Plinius 9200 or separates?

Trying to get a grasp of how to proceed with amplification. I have a Plinius 9200 running Totem Forest speakers. Sounds good but not incredible. Recently subbed in some 70's era Audio Research pieces (SP-6 pre amp and D52-B power amp). These have in the past had some problems with distortion but worked this time just fine. It seems like the sound came more alive with this combo although it felt like some more power was needed, especially with orchestral music. I was told by a repairman that the power amp was on its last legs. I'm considering having AR service the SP-6 and look for a new power amp.I would appreciate opinions about what power amp, tube or SS, might be appropriate. Or should I look for another pre amp as well? I know this is kind of vague but what do you think?

Plinius 9200 w/ Top Gun power cord
Totem Forest w/ Totem bi-wire cable
Rega P3
Exposure 2010S CD
I may be wrong but it seems you want a more forward and lively soundstage. I think tubes would be the answer for you and a newer ARC near the top of the list. The Forests, at 87 dB and 6 to 8 ohms, would seem to be in the 100 to 200 watt territory for optimum.

Transistor amps, Plinius in particular, tends to be more "behind the speakers" but Chord comes to mind. Then there's the tube integrateds, which should be fine as long as you don't want party SPL's and visceral bass. The Manley Stingray, VTL, Rogue Tempest and Cary would be near the top of that list. The Rogue is fairly unique in using KT88's. It would be unfair to compare the power of a well-used, 40 year old to the ones I mentioned but they won't be as strong as the 9200.
Yes I think your description is accurate. Instruments seemed more present and delineated with the AR's, more sense of depth. The Plinius is powerful and smooth but lacks those other characteristics. I'm wondering about keeping the SP-6 or also looking for a newer pre amp, perhaps another AR piece. I would like some substantial low end to take advantage of the Forests ability to go low......
I recently tried a Plinius 9200 with my Proac Response D25. As an upgrade from the 8200 (and after hearing Manley's Snappers & Pre combo / Naim 200 /202 combo and a few others) , the 9200 gave me almost everything I wanted. And I didn't notice any of the "2d" phenomena you guys report.
My guess is that it's simply a matter of synergy. The amp-speakers match is maybe not that good. If you like the speakers, I advise you to indeed replace the amp. BUT, it happened to me more than once that a mere change of interconnect or speaker cable gave me exactly what I was looking for.
In any case, I wouldn't get rid of the 9200 quickly. I thik it's an extraudinary amp and does a fantastic job- very powerful, dominant sound, yet musical, smooth and rounded. Even the twice-more-expensive Manley gear didn't beat it, although it had its advantages.
I agree that the Plinius is a very good amp but it feels like something is missing. When I replaced my Acoustic Zen Hologram speaker cable with Totem Sinew bi-wire it improved things significantly, but not enough. I play a lot of LP's and my Rega P3 has hard wired cables so I'm not sure what improvement I'll get there without considerable tweaking......I do need new interconnects for the CD, thinking of Harmonic any rate I won't sell the Plinius until I'm sure I have something better....
I would never accuse the Plinius of being 2D, it's more like sitting 20 rows back at a concert. Actually, I prefer that vantage because of the stability of the imaging. Many people prefer front row center. As matanoosh said, "it's simply a matter of synergy", and personal taste.

Take that tube preamp and plug it in between your source and the 9200. Turn the volume on the 9200 all the way up. Adjust your listening volume on the preamp. What are you hearing?
Spend a few hundred bucks and add a 220v outlet if you can. Then convert your 9200 to 220v. It’s a simple conversion you can do yourself by popping the lid and switching a wire at the power supply inlet. It was suggested to me by the old Plinius distributor and really made a + difference on my 9100 and Model 1’s. The sound just “came alive”. Of course you’ll need a PC with a 220v plug.
Plinius 9200 has one of the best 3D soundstage, also images have 3D quality. If you don't get it look for a problem somewhere else.

Happy listening.