ShortScale.org

if i play loud it starts rattling badly
it's not something else in the room rattling, and the cabinet is tightly built and all sealed up
sample here
http://homepage.eircom.net/~deaddonkey/roost.mp3

What type amp? Tube or solid state? Was that through pedals, or just guitar-cable-amp?

roost 50, all valve, no pedals, just straight into amp, into homemade cab

Buy some Harma preamp valves. The DR250 cryos, you problems withh be fixed

Man that was some Icey shit.

Sounds like microphonic preamp no?

One problem I've had in the past with some vintage amps has been the cloth covering over the front becoming slack and flapping from the air being pushed by the speakers. It sounds kind of like that rattle. (and is exacerbated by certain frequencies too. The Supro Vibra-Verb rattles on A)

If you can't find some acoustic cause like Lanark's talking about, I'd suspect (hope) it's preamp tubes. Start by switching the amp off and let the tubes cool (probably what they've been doing anyway since you posted). Starting at one end of the chassis, pull the tube at that end out of its socket and wipe off its pins with a tissue or a cotton swab dipped in rubbing alcohol. Carefully push the tube back into its socket and then go on to the next tube. Do this with the larger power-amp tubes too while you're at it.

With the last tube back in place, switch the amp on, warm it up, and see if there's a difference. Sometimes accumulated dirt between pins & sockets can cause that kind of behavior. If this fixes things, you'll probably still want to have a tech clean and retension all the sockets.

If that doesn't fix things, then go on to play musical-chairs with the pre-amp tubes. This is what Mike recommended to Shadow a few days ago. I don't know what preamp tubes a Roost takes, but the idea is to take a new 12AX7 (ECC83) tube, or one that you =know= works well, and swap it in place of the first pre-amp tube. Test the amp to see if that cures the rattle, and if it doesn't, then put the original tube back in, plug your known-good tube in place of the =second= pre-amp tube, test again, and so on. Put your amp on standby (or switch off) each time you swap tubes like this, or it's likely to make a big, speaker-endangering POP. If the rattle goes away, whichever original tube you replaced was the culprit.

Heavy.

Does it differ with volume?

Doog wrote:Does it differ with volume?

the louder/harder/gainier i play, the more it rattles