I was intrigued by Don C's & Widget's resonse to my question concerning 130A's bass output so I Googled "JBL 130A" and found this interesting discussion with Harvey Gerst. (www.harpamps.com/mickspeakers/early-JBL-1). He explains how, as and engineer at JBL in the sixties, his involvement with Fender Musical Instruments and the development of the D130F,D131,D110 etc. (and yes, the "F" stands for Fender) came to be. Good reading!