Question on twin triodes

I was told that twin triode tube pre's invert phase. Although my current pre (soundstage two) does not state this I did change the spkr leads just to see. It did make a difference--sounds a bit fuller all around. Bass is very good for stock jan philips tubes. My amp is a Tim Rawson bpa 300. Always learning in this hobby. Enjoy the music.
It depends on the topology of the amp. Some do, some don't.

There are 2 ways triodes are used in audio circuits. As a voltage amplifier in what is called common cathode configuration which does invert polarity and has relatively high output impedance. The other way is as a current amplifier (or buffer) in a cathode follower configuration which has no voltage gain but low output impedance.

A very common topology is to have a Common cathode stage followed by a cathode follower so you get voltage gain from the first stage and then low output impedance from the second. You can then build a preamp with only 2 tubes.

If you add another voltage stage after the first you get a second inversion which puts it back to not inverted. And so on.
Herman thanks for the reply. I'm not sure how this pre is wired. The first owner suggested I try switching the spkr leads so I assume this is a common cathode you decribe. I do know when I did this music comes from EVERYWHERE now. This is one sleeper of a pre. Now on with the rolling. BTW I just switched the pwr cord from a old Synergistic Research alpha to the Stealth HAC I had for awhile. Did I say a sleeper--hey it just woke up.
I think it is safe to say that if it uses only 2 tubes then it is definitely inverting. If it uses more tubes then you need more info. In any case glad to hear you found a configuration you are happy with.