bencat  "So am going to try the 50 and see what difference they make and take a view from there . I know once heard if the 100 are that good I will be almost forced to consider buying them"

If you have read my post's that is pretty much what happened to me to the extent I have become almost evangelistic about the Auva effect particularly if the Quads  are like mine on Rupert stands.  My experiences would suggest they will work with virtually anything. The 100's really are that special. 

Playing as suggested  Malia Raising Venus with Boris Blanc via YouTube what incredible bass my chair is vibrating with the airborne bass nothing under my bare feet., guitars/electronics are crystal & pin sharp, Malia projecting her voice (well the engineer) is both sad, sultry & ethereal.   I was playing Flag (Yello CD) earlier I can hear where MartinT is coming from when he says "It sounds so like a Yello track (of course) but with her vocals more forward. Lovely grunty bass on this and a big soundstage, especially with the backing vocals. Gorgeous recording, you can hear right inside it.

I just  texted Josh Stephenson the admin guy at stack Audio apparently there is a 5% discount using "auvaiso" for the discount 

bencat. I loved the 50's & could have happily lived with them however wonderlust prevailed,   of the 50's,70's & 100's the 70's are probably the biggest  bang for buck even though I opted for  the 100's which offer so much more I'm also on a pension though not thankfully fixed, I don't smoke & blood thinners mean no alcohol I dont shoot at Bisley more than 4 times a year,  my car petrol head V8 fetish is now vicariously enjoyed via my son with his Sunday car though not a garage princess via his tuned Holden Special Vehicle/Vauxhall VXR8 440+ RWHP.  

I don't know if that 5% Discount helps...

Okay for those still following this the Suva 50,s arrived today and they will get fitted tomorrow . Will post some initial feelings either Sunday or Monday . I also have a set of 100,s on their way so will be able to see what difference they make . That may be much later next week as current wisdom is That the feet need time to settle and sound quality improves over a few days . Some have been very clear about this but others have said there was no difference for them from first fitting . Would also be clear that I am not going to drill my stands at this stage even though a firm coupling between stand and feet is better sounding . If I decide to keep them and buy a set them will still and secure inserted threads to fix the feet .

Okay sadly pain and mobility issues (if I get down on the floor I need someone to help me up ) have prevented me from putting the Stack Audio Auva,s in place so nothing to report. However I do now have a good period with the Coherent LB Clock on place and it seems after about 15 days or so it has stopped changing . Sound is as I first commented just the same as when I first put the standard LB in my system but with additional naturalness , additional time (i do not know how to really explain this but singers and players just seem to have more time and space to play in making what they do easier to understand yes sounds silly but for me I hear it ) better width and depth . So my advice is those that have an LB Clock book it in and let Tony do his thing when he can , sorry Tony I know how busy you are but have to give praise where it is due . I have also changed a couple of things after another thread which is I have switched my Purcell to out put 44.1 material at 44.1 and I am listening to this for a few days then will switch back to 44.1 material upsampled to 176.4 and see which sounds better .

Thanks Martin but not really possible on this injury which I have lived with for over 40 years . I have learned to cope and when not to push things . But the sound advice a good thoughts are appreciated .

Well this is a bit of a saga . As mentioned I put the Auva 50,s under my Quad stand yesterday and then put on some music . Well the sound that came out was nothing like what Big John and others who tried these feet had reported . Instead I got very scratchy and edgy treble and loss of bass . Checked the installation and it was right and secure . Then remembered some reported that there needed to be a settling in , none mentions the sound being worse but we'll I have heard new electric items sound not so good . So had an exchange with Stack Audio and came back to things a couple of hours later . Well things were now much better and all the sting had gone plus bass was back along with some really nice wide and deep images . My talk with Stack had confirmed that to get the very best the feet needed rigid contact with my stands . So today drilled them all and put 6M D but inserts in and screwed the feet directly to the stands . Household this is it makes it much easier to place the speakers and get them in to accurate position . Well put the music on and blow me off the scratchy and edgy treble was not back . Ah but this was not my first Rodeo so leave things for an hour come back and things are much better . In fact they are lots better even than the feet I had in place before . Then I realise that I have lost the plot and I am hallucinating right in the middle of a track the whole sound drops like twisting a lens in to focus . Vocals sound more natural bass becomes a supple living rhythm behind the music Say a Little Prayer comes in and Aretha is just majestic . Then something I have heard a few times but really feel it hard to explain voices , instruments everyone seems suddenly to have more time they feel relaxed and just delivering with all the time in the world to be there . I now have been declared insane and I may well retire to a darkened room to contemplate my navel . Do I think these feet are good , yes I do , are they staying, yes at least for the next few weeks and probably beyond that . I am not as convinced about them as others seem to be but they do offer decent improvement and if the settling in continues then they may just offer even more .

John no arguments from me and I waited until things settled before writing anything . As noted the comments from others have all been positive from the very start . Now there others are commenting about increased treble . Nothing like what I am writing about but certainly not the smooth sailing others have stated . I think it is important to mention issues like others do about problems burning in fuses and how things can get worse before they get better . If I had not mentioned this someone else may have just dismissed this product . At least they are now warned and can be a little patient . I am convinced that these feet work and when allowed to improve the sound . But for me at least it was certainly not a straight out the box good thing . Just because it was so strange I have in the last couple of hours removed the feet left them on a chair for them to settle . Returned them back to the stands and then put some music on and straight away the sound is awful . This time within fifteen minutes this faded and improved . That is hopefully the last time I do this but I have proved to myself that what is happening is real .

Bencat: I noted your restraint before rushing in to print,  I have also noted an improvement in the treble & midrange it is cleaner/clearer although most treble/midrange comes from the 57's, I have placed  shaped brass discs across the horn of my super tweeters to prevent the Bat Pure super tweeter beaming , allowing me to align the horn with the Quad 57's front rather than pointed towards the walls, to be fair I can't hear the Bat Pure super tweeters but disconnecting them makes a difference & they are soon reconnected.

I suspect that the gentle agitation of playing music with the feet in place causes that settling a bit like tapping the side of a pot to settle the contents. Moving/tipping them I believe will negate the previous settling. 

Somewhere in my ramblings I noted removal &  replacement cemented my admiration for Auvas. It provides confirmation as did putting Auva 50's under my unsprung turntable as they settled they absorbed too well sucking the life from the turntable removing them, like Lazarus life returned I understand that others have found Auva EQ's work well under sprung turntables.