K&K Sound Pure Pickup Acoustic Guitar Pickup for Steel or Nylon String (Classical) Guitar

PURE Pickups
for Acoustic Guitars (steel-string and classical guitar versions available)

This specialized, easy to install transducer (pickup) system does not sound as harsh and is less percussive than saddle transducers! By positioning transducers directly beneath the bridge inside the guitar body, high signal-to-noise ratio and high gain-before-feedback can be achieved. In addition, the guitar top plays a more important role than with saddle transducers, yielding a warmer, more microphone-like tone. The Pure 12-string (shown at left), for steel string guitar, has three transducers, as does the Pure Mini. The Pure Classic, for classical guitar, has four transducers to allow for its different bracing pattern. A two transducer Pure Bass/Tenor Guitar version is also available.

The Classic model is shown in the illustration below, which demonstrates where the transducers are located. Installation is far easier and precise positioning is less critical than with the typical undersaddle transducer. Special tape is included to apply to your precious guitar's soundboard, so you don't need to superglue the transducers directly to the wood - removal is easier and the installation is non-destructive. The special tape and a tube of Super Glue are included, and the transducers are prewired to a high quality endpin jack K&K Sound, manufacturer of the Pure Guitar system names the following ADVANTAGES of the PURE GUITAR's transducers and mounting system:

The special PURE surface transducers DO transmit a significant portion of the soundboard because they are not as close to the strings as an undersaddle pickup. Each of the 3 or 4 transducers is designed to pick up a specific string pair, but also “listens” to the adjacent area around the bridge.
The PURE pickups are not under pressure and therefore do NOT sound percussive or harsh.
The PURE system reproduces all strings nicely balanced, a known problem with undersaddle pickups.
The PURE system sounds great just in passive mode! Unlike undersaddle pickups which passively sound thin and treble-only, the passive PURE system puts out a nicely balanced, warm, full range signal.
How safe is the PURE GUITAR System with feedback? Due to PURE GUITAR’s location on the bridge plate under the bridge, feedback resistance is comparable to undersaddle transducers. Technically, a pickup installed in or on the bridge is a lot less likely to feedback than one which is attached to the open sound board. The 1/8” thin sound board can act like a diaphragm and vibrate along with loud sound-signals from speaker cabinets. This is the kind of feedback you experience on an acoustic guitar. The thicker bridge area is a lot harder to be set into vibration from an outside source simply because of its mass.
In K&K Sound's tests with both steel string and classic guitars equipped with an undersaddle pickup plus the PURE system, they were able to achieve about the same gain-before-feedback with both systems.
Disadvantages of undersaddle transducers:
Hard, percussive tone, because the piezo transducers are under high pressure.
They picks up mostly string and finger sounds, and capture very little from the guitar's soundboard, so crucial in reproducing your guitar's true voice.
There is always the chance of unbalanced volumes, with individual strings louder or softer than others. Trying the equalize loudness can result in a very work intensive balancing procedure.
Needs special preamp to compensate for the hard sound.

Of course, every manufacturer swears that his undersaddle transducer is far better than anything else. Let’s face it, as long as the pickup is in the undersaddle position, they have to deal with the above mentioned characteristics.

Do you need the Mini or 12-String Guitar model??

The Pure Pickup is the transducer network designed to be placed on the inside of your guitar. For ease of installation, K&K Sound now recommends the "Pure Mini" as the pickup of choice for most common 6-string guitars; its smaller transducers fit more easily on the majority of guitars, yet still produce a full-bodied sound. However, the Pure 12-String's larger pickup heads produce an extra strong bass response and pronounced midrange, which might be of interest to some players. While this bass and midrange response is too strong for many guitars, especially very resonant ones, it sounds great in 12-string guitars and is a good alternative for guitars with heavy spruce tops and maple bridge plates.

So it's your choice. But you should note that in some instances, bridge designs are not wide enough to accommodate the larger transducers without touching. 

To aid you in determining if the 12-String transducers are appropriate for your guitar, here is a diagram of the PURE 12-String pickup in original size:



Total: 22mm (height) x 61mm (length). You can print it out and cut along the outer edges of the left and right pickups and along the dotted line so you end up with all three pickups on ONE piece of paper. Use the "mirror method" described in the manual (downloadable from link above) to visually check the fit.

Make sure you take about 1/8" (about 3mm) space for the ballends in consideration.

If the diagram overlaps on the soundhole side of the bridgeplate by not more than 1/8" max.(about 3mm) it is no problem. If it overlaps more please order the Pure Mini with 1/2" diameter transducers.

This does not apply to the Classical Guitar systems, which have four rather small transducers.