The EL844 is similar in design to the EL84 with slots cut in the Anode to reduce dissipation.
They sound like worn out EL84s with no headroom and poor linearity, (not that the EL84 is linear in anyway but to reduce it even more seems a mistake).
I have had five amplifiers in for repair with these fitted and the sound issues with all of them stemmed from the EL844s.
In my view, a horrible clone of a particularly poor quality valve we used to see in the PYE colour tvs back in the 70s before high voltage transistor stages became common place.
Sorry but I won't entertain them and place them straight in the bin.