2A3 / 300B / 811 / 572

This is the category for directly heated triode (DHT) fans. We carry current production 2A3 and 300B as well as SV811 and SV572 super triode tubes.

2A3 Tubes

2A3 tube was introduced in 1932, designed specifically for audio amplifier output stage. Despite being relative low powered, 2A3 still is the triode of choice for many high end audio amplifiers and DIY projects.

Sovtek 2A3 is a close replica of classic American 2A3 tubes, excellent for classical sources. Electro-Harmonix 2A3 Gold is very similar in construction to Sovtek 2A3, but it handles more contemporary sources better than Sovtek 2A3. JJ 2A3-40 sounds very close to their 300B, allowing you to listen to venerable 300B JJ sound with your 2A3 amp.

300B Tubes

300B was designed as audio power triode by Western Electric. Electro-Harmonix 300B, both regular and Gold versions are clear and honest sonics, reliable and are great value. Genalex PX-300B is one of the best current production 300B. It is meticulously built, handles 40W, and provides very good balance from bottom to top. JJ 300B is a great go-to choice, with its smooth and focused sound.

SV811, SV572 Super Triodes

Svetlana SV811 and SV572 tubes are high output triodes. With bright Thoriated Tungsten filament, with no getter these tubes have one of kind special look. We think these tubes are the ultimate final evolution of audio triodes, and very deserving for special DIY audio amp projects with high aspirations.