Grateful Dead Music Forum

I have had MySCXD for about a yearand 1/2 and it suddeen was making a noise w/out anything even plugged into it ,so checked the power tubes to see if they were plugged into the socket and they were the wrong tubes. They are supposed to be 6v6 but were 6l6 . someone at the factory made a mistake .did this do damage ? any of you experts have any ideas ?

Wow, that's quite unusual - never heard of this before with a factory Fender. Oh well, you're the first!

I'm guessing you're OK. Here's why.

I don't have any experience with the Super Champ XD. However, I do with replacing the stock 6V6s w/6L6s in Deluxe Reverbs. The 6L6s draw more current so you have to rebias but the trannys are sufficiently robust to handle the replacement tubes. With a DR Reissue, you're done with a rebias. For an older BF or SF, it's usually advised to replace the filter caps (and perhaps the screen resistors) to ensure you're safe to handle the extra juice. (Do not, however, try this trick with a Princeton Reverb - the trannys can't take it).

If you ran the amp and it worked for a year and a half with the 6L6s, I feel pretty confident that the amp handled it fine. If it hadn't, you'd have known sooner! But this is just my best guess.

I did some reading on this cause I am interested in tubes and their types and use. Though I do not own an amp that use 6 series tubes (El84s in mine) I did see where a 6L6 can be substituted for a 6V6, primarily can be done with low risk in a cathode bias amp, which I think the Champ is. Jon S. notes that re-biasing is needed in some amps. I also found a reference that since the 6L6 will want more current than a 6V6 but is in a circuit designed for 6V6s, it will run hot. That could cause extra wear and you might just have the tubes going microphonic earlier in their life. Also depends on how much you play, how loud and how much you transport your amp around and shake the tubes and such.

Jon S. certainly knows more about the tubes than I but just looking at it from a laymans point of view, I think you should just get new tubes, either 6L6s or 6V6s. You will get more power out of the 6L6s most likely but may have to deal with shortened life spans of the tubes. Maybe I am totally off base, who knows.

Re: screw up at the factory. Would sound like a first. you sure that you got a factory new amp?

Hope it works out for your amp.

Dave

The story on my SCXD amp. The ribbon cable vibrated loose and came disconnected The tubes were in fact 6v6 but did have the letteres 6l6 on them also. It was under warrentee and didn't cost me a penny exept an almost 2hour ride to N.H