I hate to say it, but now I think maybe I like my amp in ultralinear mode versus triode

+1 @ozzy62, you said it all. I’ve owned 4 amps switchable between triode and UL, still have 2, and have auditioned a few others in my systems. Each is better in UL. This is true on all 6 pairs of speakers that I currently own, ranging from 86db to 102db. OTOH, I have 2 SET amps that sound better on my high-eff speakers (102, 99 db) than any of the UL amps. The triode option on a UL amp is simply not the same as a purpose-designed SET.

All I know is that on my system some music cds sound better in ultralinear but most sound better in triode.

I’m a big fan of high definition music (Blu-ray audio primarily). Nearly all of them sound better in ultralinear.

i have a horn system with a tube integrated amp fed by an oppo UDP-205 with the Modright magic tube modifications.

@immatthewj "Again, with not intent of being argumentative, does this sound incorrect? (I was actually asking @decooney if he had rolled any tubes besides EL34s as I do have some 6550s for another amp,"

Sorry for the late reply this week. No, I did not, chose not to. I was sort of enamored with the Shuguang EL34BSTR (Ruby labeled) tube that Dennis chose for that amp at the time. Note I had two colleagues with V12Rs at the time, which offered the small [odd TV tube 12bz7] option up front, along with EL84s, and combined with those specific EL34 output tubes AND mixing in the later version Mundorf EVO Silver Gold (non oil) coupling caps was the ticket. Some guys went on to KT88s in the amps, and the tubes are too wide (imo) for that amp, sitting too close to each other. THIS is also why I’d stick with good EL34s, narrower tubes, more air spacing between the tubes. Good EL34s work in that amp.My local retired tech friend listened to the amp at his house and compared with different amps at the time. That combination of it all just worked well together. Sounded pretty amazing, actually. However he cautioned me about turning up the bias too much - and I did not. However as the V12R original manual recommended (280ma per side). Not good. Too hot. We got on the phone together with the designer that replaced Dennis at Cary later on. All of us agreed to run those tubes and to back the bias down a lot more. At the original manual spec, it just ran way too hot imo.

That tech [no longer there] told us the V12R factory original manual needed to be updated - Cary did not update it, new boss did not care - heads up. I was at 230 a side for a while [38.3ma per tube] and even the sound at 200ma per side kept the tubes sounding close, running cooler, and everything was still happy. Long story, be careful, those big transformers are very expensive to replace, and the R version had that large one in the back. Std V12 has the smaller transformer unit, both the same size, which might be easier to replace.Not sure if you run yours too hot, just beware.

My local tech friend was surprised by the sound of that amp I had - once upgraded, yet he got all over me about the wire maze in that unit, switching, modes. Kept pushing me to dedicated monos in UL or triodes. That V12R amp caused me to want to try two separate mono amps with KT120s/KT150s. 1/4 the output tubes, half the weight divided into two amps vs massive unit. Easier for amp rotation too. So, next I did the exact same cap and small tube rolling in the new mono amps with the idea of biasing the tubes [in the window] while keeping the main power transformers running a bit cooler, tubes running cooler - lasting longer too fwiw.

In summary: Does the new UL design mono amp setup have that same rolled off euphoric sound as those banks of EL34s, in the Triode switch position (no). Not the same. Is it a bit more clean sounding and more dynamic and extended, not rolled off, in a dedicated UL design mode with fewer tubes, (yes). Yes, you can run just two EL34s per side in that amp, if you can drive your speakers with lower power.

Even after using the exact same coupling caps [identical], It took me a while to adjust to my new mono UL amps. I too had been listening to that Triode switch mode for a long time. And, I agree with @atmasphere’s comments, UL is just quieter, cleaner, less distortion, offering something closer to your own renewed and updated realization about the sound in UL switch mode. Glad you tried it again.

I’ve stayed here [with self restraint so far, LOL] trying to avoid going with two larger dedicated 211 / 845 Triode amps. Btw, LOL I had that same B&K preamp, and three of the EX-4420 dual mono lush mosfet SS amps for a few decades before the various Cary tube and solid state amps by Cary. If you need the power for any reason, I will say the two separate beefy UL mono amps seem to drive and control my custom multi-driver speakers really well. They just light up and fill the room more easily. I think if I sold my existing mono UL tube amps I’d really kick myself later, fwiw. We all get the bug to try something else, yet keeping a few of the good ones around is nice too, if you have the space for it. Good fun. Enjoy.

I always run my ARC Reference 160s or 160m's in triode mode. If I unplug it for some reason and it defaults back to ultra linear within a minute of listening I will start to wonder what is wrong...the hardening of the midrange, the reduction in rhythm and pace. I find rhythm and pace is almost always superior in triode mode... either design or when amps are switchable. 

Other folks that have heard my system and I have switched back and forth, I think all have preferred triode, an commented about being more musical. 

@ghdprentice: I, and presumably atmasphere, and all other rational thinkers, would rationally conclude that your amps are optimized for triode topology...and, necessarily, that the ultralinear topology was added, presumably as a gimmick, to presumably, attract more purchasers. Let’s hope so anyway, as the other option is that the amps are not optimized for either topology and that you and the other folks just like the same not optimized topology over the other not optimized topology.