Accuphase E-302/E-302B
¥220,000 (released in December 1984)
Features
Based on the development technology and elements cultivated in high-grade separate amplifier for many years, the integrated amplifier which aimed at the correspondence to a digital source.
There were two kinds of champagne gold color E-302 and black color E-302B.
The output stage of the power amplifier section has a parallel push-pull configuration with four Pc (collector loss) 120W transistors.
The FET drive stage is adopted. MOS FET is an optimum element for this stage where low output impedance and high drive voltage are required, and in combination with low emitter resistance in the output stage, high quality output without notching distortion is obtained.
Moreover, the input stage of a power amplifier comprises bootstrap cascode differential amplifier of FET and a transistor, and has acquired the outstanding high region characteristic and stability.
The power amplifier section of the E-302 is designed for low impedance loads, and the output stage Pc has a large power configuration of about 500W, and a large 700VA transformer is used.
All the unit amplifiers of each stage from the Disc input are in the direct connection system.
The problem of DC drift caused by direct connection is solved by stabilizing each unit amplifier by DC servo.
The equalizer amplifier part has adopted the 1-amplifier system which switches the gain of a high gain equalizer amplifier based on the required gain of MM and MC.
With this method, stable operation against changes in the NFB amount and measures against residual noise when using MC cartridges are used, but for stability, a bootstrap cascode differential amplifier is adopted with an FET and transistor at the input, The characteristic of the range is improved. And the stable amplifier circuit is realized by adopting the simple composition that the next stage is an operational amplifier and the final stage is complementary push-pull. Moreover, for S/N at the time of MC input, the residual noise is reduced by making the input FET 3 parallel.
At the time of MC input, it becomes a high gain equalizer of 60 dB, which is 30 dB higher than the gain of 30 mm at the time of MM input, and it can support all types of MC cartridges, and at the same time, select the optimum load impedance of the cartridge by switching the input impedance in three stages. Is possible.
By routing the signal path for input switching, in order to prevent inducing deterioration of high frequencies and instability elements, a relay is placed in the middle of the signal path and the signal path is controlled by the logic circuit. The logic relay control which connects in the shortest is adopted.
The relay of the crossbar twin method which formed the gold layer on the silver palladium alloy especially developed for small signal audio is adopted as the relay, and by sealing it, the outside air is shut off and the durability is improved. I am making it.
The switch and the input/output terminal which separate the preamplifier output and the power amplifier input are carried.
It is equipped with a loudness compensator, which automatically corrects the hearing at low volume and adjusts the energy balance.
You can select three types of auditory curves according to the acoustic characteristics of the room, the speakers, and your preference.
The power meter of logarithmic compression type peak indication is carried.
Meter scale lighting is indirect lighting that is illuminated from above.
The functions, such as a subsonic filter, an attenuator, and a mode switch, are carried.
There was a wood cabinet sold separately.
Model rating
Model | Integrated stereo amplifier | |||||||||||||||||||||||
Continuous average output (EIA, both channel operation, (20Hz to 20kHz, distortion rate 0.02% or less) |
180W+180W(4Ω) 120W+120W (8Ω) 60W+60W (16Ω) |
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Total harmonic distortion (EIA, both channel operation, 0.25W ~ rated output, 20Hz ~ 20kHz) |
0.02% (4Ω) 0.01% (8Ω) 0.01% (16Ω) |
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IM distortion rate (EIA) | 0.01% | |||||||||||||||||||||||
Frequency characteristics (EIA) |
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Damping Factor (EIA) | 120 (8Ω, 50Hz) | |||||||||||||||||||||||
Input sensitivity/impedance (rated output/EIA 1W output) |
Disc MM:2.5mV/0.22mV/47kΩ Disc MC: 0.08mV/0.007mV/10, 30, 100Ω High Level input: 76mV/7.1mV/40kΩ Main amp input: 1.23V/113mV/20kΩ |
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Disc maximum input (1kHz, 0.005% distortion, Rec out) |
MM:300mVrms MC:9.5mVrms |
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Rated output/impedance | Pre output:1.23V/200Ω Tape rec output: 76mV/200Ω (at Disc input) Headphones: 0.4V, compatible impedance: 4Ω to 32Ω |
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Gain | Main input → Output:28dB High Level input → Pre output: 24dB Disc MM → Tape rec output:30dB Disc MC → Tape rec output:60dB |
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S/N, input conversion noise |
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Loudness compensator | Comp 1:+3dB(100Hz) Comp 2: +6dB(100Hz) Comp 3: +8dB(100Hz), +6dB(20kHz) |
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Subsonic filter | 17Hz, -12dB/oct | |||||||||||||||||||||||
Attenuator | -20dB | |||||||||||||||||||||||
Power meter | Logarithmic compression type peak level display Direct reading of output at dB and 8Ω load |
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Load impedance | 2Ω~16Ω | |||||||||||||||||||||||
Semiconductor used | Transistor: 86 pieces FET: 24 pieces IC: 14 pieces Diode: 86 pieces |
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power supply | AC100V/117V/220V/240V, 50Hz/60Hz | |||||||||||||||||||||||
Power consumption | 55W (without input) 280W (Electrical Appliance and Material Control Law) 450W (at 8Ω load rated output) |
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Outer dimensions | Width 445 x height 145 (including legs) x depth 370 mm Wood cabinet: width 466x height 170x depth of 380mm |
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weight | 16.2kg | |||||||||||||||||||||||
Sold separately | Wood Cabinet A-16 (¥16,000) |