Audio Database


210,000yen(November, 1979 release)

Amplifier which pursued the ideal "the amplifier must be one lead wire with the amplification degree which tells a music signal faithfully" as much as possible, and was designed.

The abbreviation one-half of the space is a power-source fraction. Even a whole page right-and-left independency, a power stage, a predrive stage, flat amplifier / equalizer, and MC head amplifier have adopted the form of an independent 8 power-source stream composition.
They are 2 transformer schemes of the mass toroidal transformer of 600VA, and 80 vi-EI transformer,Even if parallel connection of the 10,000 micro F of custom-made mass electrolytic capacitor x8 developed only in the audio is carried out and it changes a speaker impedance with a frequency combining a 1.2mm thickness copperplate in a grounding circuitry for a using and this reason, the operation stabilized by the powerful power-source part is performed.

A diamond differential circuit is carried. Furthermore, newly developed linear high-speed output element NM-LAPT (Non Magnetic-Linear Amp.Power Transistor) is adopted. It succeeded in this bringing a dynamically distorted TIM distortion which checks a tone quality, and envelope distortion close to 0 infinite.

One one-piece part is selected in a positive property checking and hearing from the heat sinker made from large-sized die-casting to the product line in a high-efficiency Mie braid structure speaker code etc.

Separation of a pre and power is possible with the power amplifier operation switchpoint of the front panel.

The powerings to a power stage are two coils which made the right-and-left channel become independent,Parallel connection of the 10,000 micro F of custom-made mass electrolytic capacitor x8 which developed the good large-sized toroidal transformer (power-source capacity 600VA) of the regulation by two rectifier circuits in the using, in addition only the audio is carried out, and it is used for a grounding circuitry combining a 1.2mm thickness copper plate.
Moreover, to the predrive stage, the right-and-left channel independent 2 power-source scheme by a large-sized EI transformer (power-source capacity 80VA) is used, and a diamond differential circuit is driven powerfully.
Furthermore, a supplying and MC head amplifier part are supplied from the voltage stabilizer which achieved the right-and-left independency to an equalizer-amplifier part and a flat amplifier part by the low-voltage circuitry by another coil which achieved the right-and-left independency.

It excels in a power transistor at a high-speed and a linearity, high newly developed NM-LAPT of a destructive intensity and cut-off frequency (ft100MHz) is made a triple push pull interconnection, and it is used in the operating point which was excellent in the linearity.

A head amplifier part is DC amplifier stream composition which advanced further the symmetrical push pull input/output which uses newly developed low-noise high gm P-ch and N-ch FET. The first rank realizes an ideal input impedance and a high S/N ratio by the direct couple scheme in a low-noise, high gm P-ch, and the push pull input that made the Para interconnection of much N-ch FET.
Moreover, the 2nd step is excellent in the open loop property by the 2 steps of push pull drives hardwired-connection circuitry by the combination of a NPN-PNP transistor, and has become MC amplifier circuitry with a sufficient linearity.
Furthermore, very high operational stability has been obtained by the right-and-left independency and the powering only for MC.

An equalizer-amplifier part is DC amplifier stream composition of diamond differential-circuit loading by a direct couple scheme. A pair property is good, and adopts the difference input circuitry of a low-noise and high-gm, and a Dual-FET using, and the first rank constitutes the cascode bootstrap circuit which does not receive the influence by an input impedance.
Moreover, by the highly efficient constant current circuit (PAT.PEND) constituted from a two-step hardwired-connection circuitry by NPN-PNP transistor combination, high CMRR (inphase component supression expense) in a summing point was taken, and the outstanding dynamic behavior has been acquired. The 2-3rd step is the diamond differential-circuit + electric-current differential push pull excellent in drive capacity,An output stage has electric-current margin sufficient by the SEPP circuit by a Darlington connection, and enough dynamic ranges can be taken also to a transition of a load impedance by the low-power-output impedance and a low-impedance NF circuit design, and also the improvement in an S/N ratio is measured.

