Some considerations about the sound of that time
Throughout the On Location tour, Mark's equipment was: two Music Man HD 130s, 2 x 12", 130 Watts, with Marshall 4 x 12" cabinets
A big change came on the LOG tour 82/83, when he started using: Mesa Boogie heads with Marshall 4 x 12" cabinets with Electro Voice speakers, we noticed the big difference in how Schecter sounds between the two tours 80/81 and 82/83, he found the ideal sound for Schecter through Mesa Boogie heads with Marshall 4 x 12, this is evident in the bootlegs, the tone of the guitars on Alchemy is much more defined and present than what is found on Dortmund 80 or Werchter 81, especially the 1980 shows. When Mark originally acquired a Schecter it had three original Schecter F500T pick ups, which later, in 1981, they were replaced by Seymour Duncan
Old (SSL1?) and later with Seymour Duncan Alnico Pros, this change was a quantum leap in the sound, it still has its distinct beauty in 81 with the presence of the two Music Man HD 130, 2 x 12", 130 Watts, with Marshall 4 x 12" cabinets, but, definitely, in 1982 things were on another level.