Again, when reading the content for this issue of Pro Audio Review, I'm reminded of a story. This time, unsurprisingly given the issue's theme, the story involves a compressor. Not just any compressor, but a particular example of the legendary Fairchild 670 stereo tube compressor. But in this case, the story doesn't actually end with a moral about sonic quality or integrity or musicality or engineering prowess. Instead, it's just a story begun in dangerous filth and ending sparkly clean.
The tale is set in the same time frame as last month's column — part of the same used-equipment package that brought the Trident TSM console for an early '90s Nashville studio build, included a Fairchild. The former owner of the gear package had left the 670 in a machine shop for a number of years. The result: When we got it, it was covered in an oily film with embedded metal shavings, and the mess had penetrated to the inside of the chassis. We didn't dare turn it on, fearing catastrophic results.
Someone suggested, likely Milan Bogdan, then chief engineer of Masterfonics, that we run the Fairchild through a dishwasher. Perhaps the suggestion was in jest, but wanting a penetrating cleaning, Milan and I set about seeing if the suggestion was viable and safe. I removed the meters, the tubes, the paper cylinder capacitors, and anything else that water would destroy. We figured out how to remove the top basket from the dishwasher and put the 670 open like a pup tent on the bottom basket. Two cycles later (light soap on the first, no heat dry!), we pulled the Fairchild out, grease-free.
Of course, we didn't try to turn it on in any hurry. We kept a dry nitrogen tank in the shop with hose and nozzle mounted (the mastering engineers used nitrogen to clean lacquers before cutting discs), and I sprayed out all the moisture I could detect. Then I flushed the tube sockets with our favorite, now banned, chemical solvent. Then it was ignored for a couple of days.
With tubes pre-tested, all the parts put back in place, the big moment came. Plugged in. Powered up. No sparks, arcing or that sort of excitement, but exciting indeed, watching the needles rise and verifying signal flow, and then giving a listen — all good, now three Fairchilds in the collection, ready for client use or rental. I said there was no moral, but maybe I did learn a little about the viability of considering audacious solutions. At the time, a Fairchild was valued at $12,000 to $15,000. Today, prices are running $30,000 and up. I wonder what an especially clean unit would bring?