Reverse winding in a pickup is one that has been wound in reverse, but what difference does this even make? Well, not a single difference if you are just comparing a single pickup to another, but when combined with an opposite-wound pickup, the magic happens. It's not really a change in tone, per se, but it can greatly improve its quality so it's definitely something guitarists should know about.
This is essentially the same principle that is applied to humbuckers; get two single coil pickups wound in opposing directions and install them in a certain way – which I will explain in a less cramped sentence – and not only do you get a nice midrange tone boost but more importantly the effect of cancelling the hum!
What many don’t realize about humbuckers is that their two pickups don’t actually have to be placed next to each other in order for the humbucking benefits to take place. As long as the signals from a normal wound and a reverse wound pickup eventually combine, such as when selecting both the neck and bridge pickup during play, the humbucking effect can be achieved – assuming that the bridge and neck pickups are wound in reverse of each other, got it? Good!
Although those of you out there with guitars equipped with humbucking pickups might not get much out of this information, players who gravitate more towards single coil variety such as the Telecaster or Stratocaster can use this mod to equip their instrument with a good degree of hum cancelling without having to sacrifice their axe’s signature tone.
For comparative purposes, pickups with reverse winding and polarity of another pickup are known as RWRP, or Reverse-Wound Reverse-Polarity, although since both essentially sound the same when used on their own there is no universal designation of a standard RWRP pickup and is only used as a term of comparison.
For those Telecaster players who just don’t want to sacrifice the signature twang of their guitar but would like to get rid of the hum, make one of its two pickups RWRP. When both are selected with the knobs, the hum cancelling effect will applied. If you have a Stratocaster, place the RWRP pickup in the middle position so that when combined with either the bridge or neck pickup, humbucking will be achieved.