[Skibumdog]

:shock:
I recently bought a used Dobrolectric at a local shop

It is basically a thin line tele with a biscuit cone and a p90 pickup at the neck position and some kind of Piezzo type pickup on the bridge.

there are 3 knobs on the guitar body.

The top one, closest to upper bout, is the volume control

the middle one is some kind of tone control, but with a push-pull feature on the switch. It changes the tone, but I'm not sure how it does this

The third knob seems to blend the pickups, but if you try to put all Piezzo, you wash out and get nothing.

So.....

Dobro/Gibson experts, what exactly does the push/pull function of middle knob do

And

Why don't I get all accoustic pickup when I roll the third knob away from
the p90 postion and all the way back to the Piezzo position?????

Thanking everyone in advance
Skibumdog