Phasemation EA-200 Phono Amplifier
High Gm FETs (field-effect transistor) are adopted in the first portion, so, a voltage-current converter of extremely low noises has been structured.
Due to a constant current circuit of low noise in which this circuit thoroughly discards deteriorating causes of sound quality and inflow of noises, the operation point is stably fixed.
By changing this voltage-current conversion coefficient, it makes the gain which is requested to the MM or MC cartridge.
b) In the second portion, stable current amplifier and voltage converter are structured, and the RIAA impedance elements arranged at the output point make the reproducing characteristic. As a result, CR type equalizer circuit having a very high frequency limit without RIAA deviation has been structured, so, it has an excellent transient characteristic.
For this circuit, various circuit techniques are adopted to perform accurately without influences of any current conversion tolerances and any variations of amplifier element parameters depending on the output voltage. Although it is a non-feedback type amplifier, it has various excelled characteristics that make it to be equal as a feedback type amplifier.
c) For the output buffer, the inverted Darlington circuit is adopted to ensure a high input impedance and low output impedance, which strongly drives the device in the next circuit.
|Form||MM/MC Non-Feedback Type Equalizer Amp|
|Input Impedance||47 k-ohm||470 ohm|
|Input Equivalent S/N ratio||–124dbV||–140dBV|
|Maximum Allowed Input||90mV||4mV|
|Rated Output Voltage||200mV (1kHz)|
|Rear Curve Deviation||±0.3dB (20Hz to 20kHz)|
|Output Impedance||250 ohm|
|Channel Separation||90dB or more (20Hz to 20kHz for MM or MC)|
|Power Consumption||2W (115 or 220 VAC, 50/60 Hz)|
|Input/Output Terminals||Machined gold-plated terminal|
|External Measurements (mm)||220 (width) x 57 (height) x 228 (depth) with terminals|