2. amps-preamps
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Can anyone recommend a better rectifier tube?

I have replaced the 5R4 rectifier tubes in my Jadis SE-300B amps twice in the past year. In February I installed JAN CETRON NOS 5R4WGB tubes purchased from TubeDepot. The amps have been used sparingly since then yet the tubes are now weak. This was the case with a previous set of theses tubes. Since installing these tubes I have been running the Royal Princess™ 300B tubes. Prior to that I used Western Electric 300Bs (manufactured about 10 years ago). Can anyone recommend a better brand or type of rectifier tube for this amp? Thank you.
cjbeach
sidssp
1,077 posts
 
Many of the so called NOS tubes are actually OUT (Old Used Trash). Be careful when you buy them.
salectric
753 posts
 
I have had very good results with RCA 5R4GY rectifiers in both my preamps and choke-input power amps. They are pretty cheap and easy to find, and they last a long time.
dodgealum's avatar
dodgealum
1,404 posts
 
I'm trying to persuade Sophia Electric to make a 5AR4/GZ34 rectifier tube that would replace the Mullard NOS in my Modwright LS100. I am already using Sophia's 6SN7's and they are wonderful. So, anyone else interested please send them an email and let's see if we can encourage them to add to their product line.
hifihvn
943 posts
 
11-14-11: Dodgealum
I'm trying to persuade Sophia Electric to make a 5AR4/GZ34 rectifier tube that would replace the Mullard NOS in my Modwright LS100.

Just to be on the safe side, don't try a 5AR4 in an amp that calls for a 5R4. The 5R4 can handle more voltage, so stay with the one the manufacturer of the amp recommends.
raquel
841 posts
 
Some tubes in power supplies handle a lot of voltage relative to their maximum voltage. As such, they will wear out relatively quickly. If I were you, I would ask Jadis what voltage that tube is exposed to in the power supply. If it is close to the maximum voltage specified for that tube type, then you are going to have to replace the tube more frequently, unless there is a more sturdy version of that tube type available (for example, the "GTA" and "GTB" versions of the 6SN7 can handle 50% more voltage than standard 6SN7's), or an alternative tube available that will work in that application and that can handle more voltage. If you have a good, trustworthy tube vendor, another alternative would be to have him screen a large quantity of 5R4's in order to find the top two or three performers - there is often great variation in performance between tubes of the same type and brand (like dogs and people), and the better performing tubes stand a better chance of withstanding the stress of the application.

Whenever a tube is run near its maximum voltage level, it will die relatively quickly because of the extra heat.
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