magnetic pickup in series with piezo active

[Guitarist]

Just an idea, do you think this could work well to capture the better aspects of both? I siliconed a old humbucker underneath my dreadnaught soundboard and thought this could be an easy tweak while using just one buffer/preamp.

[David Schwab]

They would have to be wired in parallel. A piezo is not a coil, so you can't run it in series.

I have seen preamps in series with pickup coils however... I think G&L had some kind of setup like that.

[Guitarist]

thanks again! too bad they can't be run in series because in II the active piezo is way louder than the humbucker. I also know this from my Godin.
Man, wiring acoustics is a pain isn't it?

I keep thinking about that piezo wire..

[rocket]

Actuall I think it is possible to wire them in series.
The humbucker might work only when the active circuit is on, depending how the circuit looks like.

The active circuit is just a voltage source in series with a resistor (impedance), and the humbucker is the same. If the impedances of either are smaller than the impedance/resistance you connect them to it might work well.

However like always with PUs in series, only one may be connected to ground!

Connecting them in series might work well if the 2 PUs are equally "loud" if they are connected seperatly and if the difference in signal strength comes mostly from the active PU loading the humbucker with a low impedanc (which it surely has) .

If the active PU is louder anyway, you can't change that with wiring the PUs in series. But maybe it gets a little better.

The humbucker wants to be connected to a rather high impedace (100s of kOhm) and will not perform well into a very low impedance of some kOhms, as an active pu will have.


oh I am afraid that this is not very clear but I am rather tired now and may try again tomorrow.

[David Schwab]

thanks again! too bad they can't be run in series because in II the active piezo is way louder than the humbucker. I also know this from my Godin.
Man, wiring acoustics is a pain isn't it?

I keep thinking about that piezo wire..

Part of the reason is your magnetic pickup is too far from the strings... but just do this, make a JFET buffer, and wire it up like a mixer. This was you can mix the output of the two pickups and get a nice balance.

There are a lot of FET mixer circuits on the 'net... you just need to use high value resistors for the trim pots to stop from loading the pickups.

Alternately you can add a buffer amp to the magnetic pickup to boost its volume.

[Guitarist]

OK that's good advice. I have a J201, and the tubefreak recommended BF2345 or whatever it was. I was just trying to clever and lazy at the same time by going putting the piezo into the mag in series to get them both buffered and I figured that the resistance of the humbucker being 12K wouldn't make a big difference subbed into the signal path prior to the Powerjack style preampbuffer.

But piezos, if I recall, have infinite resistance or something insoluable that may make this impossible.

I saw a $80 triple mixing preamp and complete setup on eBay so if I wasn't so triggerhappy with the soldering iron and learned from the lessons of specialty offered by Econmics 201 I'd go that way.