Does such a thing exist as a valve damper for KT66s? (Marshall Vintage Modern 2266c)

imalrightjack

Evening all,

I've recently acquired a Marshall 2266c Vintage Modern combo.  I've yet to test it out in a suitable environment, as my tiny man-cave isn't the best place to really crank an amp (so much stuff vibrates or resonates oddly) but I have noticed what I read is a common problem with these (and many other) combos: rattling.  It sounds like the power valves (BIG KT-66s) or something is making an odd noise as the volume dials up.

Does anybody have any ideas on whether you can get dampers for these valves?  Hotrox do others but not for such big valves.

Any thoughts welcome.

Thanks!

ToneControl

silicone rings
there is another compound that can stand the heat
I bought loads
send me the diameter and I'll see if I have any left

imalrightjack

Thanks! I'll check the size asap

imalrightjack

@ToneControl - 6.5" circumference, so just over 2" diameter.

ToneControl

I don't have any that large, here's where I got mine

btw I also found that, as well as an amp vibrating its own valves, if you have a few amps in a room, they rattle along sympathetically like guitar strings even when not in use, especially if they rest on an active cab.

Here's my general advice on  valve dampers:

I've looked around and found Viton ones in the UK, http://www.polymax.co.uk, and I've bought some from there. 

Silicone is hard to find.

There are some preamp sized ones cheap from China on ebay (search for "tube dampers")

Viton is rated to about 205 centigrade (and much higher peaks), SIlicone to 250C
I measured a 6v6 in my 5E3 clone, and it didn't go past 120C, and came down a little when driven hard
 I'm assuming none go past 200C very often

The quantity I got wasn't much cheaper than from the US, about 20p for thinner cross-section (2.5mm) ones, 40p/50p for bigger ones (5.5mm) (plus vat and postage)
here's what I ordered, and the prices from 5 years ago:

BS122V75 BS122 20	£0.18	£3.60
BS124V75 BS124 20	£0.18	£3.60
BS125V75 BS125 20	£0.20	£4.00
BS320V75 BS320 10	£0.40	£4.00
BS322V75 BS322 10	£0.44	£4.40
BS323V75 BS323 10	£0.46	£4.60
BS324V75 BS324 10	£0.50	£5.00

these are 28mm, 32mm, 34mm
which covers most output and rectifiers I have.  The thicker ones don't stretch much, so I get just under the valve diameter.

I put thick ones where the internal metalwork inside the valve touches the glass, and another thinner one in the middle for luck.
Advice seems to be "don't cover more than 35% of the glass"

I've now used these for over 5 years, they don't melt in any of my amps
https://www.polymax.co.uk/o-rings/rubber-viton-oring/
use this page to get the size you need

imalrightjack

Thanks very much!