Rectifier tubes?

I may try the Sophia version just for fun but am still using the RCA which sounded just fine last night. I will use it until finding someone for testing and always have the other two for replacements. Why can't new tubes be made like the old ones? Anyone know?

You should try out the U52 (same version as 5U4) Osram or BVA as I used two pairs for my Silver Eagle Audio Signature monoblocks.

The original Western Electric 274B is the king of all 5U4G rectifiers. The Sophia exhibits some of the traits. It is open and extended and strong in the bass. The mesh version may even be better than the standard one. It is priced fairly for a very well made and robust tube.

Good Evening,

Does GZ34 and GZ37 are the same?

Thank for any help provided

Best regards

Does GZ34 and GZ37 are the same?

According to the Tube Substitution Handbook the following tubes can be substituted for each other.

GZ34, 5AR4, 52KU, U54, GZ37, and U54.

5AR4 shows the following are also compatible, U77, 5U4GB, 5AS4, 5AU4 and 5V3A

There is also an antique tube, the CV378 (British) which is excellent. I have a couple of them myself.

Last, if you want something cheap but decent there is a Chinese rectifier called 5C3PJ that subs perfectly. I bought some on line for $3.00 each a couple of years ago.

Have fun experimenting, you never know what will sound best until you experiment.