Hey H1, the EL38 is indeed a very special tube, and -I have to say- that your “discovery” of this tube for Euforia, for headphone duties, opened (for me) a whole new level of power amplification and top notch triode pre amplification with Euforia.
So yes, the quartet can be kind of wild and OTT sometimes with cans, but in a pre/power configuration there are other stages, cables, circuits, speakers and a room to deal with, so the extra definition is simply a blessing. The 4 EL 38s (triodes) really stand out in the OTL preamp, with a beautifully musical and commanding performance. The synergy was stunning, exemplary, and I was amazed with the delicacy and musical detail of the tubes in triode mode compared to the powerful personality of the same tubes as pentodes. By the way, they run barely warm in Euforia, and quite hot as powers...
Not to mention the Euforia with 4 x EL38s driving my two NAD mono solid state amps, capable of 450 watt peaks. Fantastic. The word is total, absolute domination of the Euforia sound over the amps (that sounded like tube amps) and its powerful, unrestricted OTL output generated such enormous dynamic swings and awesome bass to the point of being dangerous to my speakers !! I was shure to set the amps at 1/4 power...more than enough. But the danger was part of the fun...rock & roll sounded like a live concert, and any music came clean, clear, smooth, “tube like”. My SS amps never sounded better. In fact, I have tried many quite good preamps, but nothing like this. The OTLs do have a special synergy with SS amps, that’s for sure, and I don’t know why, there must be some technical reasons.
Anyway, the magic of the “full tube” setup is another matter, and at this level of amplification the question is how to optimize the rest of your gear to take full advantage of it. I do use a dedicated computer for music, played with quite a few USB processors and the like, and you know what ? simpler sounds better... will comment in my next post !
I take it then, J, that you rather like these EL38s lol?! ...really happy for you. (Methinks your poor ticker would have a bit of trouble coping with such a collection of the earlier large bottle version, and/or the silver-banded, black glass Philips/Darios, being yet another notch up the ladder!! ...but keep a look out nonetheless lol...).
And yes indeed, my Euforia setup also does wonders as preamp for my own SSamp...the Vincent SV121 integrated being no slouch already by any means. But 4x EL38s are a bit much for my poor (smallish) Dynaudio speakers!! Another plus from using the more 'delicate' EL11 drivers.
And yes again, at this sort of performance level, source becomes much more critical IMHO...along with cables. For this reason I still much prefer top flight CD drive delivery (along with hi-end DAC of course!). Or, better still, something like the Naim UnitiCore, that rips from its own exceptional CD drive straight to its internal SSD drive... (also having external USB drive function for hi-res files).
Via this source,the quality from well recorded CD is often better than a lot of of so-called hi-res fare! But feed it good hi-res material, and the sound can be quite stunning...especially through top flight headphones .
So, good luck with your own trials...and look forward to the results you hinted at!