SONY TA-F55 Integrated Stereo Amplifier [Junk]

SONY TA-F55 Original Retail Price: ¥59,800 (around 1979)
The power turns on, but there is no sound output.
This is a very old item, so we recommend it for those who can repair it themselves, for parts, or for collection.

From Audio Heritage:
This integrated amplifier focuses on maximizing the potential of the cartridge, featuring a 4-step cartridge load selector and a simple & straight signal path. The cartridge load selector allows for two positions of adjustment for both MM and MC cartridges. It employs a DC power amplifier system, utilizing Sony's proprietary Hi-fT transistors, born from their semiconductor technology. These transistors possess excellent high-speed response characteristics, enabling the suppression of dynamic distortion, including transient intermodulation distortion, with a simple circuit, thus preventing adverse effects on sound quality due to circuit complexity. For heat dissipation, a heat pipe system is used. By employing heat pipes, which have hundreds of times the thermal conductivity of copper rods, it eliminates the need for lead wires to connect the transistors and circuit boards, preventing electromagnetic wave generation from lead wires. The power supply section uses a pulse power supply. This pulse power supply instantly converts AC100V to DC, preventing the 50Hz/60Hz AC magnetic fields and contributing to the amplifier's flux-free design. It also suppresses voltage fluctuations in response to signal changes, allowing signals to flow electrically straight. Furthermore, the TA-F55 achieves a more stable power supply by using high-speed rectifier diodes. The preamplifier section is equipped with a dedicated FET buffer power supply. The simple & straight signal path pursues the shortest component layout along the signal flow, preventing sound quality degradation due to electrostatic coupling between wires and components. It features self-defeat tone controls, dual monitor & tape copy switches, audio muting, a low filter, and loudness. Oxygen-free copper wire is used for the signal path, and gold-plated terminals are employed for the phono jacks.