@LoryWiv
Hello,
I got adapters on loan from
@albertmuc and the Russian EL84.
I don't have a bad impression of them, even if the Russian ones are a bit dry sounding, I think other EL84 are better like Mullard or Japanese.
However, there is something to consider when using EL84s because they have a high mu factor, 12AU7/6SN7 are the better tubes and because they have a low mu factor it balances out wonderfully.
You will notice this immediately when operating the potentiometer if you previously had 12AT7s in it.
The potentiometer reacts quite sensitively to this.
In terms of sound, 12AU7/6SN7 also sound a little rounder and fuller with more air.
12AT7 is not wrong, everything is a little more tightly structured, depending on the 12At7, details can sometimes be lost because it is a little overlaid.
Similar to 12AX7, when 12AT7 is better you immediately realise that 12Ax7 is good but everything sounds very layered.
Like a kind of clipping from a visual point of view.
As so often there are good 12AU7/6Sn7 on the market that the El84 is definitely worth it, especially for high impedance headphones, for low impedance headphones it might be too much.
But you have to try it out.
It's not quite as serious as it sounds, but you should keep it in mind.
Low-ohm headphones may react more sensitively to the 12AT7.
So far I've only tried the EL84 with the Mullard M8162 and haven't got round to trying out any other 12AT7s as I have another project to finish.
6SN7 Brimar GTY also sounded very reasonable with the Russian I just remembered.
If you take all this into account, EL84 is an absolute predator tube on Ultimate.
You just need to know how to drive them properly with the right 12AU7/6SN7 tubes.
The whole process also affects other output tubes and driver tubes on Ultimate in general as I mentioned.
Ultimate gets more out of the sound when you understand how to drive it.
In Euforia I don't have any options here and everything runs on the warm/neutral track depending on the tube, and that's it, so Euforia is almost boring again.
And there are only combinations that work or don't work.
With Ultimate this is not a priority, but if you know the Mu factor of the tubes you want to use, that's what makes it to the end game.
Warm/neutral tends to come in third place, which then goes into the category if you like the whole rough and have found out that you like it that way, it's a matter of taste.
In 2nd place I would say if you have considered point 1 you have to consider whether you like it that way before you move on to step 3.
If you take this into account as a total package, you will always have a good match with the tubes 90% of the time and never have problems driving headphones and consciously directing them where you want and desire.
With the Meze and Focal, I would still be a little cautious if you were to try it.
Always set the potentiometer to zero before you plug it in and pay attention to the sensitivity.
If it really is too much, I would try to reduce the volume on the Matrix X-Sabre Pro preamp if possible.
But this is only a last resort.
I don't think you will lose headroom and dynamics if the control system allows more leeway.
In any case, it should be there again if you can turn up the potentiometer on the Ultimate further.
. @David A Silva 
