker as one of the internal wiring of the amplifier, the distortion of the speaker is suppressed. This method realizes an incommensurable high performance with a damping factor of 15000 at the 3m Σ cable.
First of all, a unique Σ cable is installed to connect the + side of the speaker to the feedback point of the power amplifier. This cable controls the input terminal of the speaker so that various kinds of distortion, including reverse distortion caused by the magnetic circuit of the speaker, are not generated. The Σ cable is also installed on the - side. The ground point and power loop of the - side cable are separated. This eliminates the potential difference between the input terminal of the speaker and the ground point.

Current mirror 3-stage amplification is adopted for the pre-driver stage, and by using current mirror load, naked gain of the amplifier is taken large, and distortion factor is greatly reduced.
Both positive and negative cycles of the signal source impedance that drives the output stage at the same time are made equal, and the time constant of the rise and fall of the square wave is made equal to realize high-speed characteristics.

All signal paths, including the NF loop, use a DC amplifier configuration that does not have a time constant due to a capacitor to stabilize low-frequency characteristics, and a newly designed high-speed circuit and high-f_TBy using a transistor, the range is expanded to the ultra-high band.
Delta V_GSThe offset voltage is reduced by adopting the dual FET with less offset voltage and sufficient loop gain is secured. Since the dual FET contains FETs with the same characteristics in one package, the two FETs change in the same state even with temperature drift. This compensates for offset drift with an excellent accuracy of ± 20 mv even at -10 ℃ to + 60 ℃.

It uses particle board on the bottom and non-magnetic aluminum die-cast on the back panel through which signals pass.
Although the transformer is inside the housing, the new design achieves the same effect as a separate housing, reducing the occurrence of magnetic distortion, which adversely affects the signal system.

The power supply uses a large-capacity transformer and two capacitors of 12,000 μ F, which are resistant to current fluctuations.

Equipped with an ASO detection type current limiter, it protects the transistor when the output is short-circuited and weakens the limiter effect when the speaker is connected to prevent noise.

Equipped with speaker protection, the relay operates after the circuit stabilizes after the power is turned on, so that no excessive power is applied to the speakers. In addition, even when DC voltage is applied to the speakers, they are protected by turning off the speakers within 100 ms.

Remote Power Switch RC-55 was sold separately as an option.
The RC-55 can be turned on / off in conjunction with the power switch of the control amplifier L-08C. The RC-55 uses two highly reliable power relays designed to turn on each of two AC outlets with a difference of approximately 0.5 seconds.

Model Rating

Type	Monaural power amplifier
<Audio characteristics (Power in → SP out)>
Rated output	120W (8 Ω, 10 Hz to 100 kHz, 0.02% distortion) 150W (4 Ω, 1 kHz, 0.002% distortion factor)
Total harmonic distortion factor	0.002% (20 Hz to 20 kHz at rated output) 0.002% (20 Hz to 20 kHz at 1/2 Rated Output) 0.0005% (at rated syth pain force, 1 kHz, 8 Ω)
Cross modulation distortion factor 60Hz:7kHz=4:1)	0.001% (8 Ω at rated output) 0.001% (8 Ω at 1W output)
Frequency characteristic	DC ~ 500 kHz -3dB
Signal-to-noise ratio	120dB
Damping factor	20,000 or More (55 Hz) 15,000 or More (Sigma Cable 3m Tip)
Rise time	0.7 μ s
Slew rate	± 170 V / μ s
Input Sensitivity / Impedance	1V/50k Ω (at IHF reference output)
Power Supply Unit and Others
Power outlet	Power switch not linked : 1 system (300W)
Pwer	100 VAC, 50Hz/60Hz
Rated power consumption	120W (Electrical Appliance and Material Control Law)
External dimensions	Width 200x Height 165x Depth 400 mm
Weight	8.7kg
Attachment	5m ground wire
Sold Separately	Remote Power Switch RC-55 (¥ 7,000)