SRPP Headphone Amplifier Circuit Diagram
Mention valve amplifiers and many designers go depressive instantly over the thought of a suitable output transformer. The part will be in the history books forever as esoteric, bulky and expensive because, it says, it is designed and manufactured for a specific valve constellation and output power. There exist thick books on valve output transformers, as well as gurus lecturing on them and winding them by hand. However, with some concessions to distortion (but keeping a lot of money in your pocket) a circuit configuration known as SRPP (series regulated push-pull) allows a low-power valve amplifier to be built that does not require the infamous output transformer. SRPP is normally used for preamplifier stages only, employing two triodes in what looks like a cascade arrangement. SRPP Headphone Amplifier Circuit Diagram Here we propose the use of two EL84 (6BQ5) power pentodes in triode SRPP configuration. The reasons for using the EL84 (6CA5) are mainly that it’s cheap, widely av...