K & K Sound Systems Pure Macaferri

It is a passive, dual transducer, piezo-electric pickup, with stereo endpin jack. This is apparently a low(er) impedance pickup system, relative to some other models offered by other manufacturers.

I installed it in a Gitane D-500 "D" Selmer-Maccaferri style guitar, with modest previous guitar/electronic installation experience. I drilled the endpin hole through the endblock and superglued the transducers per the instructions (inside the top, below the ends of the moustache bridge). It took some rehearsal for the glue and endpin procedures, including devising an endpin holder by taping chopsticks together.

I bought this guitar to play brazilian and acoustic jazz with my fingers. I realize that I cannot own this guitar and not attempt the Django vibrato, and some gypsy elements that require picking, but I mainly back up a vocalist.
I use a Phil Jones Briefcase amplifier, designed for acoustic bass, which has a nice parametric e.q. and a switch for either passive or active pickups. The sound plugged in direct was very full, and sounded just like the acoustic sound. It could not be turned up without feedback, so I tried a Baggs Gigpro with the polarity switch reversed. It worked wonders. The greatest thing about this pickup is that the amplifier and e.q. settings needed to be flat for the most natural sound. It needed no boosts of any kind.
The company suggests that for the best sound and less feedback, using their Pure Preamp. They state that an impedance mismatch may be the culprit with some feedback problems, and since their pickups donot have as high an impedance as others, this may be the cause. Only time and my next gig will tell.

I read such great reviews of the products on this website, and had heard that a great local luthier in St. Louis loves them (Tom Bills), that I did not need to look further for a great pickup system.
I have been playing guitar for 29 years, have played archtop guitars almost exclusively, and only use amplifiers that are made for acoustic instruments (Phil Jones Briefcase, and Acoustic Image Contra). This was the first acoustic instrument that I've owned that I needed to amplify, and I am thoroughly impressed with this system.