Weak or failure-prone sovtek 5AR4 tubes.

[Duo]

An interesting issue has come up in my experience with using Sovtek's 5AR4 tubes.

I wish to find out if anyone else is having a problem with the cathode coating flaking off and shorting the tube.

I ran through a series of Sovtek 5AR4 tubes in a number of cases which had failed for no apparent reason. I kept concluding that too much power supply capacitance and/or amplifier malfunctions were the cause but these cases are becoming too common to be coincidental.

Please tell me of your experiences with these rectifier tubes, good or bad.

 

[indianajo]

I've got a Sovtek 5AR4 installed in my Hammond H182 organ for a year and a half. Date code 08 04 . Works fine so far. Has a 40 ohm choke (original) between it and the 50 uf film type Genelec motor cap (aftermarket).