i exchanged emails with VHT customer service once b/c i had some questions about the amp i was considering buying, and then eventually did buy, and after i got it i noticed that a washer and a small screw were missing, which i mentioned....i then mentioned a crackling noise when switching from standby mode in a later email, which they said could be a preamp tube and to try switching out V1.
a few days go by and a package arrives....they sent me a 12AX7 for free....but no screw or washer, which was all i'd asked for
they ended up sending the screw and washer later though.