bmdduck,
My first headphone amp was a Project Head Box II which I used to drive a pair of Grado 325's. I picked up the Project for $100 used and they worked great together. In fact I probably preferred the Project/Grado combo better than using a Creek Destiny 2 which was my amp at the time and had a headphone out. Don't think you have to pay a fortune to get those 60's working.
My first headphone amp was a Project Head Box II which I used to drive a pair of Grado 325's. I picked up the Project for $100 used and they worked great together. In fact I probably preferred the Project/Grado combo better than using a Creek Destiny 2 which was my amp at the time and had a headphone out. Don't think you have to pay a fortune to get those 60's working.