[sdiy] The annual I/O impedance/protection thread! (revised)

[Neil Johnson]

Hi Harry,

> I just read the draft of your paper. Did you know that this configuration
> (minus the opamp) is common in electric guitar

Yes, I'd heard of something along those lines last weekend, I think
Phil Macphail or Tony Allgood mentioned it.  Although, as you note,
without the op-amp.

The closest I've ever come to a guitar was riding over one on a bike
when I was a kid, so I confess my knowledge of their electrical
properties is rather lacking.  Knowledge of the sound they make whilst
being ridden over by a bike is rather more substantial, based on
first-hand experimental evidence, although that was many, many years
ago.  I hasten to add that no synthesizers were hurt in that
"experiment".  Fans of avant-garde "plinky-plonky" music would
probably enjoy repeating the experiment.

> to avoid the trouble of having the volume control
> of one pickup load (and maybe even short out) another pickup? In this case
> the impedance of the coil is the first resistor, the pot is (uhhh...) the pot, and the 'mix bus'
> is the amplifier input.

Yep :-)

> backward thinking. brilliant !

That's a polite way of putting it!!

;-)

A bit more polishing to do.  I'll add in some reference to guitar
circuits (some googling tonight).

Cheers,
Neil
-- 
http://www.njohnson.co.uk