Re: Sustainer Update+ NEW approach

[SoundFNR@aol.com]

In a message dated 09/06/97  11:55:03, you write:

<< I've just been talking with Kent Armstrong, who recons a low-Z pickup
could
 be built for about #50 ($70-ish).  How could I refuse?
 
 Problem is, this needs to be done right, so I'm asking everybody for
 suggestions on this... any idea what's required?  I'm just going for a lot
 of bigger-gauge turns - we'll have no idea of the impedance 'till it's
 built - but does anybody have any ideas of the impedance of the Fernandez
 neck pickup?  Or the current flowing into it, at least? (You guys with 
Fer.
 guitars could measure this by checking the draw from the batteries)
 
 I'm guessing (literally!!!) that I'll need a Z of about 100ohm, producing 
a
 current of about 100mA - a total draw of about 1 Watt.   Is that OK or a
 bit too extreme?  Is 10ma sufficient (I'm guessing it probably isn't)? 
 Opinions, _please_!! >>

I think it also depends on the efficiency of the p/u.
As the standard p/u is optimised for a linear response to the movement
of the string the magnetic field isn't be as focused as it could be.
A coil to drive a string could be arranged so that most of the magnetic
flux lines went through the resting position of the string, meaning you'd 
get more push for your watts.

BUT today's big idea.
If you've got a strat. type bridge all you have to do is slide a 
piezo transducer under the bridge saddles, readjust action accordingly,
send your signal to the piezo and surely something will happen.

Piezo transducers can be salvaged from those wristwatches that bleep,
or purchased from electronic component suppliers.

In UK  Maplin (mail order catalogue) has a number of options,
thin brass discs with a layer of piezo-crystal topped by a silvered
"electrode"
price about 50p.  I reckon they can be cut to shape if necessary.
"They can be driven direct from CMOS ICs with low power consumption" 
-Maplin
Input :- 3V suggested     15 or 30V max.


The only doubt I have about this approach is that  it 
would energise the strings to vibrate towards + away from the fretboard,
which isn't ideal as the p/us mainly pick up string motion at right angles 
to
this.

(my guitar has the wrong sort of bridge though)
   
                                 Andy UK

........And you'd have to make sure the bridge didn't short out the piezo.