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

Apologies if this came up earlier in the discussion...Do you guys re-bias and adjust for volume difference when you change between UL and triode? UL plays notably louder at the same volume setting than triode on my amps, and I’m assuming others too.

@knotscott , the owner’s manual says nothing about needing to adjust the bias when switching from triode to UL or vice versa, and I have checked the bias after I made this last switch and there was no noticeable swing in the bias.

As far adjusting the volume when moving from triode to UL, I would have expected that myself, but it seems as if I am mostly leaving the knob on my SLP05 where it was. Maybe turning it just a hair down, but if so, only a hair or so. Not much at all. Mainly what I noticed was a change in "the body" of the sound. (or maybe the "shape of the sound" or maybe the "location of the sound."  I am bad with terminology.) The gain on that preamp when using the balance ins and outs (and that’s all I have used so far, but I am thinking about experimenting with that also) seems pretty high to me, and with most CDs or SACDs it is about 9 oclock give or take a hair.

@dogearedaudio , coming back to the feedback, and again not arguing with you, but almost at the bottom of page 4, the page I believe should be just before the un-numbered specifications page, there is a header "OVERVIEW AND CLOSING THOUGHTS" and under that header Mr. Had had written that, "The V12 is in reality four single-ended amplifiers operating without any form of feedback."  

@brianlucey , what sonic changes did you note when in 1/3 triode 2//3 UL and in vice versa?

@dogearedaudio "Zero" feedback? Really? I’ve looked at the CAD-280SA V12 manual online and it doesn’t mention feedback, but perhaps that’s a different model. Hard to imagine they use NO feedback. Maybe not global feedback, which encompasses the output transformer. Internal feedback can be used to good effect, but no feedback at all is hard to imagine.

Re-checking my own prior Cary amps on this and there are several I can account for that followed Dennis’ vision for "absolute zero-feedback designs", and talk some here about "low- and zero-negative-feedback triode circuitry " and how it "tended to generate the sound he preferred—to his ears" unquote.

Some of the older Steroephile articles in the early to mid 2000s challenge and mention this too;

 https://www.stereophile.com/tubepoweramps/1098cary/index.html

On some search engines you can look for these words and hyphenated phrase +Cary +"zero-feedback" and different amps will pop up references this about some times.

To @xenolith, agree, yes, you are fortunate to own those very unique and interesting big blue amplifiers from Gary and Charlie. I love one-off boutique custom builds like this with audio, cars, and motorcycles. Great story how they got finished. Very cool, and Thank You for sharing the info and photos. Happy listening.