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• PHASE TECH EA-3 Phono Preamplifier / Voorversterker / Vorstufe / Préampli
  

• PHASE TECH T-3 MC Step-up transformer / Übertrager / Convertisseur

PHASE TECH EA-3 phono preamplifier / Vorstufe / préampli
Price / Preis / le prix : 1.980,00 euro

With our slogan “Analog still does not reach the limit” Phase Tech brings High End audio equipment to analog disc fans. Our product line has expanded since 2005 when adding Model 3 series. Besides, we have been providing the music impression of only analog disc intending by Phase Tech and gaining support among lots of customers. Making full use of semiconductor-circuit technology Phase Tech has developed the EA-3 Phono Equalizer Amplifier.

FULL SYMMETRICAL NON-FEEDBACK CIRCUIT
Aiming to expand expression of music, we developed and newly implemented a full symmetrical non-feedback circuit by current  amplification. As a result, we achieved “rich expression of tone scale, sense of energy and a high Signal to noise ratio, plus a prominent spatial sound picture”, normally difficult to achieve in an amplifier with a traditional transistor device.


Detail of amplifier

The first layer consists of a voltage current conversion circuit with extremely low noise by a complimentary connection of FET (field-effect transistor). The well-selected device of which the operation point is decided by the self-bias function does'nt need a bias circuit, neither is there an inflow of noise or a deterioration of sound quality. So the device’s original operation functions with low noise.

The second layer handles current amplification and the voltage conversion circuit It obtains the reproduction characteristic with the RIAA impedance device connected with the current output point. Therefore, it is composed of the CR type equalizer circuit without the RIAA deflection to the super-high frequency and obtains an excellent transient characteristic. In this circuit, various techniques for operation with high accuracy are utilized without the influence of parameter change of the amplification device that depends on the current conversion error margin and the output voltage. It results in obtaining an excellent characteristic that equals the feed-back amplifier though this one is non-feedback.

The output buffer circuit assures wideband high input impedance by the input bootstrap. The output device by Darlington connection has enough current amplification at the same time, and drives the equipment connected with the next section strongly.


Realizing vibration free, resonance free and interference free operation

In a phono amp that amplifies a minimal signal, realization of vibration free, resonance free and interference free and simple signal transmission is important for signal purity.

Direct grounding construction
The R-core type power transformer of the EA-3 operates within margin by magnetic flux density, and magnetic vibration and generation of leakage flux were reduced as much as possible.　
In addition, the two transformers are assembled directly to planed brass feet through a 5mm bakelite board, this being an insulator of high electric resistance and reluctance. As a result, any vibration originating from the power transformer is discharged directly into the earth without transmitting to the chassis.

Dual monaural construction
   - Except AC1 withdrawing line, this amplifier is set up as a fully symmetrical dual monaural construction, achieving advanced uniformity of right and left channel.
   - It supplies ideal power without changes due to different power supply loads in right and left channels, by implementing two independent power transformers and shunt type local power supply. A channel separation over 100 dB (20Hz - 20KHz)
     is achieved by minimizing the loop of the electric current circuit.

A housing free of vibration, resonance and interference
   ・The delicate amplification part was mounted as a sub-chassis screened from electromagnetism, not influenced by harmful signals and vibrations other than the music signal. Consequently, its construction is vibration free, resonance free and interference free.
   ・1.2 mm and 1.6 mm copper plated steel plate is used for chassis and top cover, finished by painting. This way, reduction of magnetic distortion and securing strength was achieved.
　 . The housing is further strengthened by a front panel of 6 mm planed aluminum.

High sound quality components
Metal film resistors are used for all sections of the EA-3 amplification circuits to obtain high stability as well as making less noise. 

For RIAA impedance devise or the main part of the signal system the following was obeserved:
  1) OXYGEN-FREE guilded leads　　
  2) High sound quality parts with an excellent reputation like high quality dipped Mica

For extremely low noise power supply we observed:
  1) For the power supply circuit: a first recovery diode with higher typicality to avoid speed decrease of recovery
      time in a high electric current domain
  2) Low magnifying power, high sound quality electrolytic condenser
  3) Low noise Zenner diodes

Installing an active type subsonic filter circuit
We achieved a steady reproduction which quality of an analog disk was not controlled because it is installed the actual active type subsonic filter circuit of cut off frequency 20Hz,40Hz (18dB/Oct). Especially, in setting 40Hz subsonic filter, there is a significant  effect in limiting the howling margin, putting high quality analog disk playback within reach to others than only high end lovers.

Phase Tech EA-3 Phono Preamplifier Specifications:

PHASE TECH T-3 MC STEP-UP Transformer / Trafo / Übertrager
Price / Preis / le prix : 490,00 euro (= new)