[Harp-L] Re: Volume Controls and Tone

[Greg Heumann <greg@xxxxxxxxxxx>]

I'd like to clarify some points about volume controls and tone. Do  
volume controls affect tone? Yes - in both good and bad ways. A  
properly set up volume control has minimal effect on tone and most  
players feel the benefits far outweigh the disadvantages. HOWEVER,  
anything and everything you connect your element to, INCLUDING YOUR  
AMP, affect its tone.

All elements are effectively generators. Moving air induces a tiny  
electrical current, either by flexing a crystal (this is called the  
piezo-electric effect) or by moving a magnet through a coil of wire,  
just like you did in high school science class.  A generator not  
connected to anything spins freely - but if it is connected to a  
load, like a lightbulb, it takes some muscle turn the generator. In  
effect, the load "pushes back" on the generator. Microphone elements  
are the same. The bigger the load (which in our case means the lower  
the impedance), the more "pushback" there is on the element, which  
affects both its output and its tone. However microphone designers  
knew this and their elements were designed to function properly so  
long as they were connected to the load (impedance) they were  
designed for.

Here is a good time to point out that crystal and ceramic elements  
are considerably more sensitive to the impedance of the circuit  
they're connected to than magnetic-type elements like the Shure  
controlled reluctant and controlled magnetic elements so many harp  
players like. This is why some of the custom harp amp builders like  
Sonny Jr. include a 5 megohm input on their amps. That's right - the  
amp itself places a load on your mic. So your amp affects your mic's  
tone. Deal with it. So does any effect you use like a foot pedal, or  
a volume control. So it is important that a volume control is  
"matched" to the characteristics of the element. The "right" load for  
a magnetic element is not the same as the right one for a crystal.

Although I've always recommended to my customers that they set their  
system up so that they can solo with their control at full volume,  
another post and some recent personal experience suggested an  
alternative to this. When you want to be able to turn your amp up  
louder to affect ITS tone,  you can reduce the output of the mic with  
a volume control. (Note that microphones'  output is considerably  
greater than that of a guitar.) I recently got to play through Andy  
Just's rig - a Super Reverb with an effects box up front. Andy sets  
it up so that you can't get to full volume on the control without  
feedback, allowing him to set the amp up very hot. In the case of  
that system, I can't argue with the results - the sound was  
tremendous. My point is, a volume control gives you one more variable  
to trade against the others in search of the tone you want.

In the end, it is a personal choice. Ain't that great?

/Greg
http://www.blowsmeaway.com