Good to know the volume isn’t malfunctioning. I didn’t really think it was, but I thought I’d ask to be safe.Yes, the volume should change in sharp steps rather than smoothly. To me the signal does sound kind of clicky during volume changes, but that may just be because the volume is changing instantly.
I don't have any experience with the Darkvoice and I don't know what sort of tube it uses. My Lyr+ came with a new manufacture Tung-Sol. If you mean the appearance of the tube in operation, I suppose the filament looks less bright than what I'd normally see in a guitar amp, though I imagine those are being run quite a lot harder. If you mean the tone, I suppose it sounds ever so slightly rolled off in the treble to me, but I would also say I might be imagining it.
The stock Lyr tube is so dim I can’t even tell it’s on from a few feet away. It makes me wonder if it’s working ok. Probably is, just hasn‘t burnt in enough (that or the amp).
Thanks for your help tonight.