This board has a power consumption within the range of 3W. Some customers have measured it at 28W, but you can see from the actual evaluation images that the two LEDs in the middle of the board were not installed, causing the current to exceed 400mA. In such cases, the board will definitely overheat. Under normal conditions, the board should only feel slightly warm. If installed correctly, it will work perfectly on the first try, delivering excellent sound quality with no background noise. If you lack experience in assembly, it is recommended to purchase a pre-assembled unit. Please do not leave negative reviews if the board is not installed correctly or fully assembled. This product is very mature and stable, capable of competing with preamps that cost several times more!________________________________________________________________________________________________
Marantz HDAM Audio Linear Amplifier Circuit (Japan): This circuit delivers exceptional sound quality, with outstanding bass, rich midrange, and delicate highs, offering a comfortable listening experience reminiscent of tube amplifiers—far surpassing typical op-amp preamps. Unfortunately, the core transistor K170 was discontinued, and replacements like K246 or K30 couldn't replicate its beautiful sound.
In 2024, we sourced Toshiba original replacement transistors from overseas, which are fully compatible with K170. These SMD transistors contain two identical 2SK transistors, eliminating the need for matching and offering even lower distortion. The output stage uses BD139/BD140 transistors for Class A operation, providing excellent drive capability—even capable of powering low-impedance headphones. Paired with a power amplifier, it performs flawlessly.
Premium Components: - Double-sided gold-plated PCB
- Voltage regulation with ON Semiconductor LM317/337
- NOVER gold capacitors
- German red WIMA capacitors
- Beijing 718 copper-pin resistors
- Philips BC556/546 transistors for excellent vocal performance
Specifications: - PCB Size: 136mm x 122mm
- Power Supply Range: AC 14Vx2 to AC 18Vx2
- Recommended External Potentiometer: 50-100kΩ
- Frequency Range: 10Hz - 40kHz
- Input Impedance: 47kΩ
- Output Impedance: 10Ω
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This HDAM replica combines vintage sound quality with modern precision, making it a perfect choice for audiophiles seeking a tube-like experience with solid-state reliability.
