PAT-5a

About the PAT-5a

The Dynaco PAT-5a is an updated version of the PAT-5 preamplifier, serving as the control center for high fidelity stereo systems. It is designed to be used with power amplifiers such as the Dynaco Stereo 400 or Stereo 120 and supports two pairs of speakers and headphone output. The PAT-5a features a fully regulated power supply, multiple audio inputs including two phono inputs with RIAA equalization for magnetic cartridges, and tone controls that can be switched out of the circuit. It includes facilities for two tape recorders, an external processor loop, and speaker switching capability. The preamplifier uses a direct-coupled transistor pair for the preamplifier-equalizer circuit, a voltage follower for control functions, and a high-performance operational amplifier for the tone control-output section. The power supply is designed to maintain stable voltages despite line voltage variations, ensuring consistent audio performance. The PAT-5a is known for its low noise, low distortion (THD around 0.007%), wide frequency response (10 Hz to 50 kHz), and high signal-to-noise ratio (70 dB for phono, 85-90 dB for line inputs). It was originally available as a kit (DynaKIT) for easy assembly and superior parts quality. The unit is no longer manufactured but remains popular among audiophiles for its flexibility and sound quality.