COPLAND : CTA 506. What they said ….. at the time

The CTA506 power plant is based on the KT120 power valves. These valves are a new variant of the legendary 6550 / KT88 power valves. For more than half a century, these classic valves have been the foundation of numerous of high quality amplifiers and surely, they will continue to serve as one of the premium choices among manufactures of high-power valve amplifiers