ARC Ref 6 tube dampers.

Would like to know if anyone with a ARC Ref 6 put tube dampers on the 6550 power supply tube. Was also wondering if there was a reason why they didn’t put one on that 6550 and they did on the 6H30 power supply tube. Anyway I will be ordering the Herbies tube dampers. 6 Ultra Sonic tube dampers for the audio circuit which has 6 - 6H30 tubes and 2- HAL-O Herbies tube dampers for the 6550 and 6H30 for the power supply. Has anyone had either positive or negative results with dampers on the power supply 6550 tube. Thanks to all. 
I used a full complement of Herbies in my 2 Ref 5se’s. There was slightly better balance top to bottom than with the ARC factory supplied thick rubber bands. No difference whatsoever on the 6550 with or without. Trust those guys in Minnesota! Alas, I’ve sold both Ref 5se and your post reminded me that I have a surplus of Herbies to address. Good luck.
@ghasley thanks for your input. So u thought there was a slightly better balance top and bottom sound with the stock ARC thick black rubber bands ? And no different with the power supply 6550. Which Herbies tube dampers did u use for your 5se. Would be be selling the ones you have ? Thanks. 
Btw. I heard a lot of good reviews with the Herbies. Just want to see how other members with either the ARC  5se or 6 felt about the Herbies. Thanks to all. 👍👍
I had good results with Herbies on the 6550s in my Ref 40, appreciable tightening of the sound. More consistent top to bottom and more crisp leading edges. Perhaps less of that warmth and bloom that some like but which I increasingly see as a coloration. I used the Rx dampers with no issues
@folkfreak. Thank you for your sound advice. Willing to give it a try. I’ll let u know the results I get.