Refer to the Accuphase A75 Pure Class A Circuit 120W High-Power Field-Effect Transistor Pure Post-Stage Amplifier

A75 machine power:

60WX2 pure Class A @ 8 euros

120WX2 pure Class A @ 4 euros

240WX2 Pure Class A @ 2 Euro

480WX2 Pure Class A @ 1 Euro

Frequency response: 10HZ-40KHZ

Distortion: 0.001%

Load range: 1-8 ohms

Weight approximately: 68 kilograms

Dimensions: 480 W x 260 H x 444 D (excluding front and rear handles)

The main capacitor is a brand-new imported original 67,000UF unit, with a reserve capacity of up to 268,000UF in total.

Why should I make this circuit?

The A-75 is the successor model to the classic A-70. It incorporates new technologies from Golden Voice and features improvements to certain circuits, along with corresponding component upgrades. This high-end stereo power amplifier utilizes MOSFET field-effect transistors for pure Class A amplification, delivering a rated output of 480 W×2 (1Ω), 240 W×2 (2Ω), 120 W×2 (4Ω), and 60 W×2 (8Ω). The dual-channel design employs 10 sets of balanced "power MOSFET" amplification modules. Fully balanced amplification technology offers advantages such as superior symmetry, minimal distortion, high stability, and strong driving capability over conventional amplification methods. The A75 builds upon numerous outstanding designs while introducing comprehensive upgrades in key technologies, including an enhanced MCS+ circuit, a primary buffer amplifier circuit, and a refined multi-stage parallel circuit design. The current feedback design ensures linear response across all levels, with amplifier unit circuits connected in parallel to reduce noise. DC stabilization power supplies are integrated into the driving section and MCS+ circuit to improve the S/N ratio and enhance sound purity. To ensure stable and sufficient power supply, the power section employs a high-efficiency, large 1200VA transformer paired with four 67,000μF "capacitor reservoir" filter groups, providing ample and stable power. Using low dielectric constant and low-loss Teflon-based materials, and applying gold plating to critical areas such as input terminals, further elevates sound purity. The oversized speaker output terminals facilitate easy connection to premium speaker cables. The front panel features a fully digital display of the amplifier's operating mode, calculated via DSP digital circuits, showing output power and operational status.

As a masterpiece of the peak period of Golden Voice, A75 has received widespread recognition and praise since its birth, and is one of the most representative works of Golden Voice. The sound tuned with numerous beautiful sound elements such as pure A-class and field-effect transistors breaks the bias of audiophiles towards Japanese sound. Its tone is mellow, with gorgeous and precise details in the mid to high frequencies, accurate imaging, stable and surging low frequencies, and smooth and natural connections. The strong thrust is enough to handle any speaker that is claimed to be difficult to push, even ordinary speakers can feel like a small box is being pushed out of the ground. Through this machine, I also understand why so many amplifiers with high fever require high thrust.

Based on the above characteristics, we have been preparing for this machine for three years, from molding the shell material, to collecting various scarce field-effect transistors, strictly screening and matching components, and testing multiple versions, and finally finalizing the current product. Now this machine is strictly designed according to the original design concept, and better materials than the original machine are also used as much as possible in terms of materials. The main tube uses the same K1530/J201 field-effect transistor as the original machine, and the filtering capacitor uses a larger capacity than the original machine. Currently, there are only 67000UFX4. The power transformer uses independently molded cast iron cow covers. The dimensions of the chassis are basically the same as the original machine, and the internal structure is also the same layered structure. At the bottom, there is a power soft start and signal input board. We have been making improvements and adjustments to this machine for over a year since its development (one of the main reasons is that our good friend is also working on this machine), until he ran out of field tubes and stopped production. Only then did we take it out for sale.