Ultralinear and Triode. What's the difference


What are the tonal differences between these two modes of operation?
gnugear
Bringing back an old thread for my first post here!
What a way to say hello lol...
For a quick primer, I decided to fall into this audiophile black hole. Had a few wake up's and is something I have always wanted to explore.
My tumble into the abyss started just about 1 year ago. Had a few drinks which gave me the courage to make my 1st purchase (Elac's... Loved them, but upgraded already) My second purchase was the Yaqin Mc13-S. (Upgrade path in progress ;-) ) Have been learning every day, doing DIY (ACA, Elsinore's) and I'm pretty much a gonner!

My question... I hear many talk about UL/Triode mode for SE amps, but have only come across one page/post mentioning this for push pull setups. Looking at the MC-13S schematic I see its wired in UL on all 4 tubes...  Pin 4 or the screen of the EL34B's comes straight off a tap (not sure if its 43%).. but the topology looks similar enough to many popular DIY amps that it might work...  

My question, before I tear into a working amp (and dont yet have my new one) is will the differences between the to modes be less noticeable in a push pull  ??
For the price of 4 100ohm resistors and a switch, it seams silly to not add the mod if it works... Can only imagine its not mentioned anywhere as you guys who know this stuff would prefer to spend on parts and build yourself something proper.... 

Glenn
Yes, an old thread, however  great one! I bought a used Line Magnetic 211ai which is EL34 output based and runs in triode and ultrlinear. I just received it and played in in UL yesterday. Going triode today.  I bought it for exploration. Wanted to hear the difference between modes of operation and also to see how a lower watt tube amp can drive my Tannoy Sterlings.  I have heard the Line Magnetic 845 integrated amp which was lovely. Should, after discovery, I choose to I will likely sell the LM211 for a more upscale amplifier. In the past I didn't have the resources to explore my passion in audio. Now that my wife and I am retired and have put 3 kids though college, one each BA, MS and PhD, we can direct funds toward our hobbies. 
Audio-fanman,  I am not the one to answer your question as a reason for reviving this thread, but thanks for doing so. Please forgive me for my intrusion.

Regarding the LM211, I believe I like the triode mode better. The 15wpc seems to drive my Sterlings to as loud a level as I want in my 12.5 x 14.5' room. I imagine the LM211 is operating in parallel triode mode to deliver the 15wpc. Still have much to learn and experience about tube amplification. 

I have a Aric Audio Special all tube 6sn7 based preamp which drives my BEL 1001 MK5 (13 years old) which is tough to beat at my price point. When the time comes I am thinking of replacing it with a Pass XA25 amplifier. Also wish to own an all tube integrated, yet to be determined. Giving my power requirements I am not sure I can go SET. 
Dennis Had has designed a lot of amps and I've owned a couple of them. The Inspire Firebottle HO (High Output) I currently use (few years now) is designed for Single Ended Class A Pentode use. He's described the design in detail here and there so look around if interested in that, but suffice to say his amps are astonishingly well made point to point wired sonic masterpieces.
From the original posts, sans the heat, I gather:

SETs = 1 triode/channel = low number of high quality watts.

Parallel SET = 2 triodes/channel = more power = some concession on quality?

Pentode and tetrode (P/T) tubes can be wired as triodes, many feel sound better this way.

This not to say P/T tubes wired in triode sound better than a pure triode. However maybe supply more power?

Would love clarification/correction in my gatherings.