As long as we're ruminating about the historical progress of our equipment we would be remiss not to include the inputs and outputs.
In the 70's and into the 80's all consumer audio equipment—high end or not—had one type of input and output connector, the ubiquitous RCA.
The RCA connector, named after the Radio Corporation of America, made its debut in the 1940s. It was initially developed as a low-cost method for connecting phonographs to amplifiers. The simplicity and ease of use quickly made RCA connectors the standard for consumer audio equipment. Their design, featuring a central pin for the signal and an outer shell for grounding, became ubiquitous in connecting everything from turntables to receivers, and later, to various types of audio and video devices.
But, it wasn't (and isn't) a great connector. Because it had one hot and one ground any noise or interference picked up by the cable was passed along to the receiving unit. And worse, whatever distortion products inherent to the sending unit were merrily passed along to be amplified by the receiving unit.
Enter the XLR connector. Originally developed by James H. Cannon, founder of Cannon Electric in Los Angeles, the XLR connector was introduced in the 1950s. The name "XLR" stands for "X Series, Latch, Rubber," describing some of the connector's features, though it's also simply known as a Cannon connector after its inventor.
XLR connectors were a game-changer, primarily in professional audio settings. Their design includes three to seven pins (with the three-pin version being the most common), allowing for balanced audio signals. This means that two of the wires carry the audio signal in opposite phases, and any noise picked up along the cable—or differential distortion generated by the equipment—is canceled out when the signals are recombined.
In the mid 1980s, PS Audio was among a handful of brave (at the time) high-end audio manufacturers who added the XLRs to our ins and outs. Brave because very few pieces of equipment had the same connector. So, if you purchased one of our preamps with XLR outs, chances were pretty good your amplifier (if it wan't from us) would not have a similar input.
It took time to make the transition. But transitional equipment is always the path towards better audio.
Imagine today if we (and our fellow braveheart manufacturers) had not stuck our necks out to include XLR ins and outs. We'd still be stuck with the old RCA which is clearly inferior.
