Loving the xa252. Of course it was probably obvious to everyone but me. But don't un plug sources with the amp powered. First blew the left channel, which sent 40vdc to my speaker. Then in my brilliance I accidentally swapped bd140 and bd139 repairing that channel which blew r22, r19 and t6. always disappointed when I smoke things but always learn a ton repairing.
majority of amps I made in last period are having SL OS
and - Plethora of Pinjatas is pretty much nothing else than Mini XA252
I got one of each.
The XA252 SIT ( I call it Macho SIT ) sounds better than the Sissy because it has more power and sounds more dynamic. The treble is more extended and the bass is deeper and better controlled. Both do a really very good midrange. My speakers are 90 db/w.
I have a Sissy42, original SB and a XA252 big puck. All sound great with the Tannoys. AT this time I'm guessing I listen to the Sissy42 50 or so per cent of the time with the others splitting the remaining time. In general I think preference may depend on speakers, room size, type of music and mood. IMHO you can't go wrong with any of these amps. 
The Tannoys are high efficiency, huh? I'd be interested in hearing the Sissy 42 and Macho SIT over a truly high efficiency speaker. As it is, the Sissy lacks the oomph to really drive a 90db/w speaker to 11.
The Macho SIT, OTOH, from the very get go, the very first notes, simply sounded more powerful. Mostly better frequency extension.
Another thing to consider, though, is the preamp. The Sissy has far less gain than the Macho. If your preamp, like mine, puts out 20Vrms with gobs of gain, you might find out the Macho has too much gain... I suppose I could try a different preamp, but I got too many things going on to go into that rabbit's hole.
In my combination, the Macho sounds more dynamic too. Again, could be the gain. I can hear the LP background grunge noise with the Macho, and the preamp's volume switching ( resistor ladder ), but not with the Sissy.
Let me put it this way, if your preamp can drive an F4 and your speakers are more than 90db/w then I'd suggest the Sissy 42.
But then... you'd be missing the better treble and stronger bass.....
Get one of each.
The Macho SIT, OTOH, from the very get go, the very first notes, simply sounded more powerful. Mostly better frequency extension.
Another thing to consider, though, is the preamp. The Sissy has far less gain than the Macho. If your preamp, like mine, puts out 20Vrms with gobs of gain, you might find out the Macho has too much gain... I suppose I could try a different preamp, but I got too many things going on to go into that rabbit's hole.
In my combination, the Macho sounds more dynamic too. Again, could be the gain. I can hear the LP background grunge noise with the Macho, and the preamp's volume switching ( resistor ladder ), but not with the Sissy.
Let me put it this way, if your preamp can drive an F4 and your speakers are more than 90db/w then I'd suggest the Sissy 42.
But then... you'd be missing the better treble and stronger bass.....
Get one of each.
tonyEE
My pre is Aleksandar's Iron Pumpkin and I think the Tannoys are 96db (subject to correction). My XA252 is the big puck ver.
Your MACHO is XA252 SIT driving F4s through 16 ohm resistor - right?
I have some F4 boards set up as headphone amp somewhere in the garage - could be an interesting experiment.
My pre is Aleksandar's Iron Pumpkin and I think the Tannoys are 96db (subject to correction). My XA252 is the big puck ver.
Your MACHO is XA252 SIT driving F4s through 16 ohm resistor - right?
I have some F4 boards set up as headphone amp somewhere in the garage - could be an interesting experiment.
I did both. I tapped the holes, which worked great. Just in case, the holes I did drill were indeed through and in-between the fins. That way if the tapped hole messed up somehow, just increase hole and put screw in.
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and all sorts of wrong speakers and preamps
F4 can't be in same sentence with XA252, different beast, for different courses
^ "F4 can't be in same sentence with XA252..."
But, you just did! You just put the F4 and XA252 in the same sentence, huh?
They are very different beasts indeed. Heck, one of my plans is to see if I can get another F4 and try running them bridged via a balanced preamp. I'm not quite sure the Iron Pres will swing them. I'm just waiting patiently for that time to come.
That would be yet another configuration!
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Speakers, there's is that pair of 15 year old Audio Note AN J/SPx speakers.... 93 db/w... They come with the factory stands. But, could, would, sell my beloved, restored ADS L810 speakers?
Naw... couldn't do that. Yet more speakers? My wife will surely kill me.