2-bus Tube/transforme equipment for 3d soundstage/depth etc?

This doesn’t help but the second I read your headline i thought, “he needs to hear a sebatron pre across the 2bus!” Lol…turns out you’re way ahead of me.

Like you, I love the sound of my seb Pres on the stereo bus…and also like you, hate fiddling with the controls to get it stereo match.

When I want the thing you're describing (which is often), I turn to the Manley Vari mu and run it with the threshold fully open, drive the input until it spits out some glow. Rarely use it as a compressor.

The Pulse pultecs without any EQ going on are very open and unimposing and really don't stamp a whole lot into the sound in the same way that something like a HG-2 does. The HG-2 tucks in the tops and bottoms and it most cases gives a presentation of more depth but maybe less width. More complexity and more for me to worry about. It's a really great sounding box but also super fussy with the gear that might go before or after it. Something that isn't mentioned in comments I've read about it. I don't own a pultec of any description and have never been all that into them. So there's probably some bias there.

A touch of red silk on the RND MBP can be a really gratifying thing on a mix. I'd imagine the RND silk function is the same across the line. You could think about a pair of the pre's or whatever else they put it in.

I like API 550As if I need some color on the 2 bus. No EQ, just running signal through them.

That does look really cool.  Did not know that existed!

Hah!  Isn't that funny.  We're in the same boat.  Great sounding gear, that Sebatron is.  Have to run tones through it to get it set and all that.  No stepped knobs.  It would make the most sense to have one just for the bus but then what a waste of great pre's.  Just doesn't make sense.  However that is what I am using now on this project. So maybe it'll have to stay there for a while.

I also replaced the JJ tubes in the 200vu with NOS Mullards.  A little more colored and dark but again, I like it for preamp duties.  I might like a more hi-fi tube for the 2 bus...

Oh nice.  Manley Vari Mu. I will have to keep that in mind.  That does seem like a bit of a magic box.

Also, did not realize that about the Pultecs.  Good to know.  The HG-2 seems like it does quite a lot, and can be set for a lot of color... so maybe not.

The red silk on the 542 pair I have is pretty nice.  Maybe I will revisit that.  Possibly in line with my Sebatron... hmmmmmm. Thanks!

I have a pair of 542s but the style of this setup makes them a tad much with tape effect in, however I may revisit the silk red thing!

I definitely need dual mono comps separate mono units for this to work it seems...

Try this on your stereo bus with SDRR2

One plugin that seems to have this effect to my ears is the Kazrog True Iron. The Western Electric setting(it's at 1 0clock on the dial) does some nice sizing up and spatial things.

Depending on the mics and preamp settings, I can see the 542’s being too strong of a sauce for solo piano.

ART VLAII (what I meant to suggest) can be run dual mono, and although mine has some mods, I can vouch that it is really nice for vibey piano.

If cost isn’t a concern, there are of course lots of great opto/vari mu comps that’ll do the trick. A pair of APA Leviathans are very flexible compression-wise and add a nice polished sheen.

I can speak to this if anyone wants.  I've tried all the plugins mentioned.  Honestly, they rarely get used and never on mix bus when they do.  

I have 8 Silver Bullets - 3 of the the newer mk2's, which are especially killer for height / width and dimension (the A and Aspect Ratio excell on this), and 5 of the originals which get used on individual instruments/vocals and busses primarily.  

I have the Manley VariMu which primarily gets used on Piano during mixing, and for mastering duties on final mixes pre SBmk2 (again) and Miad LCPQ4040's - very rarely to never on the mix buss during mixing.  I have ZOD IDDI's which live on the 2 buss after the Silver Bullet mk2's 99% of the time during mixing.

The ZOD IDDI's are incredible, insanely affordable for what they do, and they are used here constantly for lending that "tube" vibe.  When I just need a tube vibe and don't need compression, they get the call over the Manley's, Coil CA70's, Locomotive 14B's, Weight Tanks, and 286A's, VComps, Tube EQP's, etc..  If I need to go very retro, the Coil's or VComps can come into play.  The 14B's are very cool, but bring things to the front, which kind of works against me when mixing.  Perfect for vocals for me.

For instant mix goodness, the SBmk2's followed by the ZOD's instantly get me 150% further than anything I have ever tried ITB.  Instantly - just my standard settings on the mk2 with the ZODs.  So easy and simple it feels like cheating.  Always easy, very rarely to never do they ever get in the way of the musical output.  And rarely do I even have to twist a knob.  They just work.

I prefer the ZOD's over the Manley on the mix buss for size - although I must say, I've never tried the above technique of turning the threshold all the way up and not using it for compression - just box tone.  That's sounds interesting, but I'm pretty familiar with the Manley's box tone, and for work flow and max dollar impact, I'd rather use the Manley on Piano and the ZOD's on mix buss.  

The Manley VariMu has been my absolute favorite piano compressor of all time.  It's got high headroom so it doesn't crap out on transient hits, and it softens up ITB VSTi pianos that can easily get harsh.  The softening it gives on the 2Bus in not what I'm looking for these days.  The ZOD's give me some size that seems unique to tube gear, and the SB can open the mix up a bit more with it's AIR EQ if they get too "tubey" for a particular song.  

I have not tried the LTL Pentodes in the mk2's.  I really should have.  Nobody tell Brad.  Hahaha!  I'm enjoying the API>NEVE>SSL topology that it comes standard with though and am reticent to swap out the SSL for a tube mojo amp.  Never been a big SSL fan, but honestly, the SSL circuit in the SB is pretty special for what it adds.

The aspect ratio on the mk2 has really upped my mixing game considerably in terms of width/height - and I thought I was pretty good before mk2.  LOL

That's my thoughts.  If you have any other questions, fire away.  I use all the above every day when mixing. (Which is most days lately)