DYNACO ST-120 PC-14 COMPLETE QUICK REPAIR KIT. THIS KIT CONTAINS EVERY TRANSISTOR AND DIODE ON ONE CHANNEL OF THE PC-14 DRIVER BOARD PLUS ASSOCIATED OUTPUT TRANSISTORS. (D1 THRU D3 , AND Q1 THRU Q6 --- 9 SEMICONDUCTORS IN ALL)   INPUT AND OUTPUT DEVICES ARE SCREENED FOR NOISE AND/OR GAIN. KIT COMES WITH SCHEMATIC, INSTRUCTIONS,  AND PC-14 PICTORIAL SHOWING DEVICE LOCATION AND EBC ORIENTATION. DUE TO CHANGES IN THE ST-120 DESIGN,  Q3 AND Q4 ARE TIP PACKAGE (FLAT WITH HOLE)AS OPPOSED TO  TO-39 PACKAGE (ROUND CAN) TRANSISTORS WHICH IS TO THE LATEST REVISION.  IF YOU WANT EARLIER REVISION PARTS, CONTACT ME FOR AVAILABILITY AND PRICING.