I have been using my SS amp now for several months, and its time for me to write a short report.
I am using a pair of ancient but well looked after SR5's and I route my iPhone, iMac and Maranz SACD 7003 player through my CambridgeAudio azur 840A amplifiers tape output to provide switching.
Comparison to other Stax amplifiers is not possible asI only have the Stax SRD6 box connected via the Maranz[ edit: of course I meant the Azur 840A] and I don't think this is a fair comparison.
I listen to a fairly wide range of music. I am a professional french-horn player working in a symphony Orchestra, as well as the occasional studio "gig". My main listening preferences are for Classical Romantic Orchestral , 1970's Progressive Rock, Big Band and Jazz vocal music.
The first thingI notice aways when listening to my eXStatA is that it always sounds much better after at least 30 mins warm-up. Even up to an hour I can hear a noticeable roll-off in the Bass. Also the Highs are quite Hard and at fairly moderate volume levels the resolution of complicated Orchestral passages is less clear. However once the initial warm-up has been done, the Bass is really impressive. Only a very few raw Organ recordings and sometimes the Bass line on Albums Like "Love Over Gold" seems to have a distinct "floor" It doesn't get muddy though and I get the feeling this may be a limitation of my SR5's rather than the eXStatA. I will have to invest in some more modern Headphones to test this out.
The biggest plus I notice is the absolute solidity of the soundstage. I can place instruments exactly where I would expect them, and there is no apparent vertical stretching I hear on other headphone setups I have experienced (including using the SR5's with the supplied SDR6 unit through my Maranz Amp.)
Highs are very clear and not at all hard as I was actually expecting. There is a transparent quality to String Playing but still a solid real centre to the notes. Mid-range is superb. A warmth without colouration which lets me hear the acoustic in the recording. I have a few self made digital the recordings playing in a Church with an orchestra and I get the sense of dimensions, and can almost smell the candles etc.
This amp lets the SR5's work really fast. In some very busy and complicated recordings where I thought it was just badly recorded I can now hear what is going on. Sure its still not perfectly "live" but this is after all a budget amp and I do have to remind myself of that often. I would certainly class the amp in the 1500 -3000 Euro price range and were I in the market for one would not hesitate to pay the upper range of this price band.
I haven't listened to any STAX amplifiers yet, and will get back to you when I get a chance to do this, but right now I'm a very happy camper and now I have a nice 5m extension cable I can dance around the room, which is something I don't feel the urge to do when listening to any other source I have at home.
Alex just sent me the boards for the Hybrid version which I am am now waiting for. I can't wait to see if there is any difference. I can't believe they will be any better though.