Build Your 35W EL34 Tube Amplifier – Classic Design!

Description

This represents a traditional design for a final amplifier, delivering 35 Watts, utilizing two EL34 tubes in a push-pull configuration, originating from the work of Siemens and Halske, with a design date of 24/3/1953 and a code of SV410/1. The amplifier operated continuously from 1954 until 1989, typically running for approximately 15 hours daily. Maintenance primarily involved replacing the tubes, resistors, and capacitors due to age-related degradation. A key alteration incorporated the substitution of the original tube-based restoration circuit with diodes. The sole challenge encountered by those attempting its recreation is the expense transformer, a common requirement for all tube manufacturing processes, and a single, standardized model exists to facilitate this. This can be swapped for a suitable classic expense transformer specifically designed for EL34 tubes. Its fabrication necessitates considerable experience and caution when working with high voltages, posing a significant ELECTRIC SHOCK hazard.

Circuit diagram

Part List

More about components

This design utilizes several key components, including the Z2C rectifier tube, a standard device for converting AC voltage to DC. The Z2C (often a silicon-based diode) provides efficient rectification, a vital step in many electronic circuits. The operational characteristics of this tube are critical for its function, and understanding the behaviour of these semiconductor devices is crucial for diagnosing and troubleshooting potential issues. The specific characteristics of this tube, such as its forward voltage drop and reverse leakage current, directly impact the circuit's performance.