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Posted: 5 Aug 2018 3:59 pm
by Jon Light
A dedicated power supply. Not a standard 9V and not DC.
Dimmer switches hum solutions?
Posted: 5 Aug 2018 6:28 pm
by George Kimery
No battery. Uses an odd 7.5 volt power supply. It's sort of like carrying pepper spray. You feel more secure having it but hope you never have to use it.
Re: Dimmer switches hum solutions?
Posted: 6 Aug 2018 7:37 am
by Chris Walke
George Kimery wrote:No battery. Uses an odd 7.5 volt power supply. It's sort of like carrying pepper spray. You feel more secure having it but hope you never have to use it.
Exactly. I always have it with me, find out during set up if it's needed.
My Solution For Hum
Posted: 6 Aug 2018 6:14 pm
by Robert Leaman
Many, many years ago AC powered, small 5-tube radios were sold in United States. These units had one side of the incoming AC line connected to the radio chassis. Now, if one was unfortunate enough to have the hot side on the chassis, there was a severe chance of shock. A local radio repair shop showed me how to avoid this hazard when servicing these death traps. He sold me a Triad isolation transformer! This solved the problem for me in several ways. During my career as an electrical engineer, I diagnosed problems in industrial electric motor controllers. Usually an oscilloscope was necessary but when connected to high voltage equipment, the scope power transformer had insufficient voltage standoff and insulation abilities. An isolation transformer was always the answer.
What has this to do with steel guitars? Over the years, I played in many places with questionable, bad AC power wiring supplies. Many times the sound man had equipment he didn't understand well and used lots of curious hookups for his power needs. Any attempt to connect to this unknown death trap usually produced a large hum or a large electrical shock. Remember that you can never tell a sound man anything that he doesn't know about sound equipment. In every case, my Triad isolation transformer solved the problem. Primary to secondary isolation is rated at 3000 volts. The secondary is isolated from the primary with copper foil ( the foil can be connected to earth ground). Output voltage is whatever is the input voltage (115VAC to 130VAC). The transformer is rated at 350VA and powers my Nashville 1000 just fine. However, this is NOT a light piece of equipment.