Gibson Blueshawk

[TinPan]

I never heard of this guitar, but I like the idea of this "dummy coil" and would like to ask "can this dummy coil be implemented in other guitars"? And exactly what is it or how is it made? Mainly a gibson LP with 2 vol split coil pots, in single coil can this method be used to eliminate the single coil hum? Will there be a loss of tone or vol quality?

 

[freefrog]

Re: Gibson Blueshawk

I never heard of this guitar, but I like the idea of this "dummy coil" and would like to ask "can this dummy coil be implemented in other guitars"? And exactly what is it or how is it made? Mainly a gibson LP with 2 vol split coil pots, in single coil can this method be used to eliminate the single coil hum? Will there be a loss of tone or vol quality?

The kind of Dummy coil mounted in a Blueshawk is just a P90 without magnets.
It's mounted in such a way that the dummy coil is "reverse wound" comparatively to the noisy PU's. That's how the hum is cancelled.
Yes, it can be implemented in other guitars. That's exactly what I've put in a Hamer with P90's.
Yest, there's a loss in volume AND tone quality. That's the price to pay for silent operation with dummy coils (except with large "air coils" and dummy coils associated to active circuits).
Technical explanations on request. I lack of time right now.



I've something about the Blueshawk somewhere in my archives. More later maybe.


EDIT - Below is the frequency response of "P90's" with and without the dummy coil in the Blueshawk. This pic comes from a site launched in 2005 but apparently vanished in the air nowadays. If needed, I'll explain in simple terms why the curves look like that.

 

[Mincer]

Re: Gibson Blueshawk

Many Music Man single coil models have a dummy coil that is active. It really works well.

 

[Juanhanglo]

Re: Gibson Blueshawk

Wow.

That's a pretty big drop on the high end.

I wonder how regular vs noiseless p90s look in comparison?

 

[freefrog]

Re: Gibson Blueshawk

Wow.

That's a pretty big drop on the high end.

I wonder how regular vs noiseless p90s look in comparison?

In fact, the pickups in the Blueshawk were not exactly P90's... They were "Blues" PU's, with AlNiCo rods instead of the pole screws. Like Jazzmaster pickups.

It allowed to obtain less inductance and therefore more high frequencies from the pickups alone.

In such a way that the response of the "Blues" bridge pickup in series with the dummy coil, as seen above, is actually close to the frequency response of a "normal" (and noisy) P90. The only big difference is that a P90 alone wouldn't produce a secondary peak beyond 10khz.

IOW: the "Blues" pickups have been voiced with more treble than regular P90's, in order to sound close to real P90's once associated to the dummy coil...

Anecdotically, it's not rare to see a dual resonant peak in the spectrum of "noiseless" PU's. it's even difficult to avoid this side effect due to the presence of two coils in series.