I tried several kinds of contact pickups for my classical guitar and this one is the best solution. The DiMarzio is simple and no drilling holes or fiddling about with the kind of pickups that fit under the strings on the bridge is needed.
You will need to find the best spot to attach the pickup, which is usually found behind the bridge. I find I get the best sound balance behind the centre of the bridge but this varies depending on the guitar. A small amount of putty is used to stick the flat contact side of the pickup to the guitar. This should not be harmful to the varnish or finish and any residue can easily be removed with a guitar cloth. I was surprised to read in the little manual that you might use lighter fuel for this! You would not want to do that. It is not necessary and there is no way I would use a solvent on my beautiful hand-made classical guitar. You want to make sure that you use about four very tiny pieces of putty for the adhesive (supplied with the pickup). The pickup does not actually touch the wood but is very close to it. If one side of the metal touches the wood you might get problems with vibrational noise so do this carefully. A small clip is provided so you can tuck the cable out of the way but you really need to have a guitar that has a strap pin. Mine does not have a strap pin but I find it is easy to simply trail the cable over my right leg. Not a problem.
The sound and quality is good and much better than other pickups I have tried. It will not change the sound of the guitar if you use an acoustic amplifier (I use a Roland). The downside is that these kind of pickups are quiet but I do not find this a problem, as there is a volume control on my amplifier. One thing to bear in mind is that this kind of pickup is not suitable for recording. If you want to record the guitar then use a dynamic microphone in a nest as usual. Also it is worth mentioning that I sometimes use a standard Sure SM58 unidirectional stage microphone on a stand and point that about 6 to 10 inches away from the bridge. Surprisingly, the sound quality and volume is superior to any contact pickup! The pickup solution is when you do not want to be bothered setting up a microphone stand and angling it if you are performing for example. In many ways though I find that when performing, the microphone on a stand is simple and very reliable. Also the microphone cable is shielded whereas the pickup cables are not, so if you bang them around you will get noise.
