This project is awesome! Thanks Boatman and everyone else that has contributed. I built 20 v1.2 beltpack pcbs up about a year ago and finished off 6 complete units, using them in a school for theatre and outside broadcast work, metalwork needs improving, but I'll probably end up getting the end panels made up properly. We hang them off a canford tecpro master station and use in conjunction with a whole heap of original tecpro, results have been good! My next plan is to build a 4 way rack psu, and then to go on to build a 4 way rack 2-4 wire converter (using the internal 4 pin header on 4 beltpack boards) Later I plan to build a 4ch control panel with mic splitter and circuit 'listen' mixer plus IFB out etc. Question1 does anybody have 2 PSU v1.1 boards available? Question 2 Does the 4 pin header function well as a 2-4 wire ie does it null properly? Question 3 not being into electronics any more, does anybody have the time to work out the resistor changes to convert the 'mic' in on the 4 pin header to a line in? Any help would be greatly appreciated thanks and keep up the good work! swen