The first AES (Audio Engineering Society) convention I ever attended was 1968 in Los Angeles. At the AES that year were a dozen or so exhibitors. One was a guy named Ray Dolby who was showing his revolutionary “Type A” noise reduction, one channel of which took maybe 7 rack units?! Across from him was Paul Klipsch showing his “Heresy” bookshelf speaker (since he only believed in horn loaded speaker designs). Of course, I didn’t know that I was seeing history in the making, that these people were the icons of audio. How little we know when we are young and foolish. (Now I am old and foolish.) I snuck in to the AES show in 1968. I joined AES in 1969. Read more
We recently received a letter from Jim Schultz in Warren, CT and thought we’d share:
I have been meaning to write for almost a year now to extol the virtues of this excellent microphone cable.
30+ years ago, when I was doing broadcast and remote work aside from my “regular” job of air personality, production director and assistant CE for an AM/FM combo here in Western CT, I decided to bite the bullet, spend some money, and make up some microphone cables that would last for a while. I bought a 500 foot roll of 8412, a bunch of Switchcraft XLRs, and went to work making up 10 fifty footers. Read more
If you’ve read the last few blogs, you’ll know we’ve been discussing balanced lines, differential signals, and common-mode noise rejection. But one of the key factors we really haven’t discussed is the cable itself.
In the last blog, we talked about how electromagnetic noise signals, called common mode noise, hits both wires in our twisted pair and cancels out. But, to be truthful, the noise is cancelled out only if the two signals are identical. The closer to identical they are, the greater the rejection or common mode rejection ratio, CMRR will be.
We have a saying in cable manufacturing: physicals equal electricals. What this means is that the two wires need to be physically identical if we want the noise signals to also be identical, and the noise rejection to be 100%.
Well, aren’t the two wires in a twisted pair ‘automatically’ identical? After all, we twist those wires together. Isn’t that enough? Sure, twisting helps a lot, but it doesn’t make the two wires identical. Those two wires should also be the same AWG (gauge) size. Read more