Awesome piece of kit. It is a real vacuum tube amplifier, not some wanna-be hybrid excuse. I like the fact that I can change the sound of the amp with rolling tubes. The stock tubes are not that bad, I kept mine as a back up set, but do yourself a favour and get something else too. Replacement tubes are readily available and not expensive. Sure there are some expensive tubes if you want to splurge. The fact that there are only two tubes to change makes it even better, no matching of sets of tubes to be done, again that makes it easy on the wallet and user friendly. You can even do tube rolling with one tube only. The 6SN7 is what I would change, if I was only rolling one tube. I had some hum on a NOS 6SN7 tube, but disappeared after a while. My favourite combo is currently with a NOS Mullard 6080 and a NOS Ultron 6SN7GT. The Ultron valve is buttery smooth tube with fine detail, good bass and wide sound stage. The NOS Sylvania 6AS7G paired with the Northern Electric 6SN7 sounds good too, a little bit more bright and detailed, perhaps a bit more solid state sounding. But I digress... I love my DarkVoice 336SE, it's the real deal!
9 Months later:
I love my Darkvoice ... even more! I have started experimenting a bit more with tube rolling. All old tubes, some second hand and some NOS.
My favorite driver tube at the moment is the Mullard 6080. It is a beautiful sounding tube with a lovely sound stage and a very good balance between the lows, the mids and highs. In second place, a very close second indeed, is the RCA 6080WA. The RCA also has a beautiful sound stage. It seems a little bit more lush sounding than the Mullard 6080, but at the same time, it has "vaguely less" detail than the Mullard. Another great tube is the GE JAN5998A. It has great bass reproduction, but a little bit less of a sound stage and separation between the instruments are less defined. I really like this tube though. That is the lovely thing about rolling, if the mood strikes, you roll. Then there is a Sylvania 6AS7G, it is very detailed and a bit dry, it reminds me of solid state, but good old school solid state sound ... I have more preamp tubes coming, so will update on them later.