D*A*M Forum

I’m going down the rabbit hole of trying to solve tube rattle in my old AC10. Once it gets would up enough to start overdriving I get some rattle. It has the EF86 preamp tube and these tend to be microphonic from what I understand.

Has anyone had experience with tube dampers? Also, would NOS tubes tend to have this problem less? I’d love to hear from anyone who has tried to solve this problem, and especially anyone who has dealt with this particular tube in an old Vox amp. Cheers!

I have tube dampener rings on my Gibson GA6 phase inverter.
It’s a 6SL7 and is prone to being micro phonic.
They seem affective.
Also maybe swap out different brands.

rattles are usually from loose internals inside the tubes... microphonics are pitched ringing noises like feedback... i'd pull each tube out and tap it next to your ear to see if you hear rattling... even the rectifier can impart that type of noise.. EL84's are prone to rattles too

Yes. I think this must be rattling. It’s not a squeal or a feedback-y sound. You can keep on playing. It almost s sounds like a loose bolt is rattling around.

Other than that this amp is insane. It needed quite a bit of work. Had the original e cap in it. So glad the transformers didn’t get smoked somewhere down the line.

You’ve got an AC10 don’t you Jim? Do you run into this issue?

Old thread I know, but in case it helps: I have a couple of old AC15s, one of which is prone to this. For that one I use an E80F as a substitute for the EF86 and two of those silicon damper rings. Of course, there could be a mechanical/vibration issue that the EF86 is picking up due to its inherent microphony. (Most E80F are taller than an EF86 but it shouldn't be a problem with an AC10 other than a tube cover or wire clip won't work any more if there is one. )