In flat amplifier, the operation which was excellent with adoption and a right-and-left independent-source supplying in the push pull drive-D C amplifier stream composition by the difference input circuitry by newly developed 1Tip(4 element enclosure) FET was realized at the first rank.

The speaker product-line code from LAPT adopted super-low direct current resistance and the three-fold high-efficiency braid structure of the low inductance, and has acquired the transmission characteristics which was excellent without getting worse a slew rate.

CP type (conductive plastic) master volume is adopted.

Interior The

Rating of a mode
Form Stereo Integrated Amplifier
<Power amplifier part>
Effective output (5Hz - 20kHz, THD 0.007%) 160W+160W (8ohms)
220W+220W (4ohms)
Effective output (1kHz, THD 0.003%) 160W+160W (8ohms)
220W+220W (4ohms)
THD (5Hz - 20kHz) 0.007% or less (8ohms)
0.008% or less (4ohms)
Cross modulation distortion (70Hz:7kHz=4:1) 0.007% or less (8ohms)
0.008% or less (4ohms)
Output bandwidth (IHF, THD 0.02%) 5Hz - 70kHz (8ohms)
Frequency characteristic (1W) DC-500kHz (+0dB, -3dB)
Input sensitivity/impedance (1kHz) 1V/33kohm
S/N ratio (IHF, A network) 125dB or more
Channel separation (IHF, 1kHz) 95dB or more
A rise time / fall time 0.5microsec
Slew rate ±260v/microsec
Headphone jack output 150mW (8ohms)
The speaker used 4-16ohm (A, B)
8ohms or more (A+B)
<Preamplifier part>
Input sensitivity/impedance (1kHz) Phono1, 2(man-month):2.5mV (47kohm)
Phono1, 2(MC):0.1mV (0.2 or less kohm)
AUX, Tuner: 200mV (33kohm)
Tape, Play1, 2 (PIN):200mV (33kohm)
Maximum permissible input (1kHz, THD 0.01%) Phono1, 2(man-month):330mV
Phono1, 2(MC):40mV
Output voltage (1kHz) Tape, Rec1, 2 (PIN):200mV (at the time of 47kohm)
Pre Out1, 2:1V (at the time of 47kohm)
Max Pre Out(THD 0.05%): 10V (at the time of 47kohm)
Output load impedance (1kHz) Tape Rec1, 2 (PIN):600ohms or less
Pre Out1, 2:600ohms or less
THD MC (1kHz, Rec Out): 0.005% or less
man month (20Hz - 20kHz, Rec Out): 0.005% or less
Aux, Tuner, Tape Play1, 2:0.005% or less
Cross modulation distortion (70Hz:7kHz=4:1) Aux, Tuner, Tape Play1, 2 (1 V:00):0.005% or less
Frequency characteristic Phono1, 2 (MC, RIAA deflection, 20Hz - 20kHz):±0.2dB
Phono1, 2 (man-month, RIAA deflection, 20Hz - 20kHz):±0.2dB
SN ratio (IHF, A network)
Short circuit
Phono1 and more than 2(MC):76dB
Phono1 and more than 2(man-month):91dB
Aux, Tuner, Tape Play1, 2:100dB or more
Input conversion noise
(A network, a short circuit)
Phono1, 2(MC):-156dBV
Phono1, 2(man-month):-143dBV
Channel separation
(IHF, 1kHz)
Phono1 and more than 2(MC):70dB
Phono1 and more than 2(man-month):75dB
Aux, Tuner, Tape Play1, 2:80dB or more
The separation between inputs
(1kHz, short circuit)
Tuner-Phono1 and more than 2(man-month):90dB
Tape Play1, 2-Phono1, and more than 2(man-month):90dB
Tuner-Tape Play1, 2:100dB or more
More than Tape Play1-Tape Play2:100dB
Subsonic Filter 16Hz (-3dB, 6 dB/oct)
Power consumption 400W (Electrical Appliance and Material Control Law)
Dimensions Width 480x height 195x depth of 450mm
Weight 27.7kg