The Nobsound is a cool little tube based headphone amp.
It uses two 6J9 tubes for the preamp which are small pentodes. The amplification is solid state based.
It’s a great looking little package that shows off the glow of vacuum tubes while you’re listening to your music.
It is especially good for listening to vinyl records. You get some of the warmth back that is lost with modern day digital. Most older records were mixed with tube based amps in mind so you’re one step closer to the audio reproduction the producers and engineers of classic records had in mind.