First of a long long long long line of tubed integrated amplifiers, with many variants, versions and LuxKit versions and variants, the SQ38FD is nevertheless Luxman's bestseller of the entire series, alongwith the SQ38FD mk-II version.
Said long line sort of ended with the release of the (rather different) SQ-38 Signature in 1995 and the recent SQ-38u.
Four 50C-A10 output tubes in push-pull configuration, one BA-70B and two OY15-5 transformers for 2x30W of warm musical bliss.
A real life SQ-38FD at the indispensable amp8.com.