So 2nd unmatched mullard 12ax7 long plate arrived and I got a chance to test it out.
Before I put in the 2nd mullard, I had 1 mullard in V1 and the original Chinese tube (which is awesome) MP-1 in V2.
In V1, I had intense color and a very fat tone from the Mullard and I enjoyed using El Chiguete's settings (putting V2 close to zero).
Basically I could get the fat sound and then add more distortion with V2 when I wanted it. Really, really nice.
So, in goes the 2nd mullard in V2.
Day 1: Might be too much of a good thing. Plenty of distortion and it is very British but far beyond a Beatles British but more like a thick Marshally British. It takes articulation to an extremely higher level....you have such HD sound it is like hearing Angus' vibrato scraping the frets on that Gibson SG type of articulation--not something you hear in today's amps. And if you make a mistake, you guitar will scream it out. It is hard to explain in a convincing manner, how much of your playing it projects....I heard Rnolan say it was HD and I thought "sure, maybe"....but it is a lot for me and I am big into articulation. Huge difference between tubes.
With 2 mullards, I did not get very good sound at El Chiguete's settings. Not sure why, maybe the Mullards do not work well at low levels?
Also, with 2 mullards, the color changed to where it seemed like V1 and V2 were competing for who will color the sound the most.
I will keep trying it out but my first thought is that I might prefer the Mullard in V1, an original in V2, and El Chiquete's settings. Reason is I get the thick sound, Mullard distortion, and basically clean to overdrive pedal from V2 with the Chinese tube.