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Pickup Levels?!


donbenjy

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hey, i've just installed a P90 and a motherbucker into my guitar and the P90 seemd a little hot...so i decided to record some chords clean into my PC (nothing fancy, just plugged straight into the mic in and recorded using abode audition). so anyway, i did one with the P90 and one with the motherbucker- all 4 coils, series wired.

the P90 is toooo high, is there any way to fix it?

pickups.jpg

the top and bottom of each shot is the limit it records cleanly at- ie anything higher or lower causes clipping. so the P90 clips alot and the MB is clean.

im using a 500k dual concentric pot for each pup...so there any way to dial down the P90s output? space is premium in there but theres a routed middle single coil space and possibly a BIT of space inth e contro cavity, not much though.

cheers

edit: thats not the exact same time in the recording to compare, but it was just 3 chords strummed repeatedly and the levels were the same allt he way through

Edited by donbenjy
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ok heres all the switching options (aside having both P90 & MB on)

all%20pickups.jpg

the series/parellel might be the other way around, i didnt check, jsut flicked the switch :D the Pole peices ont he P980 are roughly the same height as the MB rails (i actually screwed the pole peices into the P90 to try and fix the problem)

i maintain the belief that the P90 is too hot, although MB is surprisingly cool...anyway, i think lowering the P90 level is better...er...help!

if i put a 250k resistor in between the P90 and the pot, this wouldn;t cause it to function like a 250k pot, but would it mean that it would be x - 250 where x is the value on the pot at whatever positon? would this kinda help?

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hmmm i was thinking that...

i used lovekraft's diagram so i don't think anythings wrong with that...

donbenjy.png

wheres lovekraft when you need him :D

i could check the mobo with a multimeter...but i dont realyl know what im looking for. is the Dc resistance acrosss all 4 coils in series?

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Gotta agree... I don't know enough to say 'why', but it's pretty clear that the Motherbucker, and not the P90, is the culprit. My very poor amateur guess is that somehow you've crossed wires and are having phasing issues (the signals from each coil are largely cancelling each other out).

Greg

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oooh i didnt think of that, thanks greg! i think the problem was actually both pups yesterday cos the P90 was clipping and way too high output! but i lowered it with brute force :D maybe theres a short circuit somewhere thats causing phasing problems too?

i think it's possibly the middle position...some positions are higher output, one is phased so that will be lower in output anyway..

hmm looking at the recordings i think the problems are with positons 3 & 4 and possibly 1 although thats reverse phased for the P90 but it should be lower on it's own. oh actually it looks like positons 1 &2 were swapped...doesn't matter but that means its the front 2 coils

so position 4 is a single coil-i'd expect that to be lower, seeing as its half the size or a regular coil so its got less range to pickup...

position 1 seems to be the "neck" hotrail...can't see why that's so quiet!

position 3 should be full output!

seeing as i can get some louder levels i know it's PROBABLY not a faulty pickup, although it could be a faulty coil :S

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i just pushed the P90 down into the body more (it's abit tight in the scratchplate so i took the screws out, pushed it own and then put them back in).

anyway the low MB output was masked by the fact that the P90 was too close to the strings and so clipped! the next problem is working otu whats wrong with the MB?!

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wheres lovekraft when you need him
I was working on somebody else's switching problem for a change :D

i think the problems are with positons 3 & 4 and possibly 1 although thats reverse phased for the P90 but it should be lower on it's own. oh actually it looks like positons 1 &2 were swapped...doesn't matter but that means its the front 2 coils...so position 4 is a single coil-i'd expect that to be lower, seeing as its half the size or a regular coil so its got less range to pickup...position 1 seems to be the "neck" hotrail...can't see why that's so quiet!

position 3 should be full output!

All this guessing tells me you still haven't got the superswitch squared away - you're going to have to debug it before you do anything else. Turn the P90 off, cycle through the Superswitch, and find out what coils are working in each switch position, first with the series/parallel switch in series, then in parallel. Write your results down (not for your benefit, but so we have some idea of what's actually going on). I think if we can get that fixed, the majority of your other problems will cease to exist - I do believe that I warned you how long and laborious this could become if you don't follow some kind of pattern and just try things at random. :D And just so we're on the same page, are you calling position 1 with the switch towards the neck or towards the back pickup?
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okies then...position 1 is towards the neck- number one on the schem you drew.

the problem i've foudn with finding which coils are working in each postion is that because they're all on one baseplate tappnig with stuff on a coil which is off still generates noise and its hard to distinguish if its on or not. i could try reording the levels when tapping them?

isn't the sereis/parellel switch just for the middle (3) position? it doesn't affect any other positions, but ill do it for your benefit :D ill try and write down what i get first, but if its too hard ill record it

oh yeh i havn't got a multimeter to hand, but i'm gonna grab 1 later and measure the resistance across the output terminals with each position...that'll give me DC resistance right? and it should be around the level given on the KA website right?

Edited by donbenjy
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right:

position:

1-front 2 coils

2-frontmost coil (possibly the 2nd coil too...hard to tell)

3-all four coils

4-back 2 coils

5-3rd coil

when i was tapping the 2nd coil in the 2st position and flicked the sereis/parellel switch the tone changed...but not enough to notice when i played anything :S

ill check back inside the guitar tomorrowand make sre of no short circuits...hmm one issue that does spring to mind:-when i was soldering onto the super switch, a blob of solder slipped down in between the pins that the blade slips between- this stopped the switch from moving! i heated it back up while i moved the switch forwards & backwards to move the blockage but maybe some solder is touching across 2 terminals then?

i can't see why this would reduce output level though

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