Is rectifier tube arcing a problem?


I did some research and couldn’t find a definite answer.  I have an amp that I tried 6 different pairs of 5U4G and 5U4GB. 3 pairs has arcing (RCA 5U4G, TungSol, Svetlana 5C3S) and 3 pairs don’t (RCA 5U4G with hanging filament, EH 5U4GB, Sylvania 5931).  I took the amp to a technician and he checked everything, he can’t find anything wrong.  The problem is, I like the sound of the TungSol and Svetlana which both have arcing.  The technician said it is ok to keep using them, but honestly I am not too comfortable.  But I like their sound.  Is it really ok to keep using the arcing tubes?  Will it damage the amp?

 

 

gte357s

Showing 5 responses by fiesta75

Finally, some real help for this problem. Thanks for helping to solve problems that the wannabees simply cannot.

+1 atmashpere too. I'm not a tube guy, but atmasphere has a point about the caps being too large. I ran into this problem while servicing a Sony V-fet amp. Both of you guys know your stuff. 

decay - Are you offended? Your multiple comments here were of no value. I was not commenting on you, as I do see that you do make valid contributions occasionally. My comments were meant to encourage imhififan and atmasphere to contribute more often. I have a lot of respect for both of them.

My 2cents - Seems clear that this an inrush current problem, which reducing the capacitor values would help to reduce. It has been my experience that reducing power supply capacitance does usually negatively affect low frequency capabilities. If I were going to reduce the cap values, I would not reduce more than necessary. Say from 220uf to 100 instead of going all the way down to 47uf.  The diode idea was excellent. How about doing both, diodes and just the 220uf caps to start with?

atmasphere - Thanks for taking the time to educate, me anyway. I have always appreciated and respect the knowledge you and imhififan have brought to the AG forum.👍

Sorry dekay, I will refrain from participating in a tread you are part of and would appreciate you do the same for me.