Heading Off Trouble

The last few weeks have been pretty technical, so I promise...no math this week!

We've spent a lot of time here talking about how to troubleshoot your systems when they fail.  And being able to do that is a skill that will carry you far.

But as most of you know, one of my big mantras is that you shouldn't be fixing things at a gig...you should set up, play, and load out.  Or, as one of my past co-workers said, "Show, blow, get the dough, and go!"

To that end, there's a lot to be said for preventive maintainence.  In a couple of my previous careers, preventive maintainence (or "PM" as we called it) was crucial.  As the chief engineer for a number of commercial broadcast stations, my job was simple...keep the stations on the air and legal.  To that end, I would schedule time monthly (usually on a Monday morning at midnight) to take a station off the air and go through the transmitter.  I would look for loose components or connections, anything that looked like it was getting hotter than it should, and give the cooling paths a good cleaning.  As a result, I had an excellent record for minimal down time. 

You can adopt the same mentality for your PA systems and instrument rigs.  There's nothing really hard about it...it's just talking yourself into doing it.  A few hours a couple of times a year can really save you a ton of aggrevation and frustration at a gig.  If you get the entire band involved, it's something that can be knocked out very quickly.  And unlike the radio stations, you don't have to wait until the wee hours of the morning (unless that's when you function the best).

So...what would preventative maintainence look like on a PA system?  Well, in check list form, it would probably look something like this:

• Test all audio interconnect connect cables (with your trusty cable tester).  Identify any that fail and quarantine them for repair.
• Inspect all cables for knicks or cuts.  Repair with either heatshrink tubing or electrical tape.
• Clean all cables, including power. (Just pull them through a damp cloth as you coil them up).
• Inspect amp racks for loose connections and hardware.
• Clean any fans or filters on force-air cooled gear.
• Exercise all audio connections (disconnect and reconnect them a few times).  Cleaning the connectors with DeOxit is highly recommended.
• Hook your PA up and run some music through it at a low level.  Now, listen to each individual speaker component and make sure everything is still working (I do this every gig).  It's possible to blow a woofer or midrange speaker and not realize it when everything is going full blast.
• Speakers vibrate...vibration causes things to work loose.  Check the mounting hardware for your speakers!
• Any case hardware (handles, latches, or casters) that's busted should be repaired / replaced at this time.  You curse that broken caster every time you load in...get rid of now!
• Replace any missing labels on any equipment.  Remember the 4x4 test!
• Check all of the pots on your main console for quiet operation.  Slide pots are easy to clean, so take care of that now. 

Your personal rigs should be checked in a similar manner.  And don't think that because you don't gig that much that you don't need to do this as often.  I find more problems with systems that sit idle for an extended period of time than those that go out on a regular basis, especially with the connectors in amp and effects racks.

Yeah, I know...this isn't the most "rock star" thing you can do with your band time.  But the payoff is that you're going to lower the stress level at your gigs by not having to troubleshoot/swap out/fix something 10 minutes before show time.  And that (at least to me) has a great deal of value to it.

Next week, I'm going tech on you again!  We're going to talk about one of those oft-quoted but rarely understood terms in electronics, and that's "balanced" wiring.  We've all heard of it, but who really understands it?  We'll break it down next week.

Until then, keep the meters out of the red!

Ken

Ken Carver has been a musician and performer since the early 70's, and involved with live music production since the mid 70's. He worked for 15 years as a broadcast engineer, building numerous studios and transmitter sites around Texas. He's also worked in Critical Care Communications for the medical industry, R&D for an automated lighting manufacturer, and owned Project Lighting & Sound in the 80's. He currently heads up an R&D Hardware Technician Team at National Instruments in Austin, and still performs on the weekends in the Central Texas area. You can reach Ken at itsjustlogistics@gmail.com