JM - dual humbucker wiring suggestions

ewal

So now deciding how to wire my two humbucker bari JM build. This circuit is interesting but I can't find a 1m rev audio taper pot anywhere.

https://www.guitar-mod.com/rg_jazzmaster_stb.html

Anyone know of a source, or have a suggestion for a better configuration? Thanks

ICBM

Use a standard 1M audio and wire it the other way round - that makes more sense to me anyway, since 'up' then becomes 'bright'.

ewal

Thanks @ICBM - if wiring a standard the other way round, would it be better to get a pot with a linear taper to get a more useable sweep?

ICBM

ewal said:

Thanks @ICBM - if wiring a standard the other way round, would it be better to get a pot with a linear taper to get a more useable sweep?

No, you need a log taper to get a usable sweep.

ewal

Thanks. I think I'm going to use this build to get my head round guitar wiring and electrics properly. I'm sure it's not that complicated!

ICBM

I forgot to say, by 'the other way round' I meant to use the other end terminal and the middle one, not to reverse the connections on the same two (which wouldn't make any difference).

ewal

Still not sure what configuration I should use for this build.

I have two push/pull pots, two mini pots and the usual JM switches.

Was thinking about the circuit above initially, but now thinking of wiring it more like a Les Paul, with the two push/pull pots used for volume, and two mini pots for tone.

Any suggestions? How would you configure a twin humbucker bari JM with normal JM controls?

Funkfingers

Does it have a conventional JM pickguard with the switch, screw and pot holes already cut through it?

If not, I suggest a five-way lever Superswitch, offering the Ibanez/DiMarzio circuit that yields
Neck HB (coils in series)
Neck HB (coils in parallel)
Neck + Bridge HB
Inside coils
Bridge HB

ICBM

ewal said:

Any suggestions? How would you configure a twin humbucker bari JM with normal JM controls?

Use the two roller controls for progressive coil splits with the slide switch to engage.

Master volume and tone, with push-pull on the volume for both pickups in series and push-pull on the tone for bass-cut.

Yes, this is going to be nightmarish to wire up (a series option means you have to be careful what you do with the ground connections to one of the pickups), but it will give you a huge variety of tones which I think will suit a baritone, while keeping it logical in use.

ewal

@Funkfingers I have a conventional JM pickguard.

@icbm that sounds exactly the sort of configuration I would like especially the idea of a bass cut. I will research this further!

ewal

Is there anyone on the forum who does wiring diagrams? Would love to have a go at @ICBM s suggestion, but don't really know where to start.

Sorry for being a bit rubbish at this!

ICBM

I’ll have a go at it. The series pull-switch does make it a complete pig though! If you can think of something else you’d prefer that would make it quite a lot easier .

Funkfingers

How high is the DC resistance figure for each humbucker? The higher their output, the less sense series interconnection between the two humbuckers makes.

I recognise the Rothstein Guitars schematic diagram from it being linked into an article by Michael James Adams AKA Puisheen.

The single most important feature of the diagram is the use of single coil pickups.

ICBM

Funkfingers said:

How high is the DC resistance figure for each humbucker? The higher their output, the less sense series interconnection between the two humbuckers makes.

Agreed, although that's offset by using the roller pots for coil splitting, so essentially you can have two single coils in series in that mode. Which ironically is what makes the series wiring such a pain...!

ewal

@Funkfingers the pickups are Railhammer Chisel neck and Alnico Grande bridge - will check the resistance and report back.

@icbm thanks for offering! I'm currently in a band with @camf so hopefully I'll get the chance to buy you a beer as a thank-you for all the help and advice you provide on here some time soon.

To be honest, I don't mind if you leave the series-parallel option out of it - I'd be more than happy with progressive coil splits and a bass-cut switch. I spend most of my time in bridge or middle positions so these options make the most sense.

ICBM

OK, how about this - tone control push-pull is still the bass-cut. Volume control one is the master coil split. The slide switch and the roller pots select which coil remains on, and how much.

That keeps all the ‘main’ functions on the lower side of the guitar, and the more fiddly - and quite possibly ‘set-and-forget’, once you’ve found your favourite sounds - on the upper side.

That’s also somewhat less of a pig to wire! Although it’s still going to be quite a faff...

ewal

@ICBM sounds good. Again thanks for the help.

Funkfingers

ICBM said:

Volume control one 

The terminology in this Discussion needs standardising. Otherwise, there will be endless confusion.

Any confusion on my part stems from the Rothstein Guitars schematic diagram. (Two vols, no master treble roll off.) Should that diagram be eliminated from enquiries?

I assume that "volume control one" refers to the conventional pot near the output jack socket. "Volume control two" would refer to the Rhythm Circuit roller pot.

ICBM said:

That’s also somewhat less of a pig to wire! Although it’s still going to be quite a faff.

If this is a bespoke build, it might help to know whether the wiring channels are narrow, like a Jaguar, or cavernous, like a Jazzmaster.

ewal

I've already widened the wiring channels a bit, and will widen more if required.

Pickup resistance now measured - Chisel neck 7.4k, Alnico Grande bridge 14.3k. Again my ignorance about guitar electrics comes in to play here, however I believe the outputs of the pickups are better matched than these figures suggest...

Funkfingers

The DC resistance stats tell only some of the story of a pickup. On the other hand, four coils, all interconnected in series, totalling a notional 21.7k Ohms, is likely to sound very muddy. Neither a bass cut switch nor G&L PTB tone circuitry is likely to rescue the situation.

Jags are straight channels running between the ends of its pickups. JMs are usually chambered - like a "smuggler's Telecaster.

ICBM

Funkfingers said:

I assume that "volume control one" refers to the conventional pot near the output jack socket. "Volume control two" would refer to the Rhythm Circuit roller pot.

No, 'volume control one' meaning the push-pull on the volume control as opposed to the push-pull on the tone control!