Guitar amp tube help...

[mrdazobee]

I just got myself an early fender vibrochamp in great condition.Sorry to sound a bit dumb but is there a way to check all the tubes are working ok?Would it be obvious in the sound or maybe a bit noisy something like that?The reason I ask is I pulld out the tubes and one of them had a few of the contact /plug things missing.It still gets hot though when switched on does this mean it is still ok?

[RefD]

does the amp even pass a signal?

missing pins = not okay

which tube(s) are missing pins?

replace them!

EDIT: better yet, get the amp checked out by a tech competent to work on tube amps.

[GooberNumber9]

A typical tube does not always have pins going all the way around the tube. If there are obviously broken off pins then that is definitely bad. If it looks like there never was a pin in a few places on a tube, that might just mean that the type of tube in question doesn't have a pin there.

If the amp works, then all the tubes are fine. You might want to buy all new tubes for it anyway, just so it sounds its best. If the amp doesn't work, then I would say you should get a pro to look at it. Messing around in an amp yourself can literally get you killed.

Todd Wilcox

[mrdazobee]

Just checked the tube in question (5Y3 gt) and there is no sign of breakage, it looks as though they were never there.The amp works great I was just wondering what if anything to look out for regarding the tubes.Seems as though all is fine

[RefD]

Just checked the tube in question (5Y3 gt) and there is no sign of breakage, it looks as though they were never there.The amp works great I was just wondering what if anything to look out for regarding the tubes.Seems as though all is fine

that's the rectifier tube.

you're probly fine.

*forces paranoia back into footlocker under guest bed*

[Rolsen]

If the amp works and you are generally pleased with the sound, you could keep those tubes or try swapping - just don't get rid of the ones in your amp! They may be quite valuable if you've got some 50's - 70's vintage 6v6's and 12ax7's in there (or whatever's in there). Many say that old functioning tubes will likely out-live your brand new variety. Not to direct you away from a fine forum, but the folks at www.vintageamps.com forum know their stuff and are generally not dipshits like you'll find on other 'gear' forums.

[lacquer_monkey]

Octal tubes often do not have all their pins in place. Rectifier tubes commonly only have 4 of the 8 pins because that is all that they use. Many octal power tubes (6L6, 6V6, etc.) only have six of the eight pins because that is all they use. I suppose it is just to save money in manufacturing. If it's not used why put it on there.

[Scodiddly]

Specifically, the 5Y3 will probably not have all its pins. Maybe 5 or 6 of them.

[RefD]

in the interest of self-defence, i feel i should mention that the way the first post was phrased i was under the impression some of the pins had broken off of one or more tubes.