5AR4/GZ34 Rectifier Tubes


Is anyone currently making a tube of this type that rivals the performance of the best NOS Mullard tubes? I'm surprised that Sophia, Psvane and others appear not to have offered this tube. Suggestions?
dodgealum

Showing 4 responses by whart

I have been rolling rectifier tubes in my Allnic H 3000 phono power supply- the standard chinese tube didn't sound bad, but the unit wasn't really broken in much; an old Tung-Sol sounded very good; I still have to try the RCA NOS and am currently running a Mullard Fat Base first series, which sound terrific. I haven't tried any tubes that are currently manufactured, apart from the Chinese tube mentioned above.
Trelja- according to the importer of the Allnic, the factory supplied tube was a Shuguang 5Z3PJ. I can't say i listened to it critically, because the unit was burning in at the time. I have a whole pile of vintage rectifier tubes including a couple more of the factory supplied Shuguang. The fat base Mullard first series, which was pricey, sounds lovely, particularly now that I have several hundred hours on the unit, and the step up transformers have broken in. Interestingly, this piece doesn't require any tube rolling on the audio circuitry, only in the power supply. And, I've been playing with various types of physical isolation for the power supply- I did a blind test with my wife as the beta-tester, and she heard noticeable differences in various cones, footers and isolators on the PS. It all makes a difference.
I'm hardly an expert on this, but in debates over the merits of various
rectifier tubes for my phono stage power supply, one well informed industry
person brought up the topic of voltage drop or sag. I know anecdotally
about this from the musical instrument amplifier world- guitarists often want
a tube that that ultimately compresses when pushed, to give it a distinct
(albeit distorted) sound. One of the differences, for example, between a re-
creation Marshall guitar amp that has solid state rectification and one that
still uses a tube. For hi-fi, you don't want that. :)
In any event, some of the differences in sound may be attributable to such
characteristics. Differences in circuit design as it applies to this are beyond
my pay grade. There are various sources for rectifier tube data sheets free
on the Net. You should consult the manufacturer of your equipment too if
there are questions.
From what I have been able to determine the NOS Mullard I am using (first
series fat base) has different voltage characteristics than other vintage
Mullard tubes.
Also, don't assume that because the tubes of different designations can be
swapped, that they are appropriate for your particular device. Again,
beyond my competence, but a little due diligence on various tube
charactistics may be advisable, as well as consulting with your
manufacturer.
If someone else here has more knowledge on the last subject, they are
welcome to chime in.
Mr. Tennis: I believe Brimar is an acronym for 'British Made American Range" tubes, and they do make an equivalent rectifier. I also saw a pair of 12AT7 for less than a comparable pair of Telefunken small tubes. Just have a web search. Have fun.