Wiring help

andyg_prs

Hi,

I have a guy routing my guitar (Vigier Ultrablues) to install a humbucker in the neck position of my guitar - actually a single coil sized stacked humbucker - deeper than the existing single coil, hence the routing. The guitar is currently SSH and the pickups are direct mounted...no scratchplate / cavity hence the routing necessity. So, I'll end up with HSH.

He'll do the wiring (actually his dad)....but I don't want to take any chances (I know the guy is great at his woodwork - he builds classical guitars from scratch, I have no idea of his dad's capabilities) hence this query.....

The pickups are actually all Dimarzio.

I'm looking for a single coil-like option for the new pickup - and will supply a push push pot (I don't like push pull for live work) to coil tap. But in reality I don't know if a coil split (tap) or the two coils in parallel are going to give me the effect I'm looking for. Hopefully I'm not confused and normal HB wiring is the coils in series.

So I was thinking, there must be a way to have a simple switch tucked away in the control cavity that sits between the new HB and the DPDT switch on the pot. And I'm hoping there is a way to wire that switch such that the push/push pot/switch will either go from full humbucker to coil split or to coils in parallel.

Does that make sense?

If so, does and clever and kind person have a wiring diagram / illustration they could provide?

I'm only looking to do this for the neck stacked humbucker, not the bridge.

Apologies if this is unclear.

Thanks,
Andy

Winny_Pooh

Stacked singles will be quite weak split or in parallel (sounds better though). Not worth the bother IMO. You could try a partial split with a 5-8k resistor which rolls off one coil to ground and you can do it with a 5 way superswitch or push pull. If you search "PRS coil split" you will find wiring for a partial split on a push/pull tone pot (although the resistor value they use is too low).

andyg_prs

Winny_Pooh said:

Stacked singles will be quite weak split or in parallel (sounds better though). Not worth the bother IMO. You could try a partial split with a 5-8k resistor which rolls off one coil to ground and you can do it with a 5 way superswitch or push pull. If you search "PRS coil split" you will find wiring for a partial split on a push/pull tone pot (although the resistor value they use is too low).

I was going to try the split / parallel first as supposedly this pick up splits 'well'.  But, yes, I have done the partial split myself before and that was my back up.

My OCD demands I work out how to wire my first option though

ICBM

Actually a stacked humbucker which is normally series will be *louder* than the full stack when split. Confused...?

It's because in order to cancel hum, the two coils are out of phase, and rely on the lower coil being much less sensitive in order to not cancel much of the string signal - but some still is. So bypassing the lower coil actually makes the upper coil louder.

ie, you want parallel, which also has the benefit of remaining hum-cancelling.

andyg_prs

ICBM said:

Actually a stacked humbucker which is normally series will be *louder* than the full stack when split. Confused...?

It's because in order to cancel hum, the two coils are out of phase, and rely on the lower coil being much less sensitive in order to not cancel much of the string signal - but some still is. So bypassing the lower coil actually makes the upper coil louder.

ie, you want parallel, which also has the benefit of remaining hum-cancelling.

Interesting.  I mainly want a  "single coil like" tone from the stacked humbucker as an option.  I can't really say whether the split coil being a bit louder would be an issue or not......we're all conditioned to accept split coil being quieter!

Any idea if parallel or split would sound most like a true single coil?  This was part of my reason for trying to get the thing wired up so I could swap between the two easily.

The other annoying thing is I don't see how to establish which coil is the upper coil.  I kind of assume the red to black.....as for single coils...those are the colours they use for positive / negative...but I don't see the information on the website, and the information that came with the pickup is generic.

Any ideas?

Thanks,
Andy

ICBM

andyg_prs said:

Any idea if parallel or split would sound most like a true single coil?

Probably parallel. Single coil will probably sound much thicker than a normal traditional single coil, in order to sound 'right' when it has some phase cancellation.

andyg_prs said:

The other annoying thing is I don't see how to establish which coil is the upper coil.  I kind of assume the red to black.....as for single coils...those are the colours they use for positive / negative...but I don't see the information on the website, and the information that came with the pickup is generic.

Any ideas?

I don't know, but you could test it easily by temporarily bypassing one or the other - the (probably much) louder is the upper coil.

Funkfingers

On a DiMarzio stacked coils pickup, the upper coil is red > black. The lower coil is white > green. The bare screen is permanently grounded.

I have done series/parallel mode switching on DiMarzio Track type pickups. I agree with Winny_Pooh that the option is of limited benefit unless the pickup is of high output. e.g. The Air Norton S.

andyg_prs

Funkfingers said:

On a DiMarzio stacked coils pickup, the upper coil is red > black. The lower coil is white > green. The bare screen is permanently grounded.

I have done series/parallel mode switching on DiMarzio Track type pickups. I agree with Winny_Pooh that the option is of limited benefit unless the pickup is of high output. e.g. The Air Norton S.

That’s a pity as I liked the single coil but missed the humbucker.  Now I may like the HB but miss the single coil. 

That said, if the top coil alone is louder than in series with the weaker / lower coil - there must be something can do. 

Of course I may love the pickup as it is. 

I also have a Rothwell audio ACT somewhere I could try. http://www.rothwellaudioproducts.co.uk/html/guitar_coil-tap.html

Funkfingers

Andy_prs said:

if the top coil alone is louder than in series with the weaker / lower coil, there must be something can do. 

It isn't. Single coil is louder than parallel mode. 

Much depends on the specific pickup design and its normal mode of operation.

In Gibson P-100s and Seymour Duncan P90 Stacks, the coils are vastly overwound because they are intended to be connected in parallel.

For the parallel mode output from a Stack to equate to a traditional single coil P90, each of its coils needs to be roughly double the notional DC resistance of the traditional single coil. 

Trad. P90 = between 8 and 9k.
Upper stack coil = between 16 and 18k.
Lower stack coil = between 16 and 18k.

16 + 16 = 32

32/4 = 8

Switch off the lower coil and you get a single coil of between 16 and 18k. It is likely to sound loud but murky.

I once experimented with partial coil split on a P90 Stack. My hope was to use a trim pot to set a compromise sweet spot between noise rejection and the traditional P90 goodness. This failed.

The series/parallel thing with a DiMarzio Air Norton S is another compromise. It works well enough in an Eighties Charvel played through MESA V-Twin overdrive. Clean, it would fool nobody - either as a humbucker or as a Stratocaster.

ICBM

Funkfingers said:

It isn't. Single coil is louder than parallel mode.

Single coil can be louder than series too, because the coils are out of phase. This is definitely true with Duncan Classic and Hot Stacks, I haven’t actually tried it with any others but the principle should be the same.

andyg_prs

Ah guys, I'm an idiot and I've mislead you....the coils are side by side not stacked on the DP188....

ICBM

andyg_prs said:

Ah guys, I'm an idiot and I've mislead you....the coils are side by side not stacked on the DP188....

Ah, the old 'stacked humbucker' confusion .

In that case it will behave like a normal humbucker when split or parallel - quieter and clearer split, slightly quieter still and a bit thin parallel. You may indeed need to A/B the two sounds to know which is best for you... although parallel does have the advantage of hum-cancelling, and to me sounds less gutless than it does on a full-size one, probably just because the coils are much closer together.