Tube power amplifier made with EL34 tube

The author has made a tube amplifier (see the attached circuit). After long-term testing, the amplifier feels that its sound quality is very good. Now I would like to introduce it to you. The amplifier is composed of two E134 tubes, a pair of transistors, and op amp T1072. The op amp B1/B2 and transistors Q1 and Q2 form two completely symmetrical transconductance amplifiers. Since this circuit has the advantages of high input impedance, low output impedance, good stability, and low distortion, it is worth a try for tube amplifier enthusiasts. After installation, if the welding is correct, no debugging is required, and it is ready to go. The output power of the amplifier is greater than 30W, and the distortion is less than 2%.

Component selection: The resistors in the circuit are metal film resistors; the capacitors are aluminum shell electrolytic or tantalum electrolytic, C5 and C6 are high-quality electrolytic with a withstand voltage greater than 400V. C1 and C2 are CBB capacitors with a withstand voltage of 630V; T1 is a toroidal transformer, with 11 being AC 220V, 12 being 24V, and 13 being between 4 and 6V.