This Orange amp has awesome british overdrive tones but lacks a usable clean tone. The amp has a 3-band EQ, a master volume knob, and a gain knob. It also includes a half power switch if you need high gain at lower volumes. A great feature of the amp is its effects-loop. Overall its a great amp for driven tones but needs a better clean tone.
I've previously owned both the Tiny Terror and the Dark Terror, and neither holds a candle to the OR15. This amp is far more versatile and organic sounding that either of those. Tons of gain but with a more vintage flavour to it.
I play metal, mostly the kind that would fall under the sludge/doom banner but I do play other styles as well and this amp handles all of them quite nicely. Loads of saturated organic gain on tap, in fact far more than I need in most applications. I don't see a lot of reviews that judge the OR15 as a metal amp but for the kinds of metal that I play it absolutely nails it.
What I love the most about the OR15 is that it sounds equally great at both bedroom and rehearsal levels. For the most part I use it at home through a Mesa Recto 212 with Vintage 30's. I use the 7 watt setting with the volume at about 7:30 (quite low, I live in a townhouse) and the gain around 1-2 o'clock and in this setup it absolutely sings at a volume that won't annoy my neighbors. Not many tube amps that i've tried can sound great at this volume but the Orange absolutely nails it.
Outside of my home setup, I have used the OR15 numerous times in practice fully cranked on the 15 watt power setting. At full band volume using the same Recto 212 in a small room competing with drums, bass and another guitar this amp has plenty of volume and doesn't struggle to keep up with larger watt amps. I have also used it in a much bigger room through a Randall 412 with V30's when my 100 watt head was in for repairs and it did struggle a bit in that setting, but it was enough to get me through the night without making the other guys turn down too much. On stage and properly mic'd I don't see any reason it wouldn't hold it's own against any other higher wattage rig - though I haven't tested this yet personally. I don't tour but if I did I wouldn't hesitate to bring the OR15 along as a backup.