I own and LOVE using it as my main preamp always... a Bryston BP 26 and the accompanying power supply.
I have my Brystons up on 1 3/4" thick 22"x16" Walnut shelves (with 4 thin hard 70Duro bits of sorbothane arranged as a trapezoid two front corner, two near center, back) on my metal with glass shelves (cheap) rack However They are also further 'footed' with the preamp having 2 3/4"x3/4" by 5" Brazilian Ebony 'pen blanks, with the 3rd a Cocobolo similar pen blank in center front.. holding the BP-26 directly from Walnut to chassis 3 of them. (the BP-26 also has on top of IT, two Burmese Blackwood pen blanks holding up the phono box of a Threshold FET TEN pair and on top of the phono is again with more wood ((knife scale size Bolivian Rosewood)) FET TEN preamp)
The Bryston preamp Power supply is on a separate 1 3/4" by 22"x16" Walnut butcher block and again has additional 2" by 4x4" bowl blank Bolivian Rosewood blocks under each OEM foot. On top of the Bryston power supply is a Rudistor RPX33 mk2 headamp ..no wood between, I confess I never use headphones much and have NOT worked to find out what would be good under the headamp)
Added.. My Bryston 4B-SST² has under it, bottom butcher block is up on old Tip Toes, Maple 3" by 18"x19" butcher block, on top of that is a Walnut 3" 14"x17" butcher block. (They are separated by very small thin ebony discs in the same trapezoid pattern as the shelving) between the amp OEM feet and the Walnut block is in back a 2"x2" by 12" VeraWood spindle, and in front are a pair of 2" by 4"x4" bowl blanks of Bolivian Rosewood (not a true rosewood)
Again, all this by extensive experimentation with dozens of types shapes and sizes of exotic wood tried when listening to the effect it had on the music...

And YES the dual butcher blocks did make a notable difference over just one.
If you wonder how much time several months of constant listening (usually several days for each change back and forth) and swapping one components bits at a time..
All of the exotic wood is 'raw' no finishing, no surface treatment, I did scrape off the wax casually on touched surfaces, but not off the end grain. A few I did file a bit, but most are as bought from the exotic wood sellers (aside from some removal of wax) ((FYI 2" by 4x4"Katalox wood splits and really goes South if you take the wax off and do not kiln dry or finish it... just to mention))
And sorry to hijack the tread a bit with my getting carried away.. but you ASKED.. I answered in detail.