Hammond Manufacturing offers a full range of transformers, chokes and enclosures.
MXR is a manufacturer of effect pedals based out of Rochester, New York. Their pedals are known for their utilitarian designs and rugged stompboxes.
Hartley Peavey founded Peavey Electronics, one of the world's largest manufacturers and suppliers of musical and professional audio equipment, in 1965, having built his first amplifier in 1957.
Switchcraft is a leading supplier of a broad line of jacks and plugs for audio applications.