Cary SLP-05 owners/Tube Rings

I would like to know(since I do not have a ring that size) has anyone tried a tube ring on the (5ar4) rectifier tube in the power supply hearing better preformance.I noted from other chats about changing to different brands of rectifier tubes there was an increase in preformance.
Since tube rings make a difference in other areas on tubes I was wondering about the 5ar4..
I have 4 rings that should fit. Just basic heatproof rubber rings. I needed 8 matching and these are too big for the EL34's on my other amp. Want 'em really cheap? Give me a brand on your tube first so I can try out the size.
Switched my rectifier tube to the Philips Miniwatt... never looked back. You could go with tube rings, but think about changing it also.