Accuphase AD-250
¥ 30,000 (released in June 1994)
Commentary
A dedicated phono equalizer unit that enables the playback of analog records on the C-250.
It is possible to play back records by adding from the rear panel side.
The AD 250 is equipped with a gold-plated glass substrate printed circuit board and a dedicated input circuit to match each MM/MC cartridge.
In the MM input mode, it is matched to the high output impedance of the cartridge to provide a high S/N FET configuration.
In addition, since the MC input receives small signals with low impedance, a differential input circuit with low noise elements is constructed. By reducing the impedance of the NFB loop, low-noise reproduction is possible.
The MC input impedance selection of 10, 30 and 100 Ω and a subsonic filter for cutting ultra-low frequency noise are installed inside.
These functions can be set with switches in the printed circuit board before installing the AD 250.
Model Rating
(when connected to C-250) | |||||
Type | Phono equalizer unit exclusively for C-250 | ||||
Frequency characteristic | AD Input : 20 Hz to 20 kHz ± 0.2 dB | ||||
Total harmonic distortion factor | 0.005% | ||||
Input Sensitivity / Impedance (Rated Output / 0.5 v Output) |
AD MM : 8.0mV/2.0mV/47k Ω AD MC : 0.25mV/0.063mV/10 Ω, 30 Ω, 100 Ω |
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S/N |
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Input conversion noise (input short, IEC-A correction) | AD MM:-137dBV AD MC:-151dBV |
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AD Maximum Input Voltage (1 kHz, 0.005% Distortion) | MM:250mV MC:8mV |
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Gain | AD MM Input → Balanced/Unbalanced Output : 48 dB AD MM Input → Rec Output : 30 dB AD MC Input → Balanced/Unbalanced Output : 78 dB AD MC Input → Rec Output : 60 dB |
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Subsonic filter | 25 Hz, -12dB/oct. (set by AD-250 internal DIP switch) |