Amplifier and linearly regulated power supply for PS 1

The Sony Playstation 1 can also be used as an affordable high quality CD player. The digital and amplifier parts of the Playstation are driven with 3.3 V. Thus high output signal levels are not possible. Many CDs do not have the full level so that signal voltage is even less.

The amplifier with PCL 86 has about 10 dB amplification (ca. triple but can be raised on demand), which increases the signal level to those from usual CD players. Furthermore the distortion figure of the tube amplifier contributes to an agreeable sound because the second harmonic is predominating. through the low output impedance of the pentode tube part, longer audio cables also can be connected without loss of signal level. If a stereo pot (e.g. 22 kW logarithmic) is placed between Playstation and amplifier, the system can be used as a headphones amplifier with CD player. The PCL 86 is able to run headphones from an impedance of 300 W upwards.

All voltages are regulated linearly, stabilized and protected against shortcut. The amplifier board needs about 13.5 V filament voltage and about 300 V high voltage. The Playstation needs 7.5 V for the CD drive and 3.3 V for the signal and control parts. In the original system those voltages are generated by a switched power supply. This causes high frequent interferences and a high frequent basic noise level. If the switch mode power supply is replaced by a linear regulated one, the signal quality will increase distintcly.