I want to build a guitar with a Piezo and Mag, I want to have a volume control for each, but I want to add a blend pot in between, so that I can control the percentage of each pick up with the blend pot.
I do not want a 3 way switch, I want blend pot!
It can be done, I have an old factory built guitar, that works just like this, but have no access to the wiring to copy it!
Anyone help please?
Replies
http://www.stewmac.com/How-To/Online_Resources/Pickups_and_Electron...
I have used the top diagram several times.
The best way is to use a diode on each of the volume pots - they act as a one way "valve" for the electric signal so if you put one on the hot output lug of a pot (usually the middle lug) the pot only affects the signal before the diode (ie the pickup going to that volume pot).
This would mean you don't need the blend pot. From personal use I find mixing a magnetic and piezo with a blend pot isn't as good because it gives you a fixed ratio - as mag signal decreases piezo signal increases and vice versa. The magnetic signal tends to be greater than the piezo so the blend doesn't give you the big range in sound you expect.
Blending with two volumes with diodes gives you full independent control of each pickup signal rather than the blend pot fixed ratio.
This is where I found the original idea for using diodes
http://www.strat-talk.com/forum/stratocaster-discussion-forum/13405... check the video for use on a strat to get an idea of what it can do.
I use the 1N5819 diodes because it can handle a higher voltage (which a piezo if hit hard could theoretically put out)
http://www.strat-talk.com/forum/attachments/stratocaster-discussion...
If you get as far as the link to the wiring diagrams on page 2 note I use the middle lug for the hot output not the end one and also I don't bother with the treble bleed across the pot lugs either (the cap and resistor across each pot - this is so you get a better sound at low volumes and isn't related to the diodes).
Diodes cost pennies or 50 diodes for £1 off eBay last time I looked. If you decide to use diodes be aware that they have to go in the circuit the right way around - shaded white/gray end towards the common output and unshaded black end towards the potentiometer. You can add then anywhere from the potentiometer lug to the common live output lug of the jack, or splice one into the wire between the pots and jack.