Soudstage Height?


The other night I experimented by using my Jolida 502B integrated as a preamp running through my well renowned solid state power amp. Things sounded okay but the biggest surprise was the amazing drop in the height of the soundstage. I went from tilting my head ever so slightly back to envision Diana Krall doing "Garden in the Rain" with the JoLida doing everything, to seeing her shrink to the height of my Kestrels via transistors.The depth seemed about same though. Can somebody explain to me what gives a soundstage height?
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Initially, after this post, I had in the back of my mind a feeling that there was a slight possibility of myself being flamed to death....hmmmm, another surprise. The responses so far have been extremely informative.

Sean, I must say, many aspects of your response do fit. The ss amp hadn't been used in a while and obviously, another set of interconnects was added into the mix. The feed from the JoLida came from the sub out which is what I consider to be preamp out, while the ac power stemmed from a conditioner. But, at the time when I first switched from the ss pre/power setup to tubes about a year ago is when I noticed a huge increase in the size of the stage.

As far as phase goes, I can switch it with my cd player, and I have a few times just to see the effect. So far I haven't noticed any changes including stage height. By the way, "Amused to Death" is the most involving cd I own, almost hypnotic. I imagine phase mods do play an important part in the dog barking from behind, the submarine captain's activity descriptions coming from my IMMEDIATE left, and the horse-drawn wagon coming from the left rear, across in front, and away to the right rear. I love it, I use it as a reference for system and listening position setup. Is it possible that there is some phase trickery in the output section of the JoLida? It seems pretty well focused.

Volume level. I know things get larger when the sound gets cranked up but the level seemed to be the same in my comparisons. But I didn't check it with my Radio Shack toy.

Bloom. Is this the answer? Is this what I'm experiencing? I've heard the term but never understood what it meant. Till now? How do you get bloom?

The engineering involved in the recording doesn't seem to apply in this case. It's more about the equipment I think.

Finally, S2k dude, you made me think. Does our brain subconsiously recognize sounds that only come from ceilings and floors and somehow calculate size from that information? Therefore, equipment with very high resolution has the ability to pass this virtually inaudible info on to us to create the illusion of height. Is it the resolution?

Thanks everyone.
Speakers set up, cables and room depth. obviously electronics enhance this effect, but my own trial and error says set up first and then cable match to the system, then far field listening if possible size of room.
Try tilting your speakers slightly forward or back.
Verity suggested that I tilt their Encores FORWARD slightly to elevate the soundstage. This was counterintuitive, but makes some sense to me in that the tweeter's arrival time is slightly shortened vis a vis the midrange below it.
The psychoacoustic effect is a change in stage height. Cool.
Experiment with your listening axis, too. Adding a cushion to your chair, or taller stands, may do wonders! Have fun.
Try listening to near field, with your ears at tweeter height. In my experience that is how I perceive Diana Krall singing over the piano and bass. Further away I sit,lower the height.
I agree with Nilthepill and found much improved height in the near field after moving the listening position forward. Also, try using track 11 LEDR of Chesky JD037, JAZZ SAMPLER & TEST VOLUME 1 to check for and eliminate first reflection problems.