It's amazing just how many forum posts complaining about audio interface pops and crackles or PC 'interference' problems turn out to be simply due to dirty contacts or components. Personally I use Caig's DeOxit D5 spray ( http://store.caig.com ) to deal with such problems, and to prevent them from happening in the first place.
It has a good reputation in the audio industry, being widely recommended by manufacturers of mixing and DJ desks, guitar, hi-fi, and power amps, and rack effects (even on elderly boutique audio gear), and is good for cleaning:
· Plugs & Sockets.
· Valve/tube pins.
· Rotary pots and faders.
· Contacts on computer expansion cards.
The reason for this reputation is that many generic contact cleaners simply use solvents to remove surface contamination, but DeOxit not only removes this muck, but also leaves a thin layer of lubricant behind that improves conductivity and helps to prevent further contamination/oxidation. Basically, if you've got crackly pots or faders, a quick squirt of a generic contact cleaner generally makes things better for a few days, but then the noises come back, while with DeOxit the effects generally last for months or even years!
Zap Those Crackles!
For preventative maintenance, I go round my studio about once a year and pull out each audio plug in turn and give it a wipe with a cloth on which I've sprayed a little DeOxit. If you plug/unplug it a few times this will also get a little DeOxit into the socket as well. Don't forget your mains connections, since these can sometimes get very tarnished over the years. I pull out the fuses in the mains plugs and give their ends a wipe, and also make sure the pins on my mains plugs are really clean, since this will help prevent intermittent connections and make sure your gear gets a good earth connection, which in turn can lower your noise floor.
With crackly pots and faders, apply a quick spray of DeOxit and move them back and forth a dozen or so times to help break up any dirt and to distribute the lubrication. Leave overnight and then listen again - if any crackles remain try repeating the process, although in a few cases you may have to replace the pot/fader due to excessive wear. The DeOxit 5% formula has a carrier solvent that helps flush the muck away, but then quickly evaporates, leaving the lubricant in place to carry on doing its job
By the way, don't be tempted to try a squirt of WD40 - 'WD' stands for 'Water Displacement', so while it's a great way to resolve problems with rust, corrosion, or squeaks, and even removing chewing gum from carpets, it's not the most appropriate product for fader crackles.
Similarly, Isopropyl Alcohol will strip any lubrication from faders, leaving them clean but with a dry and scratchy action rather than the smooth silky one you're expecting, which is likely to get significantly worse fairly quickly.
FaderLube For Spills
Caig's DeOxit FaderLube is a more specialist product, described as a 'moving contact lubricant'. On their web site, Caig state that DeOxit and DeOxit Gold are formulated for conductive metal surfaces, while DeoxIT FaderLube is formulated to lubricate and enhance signal transmission on conductive plastics and carbon-based controls. In practice Caig nevertheless recommend DeOxit as a routine alternative treatment for faders.
However, FaderLube is preferred when your pots/faders have a heavy contamination of dust or other dirt, if you've spilt beer or coke on your mixing desk, or for high-use moving components in DJ and other mixing desks when the original lubrication has been worn away through extensive use or over-enthusiastic cleaning. Rane also only recommend FaderLube for use on any of their pots and faders ( Detailed Slide Pot Care Procedure ). You use it in much the same way as the standard DeOxit (spray and then move the pot/fader back and forth a few times over its full travel to distribute the product).
Caig also sell DeOxit Gold for those who have lots of gold-plated plugs and sockets. This provides extended protection for indoor use that you can wipe on after you've removed any muck using the basic DeOxit spray, or can be used directly onto plated connectors that are already clean. There's lots more information on their web site, and you can download a useful PDF file containing further instructions at:
Caig products are widely available in the US and elsewhere around the world, and in the UK can be found on-line at Russ Andrews ( www.russandrews.com )
Ban those studio crackles for ever!