Soundstage and voices lean to the left side????

If you play CD's or a tuner, are you getting this same off balance? If so you might just have a small difference in your hearing ability which can easily be allowed for by turning the balance control if it occurs only on some records, or if it is on all you can move you right speaker a bit closer to you (an inch or two might be all it takes to bring them back into balance.) If it is only LP's you might try increasing your VTF to the max recommended by the manufacturer and check your anti skate (although this shouldn't make a difference, its possible that it could).

Another possibility - if your listening position has you facing dead ahead between the two speakers and side wall and ceiling/floor reflections are the same, try twisting your chair so that you are looking into the center of the space between the right speaker and the center of the stage. If you find that the image moves back into the center go see an audiologist for a hearing test.

Have you tried a mono pressing? I often hear the singing voice from different locations in the soundstage (stereo of course), depending on the song. They are not always centered. The also shift in distance from front to rear of the soundstage.

It can happen that orchestral classical music seems to come from left channel, because the violin sections, which often carry the melody, are positioned left, and are relatively higher pitched, hence more directional. The effect is exagerated in recordings because stereo effect itself is exagerated realtive to the concert hall, when sound mixes before reaching your ears -- one reason "soundstage" is largely an "audiophile" rather than a "musical" parameter, nice though it is.

So if you are listening to lots of orchestral music, this might be part of it. I sometimes get the same effect, and then put on some blues, chamber, rock, piano, or jazz, and am reassured there's nothing wrong with my setup.

Check your cabling. Make sure everything is hooked up right. + to + & - to -.

If it continues,upon following all of the excellent suggestions above, try moving you right speaker more forward. Even 5 inches straight forward might move the soundstage more to the right, thus centering the image (listen to mono or vocal recordings or KOB from Miles get them centered). Speaker placement is your issue (if it happens with other sources as well as analog)