DIATONE DA-U650
¥ 65,000 (around 1974)
Commentary
Pre-main amplifier with 2 power supply system for all circuits.
The power amplifier section employs a pure complimentary service OCL circuit directly connected to all stages without a capacitor. Combined with a high-power transistor, various characteristics are improved.
It is also designed to reliably drive all of the speakers on the market with a power ratio of 2.8.
The preamp section also uses two power supply systems, plus and minus. The input side base potential and output side collector potential of each unit amplifier can be set close to 0 potential, reducing click noise.
The preamp section and power amplifier section can be used independently with a slide switch.
It is equipped with functions such as duplicate function and microphone mixing circuit.
Equipped with a muting circuit to suppress noise when power is turned on.
There was a wood case as an option sold separately.
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Model Rating
| Type | Pre-main amplifier | ||
| Power Amplifier Unit | |||
| Output |
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| Power Ratio | 2.8 | ||
| Harmonic distortion factor | 0.5% (Rated) 0.03% (at 1W) |
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| Cross modulation distortion factor | 0.034% (at 1W) | ||
| Power bandwidth | 10 Hz to 30 kHz | ||
| Frequency characteristic | 10 Hz to 50 kHz -0.5 dB | ||
| Residual noise | 0.25mV | ||
| Input Sensitivity / Impedance | 1V/50k Ω | ||
| Preamplifier Section | |||
| Input Sensitivity / Impedance | Phono : 2.5mV/50k Ω Mic : 1mV/10k Ω Aux, Play : 150mV/80k Ω |
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| Output level | Pre out:1V Rec out:150mV |
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| Frequency characteristic | Phono : RIAA ± 0.5 dB Aux : 20 Hz to 20 kHz -0.2 dB |
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| Tone control | Bass : ± 10 dB (100 Hz) Treble : ± 10 dB (10 kHz) |
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| Low-cut filter | -12dB/oct(40Hz) | ||
| High-cut filter | -12dB/oct(9kHz) | ||
| ATT | -20dB | ||
| Equalizer allowable input | 200mV | ||
| Equalizer input conversion noise | -118dB(V) | ||
| <General> | |||
| Pwer | AC100V 50Hz/60Hz | ||
| Power consumption | 72W | ||
| External dimensions | Width 400x Height 138x Depth 311 mm | ||
| Weight | 9.4kg | ||
| Separately Sold : Wood Case CA-650 (¥ 7,500) for 650 Series | |||
| External dimensions | Width 465x Height 170x Depth 307 mm | ||
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