5AR4 and GZ34 are the same tube. I think that the Mullard is the best I have heard but the Matsushita made 5AR4s are actually very good. I am not a fan of substituting different tube types and would stick with the rectifier around which the circuit was designed.
Preamp Rectifier Tube Confusion
I have a Primaluna Prologue 3 which uses 5AR4 rectifier tubes which id like to roll. I’m looking at ShuGuang WE274B tubes which list as replacements for 5AR4 / 5U4G / 274B.
However, the Primaluna manual lists compatible tubes as: GZ34, CV1377, 5V4G, 5T4, 5Y3 and Upscale Audio also list the Philips 5R4GYS.
Any idea if the ShuGuang would work?
However, the Primaluna manual lists compatible tubes as: GZ34, CV1377, 5V4G, 5T4, 5Y3 and Upscale Audio also list the Philips 5R4GYS.
Any idea if the ShuGuang would work?