Replacing 5U4G with 274B's - Which 274B's are best?

[iaxel]

A bit OT, can anyone recommend a good source for a NOS GEC U52?

 

[ketcham]

Infonosaudiotubes@gmail.com
Umar Shaikh - Mumbai, India.
I purchased 50 units some years ago.
All tested strong
Highly recommended. They have many.

 

[NaimYourTubes]

Mullard Blackburn GZ33 are a 5AR4 on steroids and are compatible with the majority of 5U4G circuits. Fantastic rectifier tube. Also labeled CV5475 IIRC for military issue tubes.

 

[warnie7]

Did they blow up pretty quickly, i.e. there was an immediate reaction to the tubes when connected with your Lampi? ...or did it take a while then they died? This is an important point for me on my end. Thanks.

Mines hasnt blown up yet but when I turn on my Lampi it flashes. I wrote SE and the lady said they are coming out with a upgrade version in July-Aug and she will replace it for free

 

[Cellcbern]

Infonosaudiotubes@gmail.com
Umar Shaikh - Mumbai, India.
I purchased 50 units some years ago.
All tested strong
Highly recommended. They have many.

Just looked at their website - they have only one CV575 U52 with the beveled/curved bottom edge brown base (see photo) which is the legendary version and the only one worth having. I have seen this tube labeled Brimar, GEC, Marconi, MWT, and Osram. They have lots of the cheaper straight edge base versions which are not in the same league sonically and are typically much cheaper. There are also a couple of the beveled/curved base edge tubes for sale at ebay (where nosaudiotubes also sells). There was a similarly beveled/ curved black base version which I haven't seen in more than a decade. Haven't heard it so don't know how it compares with the brown base version. You will never see more than a couple of the premium tubes for sale because they are scarce, and they will typically be north of $500 per tube. I use the beveled/curved edge brown base tube in my Modwright PS 9.0 power supply where it is one of the two best rectifiers I have heard, the other being the Sophia Aqua 274B. The Sophia is a little more resolving but also a little bright. The two are in a class by themselves in this application.

FYI: https://www.nosvacuumtubes.net/product/gec-u52-5u4g-cv575-1950s/

 

[ketcham]

Just looked at their website - they have only one CV575 U52 with the beveled/curved bottom edge brown base (see photo) which is the legendary version and the one worth having. There are also a couple for sale at ebay. There was a similarly beveled, curved black base version which I haven't seen in more than a decade. Haven't heard it so don't know how it compares with the brown base version. The other base types don't compare. You will never see more than a coupe for sale and they will typically be north of $500 per tube.

Contact them directly. Whats App : text or call. They have more. (I have no financial affiliation with them). I purchased from them on the regular and every tube has been consistently strong - NOS

 

[Cellcbern]

I have had 2 Sophia Electric Aqua IIs. They sound great. Both blew up, the first time requiring the DAC to go back to the factory...

I replaced a Sophia Aqua with the Aqua II after 4+ trouble-free years of use, and have more than a year on the Aqua II, also without issue.

 

[Anyoldears]

I replaced a Sophia Aqua with the Aqua II after 4+ trouble-free years of use, and have more than a year on the Aqua II, also without issue.

Lucky you