The Guitar Player's Resource
Welcome readers. As we approach the summer my days are getting more and more out of control! In a good way I guess.
After fighting with my studio for months, I think I have finally all of the bugs worked out. You can never be too sure though! Urgh!
As you remember the last time we spoke I left you with a certain hum in your head. I was going to get into the world of ground loops and proper wiring in the studio. I am talking about that annoying 60-cycle hum that seems to come from everywhere! Damn that hum!
First things first. It is hard to sometimes notice ground hum at a low volume level. I would suggest turning on your system and cranking it up without any signal going through the studio. Just open it up. If you are using software or a computer system, have one of the recording inputs live with nothing plugged into it. Besides the noticeable white noise that is present, listen for a low hum. Most systems will have this.
I will now inform you on how to get rid of most of it. Be forewarned, this could take up to a full day, but is worth the effort.
First, the wiring is most important. You should make sure your studio is plugged into good power. This can be checked with a 'must have' in your studio, which is a power conditioner or a UPS. This is basically a surge protector or voltage line regulator. Furman makes them and many studio shops have them. You must have this in your studio! How would you like a voltage peak to come and destroy your thousands of dollars of equipment not to mention your files. Ouch!
The second is to make sure that all of your audio cables are run separately from your power or AC cables. They should be at least a foot apart and should not touch. If they must cross they should cross at a 90 degrees angle. This is quite important. This is a large factor why many project studios have ground hum. Another important factor is to make sure you do not have any lights on the same circuit as your audio equipment. This can bring a buzz into your audio lines. Most project studios can run on 1 circuit, which is 15 amps. That means have all of your equipment plugged into your line conditioner or UPS and that into the clean 15amp circuit. If you have a wiring fault, the ground wire has been probably knocked off in the wall. You must connect this. Please be sure to kill power to that circuit from the main breaker box in your house while you reattach it.
Secondly, you must deal with any outboard hardware that you might be using in your studio. I have found that if my front-end piece of gear (Drawmer 1960) or (Presonus Digimax) is too close to my mixing board which it is tied into, I will get a ground hum. This is fixed through trial and error by finding the best spot in your rack for your equipment. I did this by having the signal cranked in the studio while moving certain pieces around in the rack while listening to that hum come and go. I finally found the best place for all my equipment. This might seem quite anal, but trust me, it is well worth it.
One last thing is to try and use good quality XLR cable in your studio. Some cables you can get are actually double grounded for almost minimal hum. Sure, it costs a little more, but this is your future dude and dudette! Also use TRS 1/4 cable for studio patching where applicable, this will help with grounding issues also.
Hope this month's column has you playing and singing in absolute hum-less silence.
May the tone be with you.
David Martone is a guitarist from Vancouver, Canada who has released seven solo CDs which showcase his musical diversity and brilliant guitarmanship.
His 2007 CD is entitled "When The Aliens Come", which features a progressive sound incorporating jazz, rock, fusion and metal influences.
