A while ago I found this very interesting article by Dirk Wacker in Premier Guitar:
https://www.premierguitar.com/diy/mod-garage/fender-s-1-switch-wiringI tried this with a guitar that has HSS pickup routes. For experimentation purposes I set it up so that in position 1 of the 5-way switch, only the humbucker was active, and in all other positions it was split. I also set it up so that in positions 2, 3 and 4 it was a direct coil split (i.e. the junction between the two coils goes directly to ground), and in position 5 the junction goes
a) through a 0.047uf cap
b) in a second step through a 0.1uf cap in series with a 1.5k resistor
to ground. The goal was that I could directly switch between the "true" coil split and the modified coil split for a direct comparison.
The results:
- Effect on the noise floor (tested in a high gain setting)
In some positions (me vs. the amp) the 50hz hum (I am in Europe) was eliminated, in other positions it did not seem to matter much, and again in one position it made the hum worse. The 100hz hum that is usually also present was not affected by the 0.1uf/1k5 ohms and a tiny bit by the 0.047uf. This was with both the neon lamp turned on and turned off. With the neon lamp turned on, the buzz generally increased and was not affected at all by either the 0.047uf or the 0.1uf/1k5 ohms.
- Effect on the tone
The 0.047uf added a considerable amount of bass. I expected this as with the cap, the coil is not shunted but its resonant peak is lowered to a low frequency, i.e. at low frequencies both coils are active - that is what should get you the humcancelling effect. The cap also seemed to mask the high frequency content to some extent. The 0.1uf/1k5 added less bass and less of the masking effect. I am not sure whether this is due to the cap being bigger, the resistor or a combination of both. Whatever - tonally I prefer this to the 0.047uf.
Summary
I did this experiment to decide whether I should do this to the Bluesbucker in my HSH guitar to optimize the hum resistance in the single coil mode. By way of this experiment I found that it did not help nearly enough to cut hum and buzz, and while the added bass may be welcome on a bridge pickup, in the neck position of any guitar, the last thing I want is more bass. So - no, I am not going to put in the effort of removing the pickguard. YMMW of course.
Cheers Stephan
