Review on Enhance Your Home Audio Experience with the FX AUDIO Tube Preamp: NE5532 Replaceable Tube and OP Amp Chip, Mini HiFi Stereo 6K4 Vacuum Tube Buffer Preamplifier with Bass and Treble Control, and RCA Cable Compatibility for Amp/Active Speaker by Geoff Yates

I was excited to hear this little preamp after hearing so many good things about it. When I got mine I lit it and let it cook for a while. When I checked it I noticed that the chassis was very hot. Not enough to burn you, but it gets your attention very quickly if you accidentally touch it. I then plugged in the CD player and before I turned up the volume, I heard a clearly audible hum coming from the speakers. The demo is over and everything goes back to Revain. Lesson learned. Never buy cheap audio electronics from the other side of the world again.