Custom-Twin Leak TL/50 Power Amplifiers

This amplifier was of course never made by Leak, but is a custom made stereo amplifier constructed in 1976, and featuring:

• Leak TL/50 Plus Circuit
• Original Leak output transformers for the TL/50 Plus
• Two power amplifiers on one chassis
• Two power supplies on a separate chassis, with interconnecting multi-core cable

The only changes from the original circuit were made in the power supply, which used surplus components rather than new original parts. This gave the opportunity to improve on the power supply design, as two identical AWA Type TH11 chokes were available. These chokes date from before the Second World War, and sport very impressive cast iron covers to clamp the laminations. Unfortunately, identical power transformers were not available. One is an Australian A&R transformer with approximately 1150 Volts center-tapped output, and the other an AWA transformer with 1100V center-tapped output, and comes from surplus War equipment. This latter unit is potted in a sealed box, and is designed for operation from 40Hz mains.

Overall, the twin power supply chassis weighs approximatley 40kg, and provides two 500 Volt high tension rails delivered from a choke-input rectifier circuit for improved regulation. Ripple is approximatley 1V peak to peak. A single filament supply for 6.3V at up to 10Amps comes from a separate transformer. The amplifier has been in service for the original customer since 1976.