Ultralinear and Triode. What's the difference

I can give just a few cause I don't know all the tubes that are out there! Pentodes- EL 34,KT 88,6550,most pin guided sockets are pentodes or tetrodes. Triodes- 2A3,300B,45,PX 25,845,6C33,6AS7,etc. some of these have a 4 pin socket. My favorite amp is a Push/Pull 2A3 triode using 6SN7 as an input and driver tube. It's only 18 watts but, on my 91DB flat 4 ohm speakers it's plenty!

I was given this information by Kevin Deal at Upscale Audio . He is the N.A. distributor for Primaluna .

Philefreak, KT88 and 6550s are tetrodes. The “KT” stands for kinkless tetrode. The screen and suppressor grids are tied, hence being a tetrode. An EL34 is a true pentode.

Running a 6550 in triode mode simply means that the suppressor grid is biased to the anode, normally via a resistor. It does not compromise the working of the working of the tube or the sound in any way. The suppressor and screen grid do not “get in the way” of the functioning of the tube when run in triode mode. Most audio critics/audiophiles prefer pentode and tetrode tubes wired as triodes.

Regards
Paul