12ax7 vs 5751

Mechans, you answered for me very nicely; actually.

***I certainly think for the most part that a warm tube sounds warm where ever they are with a few exceptions. there is no doubt though, that certain tubes just don't work in all circuits***

I completely agree, although I know some will disagree. I currently own one piece that uses 12ax7's, but own and use three that use 6dj8's. In all three pieces the Telefunken 6dj8 produces a full bodied, dimensional sound with a timbre closest to "neutral" as I define it; reminiscent of the classic Audio Research tonality. In one of the pieces, a modded Melos 222c occasionally used for it's line stage, the Teles' fullness and lack of zip or edge is too much of a good thing for this preamp which is inherently on the dark side. With this pre, West German Siemens 7308, which yields a brighter, less corpulent sound, with excellent high frequency extension is
much better. I hear similar tonality/timbre from my Tele 12ax7's in my
phono pre.

I should have said: "I hear similar tonality/timbre from my Tele 12ax7's in my phono pre as I do from the Tele 6dj8's in my linestage"

Man I cant wait to get some different tubes!!
I am still getting used to the sound of this Thor, but is is very good.
Does anyone have experience with Phillips Miniwatt 12at7 from Holland factory?
Another Thor owner suggested the Miniwatt/GE 5751 3 mica black plates combo.

Mc,
Buy all means get a pair. I really like them, i use them in my VT 5.5 pre-amp, i also like and use the Phillips Mini Watt 12ax7. Very smooth i like them, as usual YMMV......

treasure tubes kt88-z

got `em!!! i got them this morning. i fitted them and left them for 20 minutes or so then set the bias. left them another 20 or so minutes then checked the bias again and then to the good stuff! from the off these are an upgrade! very open sounding. i can already hear the top end is extended. my 1st and so far only track i`ve listened to is k.t. tunstall silent sea off the eye to the telescope cd. her closely mic`d voice sounds just incredible and incredibly real! the weight and texture to her voice is just right and mind boggling! she`s right there in front of me. soooo much detail in her voice and the sharp intake of breath you hear in between her lines! i couldn`t help listening to this over and over! the bass is deep, detailed, darker, warmer and textured. acoustic guitars have realistic tone, weight and that zing that acoustic guitars have. you can hear each string being plucked. the noise floor is extremely low on these and the back ground is silent. after installing these, the first thing i noticed was the lack of low level buzz coming from my speakers. if i put my ear up to the speakers i get a just about audible deep hum.

the soundstage is pin point accurate and the seperation of the musicians is very freaky. lots of air between the musicians! the soundstage is less deep but by no means flat. it`s much easier to get that sense that the drums are behind the singer. you also feel you can almost see the performers. you can also hear k.t. tunstals lips close and open as she`s singing and her voice actually sounds like it`s originating from her throat. by the way her voice on this track will leave you needing a cold shower!!!

the most amazing thing here is i have about another 298 hours to go before they`re broken in! and the sound is said to improve! wow! i`m off to do some more listening to my other favourite cd`s. my plan now is to fully break in these tubes then do one last tube roll between all the 12ax7`s and 5751`s before i make my final choice of tubes for this amp and system. so far i have to tell you i`m amazed at this sound coming from my speakers. more to come later today guys. this is just the initial "straight out of the box" review