Re: Alumitone Pickup Design Revealed
Posted: Sun Dec 05, 2010 7:59 pm
Thanks Bent.
Are you sure it was 4.97 ohms, not 4970 or 4.97K ohms? As I'm sure you know, regular pickups are anywhere from about 7500 ohms to 17000 ohms or so. Without getting into too much electronics lets say you need something over 1 volt to drive the amp to a reasonable volume. To get that much voltage you need to with that low a resistance(impedance) you would have to either increase the current produced or increase the resistance. This is just your old OHMS LAW (E=IxR) E=voltage, I=current and R=resistance. Actually there are other factors involved when you're working with audio frequencies but in theory anyway it's pretty much the same thing. On a regular pickup the number of turns of wire that interact with the magnet at any given instant will determine the amount of voltage produced, i.e, more turns more voltage. And pickups are basically a "voltage" generator and produce miniscule current. The end result with 4.97 ohms resistance you will have almost no output voltage to feed into the amp. Other than that, no you really can't measure the Peak to Peak AC voltage with the multimeter too well. I have a high quality Fluke electronic meter and it doesn't tell you too much. Of course you'd have to have the pickup on a guitar and strum the strings to have it respond to the string vibration to produce a signal (voltage) anyway since it doesn't do anything just sittin' on the bench. Sorry for the long winded writing. I still say there must be a transformer in there somewhere to increase the voltage. It'd be like an audio transformer with the secondary winding which would have few turns and be connected to the one turn coil, and a primary winding with a lot of turns that would be connected to the output jack and amp. That would increase the voltage available at the output by perhaps a factor of 100 or more.
Are you sure it was 4.97 ohms, not 4970 or 4.97K ohms? As I'm sure you know, regular pickups are anywhere from about 7500 ohms to 17000 ohms or so. Without getting into too much electronics lets say you need something over 1 volt to drive the amp to a reasonable volume. To get that much voltage you need to with that low a resistance(impedance) you would have to either increase the current produced or increase the resistance. This is just your old OHMS LAW (E=IxR) E=voltage, I=current and R=resistance. Actually there are other factors involved when you're working with audio frequencies but in theory anyway it's pretty much the same thing. On a regular pickup the number of turns of wire that interact with the magnet at any given instant will determine the amount of voltage produced, i.e, more turns more voltage. And pickups are basically a "voltage" generator and produce miniscule current. The end result with 4.97 ohms resistance you will have almost no output voltage to feed into the amp. Other than that, no you really can't measure the Peak to Peak AC voltage with the multimeter too well. I have a high quality Fluke electronic meter and it doesn't tell you too much. Of course you'd have to have the pickup on a guitar and strum the strings to have it respond to the string vibration to produce a signal (voltage) anyway since it doesn't do anything just sittin' on the bench. Sorry for the long winded writing. I still say there must be a transformer in there somewhere to increase the voltage. It'd be like an audio transformer with the secondary winding which would have few turns and be connected to the one turn coil, and a primary winding with a lot of turns that would be connected to the output jack and amp. That would increase the voltage available at the output by perhaps a factor of 100 or more.