I've been using this for about a week now. I was not very impressed with the sound quality of the pickup, my guitar is an Alhambra 10Fc Left handed. I could instantly hear the mid highs are not captured well, and mid lows and lows are exaggerated. Which means the balance is quiet poor. However, you can end up with the sound you like/want if you know how to use your preamp well. I tried running it through my UAD Apollo Twin, I had these plugins in the chain: UA 610-B, had to add about 9db of 10k to start with, then Helios 69L with lots of top end too, a compressor and a reverb at the end. I'm very happy with the sound I ended up with, so I plan initially to take my Apolo with my mac on stage and see how this goes. The reason I'm rating this 3 stars is because, no one has to go through this to get a good quality sound of such pickup. I'm lucky i know few things about interfaces and plugins, I know how to EQ or compress etc., But what will a performer who doesn't really have to know these things will do? Not very intuitive. I was hoping it gives a clean good quality out of the box, don't think that's much to ask. You will laugh at the amount of top end I had to add via EQ plugins so that it sounds close to the actual guitar sound.

It doesn't make sense to spend $100 or $200 to add a pick up to your classical guitar unless you have a very nice classical guitar. This is a fantastic option for those of us that do not have a high-end guitar.
The installation instructions tell you to loosen the strings and then slide the pick up under the tied strings on your saddle. I would strongly recommend waiting until you change the strings to do the installation. It would go much easier if you had lots of extra string to play with vs. just loosening all the strings from the tuning pegs.

The sound is good just make sure you are not near the amp because it will cause feed back.

As others have noted, the sound is a product of whatever input or sound equalizing system you may have. I only rate it 4 of 5 stars for the reason that there's no way to control tone or volume. The device was easy to set up on the back of my classical guitar bridge. If you take care plugging/unplugging the cable, you won't have any problems. I plug mine into a Roland Cube and it sounds fine. I love having the ability to amplify my sound at a reasonable price.

It works well -- good reliable piezo amplified sound. The only problem is, it does alter the sound of my unamplified guitar: I suffer from a cut in volume, mostly, but also depth and resonance. But, this is unavoidable, and KNA's pickup is a much better amplification solution than an acoustic-electric nylon string with a cutaway, or worse: permanently installing an under-the-saddle pickup along with drilling a cord hole in the back of your guitar -- this will damage your acoustics much more than KNA's tied-on pickup. The most transparent way to amplify a classical guitar is with a microphone mounted on a tripod suspended in the air. But if this is not possible then KNA's bridge-mounted (not saddle-mounted) piezo pickup does the job.

Wow, very impressive! Normally I use an external mic for recording because I have tried all the stick-on and clip-on mics and never liked the sound. But, external mics pickup too much to use live, I have needed a way to mic my flamenco guitars for live performance for a long time also...this solves both problems. I will buy 1 for all my guitars...Very happy! At first it was muddy but strong so I knew I could tweek it, I use a pre-amp, compressor and EQ. After turning everything down considerably, (this thing is very responsive) I was able to dial in the lush beautiful natural sound of the instrument. Paul Garlits 1000psi