Turtlerock Forum

I use a G&L 2500 guitar and I have had it for 10 years. It has 2 x humbucker pickups. I have just realised one of the switches was to turn the bass from series to parallel.
What does this mean and what does it do?
Cheers

HA_DA_JA wrote:I use a G&L 2500 guitar and I have had it for 10 years. It has 2 x humbucker pickups. I have just realised one of the switches was to turn the bass from series to parallel.
What does this mean and what does it do?
Cheers

Dale, essentially you are mixing the signal of one pickup with the signal of another pickup (which I am presuming is how they are using it on your bass gtr).. like using a buss or FX send/return on a desk..
although with your bass you might be mixing the original pickup signal with the signal that passes through the preamp/EQ stage..
HTH.
Tim..

nah

humbuckers with a series / parallel switch take the two separate coils of the pickup and either connect them in series or parallel
in parallel : you get the humbucking benefit of rejection of mains radiation (hum) and a lower drive (output) impedance, meaning the tone is less affected by cable lengths and amp input characteristics ( impedance )
in series : you get a hotter output level and no hum rejection and a higher drive impedance

R

So Rob what you are saying is that I could be leaving myself open for noise/hum if I run it in series from the hotter output?
I think this is giving me a hum come to think of it. Is there anything I can do about that as it only happens when I switch it in series or is that the bad you get with the hotter signal?
Cheers
DAle

I have a two humbucker guitar that I've modded similarly, and I have a different take from TimS.

To begin, a humbucker pickup by definition has 2 coils inside it, yes? That's how it bucks the hum. Call 'em coil A and coil B. Good humbuckers (mine are Seymour Duncans to replace the bodgy ones that came from the factory) give you access wires to the start and end of both coils (together with a ground wire and maybe a earth wire as well). Now normally the two coils are wired in series - the end of coil A is wired to the start of coil B. This is all within the one humbucker, right? However, you can wire them in parallel, where the starts of both coils A and B are wried together, as are the two ends. The (normal) series wiring produces a hotter tone, the parallel wiring produces a more mellow tone.

Another humbucker mod is simply to short out coil B, making the humbucker have the bell-like single coil sound.

So my factory axe came with the standard bodgy humbuckers, a volume pot, a tone pot, and a 3 way selector switch to select neck, both, or bridge pickups.

I upgraded the neck humbucker to a Seymour Duncan Jazz, and changed the volume knob to a push/pull switch version that allows me to switch that front pickup from single coil to humbucking. I can now do solos ranging from Mark Knopfler to Jimi Hendrix. The bridge pickup I upgraded to a SD Distortion, and again changed the tone knob to a switched version that changes the bridge pickup from series to parallel. The Distortion has high output for a pickup, so the slight drop in volume when using parallel is not critical.

I can still select select neck, both, or bridge - that's unchanged. Its more the tones that I can get out of each pickups that is affected by the switches.

For more info, see http://www.guitarnuts.com/wiring/sw3.php

Dale, there is no free lunch.....hotter output or humbucking
and as Chris points out there is the third possibility of connecting just one coil only. This will give you less output than the series connection and still no humbucking

Rob

Ok, I wasnt even thinking about splitting coils - good points guys.. I went and had a look at the guitar on the G&L site - I wasnt familiar with it..
I just thought that it might be mixing the HB signal with the preamp/EQ signal of the onboard preamp..
Plenty of options by the looks of things..

BTW I have owned many Warwick, Fenders, Lakland, G&L and other basses but I ordered this G&L 2500 direct from the factory in USA in 1998.
I have always played it put it away again for a few years got it out again and loved it played and then put it back for a few more years.
I could never bring myself to sell this one as I always love its big sound and a wide palette of sounds it has. IT just weighs so much but it has an awesome tone and feel.
Thanks guys for all your answers I think I am a lot clearer on the picture now.
Cheers