Soundstage vs background noise?

I've been using tube amps for 10 years now. I just recently picked up solid state gear that admittedly is much quieter in background noise.

So now I notice the soundstage is better defined. I wonder if this is related the the virtual lack of noise that, through my prior tubed gear (CJ and Rogue), was common to both channels?
The lower noise floor of the new SS amp is now helping to reveal new low level details that were previously masked or blocked by the higher noise floor of your previous Tube gear

The newly revealed details that were there all the time but inaudible due to the masking of the higher noise floor now appear in the presentation as additional Spatial Queues

These additional Spatial Queues help fill in the blanks that were missing with the higher noise floor and the new presentation can have more detail and expanded sound stage because there is more Queues that are audible

Post the tubes that were being used in your old equipment and someone here who knows tubes will comment on if they were low noise or not

If they were not there is a chance a switch to low noise tubes may make the noise floor on the tube amp competitive with the SS amp and bring with it the Tube sound many enjoy
Tube amps, IME, rarely take a back seat to transistor amps when it comes to soundstage. So I am suspicious that there is something else going on- perhaps related to the noise you are talking about. You might want to test the smaller tubes in the amplifiers- if they are getting weak you could well experience something like this.

A tube power amp might have slightly more noise than a transistor amp, but it should not really be noticeable, since a typical noise figure for any tube amp made in the last 40 years is -95db or better. That's pretty hard to hear on most speakers. So I am thinking there is a good chance your tubes are shot.
Tube gear is only as quiet as the tubes used. Lots of variability regarding noise and distortions possible there! It part of the unique charm of tube gear. SS has other noise and distortion issues issues to deal with. Choose your poison. Either can be really good or really bad. Hard to generalize, like most things. Noise is never a good thing though. It obscures other things that might be heard.
Just an addendum to Ralph's post. Not only may the tubes be shot, but if the tube gear is old, it may be time for a recap too. I am a card carrying tube-head. So yeah, tube gear requires a little more care and feeding, but it's kinda fun, gets me involves with the technology a little more and I think sounds nice. Just me.
Well designed tube amps with tubes running as they should have a very low noise floor, and spatial queues galore...also this post has one of my extremely rare uses of the word "galore."
OP -

tubes can be noisy. A tubed amp is only as good as the tubes installed. If a tube(s) becomes noisy, it is getting weak or running out of juice (no pun).
One of the major reasons that led me to move from SS toward tubes was an increased ability to present spatial, nuances and ambience information. The realism and natural sound characteristics were superior. It may be a question of what particular component and tubes are being used. Not every tube amp does this aspect as well as others.
I appreciate all the comments. Ralph, my experience is that tubes are just noisier than solid state. Admittedly I do not listen to music with my ear 4 inches from the tweeter, but I have to tell you, at that close range I always heard a hiss through the speakers and now with SS (I'll give a plug- Pass Labs) it's dead silent. I have to think that has to make a difference.

10 years ago when I went to tubes, I found tubes a relief. SS was just too 'hard' but my impression is that the best of tube sound and the best of SS sound is truly converging.

Maybe this is going to be viewed, at some time in the future, as the golden age of audio. Truly mature vinyl at many price points, excellent digital, especially high res, excellent amplification even at modest costs and amazing speakers at price points unimaginable a generation ago.
...tubes are just noisier than solid state.

My amp is dead quite with Tung-Sol KT120s with my ears "4 inches" from the speaker(s).

Dead quite.
I appreciate all the comments. Ralph, my experience is that tubes are just noisier than solid state. Admittedly I do not listen to music with my ear 4 inches from the tweeter, but I have to tell you, at that close range I always heard a hiss through the speakers and now with SS (I'll give a plug- Pass Labs) it's dead silent. I have to think that has to make a difference.

Some transistors are indeed quieter than some tubes, but not all. IOW you are for the most part correct. Unless you have high efficiency speakers though, it sounds to me like you have a very minor noise problem if what you describe is the extent of it. If you listen further than 4" from the speaker, its likely not a problem :)

However, just as a point of reference, our speakers at our shop are 93 db and we have to put our ears right on the driver to hear the noise floor. My speakers at home are 97-98 db, and I hear some residual noise about 8" from the mouth of the horn. I have found that transistors tend to make a similar amount of noise on that system.

IOW with most speakers you shouldn't be hearing anything. That is why I suggested noisy tubes, as that is a common issue with weak tubes.

Its really in high gain circuits, like a LOMC phono section, where noise really becomes a concern.
I'm wondering if a significant contributing factor to the noise levels of your prior setup may have been noise induced by ground loop effects (which can result in high frequency buzz, as well as low frequency hum), and/or noise pickup in interconnects.

I see in your system description that you are now using a Pass INT-150 integrated amplifier, which obviously eliminates the possibility of ground loop effects between a preamp and power amp, as well as noise pickup in the cables that would connect those components. Also, perhaps you are now using a balanced connection between the Pass phono stage and the INT-150, while I suspect that your only option connecting the phono stage to the previous CJ or Rogue component would have been to go single-ended. Balanced connections are of course less susceptible to both ground loop effects and noise pickup than single-ended connections.

Assuring that a perceived sonic effect is attributed to the correct variable can often be a challenge in audio.

-- Al
Zavato -

do you have a dedicated 20A line running directly to your system? If not, you may have had a ground loop or excessive RFI.
Background noise has nothing to do with sound staging. Noticeable noise, from the listening spot, during very low levels obscures the details. This noise is mostly quiet hiss. If the ambient noise in room is not very low, system noise may not matter.

I like the system noise to be inaudible, with my ear on the tweeter, at the highest volume level setting. Only then is the noise low enough, to not ever effect the low level details in music, IMO. This only happens with certain solid state equipment. Pure tube phono stages and LOMCs never reach this level, even on mint records.
I've have a dedicated 20A line for years. The Rogue is an integrated, but my CJ gear, an MV60SE and LS172, where seperates. Presently I am not running any balanced lines but years back when I had an Pass Pre and M L amp, I ran all balanced.

My phono stage and tuner have balanced outputs. Thinking of borrowing some balanced lines and experimenting into the INT-150