I've owned or used at one time a 190B,Sorado,Sonic 1-40 and Sonaro and they all were the 60 watt version with 2-6550's. Under the hood they were all the same. Just different name plate. They were all from the late 60's to early 70's with the square pattern grill cloth. An earlier model would probably have the Dynaco transformers were others might have the Schumacher transformers. That would be something different. I have a 1967 Sonic 1 with the old style grill cloth and numbers on the face plate it has the Dynaco's. Its only a 40 watt head.