This is my review of the K & K Sound Ultra Pure Mini acoustic guitar pickups. Over my 2 1/2 years of playing guitar, I have learned one thing. Everything is subjective, to the player and listener. So with that in mind, I will begin.
I wanted to be able to plug in my two Martin guitars. One is 000-15M and the other is an HD28 VTS. I have a less expensive Yamaha FX700-SC which already had a UST (under saddle transducer) and a mounted preamp on the guitar.
There are a great number of options. There are UST's, simple sound hole pickups, clip on pickups, ect. With my Martin Guitars, I really wanted the guitars to look stock as possible, and still be able to just grab the guitar and plug in. That desire narrowed the field considerably.
UST's definitely require a preamp. Which would require cutting into the side of the guitar, and the sound is certainly not as high quality as many other options. I was very impressed with the sound and clarity of the L R Baggs anthem. In my humble opinion, it may be the very best available, at this time. But, it required some modification and you could easily see the sound hole pickup, even though it is more discreetly mounted on the side.
I decided on the K & K Sound Ultra Pure Mini's. This allowed me to mount the pickups inside the guitar discreetly, and I bought the K & K XLR preamp that I could use on both guitars. It was a cost effective system that I do not regret. The drawback to using one preamp for both guitars, is that it does require dialing in the preamp for each guitar, whenever you change. Reallyit is not necessary to have the preamp, especially if you have a powerful amp. But it does add more punch, and really allows you to dial in the nearly exact sound that is emitted from your individual guitar. The XLR preamp also has a phase button that better synchronizes the signal from the guitar to eliminate what I call phase clutter. But that clutter, doesn't always sound bad.
The bottom line here, is that the Ultra Pure Mini's are great. They allowed me to keep my guitars looking stock and replicate the actual sound of the guitar quite well. They are less expensive, and don't really require a preamp.