What to put under my VAC AMP/ PREAMP??

Hello Arthur;
GDR,' come in pack of three and one goes on the back, two at front.
Kevin from VAC modified bottom plate of my 300.1 so with little difficulties (cut outs for ventilation), I am still available to use Shun Mook.
Nothing in my personal experience comes close to these devises.
Harmonix is also good but not as natural sounding as GDR.
Shoot me an email, so I can provide you with photos and links to Shun Mook application.
P.S. Did you experience with different KT88's or perhaps some NOS 6550's?

Regards

I have tried some different KT88's (Winged C, Genelex reissues) and they were nice, but I keep coming back to the VAC tubes as my favorites. Plus the cost of tube rolling just doubled as I'm running 300.1 monoblocks....

I haven't tried any 6550's how do they differ sonically from the KT88?

Considering VAC Phi sound quality I would go the extra mile on this. If you have a dealer for HRS and our Critical Mass Systems. I would try HRS first them CMS. You'll be so please about the results. I heard these on fully tweaked systems and the contrasting results with these items in or out is mind boggling.

HRS is all custom made, so no demo there, I've talked with them about it before. Critical Mass is something I'll check out as well, although the Shum Mook are intriguing because I can use my existing rack shelves with them...

I use Mschina Dynamica Promethean springs sandwiched between HRS but I already owned them. Maple boards will do nicely in this set up. Herbies isocup/balls directly under the components