Piezo guitar test using audio transformer.
Using an LT44 is sometimes seen in scientific piezo circuits, so I put it on test.
We can use an audio transformer LT44 (£4 on eBay) to change the impedance of the piezo from 'high-ish' to medium.
The results were noticeably better than direct - a little more bass, but still a bit tinny, and NOT as good as the active preamp.
Note: This needs to be plugged into a mic input, not line in.
My verdict: it did not acheive a high enough impedance to acheive good results, don't bother, use a preamp.