Humbucker series/single-coil switching - volume balance (a solution)

[ikay]

Just posting this in case it's of interest to anyone.

[b]Problem [/b]- there's a big jump in volume when switching a humbucker from series to single-coil - a potentially useful tone option rendered pretty much unusable by the big difference in output.

[b]Desired outcome[/b] - to seamlessly switch from the girth and grunt of series to the clarity and punch of single-coil without a jump in volume.

[b]Solution[/b] - add a preset resistor to attenuate the output of the series setting down to a comparable level to the single-coil.

Sounds pretty straightforward but I googled high and low to try and find advice on how to do something like this and couldn't find anything.

Took a bit of experimenting with various switch/preset configurations but I've just done this on one of my basses and it works a treat. The difference in character between series and single-coil adds a whole new dimension which is only fully realised when the outputs are at comparable levels.

Switching diagram attached below along with pic of the installed switch.

Uses a standard DPDT two-way on-on switch and a 500k miniature preset which piggy backs on top of the switch. Bit of a fiddly soldering job but neat and compact.

This is for a single humbucker. I've set the series/single-coil balance to just slightly favour the series setting. The great thing is that it gives you the control to set the balance as you want it.

Someone with a better understanding of electronics juju than me (not hard!) may be able to suggest improvements (such as an optimum value for the preset) or an alternative method.

But this works so I thought it was worth posting!

[attachment=98274:Humbucker series-SC switching with volume preset for series setting.jpg]
[attachment=98275:P1040183.jpg]

Edited January 27, 2012 by ikay

[FlatEric]

Mmmmmmmmmmmm!!

Interesting.

What Humbucker and has it lost any of it's original punch??

Cheers.

[ikay]

[quote name='FlatEric' timestamp='1327668958' post='1515057']
What Humbucker and has it lost any of it's original punch??
[/quote]

ACG/Armstrong humbucker and no discernible change in original power and punch

[skelf]

Excellent. I will have to give this a try.

Alan

[LawrenceH]

Ha this made me chuckle as over the last couple of days I have been pondering exactly the same thing in relation to series/parallel switching. Useful post, cheers!

[ikay]

[quote name='LawrenceH' timestamp='1327672356' post='1515145']
Ha this made me chuckle as over the last couple of days I have been pondering exactly the same thing in relation to series/parallel switching. Useful post, cheers!
[/quote]

Series/parallel is a bit trickier as both coils are being used so it's more difficult to isolate the attenuating preset to the series setting alone.

With series/SC you can neatly bypass the preset in the SC setting (in the 'down' position the switch shuts off one of the coils and also bypasses the preset).

I went through various other switching possibilities and came to the conclusion that the only way to isolate some of the settings was with a multi-way 4-pole rotary switch.

In the end I went for the series/SC setup as this gives you both ends of the tonal spectrum (thick and beefy / clear and punchy). In comparison I found the parallel setting was somewhere in the middle, neither one nor the other, so dropped it to keep things simple.

[Kiwi]

I just tend to use parallel; no volume differences then plus parallel is used in Smith basses so I get a nice funky sound.

Nice mod for MM SR5 HS owners though! Thanks for sharing.

[ikay]

Haha, yes using parallel instead of series is an even easier way to solve the volume balance problem! Series does sound a bit meatier than parallel though. I guess some of it depends on the bass. Series/SC works really well with my ACG but I rarely stray from the parallel setting on my Stingray!