[Antonmb]

I really like the WA8. I use it in the bedroom, it has a very nice DAC and fits nicely on a nightstand. I use it primarily with MrSpeakers Aeon Flow closed headphones or Shure IEMs. Sound is very good: very open, well-defined bass, enough detail and a very nice smooth midrange. I don’t think there’s a tube power supply option, it’s battery powered with a charger, although I leave it on the charger all the time.

Perhaps you’re thinking of the WA7, which has a tube ps option. I have the 1st generation, which didn’t have the tube ps option. I use it mostly with IEMs, and really like the sound of the amp, but the DAC is not its best feature - it was the first model Woo made with a DAC and can sound a bit edgy on some recordings. I understand the 2nd generation model has a better DAC, like the WA8, which has an excellent DAC.