Was really satisfied with the JJ EL84 that I had in my Orange Dark Terror. I then bought a Joyo Mjolnir so that I had something that I could plug into my 4 Ohm Ampeg SVT-810E or my Orange OBC810. I was, however, prepared on needing to swap out preamp and power tubes. I was right. Now, swapping out the preamp tubes did wonders, (Ruby for V1, Mullard CV4004 for V2, and Tungsol for V3) but it was still a smidgen off. I then swapped out the stock Sovtek power tubes and put in these. Nailed it. I now have an amp that has 1 clean channel (that I can even get really classic dirt from by turning the gain up to max) and 1 high gain channel that sounds almost exactly like the Dark Terror (in which I have Rubys in V1 and V3, and JJ 83-S/Ruby 12AX7ACZ in V2). I now basically have a mini/bedroom Dual Dark that I can plug into a 4 Ohm cab (and no Orange guitar amp can do that, as of yet). Plus, it cost me peanuts; paid 600 dollars. A Dual Dark 50 costs 2600 dollars. Just fantastic.