I have an ST-120 and SP12 that I bought pre-built, and a few months ago I bought an ST-120 kit to put together. So far, I've only soldered together a headphone amp. I guess I'm spoiled by the Tubes 4 Hi-Fi equipment, because to my ears, the little headphone amp sounded a bit dissapointing. With this second ST-120 I'll bi-amp my speakers. Even though I bought the kit months ago, I haven't had the time to start on it. I'm getting married this November, (38 years of being single was long enough for me) and preparations for the big day have eaten up most of my time.
Anyhow, I'll try to post some pictures of the build as I go along. Also, I wanted to take a minute to just sing the praises of the Tubes 4 Hi-Fi equipment. My ST-120 and SP12 are amazing! They've brought the musicians on my LPs into my house, and have improved my sound better than any other components in the signal chain.
Highly recommended! Hope to post progress reports soon!