In this video we’ve got a Klark-Teknik DN300 graphic equalizer on the bench dating all the way back to the 1980s. We’re looking under the hood, talking about the specs, history, and how it compares to the current DN370 model from the same series nearly 40 years later. This one has lived a long life on the road it seems, and needs a full going over before being put back into service. There are some crunchy feeling controls and other general maintenance that we will have to tackle in the future, which should make for more good videos.

We also get into the Pin 2 Hot XLR wiring standard adoption for line level equipment and how units like this from the early ’80s are wired Pin 3 Hot. Once we verify everything functions properly and is back in working order, we can look at bringing it up to modern standards and possibly adding an output transformer. 

The DN300 manual you see referenced in the video is available for download here — DN300 PDF. You can read more about the history of the adoption of the Pin 2 Hot standard, direct from folks who were actually involved over at this ProSoundWeb Forum Thread.

The Klark-Teknik DN370 is available for purchase at the time of this video at this DN370 link, and you can find the DN370 Manual Here. Leave a comment and tell us about your experience with this or other Pin 3 Hot gear. If you were around at the time you probably have a story or two from a Pin 3 related misadventure and we’d love to hear them.