What capacitor/resistor for Jaguar?

[dren68]

I'm putting some 62 Jaguar pickups in a Mustang, and I'm just wondering what kind of capacitor and resistor I need to get? It's a little confusing.

[timtam]

Higher value caps take the guitar 'darker' as you roll off the tone control (if you ever do). Humbuckers tend to use 0.047uF / 500k pots and single coils 0.022 uF / 250k pots.
http://www.seymourduncan.com/tonefiend/ ... your-caps/
The 'type' of cap is not important.

But vintage jags have a 0.01 uF cap on the 1meg tone pot. The more recent Am Pro has a 0.022 uF (and V-mod pickups with 500meg pots).

The function of the 56k resistor you see on vintage / vintage-correct jag circuits - across the main tone pot lugs - is debated. On some newer jags Fender has omitted it.

All that is not considering an (anti) treble bleed circuit, which only some recent jags have. You can always add one later if you feel your playing habits need it (ie commonly winding back the volume and wanting to preserve treble).

Bottom line ... 0.022uF is a good place to start, but be prepared to go higher or lower if you like your tone control to work in a particular way. Caps cost less than $1.

[dren68]

Thanks for the info. I just wanted whatever was standard on the AVRIs or AV65s, so it sounds like a 0.01 uF capacitor is what I'll go with. What's the purpose of the 56k resistor since you say Fender has omitted those on the newer Jags?

Oh, and the 56k resistors also have different wattages. Does this matter?

[timtam]

OK the 56k resistor 'story' is a tad complicated ...

Not sure if it's been discussed on OSG, but IIRC previously suggested roles for the 56k resistor (1/2 watt) have included ... part of the main tone control (since that's the pot it is wired to), although what that role would be has always been unclear ... or (anti) treble bleed ie for the volume control (and that's almost certainly wrong).

Recently I came across the only proper schematic diagram for a jag I'd ever seen ....



It says MIJ HH but on inspection it's identical to vintage wiring. To anyone who can read these things, it actually makes the jag wiring much clearer. And the very interesting thing about it that was not obvious from wiring diagrams is that the 56k resistor's placement makes it clear(er) that the likely role for that resistor is as part of the 'strangle' switch circuit ('high pass' or 'low cut' filter).

All jags with strangle switches have the 56k resistor (including the Marr, which calls it a 'bright' switch, but it is the same circuitry). The one that does not have the strangle switch - the Am Pro - doesn't have the 56k resistor.

So if you're not building a strangle switch, I would leave the 56k resistor out.

[oid]

Oh, and the 56k resistors also have different wattages. Does this matter?

It does not really matter, you would be hard pressed to find a resistor with a wattage rating that would be unhappy in a passive guitar circuit. Leo tended to use massive overkill, but he also made amplifiers, so 1/2 watt resistors were at hand and cheaper since he could buy them in massive quantities. 1/2 Watt has one big advantage over the smaller sizes, the leads are thicker and it will stay were you put it, but an 1/8 watt can be tucked in anywhere.

OK the 56k resistor 'story' is a tad complicated ...

It is a very nuanced resistor which does many things! When the strangle switch is engaged the tone control sort of sweeps from band pass to high pass response, the 56k widens the pass band. When the strangle switch is off it shifts the cutoff frequency of the tone control up and gives you a few extra dbs output. Regardless of the strangle switch it alters the taper law of the tone knob. If time permits I will ask spice for a few frequency plots this weekend and toss them up here.

I suspect the Jags which do not have a strangle switch have a smaller value tone cap, 0.01uF without the 56k resistor would give you a cutoff around 50hz, so the tone control would act more as a volume than a tone.

EDIT: I am not sure the 56k resistor actually gives more output, in ideal circuits it would, but we have the effects of impedance to deal with in real life, the loading of the circuit on the pickup and the loading of what ever the guitar is plugged into on the circuit, I suspect there would be little difference in output in the real world.

[timtam]

I suspect the Jags which do not have a strangle switch have a larger value tone cap, 0.01uF without the 56k resistor would give you a cutoff around 50hz, so the tone control would act more as a volume than a tone.

Yes, the Am Pro has 0.022 uF ... with 500k tone pot and no 56k resistor .. and no strangle switch.

The more vintage-spec jags (and the Marr) have the 0.01 uF, 1meg tone pot, 56k resistor, and the strangle/bright switch - the circuit as above.

So it would seem that inclusion of the 56k resistor depends on the choice of tone control cap value and tone pot value. Plus whether you want a strangle switch.

[oid]

Yes, the Am Pro has 0.022 uF ... with 500k tone pot and no 56k resistor .. and no strangle switch.

The more vintage-spec jags (and the Marr) have the 0.01 uF, 1meg tone pot, 56k resistor, and the strangle/bright switch - the circuit as above.

I just edited that while you posted it seems! Larger resistor would lower frequency, halving the resistance and doubling the capacitance would keep things the same, just load the pickups more and dampen the highs. That is a lower cutoff than I would have expected, but it is also 4:30AM, so what I expect right now may have little to do with nothing.

[Johnny Alien]

I am bumping this old thread with a question specific to that resistor. I am going with 500k pots in my Marr and thusly am moving to a .022 capacitor. The Marr has the strangle switch so I think I should keep the resistor but am unsure if I should change the value due to the different pot and cap values.

[timtam]

I would just stick with 56k. Don't overthink it.

The jag schematic I linked above in this old thread has long since disappeared, and I've had my own version for a long time now, so I'll leave that here so the resistor's position in the circuit can be seen again ...


And for comparison, the Marr ....