EA10 High-End Class A Preamplifier Board Finished Headphone Preamp Refers to Circuit for ELECTROCOMPANIET

EA10 High-End Class A Preamplifier Board Finished Headphone Preamp Refers to Circuit for ELECTROCOMPANIET

Description:
Referring to the Norwegian circuit for ELECTROCOMPANIET, the sound of this board is thick and powerful, round, smooth, sweet, beautiful in high frequency without losing the spirit, and warm in tone. Featuring three-frequency balance and good low-frequency performance, it can be used to upgrade our MARK JC-2 and preamp board for Accuphase C200V. The board can improve the sound that is unfriendly to ears produced by your systems.

Circuit Configuration:
FET is used as a differential input buffer circuit - differential amplifier circuit - and then sent to the second stage buffer circuit - main voltage amplifier circuit - and finally to FET push-pull output stage.

The power supply part adopts a voltage regulator circuit, and the sound performance of the circuit is amazing. The differential input uses FET 2SK170, the voltage stage uses constant current element, and 2SJ74/2SK213 MOSFET (for Renesas) outputs.

Version Introduction:
Input FTE K170BL; used output FET J76/K213 for Renesas; and MR754 rectifier for ON Semiconductor.

More Details:
- The whole board of HI-END class A circuit is made of premium components. Components, layout and its parameters have been optimized
- Feedback capacitors are upgraded to capacitors for RIFA and Sprague, and the capacitors are connected in parallel
- Two 4.7UF output capacitors (for WIMA) are connected in parallel, users can upgrade with a 10UF capacitor
- The temperature compensation capacitors are upgraded to MKP capacitors for SOLEN
- Resistors of the whole board are imported ones for KOA VISHAY, Panasonic, etc.; imported adjustable resistor for BI
- Differential input stage bypass capacitors are upgraded from the original FM series for Panasonic to better FG series
- FETs are imported and precisely matched, and the matching error of the same pole does not exceed 3%. The input adopts the new FET 2SK170; the output adopts the FET 2SJ76/2SK213 (original and used)
- The power supply is a voltage regulator circuit. The main filter capacitor is upgraded to original capacitor for ELNA made in Thailand and capacitors for Philips BC MKT
- The rectifier diode adopts the audiophile original MR754 rectifier for ON Semiconductor. At the same time, the anti-interference capacitor of the rectifier tube is upgraded to original ones for WIMA, thus showing off more details
- The PCB has heat dissipation slots at the large heat sink to ensure the heat dissipation performance, further improve the service life of the FET and the overall stability of the board

Specifications:
- Name: EA10 Class A Preamplifier Board
- Frequency Response: 20-25KHz
- Signal-to-noise ratio: 106dB
- Magnification: 8 times
- Pairing accuracy: error less than 3%
- Input form: RCA (unbalanced input)
- Working voltage: dual DC 40V
- Power supply range: dual AC 30-40V; recommended dual AC 38V
- Power supply method: It is recommended to use a 50W transformer for each channel to supply power separately
- Speaker protection: There is no protection circuit, so you need to install a protection circuit board when making a headphone amp
- PCB size: 240 x 220 x 2mm/9.4 x 8.7 x 0.08" (LxWxThickness)
- Total harmonic distortion: ≤0.01%
- Finished board: 240 x 220 x 42mm/9.4 x 8.7 x 1.7" (LxWxH)

Package Included:
- 1 x Preamplifier Board Assembled
- 1 x Set of Copper Pillars
- 1 x Set of Screws
- 1 x User Manual

Note:
- Schematic diagram is not included.