Direct coupled…

…you don't want it in a turntable, it's rarely present in a tube output stage, it's highly desired in a solid state circuit. There's perhaps a lot of mystery around some of the engineering terms we manufacturers throw at people–buzzwords that mean something to us, inspire confidence in buyers, and complete lists of must-haves for consumers. Direct coupled would be one of those words. In a turntable, direct coupled would more commonly be referred to as direct drive. Instead of an interface between the motor and the platter, typically a belt or big rubber band, a direct drive turntable has a motor coupled directly to the platter. Most vinyl aficionados don't like this because jerkiness or vibrations from the motor are transmitted straight to the cartridge. Instead, it is preferable to isolate the motor from the platter through an intermediary, like the rubber band, which absorbs and dampens motor irregularities. Tube output stages would love to be connected directly to their next stage, like a speaker, preamplifier or power amplifier, but it is not easy to do. Instead, another interface is employed, like a capacitor or a transformer. Solid state output stages–at least those after the 1970's–are all pretty much direct coupled to speakers, preamplifiers and power amplifiers. And it is believed that the lack of another element, like a capacitor or transformer, helps the sound. Thus, manufacturers advertise the fact their products are Direct Coupled. Yet times are changing, the pendulum swinging back to the start as it always does. Let's spend a few days understanding these tech terms.