I received this amp in late March, 2019. I replaced the stock tubes w/matched pair GE 5670 3 mica square getter tubes, then burned it in for 150 hrs. I'll ship this w/the stock tubes packed & GE 5670s installed.
Due to medical issues I did very little listening to this amp. I estimate it has ~155 hrs total on it. It works perfectly and sounds better than an amp this small & inexpensive has any right to.
There's just 1 minor flaw: when taking pix I discovered 1 of the 4 black footer/tabs is missing. I replaced it with a cut-down furniture spacer (shown in one of the pictures). See below for operating instructions.
I have a total of ~$135 in this amp. My price is $75, including Paypal fees & shipping w/in CONUS.