Audio Research makes digital components, pre-amplifiers, and amplifiers. Avalon Acoustics makes speakers. Basis makes turntables. Benz Micro makes phono cartridges. Billy Bags makes audio racks.
Boulder makes preamplifiers, amplifiers, and digital components.
Class makes electronics. Clearaudio makes cartridges, turntables, tonearms, and phono preamplifiers. Dunlavy Audio makes speakers. DVDO makes video scalers marketed by Princeton and Seleco. Dynaudio makes speakers.