Langevin PCB is on Cinemag's website and uses CM-28121 as input transformer and CM-28122 as output transformer. I was also wondering if anybody had worked out an input pad/gain for this. I was thinking of using a 2P3T input to get the different input impedences but was still trying to workout how to do a variable pad or input pot to the unit. Anybody who's figured it out please let us know.