Audio Database
AD-290
Commentary

Phono equalizer unit developed exclusively for control amplifier C-290.
Record playback is possible by adding it from the rear panel of C-290.

Glass PRO base material adopted for C-290 is adopted, and external influence is suppressed by storing it in a sturdy aluminum case.

It uses a highly reliable DIN standard connector for connection to the body, and all functions can be switched on the C-290 panel.

The circuit consists of a push-pull type for all circuits and is equipped with a dedicated input circuit that matches each MM/MC cartridge. At MM input, it is matched to the high output impedance of the cartridge and is composed of FET elements with high S/N ratio. At MC input, minute signals are received with low impedance. Therefore, a differential input circuit is composed of low-noise elements, and the impedance of the NFB loop is reduced to achieve low-noise reproduction.

In order to match the characteristics of the cartridge, three types of MC input impedance can be selected : 10, 30 and 100 Ω.
The gain can be selected from 62 dB and 68 dB for MC and 30 dB and 36 dB for MM according to the output of the cartridge.
All of these switching can be done on the panel surface of the body of C-290.

Model Rating
(when connected to C-290)
Type Phono equalizer unit exclusively for C-290
Frequency characteristic AD input (MM/36dB, MC) : 20 Hz to 20 kHz ± 0.2 dB
AD input (MM/30dB) : 20 Hz to 20 kHz ± 0.3 dB
Total harmonic distortion factor 0.005%
Input Sensitivity / Impedance
Input sensitivity
Input terminal Rated output 0.5 v Output Impedance
AD MM(30dB): 4.0mV 1.0mV 47k Ω
AD MM(36dB): 2.0mV 0.5mV 47k Ω
AD MC(62dB): 0.1mV 0.025mV 10 Ω / 30 Ω / 100 Ω
AD MC(68dB): 0.05mV 0.0125mV 10 Ω / 30 Ω / 100 Ω
S/N / input conversion noise
Input short IEC-A correction
Input terminal S/N at rated input Input reduced noise EIA S/N
AD MM(30dB): 94dB -140dBV 86dB
AD MM(36dB): 90dB -140dBV 86dB
AD MC(62dB): 80dB -154dBV 85dB
AD MC(68dB): 75dB -154dBV 85dB
AD Maximum Input Voltage
(1 kHz, 0.005% distortion factor)		 MM(30dB):300mV
MM(36dB):150mV
MC(62dB):7.5mV
MC(68dB):3.75mV
Gain AD MM (30/36dB) input → Balanced/Unbalanced output : 48/54dB
AD MM (30/36dB) input → Rec output : 30/36dB
AD MC (60/66dB) input → Balanced/Unbalanced output : 80/86dB
AD MC (60/66dB) input → Rec output : 62/68dB