Sophia Electric Aqua 274B Rectifier Tube with Live-Like Sonic Performance
"The Sophia Electric Aqua 274B rectifiers remain my all-time favorite rectifiers for that same combination of clarity, resolving power, and naturalness that they share with the Sophia Electric 45 mesh plates. If you have an amplifier that will accept a 274B rectifier, I've found the Sophia Electric Aqua 274B rectifier an easy path to better performance."
Jeff Day's Positive Feedback Online Review: “The sonics with Sophia Electric Aqua 274B rectifiers were superb, with a huge sense of space, vividly present images, a wide and deep soundstage, lots of resolution of musically meaningful nuance, and superb dynamics.
"The Sophia Electric Aqua 274B rectifiers easily outperformed my British NOS Haltron 5U4G rectifiers and the also excellent NOS RCA 5U4GB rectifiers, making them sound lean, washed out tonally, bleached in tone color, and rather average, which they aren't!
"The Sophia Electric Aqua 274B rectifiers are just so good that my other rectifiers paled in comparison, with Aqua 274B's being transparent, nuanced, smooth, colorful, natural, and dynamic presentation, that makes the music sound live, beautiful, and emotionally involving—they're something special!"
Sophia Electric Princess mesh plate 274B and rigid plate 274B tubes have been widely praised as the best sounding rectifier tubes ever made. However there is a catch - the first capacitor after the rectifier tube needs to be small. The max value allowed for the Princess 274B mesh plate is 4uf, or 8uf for the Princess 274B rigid plate. But for a typical 300B single ended amplifier, it is usually larger than 8uf. To overcome this limitation, Sophia Electric came out with a newly designed Aqua 274B rectifier tube to raise the limitation from 8uf to 47uf. This Aqua 274B can directly replace 5U4G in most amplifiers with great sonic improvement.
Aqua and WE 274B tubes would deliver 150ma-160ma of current at 430vDC per 274B tube.
Stereo 300B tube amplifier needs to have one 274B rectifier tube per channel, two 274B rectifier tubes for two channels. If the amp was designed to have only one rectifier tube for both channels, then 5U4G is more suitable.
Option 1: $210 per tube with one year warranty
Option 2: $169.99 per tube with 30 days warranty