Description

Class A Power Amplifier Board Home Power Amp Board Rivaling E405/550/KSA50/711 for Accuphase

Features:
- Local feedback circuit, compared to large loop feedback circuit, it can get better thrust and overall control ability. Using FET differential input structure, the overall weak signal pickup ability of the circuit is strong and the tone is good. The constant current of the differential input stage adopts a current mirror structure, and a stable output can be obtained even under large dynamics. By default, the board is designed for high bias current class A and B state with good output characteristics, and it can also be adjusted to class A state to obtain better timbre.
- The soundstage is wide, with sweet vocals in the mid and high frequencies. The detail analysis is rich, and the overall control is excellent. Good low frequency performance and good sense of volume. Class A board makes the sound more audible.
- The resistors, capacitors and tubes used in the whole board are all imported, and these high-quality components ensure high stability.
- The board is designed with a perfect speaker protection circuit structure to protect your speaker unit
- All the tubes on the board are imported, and the board is precisely matched with the matching instrument, and the error of the same polarity is within 3%.
- Reasonable PCB layout improve the overall stability and signal-to-noise ratio of the board. Components for KOA, Vishay, WIMA (audiophile resistors), Philips (axial capacitors), NISSEI (film capacitors) are used. Audiophile capacitors for WIMA and Siemens are adopted. The imported BI is adjustable, the original imported tubes of the whole board are precisely matched.
- The final stage current output tube adopts new bipolar transistors for ON Semiconductor. The transistors have a strong output power, and at the same time, the have a very good performance in tone, analysis and hearing. CNC precision machining of heat conduction bridge aluminum parts.
- The input stage differential circuit board is designed with two mounting modes: 1. Two independent FETs are used for differential input; 2. A twin FET can be used for differential input directly. The first installation mode is adopted on the board, and imported FET is selected for the input stage differential circuit.
- MJE15034/MJE15035 bipolar transistor to ensure enough current required for current stage amplification, while obtaining good tone and better sense of hearing.
- There is a complete speaker protection circuit designed on the board, which concentrates the functions of voltage offset, over-current, overload, noise suppression and over-temperature protection during startup/shutdown, and can also simplify the installation.
- 30A imported sealed relay has longer service life and more stable performance.

Specifications:
- Item name: Class A power amplifier board
- Frequency Response: 20-25KHz
- Power supply: recommend two transformers above 500W, dual DC 50V + AC 12V
- Signal-to-noise ratio: 108DB
- Output power: Class AB 480W+480W; Class A 100W+100W
- Damping factor: 500
- PCB board: 280mm*91mm*2mm
- Input Sensitivity: 1.26V/RMS
- Total harmonic distortion: ≤0.01%
- Finished board size: 280mm*114mm*35mm
- Unilateral heat sink: heat sink should be above 3.5 kg

Package Included:
- 2 x Amplifier Boards
- 1 x Temperature Control Tube
- 1 x Set of Screws and Pillars
- 1 x Debugging Manual

Note:
- Schematic diagram is not included.