Rattling Tubes

[steve00]

I recently purchased a Fender Hot Rod Deluxe amp and I noticed that the smaller tubes (pre-amp, right?) rattle when I hit certain notes (11th fret A string for example). I bought it used so the tubes are a few years old. The amp plays great, but this rattling is driving me nuts. Is this a sign of bad tubes?

[Daniel Sorbera]

Bad tubes could deffinitly be contributing to the problem. First make sure they are seated in there sockets correctly, it could be something as simple as they rattled themselves a bit loose.

[JoeAArthur]

If you hear the sound of the tubes rattling being amplified through the amp, then yes it is definitely a sign of bad tubes. If you don't, it could be the preamp shield covers are loose, old, worn whatever.

Quality of tubes has been going downhill. I went through 4 sets of 6V6s before I found one that didn't rattle.

[tasty]

Steve,

You wouldn't happen to be located in RI would you? I just sold my HRDx to a gentleman there. There is in fact a piece of foam that fender includes with the HRDx which goes over the smaller tubes. If you are that guy then PM me and I think I still have the foam hanging around. Otherwise it could be faulty tubes.

[Spencer Gross]

Hello,

I would most definitely say, that you've got your hands on some bad tubes.

Are the tubes post-additional? You might want to check whether the tubes are original or added by the previous owner.

Otherwise, like Godin SD said, make sure the tubes are correctly in their sockets.

-Spencer

[steve00]

Ok thanks guys...I will check and make sure that the tubes are correctly placed in the socket. I'm new to tubes (this is my first tube amp), but I'm pretty sure the tubes are bad anyway. When I do bends on the guitar the sound cut out, which really surprised me, but I read that that is a sign of bad tubes as well. I'll change them and *hopefully* that will fix the problem, but that leads me to my next question about biasing...

Fender says that if I replace the tubes with the same kind that I dont need to rebias the amp. Does this mean Fender brand tubes? Fender refers to some coloring system as well when selecting tubes (same "type and color" or something like that), but I haven't seen anything mentioned about colors when shopping for tubes online, even on Fender brands. Any advice would be appreciated. Thanks again guys,

-Steve

[marksound]

The color codes (printed labels) on the Fender branded 6L6 pairs goes like this: White: Medium. Standard on the HRD. Blue: Bluesier. Less headroom before breakup. Red: Higher gain. More headroom. At least that's my understanding.

The power tubes on my HRD went south a while back and I replaced them with a blue set. At first it seemed to have lost some volume and high end bite. Now I think it sounds much better than stock. Warmer and fuller. Supposedly, the Fender branded pairs are matched, so a rebias is not mandatory. I'd do it anyway. Google "Hot Rod Deluxe." Lots of info out there.

WE INTERRUPT THIS PROGRAM FOR A SAFETY ANNOUNCEMENT: TUBE AMPS CONTAIN HIGH VOLTAGES THAT CAN AND WILL KILL YOU. IF YOU DON'T KNOW WHAT YOU'RE DOING, DO NOT SCREW AROUND WITH ELECTRICAL COMPONENTS. THANK YOU.

Now about the preamp tubes, I've never had to replace mine so I don't know. There are as many opinions about tubes as there are "experts." Do some studying and draw your own conclusions.

[Paul Marossy]

Biasing the power tubes on the new Fender amps is a snap. But, as was mentioned, if you haven't done it before, take it to a tech.

[steve00]

Ok well I've done quite a bit of reading on the Unofficial HRD Owners Guide website. The biasing looks pretty simple, but apparently the amp doesn't need to be re-biased if you're just changing the preamp tubes. I think I'm going to go with some JJ tubes. I don't know if the power tubes need changing, but they've been in there for 3 or 4 years, so I think I'll just change them all. I know the basics of electronics safety (I'm a EE student), so I feel comfortable working on the amp when it's live. Thanks guys for all the help and info,

-Steve

[lovekraft]

...I feel comfortable working on the amp when it's live...

If I ever start feeling comfortable with working on a live amp, I'm going to retire! Seriously, a bunch of my associates and I discussed this at length over drinks a few years back, and decided it's probably fairly difficult to kill oneself accidentally with a live tube amp, but since death is a permanent, non-negotiable state, we concluded that it's better not to take any chances. The only thing you have to have power to do is biasing the amp - all other work should be done with the switches off, the amp unplugged, and the caps drained, if possible.

[steve00]

Famous last words, huh?...I should have said that I at least feel comfortable enough to bias the amp. Good point though, thanks for watching my back.

-Steve

...I feel comfortable working on the amp when it's live...

If I ever start feeling comfortable with working on a live amp, I'm going to retire! Seriously, a bunch of my associates and I discussed this at length over drinks a few years back, and decided it's probably fairly difficult to kill oneself accidentally with a live tube amp, but since death is a permanent, non-negotiable state, we concluded that it's better not to take any chances. The only thing you have to have power to do is biasing the amp - all other work should be done with the switches off, the amp unplugged, and the caps drained, if possible.