Phono Amplifier EA-350
Product Outline and Concept
Having in mind that “analogs too have a lot more to go,” we expanded the product line-up of EA-1000, EA-500, EA-300, EA-200 and phono amplifiers due to non-feedback circuits for lovers of analog discs.
This time as the product to be a touchstone of a semiconductor phono amplifier, we brushed up all of the functions from the interior MC transformer to the circuits of EA-350
I. Inside is an MC transformer for balancing which is accomplished the first time for this class
Last year, using our knowledge gained from making T-2000 which sparkled having won many awards last year, we built in a step-up transformer with a special split winding structure supporting balanced transmissions of a 26dB gain and this makes an MC balanced transmission.
Three input terminals are equipped and MM/MC switching is possible for each. (Inputs 1 and 2 support balanced inputs)
II. A 10mm thick aluminum material is used on the front panel and the chassis is elegant and strong and it is structured following the designs of CA-1000 and T-2000.
We adopted a strong housing structure that is composed with a 10mm thick slant aluminum panel for the front, a 1.6mm thick copper platted steel plate chassis base, and a 1.6mm thick copper platted steel plate cover and this preserves the rigidity and decreases the magnetic strain.
In addition, the elegant designs of CA-1000 and T-2000 are adopted and the played sound can be enjoyed with elegance, overwhelming realism, a panoramic stage, high resolution, and high S/N.
III．V-I / I-V conversion type full-stage symmetrical non-feedback amplifier circuit due to all discreet parts
The negative feedback amplifier which is the mainstream of modern amplifiers constantly compares the input and output signals for both the semiconductor and vacuum tube and this difference can be amplified with high precision at low cost because it is amplified as an input signal. However, there is a time delay between the input and output signals which cannot be solved theoretically and this generates a TIM distortion and the like and this is a big reason why sound satisfaction cannot be attained from negative feedback amplifiers.
At Phasemation, amplifiers of semiconductors and vacuum tubes are all composed of non-feedback amplifiers. For non-feedback amplifiers, there are no amending operations like the negative feedback amplifiers and therefore high precision/technology of structured parts and circuits are required. As a result, there are no information remains of the sound source (record) but is played fully 100% and in terms of sound quality, it can play the music with excellent inspiration, dynamics, and shadowed (or the like) expressions.
IV. Prolific Features
- A non-feedback type low cut filter of CR2 step is loaded
Plays warped phonograph records without any music deterioration and prevents the speakers (woofers) from shaking.
- Three types of playing curve changeover switches are loaded.
For the equalizer characteristics, along with the RIAA characteristics for the previous stereo, Mono1 (used on the DECCA label and so forth) and Mono2 (used on the Colombia label and so forth) are equipped as characteristics particularly for a monaural. This will allow higher fidelity playback than the DECCA and Columbia labels.
- A “degaussed” circuit is loaded
By choosing “degauss” with the function and playing the record for about 30 seconds, the MC cartridge with a metal core that was magnetized is degaussed and the sound quality becomes clear.
- A monaural switch is loaded
When using the monaural cartridge, turn it on.
V. Adoption of parts having high sound quality
On the signals
- A 1% grade metal film resistance with marginal rated capacity and reputed high sound quality parts such as a Micar capacitors using silvered Micar plates for dielectrics are used on the RIAA elements which have high influence on the phono amp’s sound quality.
- On the signals, ELNA’s SILMIC electrolytic capacitors for sound quality and metal film resistance of a 1% grade are used.
On the power circuits
- The switching noises are few and adopts Rohm’s SiC diodes which have a reputation for high sound quality.
- We adopted a large-room electrolytic capacitor that is of highest rank in audio grades of metal plated terminals which uses Nichicon’s low resistance electrode foil on the commutating capacitor. In addition, the decoupling capacitor adopts ELNA’s SILMIC II.
- Low noise zener diodes are used combined with the adoption of shunt regulators that exclude the feedback circuit and this structures a fast and extremely low noise power circuit.
- The power transformer uses a transformer of low leakage flux using an R-core and made it to be a left/right independent power supply.
|Form||V-I/I-V conversion type all-stage symmetric non-feedback equalizing amplifier|
|Input Type (Cartridge)||MM||MC|
|Input Sensitivity||2.5 mV||0.13 mV|
|Suitable Cartridge Output Impedance||47 k-ohm or less||1.5 to 40 ohm|
|Gain||38 dB||64 dB|
|Input Equivalent S/N Ratio||–120dBV||–140dBV|
|Rated Output Voltage||200 mV (1kHz)|
|Rear Curve Tolerance||± 0.5 dB (20Hz to 20kHz)|
|Output Impedance||47 ohm|
|Power Requirement||AC120V 60Hz (U.S.A) AC230V 50/60Hz (Europe/Asia)|
|External Dimensions||430 (W) x 93 (H) x 362 (D)|