soundstage question: McIntosh Autoformers (MA8950) vs tube amps (chi-fi - sigh)

I wouldn't assume A or B are the only choices.

"Now I think it's A. But if someone thinks it is B - then I'm curious. What exactly is happening with the autoformers that might be causing this?"

Why would you assume the autoformers are responsible for the differences you are hearing? The 2 amps are extremely different from each other, as are the speakers. Also, your tube amp has output transformers. They're not the same as autoformers, but they do perform a similar function. Either way, I don't think the differences you are hearing are caused by the autoformers. I understand why you don't want to try the set amp on the SF's, but you can try both amps with the Klipsch. 

"In the same room, the tube-amp with Klipsch speakers seem to throw the sound all over the place while the McIntosh setup doesn't do that."

You need to try a couple of things. To start with, listen to the Klipsch/set setup. Play a song where the singer has a strong center image between the 2 speakers. When you listen, confirm that the vocals are where they should be. You could have made a mistake when connecting your speaker cables. It happens all the time. If the vocals are not between the 2 speakers, that's the problem. It will sound like the vocals are coming from one of the side walls. "Throwing sound all over the place", is a pretty good description of what that sounds like. 

If your connections are OK and you are getting vocals between the speakers as they should be, listen to both setups again. This time you are listening for scale. Using that same test track, or something similar, are the sizes of the images bigger on the set? For example, does it sound like the singer is much larger on the tube amp? The difference won't be subtle. You will hear it immediately.  

@052rc - it could very well be more than A & B. 
The "all over the place" comment was a lazy way to say that separation of instruments and/or soundstage -- was spread out very nicely. It wasn't sporadic/random. It was great. I experimented with friends' amps - Yamaha and Linn (likely 10-year old models) and with the Sf speaker only. While the MA8950 sounded really really good (great, I mean), it *still* was a tiny bit "subdued" compared to the other two amps. Linn was Class D. Yamaha - I can't remember. It could have been A/B. Now on the MA8950, when I hit 40-45% of the volume (gain? idk. I get confused), the music is definitely better - but now we're just experiencing louder volume and not necessarily the soundstage that I got out of the "low-watt + high-efficiency speaker" combo. 

And there's tons of stuff out there about the McIntosh autoformer-sound but nothing necessarily tying it to soundstage. perhaps it isn't a contributor to soundstage: soundstage is all about the output stage -- speakers + room. But I can't help but compare the experience with the other amps. I'm not saying they had a *great* soundstage but were definitely not "subdued" like the MA8950. 

I'd been stubborn about getting this soundstage via the Sf speakers but now you've given me an idea: to hook up the MA890 with the Klipsch to see if there's any impact to soundstage and the dispersion of sound. 

@oddiofyl - did you just say that you prefer your "tube amp + Klipsch speaker" combo to the MA8950 + Sf combo and yet, when I have the same preference, my brain is playing tricks with me? 

@nathandfwacoustics I can vouch for the subdued aspect of solid-state McIntosh amps versus class D amps, although I would rate them on par with the tube amp I own. I toted two (2) MC252 solid state autoformer equipped power amps upstairs and connected them to my McIntosh XRT-20 speakers. Strapped to deliver up to 500 watts to each speaker. But compared to the sound of an entry-level Sony AVR (STR-AN1000), using the same sources, and the same speakers, there was an obvious mismatch. The Sony was much clearer, and even though it was rated at only 120 watts to each speaker in stereo mode (100 watts each to the front speakers in multichannel mode). The extra power of the strapped MC252s did provide better dynamics for high and low ‘excursions,’ the clear day-to-day dialog and standard TV-type / movie accompaniment winner was the Sony amp. It wasn’t even close. 

Downstairs, the mono-strapped MC252s and C100 controller sounded on a par with the Rogue Audio Stereo 100 (with the dark upgrade) driven by a Rogue RP9 preamp powering the same B&W 801s2 speakers. In my experience, you are correct to attribute ‘sound stage’ to the interplay between the speakers and the room, although there are those who maintain soundstage is the function of the recording itself. It’s hard to argue the recording doesn’t play a major role; although it’s just as true that if you take the same system to a different room things will change as well. 
 

Having said all that, I can also say, that while I was pleased by the ‘dark as night’ quiet of the MC100 (as well as the RP9), I was less impressed by the way the MC252 presented. It was quiet too, when I wanted loud and clear. Strapping the units to mono did not help with that aspect of their sound, although, as noted above, the dynamic ‘reservoir’ increased. One person posted what I thought was a fair review of this McIntosh sound [for which he had been searching all his life], it let the important parts though and filtered the extraneous stuff, or something to that effect. The McIntosh sound is smooth and pleasant, and it does not fatigue, but neither is it for everyone. I think you might have to live with it for a while to decide.
 

I know that B&W are recommended for McIntosh because their reported ‘tipped up highs’ are muted through the McIntosh amplification. I’m not as sure about how the Sonus Farber match up. My impression from reviewers is that Sonus Farbers are also warm. Perhaps too much of a good thing. But, again, I’m not an expert on the topic, nor anything else on which I’ve given an opinion. I’m just sharing my experience and my thoughts. 
 

Note: The MC252 amps are back downstairs with the C100 controller. 
 

@oddiofyl You don’t think the 8950’s 200 Watts per channel is enough to power the Sonus Farber’s. They must indeed be difficult to drive. 

No,  the 8950 should have plenty of power. ...    it has 4 Ohm taps so it can drive the SF no sweat.    Its the cheap amp that will struggle.   

My Dad's set up sounds fantastic.   I would definitely be proud to own that system.    You should have a grin ear to ear when you listen to that combo.  

My second system is solid state and it sounds really great.  Especially for it's small form factor.    So I like a well match SS system too 

It's more about speaker/ amp synergy than anything else , assuming the room isn't the issue.