Many blown components, probably caused by dry joints failing at mosfet. Used STP6NK90Z (note case not isolated) as substitute for 2SK1548
spirit_pro_tracker user manual
CR02AM-8 400V – 0.2A – Thyristor
Also AUX/OUTPUT/RETURN PCB C70 C71 100uf 25v, 8mm by 11mm, leaking +V -V caps corroded right monitor output trace, also dry joints CN4 +V -V Gnd pins 12, 13, 14, 15
Blown limiter mosfet, one channel louder than others:
BS250 TO-92-18RM (TO-18 Lead Form) substitute e-line package
BS250 Vishay Siliconix P-Channel 60-V (D-S) MOSFET
BS250p E-Line TO92 TO18 Compatible
Power-on thump was blown -17v resistor R62 on channel card.