. The Blackjack 21 top for Fuchs ODS sounds is built on a 3x 12AX7 preamp. It also features an adjustable. Fuchs Blackjack 21 MkII Mini 1X12 Combo Amp Cover - Black,Tuki (fuchp). Tuki Amp Covers and Speaker Covers (); 99,8% de votos positivos. A unique circuit design mixes the wet reverb signal with absolutely no affect on the pure tube dry signal quality in any way. They are handcrafted in the same US factory as the larger ODS-Classic and ODS-II.