Stop using the commonly included piezo undersaddle bridge pickup. Kill the quack.

Replace it with an LR Baggs I-Beam pickup, for about a hundred dollars US, most times can be connected to the existing built in preamp box.

That's the first step.

As for your examples cited, the one you posted certainly has a bit of phase shifter in it, what kind and its settings is the unknown here, could be anything from a stompbox to one of those Acoustic Guitar Amplifiers with built in effects and multiple speakers ala the Fender Acoustics.

Steve Stills, the live version came up first on youtube for me, that is almost certainly a very good /D-45 with a Baggs I-Beam or similar pickup in it. No phase shift that I could hear, at least not from electronics, just a doggone good sound system and engineer.

The venrable old Yamaha AG Stomp pedal with the Baggs pickup might prove to be a satisfying combination for you, not only for recording, but for reproducing the sound you recorded in live performance easily.


--Mac