Audio Database

L-410
Commentary

This is a pre-main amplifier of the Revolver series with duobeta technology.

Duo-beta circuit / S of one stage amplifier is installed in the power amplifier section.
DuoBeta Circuit / S is a general term for three technologies. It is a single-stage amplifier that achieves low distortion while maintaining an open loop by setting the amplifier circuit to only one stage. It is a duobeta circuit that combines an appropriate amount of NFB over the entire band with a DC-servo that tightens from the ultra-low band out of the audible band with respect to the amplifier circuit. It is equipped with a power supply circuit plusX that provides a stable braking force with a margin of power supply.
The single-stage amplifier is stable enough to eliminate the need for high-frequency correction due to phase shift because there is little high-frequency distortion. The duo-beta circuit is free from all of the circuits in the amplifier except for the limits of the elements. The plusX power supply circuit is free from the ground power supply circuit, and the SN ratio is improved by being free from the adverse effects of power supply noise.

Duo-beta circuit is used for the equalizer amplifier section.
In addition, a high-gain design is provided to support MC cartridges.

Equipped with phono and straight functions.
In this system, it is not just a bypass, but the contact points and wiring of filters, balance controls, selectors, etc. are thoroughly separated.

The tone control uses a turnover frequency shift system.
Since the amount of change and the frequency at which it begins to change work together, effective tone adjustment is possible.

Model Rating
Type Integrated amplifier
Effective power 75W + 75W (8 Ω, 1 khz, both channels)
Total harmonic distortion factor 0.009% or Less (8 Ω, -3dB, 20 hz to 20 khz)
Cross modulation distortion factor 0.009% or Less (8 Ω, 60 hz : 7 khz = 4 : 1)
Input Sensitivity / Impedance Phono MM : 2.5mV/50k Ω
Phono MC : 100 μ V/High / Low switching
Tuner, Aux/DAD, Monitor : 200mV/40k Ω
Main in : 200mV/50k Ω
Signal-to-noise ratio (IHF-A) Phono MM : 90 dB (input short, 5 mV conversion)
Phono MC : 67 dB (input short, equivalent to 250 μ V)
Tuner, AUX/DAD, Monitor, Main In : 110 dB
Frequency characteristic Phono : 20 Hz to 20 kHz ± 0.3 dB
Tuner, Aux/DAD, Monitor, Main in : 10 hz to 100 khz -1dB
Tone control ± 8 dB, turnover shift type
Pre-part output 200mV(Pre Out)
Filter Subsonic Filter : 30 Hz
High-cut Filter : 7 kHz
Low boost + 8 dB, 70 Hz
Tape monitor Two systems (Tape-1, Tape-2)
Tape dubbing 1 → 2, 2 → 1
Speaker switch Route 2
Power consumption 180W
External dimensions Width 453x Height 135x Depth 425 mm
Weight 13.0kg