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Author Topic: Technical question for HSS wiring  (Read 13 times)

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Dante

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Technical question for HSS wiring
« on: Time Format »

I have a HSS Strat with a single Volume and Tone, that's just how I like it. I am interested in trying this mod w/my 500k volume pot because my single coils sound like hot garbage:


Url if the video doesn't load

And I see a ton of 470k resistors, each with a different Wattage rating. 0.25w, 0.5w, 1 watt, even 2 watts. What value do I use for this? Does it matter?

It could be that the single coils are garbage, but this is a cheaper thing to try before buying pickups

rnolan

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Re: Technical question for HSS wiring
« Reply #1 on: Today at 05:24 AM »

Hey Dante, very interesting rabbit hole my friend.  Short answer, wire in 2 x 470k resistors between where your 2 single coils connect to the selector switch (just tin the resistor leg and join it to the same lug on the switch along with the PU +ve wire) and connect the other end to ground (on the pot shield/case) as he suggests.  Lowest wattage is fine (e.g. 0.25w or less), as we are talking milliamps from the PUs.  Higher wattage is for much higher current signals (which PUs are not).  BTW while it makes no electronic difference to which end of the resistor you connect to either end, I believe the protocol is to have the power colour indicator/tolerance band(s) last.  So the colour bands on the resistor indicate its value, and the last band (to the right hand side) indicate it's power rating/tolerance.  So you'd wire it such that the power value/tolerance band(s) end connects to the pot ground.

Longer answer: 
I actually (though I'd never thought about it before seeing the clip) have the opposite issue, as in my tele, I have a single coil SD Hot Tele in the bridge and a Ultrasonic (single coil shape) humbucker in the neck (so SH). And (I think) 250k pots.  So the Ultrasonic sounds ok (and I can switch it series or parallel but the SD Hot Tele mmm,go figure.  So probably to really understand it, you'd have to get across why, and what difference the PUs seeing different POT resistance makes/does (to the sound, seems to affect the top end).  So basically we (kind of) know that single coil PUs like 250k pots and dual coil (humbuckers) like 500k pots.  But this will also get affected (and further complicated) by parallel and series wiring/switching of the dual coil humbuckers (which most of mine do). 

Ok, lets start from basics (based on my rudimentary understanding).  Single coil PUs are generally around 7k ohms impedance (a measure of resistance related to the amount of turns in the coil and the thickness of the wire) and Humbuckers/dual coil in series configuration around 16k ohms (i.e. 2 x 8k ohm coils in series = 16k ohms (you see where I was going with the series/parallel switching complication i.e. 2 x 8k ohm coils in parallel is 4k ohms.. just like speakers, same thing, different application, series = double, parallel = 1/2). 

This is where one of our electric minded gurus (MJMP, SC, Gregg, et. al.??) could step in to enlighten us (or I spose I could google it...).  So from what the clip is telling us, a 7k ohms (ish) coil, likes a 250k pot (which is basically a variable resistor) and a 16k ohms (overall in series) pair of coils likes a 500k pot to produce certain sounds we have grown to like.  His solution is to include a/some resistors to accommodate the coil impedance differences with the pots resistance value.

Probably the best solution is to include a balancing circuit which makes the pot resistance selection not an issue  :dunno: . Which is partly what an active circuit (has a battery) will do. 

What I do know (from what I hear when I play), is combining various PUs in either series or parallel switched modes makes for interesting tones.  What I don't know yet (but I suspect I will find out) is exactly why. Up to now I haven't cared why, I just go with the sounds I get. 

BTW I suspect it is also influenced by the input impedance of what you plug it into (preamp).
« Last Edit: Today at 05:43 AM by rnolan »
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