|99,000yen(September, 1982 release)
The Integrated Amplifier of the REVOLVER series
which supplied the Duo beta technology.
The Duo beta circuit / S of
one-step amplification amplifier are carried in the power amplifier part.
Duo beta circuit / S is with the "one-step amplification amplifier" which makes
the amplification stage of an amplifier circuitry only one step, and realizes a
low distortion with an open loop,The "Duo beta circuit" which combined DC servo
tightened to an amplifier circuitry from the super-low-pass one besides
proper-quantity NFB covering all the bands, and an audio frequency band,It is
the generic name which summarized three of power circuits "plusX" which gives
generous stabilization damping force to a power source,By this, since there are
few high region staggers, a stability to the extent that the high region
correction by phase gap is not needed is acquired, and also the factor in which
a slew rate gets worse in addition to the threshold of an element is lost out of
the circuitry inside amplifier, and it is wide opened from the ill effect of Izu
of a power source.
After considering it as the highly efficient design
of carrying out the specification of the High-Gm low-noise FET developed in MC
head amplifier by a differential amplification etc., the Duo beta circuit is
carried in the high gain MC equalizer part.
Moreover, the original phone
straight functionality is carried, and contact leading about, such as not a mere
it1 but light filters, a balance control, and selectors, is put into practice and separated about the disk reflex circuit.
The frequency-shifts type
is adopted as a tone control.
Since a variation and the frequency which
begins to change interlock and it operates, effective tone control is possible.
||105W+105W (8 ohms, 1kHz, both channel)
||0.009% or less (8 ohms-3dB, 20Hz - 20kHz)
|Cross modulation distortion
||0.009% or less (8 ohms, 60Hz:7kHz=4:1)
||Phono man month: 2.5mV/50kohm
MC: 100 microvolt/High-Low switching
Tuner, AUX/DAD, Monitor:200mV/40kohm
Main In: 200mV/50kohm
|SN ratio (IHF-A)
||Phono man month: 90dB (input short-circuit,
Phono MC: 67dB (input short-circuit, 250-microvolt
Tuner, AUX/DAD, Monitor, Main In: 110dB
AUX/DAD, Monitor, Main In: 10Hz - -100kHz one dB
||}8dB, a turnover shift type
|Puri part output
||Subsonic Filter: 30Hz
A high cut-off
|A low boost
||+ 8dB, 70Hz
||Two lines (Tape-1, Tape-2)
||Width 453x height 135x depth of 425mm