carter
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Post by carter on Jul 29, 2015 18:20:27 GMT -5
OK, so here's the results - hope they make some kind of sense!
Bridge -
Volume 10 - 119.5 (118.2 with 3rd switch pushed to split coil) Volume 9 - 119.3 Volume 8 - 112.0 Volume 7 - 99.3 Volume 6 - 76.9 Volume 5 - 67.8 Volume 4 - 55.4 Volume 3 - 36.6 Volume 2 - 22.8 Volume 1 - 07.9 Volume 0 - 0
Neck -
Volume 10 - 116.5 (115.9 split) Volume 9 - 116.3 Volume 8 - 109.2 Volume 7 - 97.2 Volume 6 - 76.2 Volume 5 - 67.2 Volume 4 - 55.7 Volume 3 - 39.9 Volume 2 - 22.8 Volume 1 - 06.2 Volume 0 - 0
Not sure if this is relevant to this issue, but one thing I did notice in testing plugged in was that if anything the neck pup sounded noticeably louder in output than the bridge which was a surprise given that the Dimarzio spec for the Area 58 (Neck in this setup) is Output mV: 125 with DC Resistance: 6.15 Kohm , while the Injector (Bridge) is Output mV: 185 with DC Resistance: 11.35 Kohm - I had always expected there to be a significant volume disparity between the two but the other way!
Anyway, those are the readings on 200K ohm setting - to my ignorant mind this would appear to be what I might expect to see in a properly functioning pot!!
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Post by JohnH on Jul 29, 2015 23:00:15 GMT -5
There’s definitely something amiss with the volume wiring! At max, the output should be connected to the pickup via the pot, so you would read the resistance of the pickup, minus a % or two for the pot being in parallel. As you turn down, the pickup becomes connected to output only via an increasing resistance so the reading rises, then at low volume, the output gets shunted down to zero by the pot.
Here is a theoretical set of readings sweeping a 500k log volume pot from 10 to 0, with a 7k pickup and a 150k treble bleed resistor. Reality may be different by a few %, usually less since pots are normally less than they say.
10 6.9k
9 54.8k
8 69.5k
7 71.3k
6 62.5k
5 35.3k
4 30.0k
3 24.0k
2 17.2k
1 9.2k
0 0.0k
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carter
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Post by carter on Jul 30, 2015 5:58:22 GMT -5
Hi John OK, at least we've narrowed down the issue! And obviously I need to do my homework on using multimeters and understanding 101 guitar electronics ...as well as get this wiring out of the guitar again and figure out where I went wrong.. Would you say it still looks likely to be a short somewhere, or too many variables to say for sure right now? Any pointers will be most helpful in knowing where to start...
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Post by JohnH on Jul 30, 2015 6:41:56 GMT -5
Hi John OK, at least we've narrowed down the issue! And obviously I need to do my homework on using multimeters and understanding 101 guitar electronics ...as well as get this wiring out of the guitar again and figure out where I went wrong.. Would you say it still looks likely to be a short somewhere, or too many variables to say for sure right now? Any pointers will be most helpful in knowing where to start... I think it is a mixture of issues. Given that the resistance at 10 should be just a few k for the pickup, the fact that it is a higher resistance means its not just a short, which could only lower any resistance reading. I can't think of a sensible scenario that would lead to those figures. But just playing with the numbers, if you take the pickup and add it to the treble bleed resistor to get 156k, and put that in parallel with the pot at 500k, you get about 119k, which is around what you are reading. But how such a connection would come to pass I cant figure out. The treble bleed should have no effect at max volume since it is connected to the two volume pot lugs which are together at max volume.
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Post by newey on Jul 30, 2015 11:14:07 GMT -5
JohnH's right, I can't make sense of the readings either, although I note that they would all be more sensible if the decimal place was off one spot. I'd say, before any dismemberment, let's double check that the meter is set to the correct range and that those are the true readings. Also, if you have a spare pot or pickup laying around that you could test as a control, just to be sure the meter isn't acting wonky.
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carter
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Post by carter on Jul 30, 2015 14:11:23 GMT -5
OK guys, probably my ineptitude - let me check this again and report back...
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carter
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Post by carter on Jul 30, 2015 15:10:34 GMT -5
OK, thought to upload a couple of pics as this may help... I checked a 300K CTS pot which is shown in first pic - I only get the meter to read it on the 2000k setting - on 200k it gives no reading at all The other 2 pics are of a different guitar lead to the one used yesterday and switched to bridge pup at volume 10. You'll notice the readings for 2000k and 200k are the same, save the extra decimal point for 200k - Is the meter faulty?! It was a real cheapo!
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Post by JohnH on Jul 30, 2015 15:26:20 GMT -5
The meter seems fine. Those cheap ones do the job well for these kind of measurements = I have a similar one.
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carter
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Post by carter on Jul 30, 2015 15:46:14 GMT -5
And just checked a vintage spec pair of humbuckers with known prior readings and they both read correctly on the 200k setting @ 7.5k and 8.1k...
..Hmmm
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carter
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Post by carter on Jul 30, 2015 18:11:21 GMT -5
Well surgery seems imminent...just wondering where I might best start...any thoughts? Remove the treble bleed cap/resistor and reconnect the jack lead and 22nF cap?
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Post by JohnH on Jul 30, 2015 20:43:11 GMT -5
I would gently disconnect the red wire that feeds the left volume pot lug from the back of its push/pull switch (per diagram). This will seperate the volume pot and treble bleed for testing and you can also meaure resistances from the switch at tbis point to ground. This should be just the total of the selected pickups with the fade control active but not the vol or tone pots. Ie you will read somewhere from 1/2 up to 2x a pickup resustance for parallel, single and series settings.
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carter
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Post by carter on Jul 31, 2015 16:32:01 GMT -5
Hi John
Thanks for this - being the total novice, definitely starting to lose me here sorry..! Disconnecting red wire - as in the wire marked red in the diagram? Disconnect from both ends or just one, and if only one, does it matter which?
"..separate the volume pot and treble bleed for testing and you can also measure resistances from the switch at this point to ground.."
Test the Vol pot as in simply much as I did the 300k pot earlier for it's basic resistance readings through it's sweep/taper? I have a suspicion my meter (pictured earlier) can't read/test capacitors/resistors - does that seem correct to you, or am I just being the perfect muppet?! measuring resistances from the switch at this point to ground - ??!
Apologies for complete muppetry!!
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Post by JohnH on Jul 31, 2015 17:09:32 GMT -5
Hi John Thanks for this - being the total novice, definitely starting to lose me here sorry..! Disconnecting red wire - as in the wire marked red in the diagram? Disconnect from both ends or just one, and if only one, does it matter which? "..separate the volume pot and treble bleed for testing and you can also measure resistances from the switch at this point to ground.." Test the Vol pot as in simply much as I did the 300k pot earlier for it's basic resistance readings through it's sweep/taper? I have a suspicion my meter (pictured earlier) can't read/test capacitors/resistors - does that seem correct to you, or am I just being the perfect muppet?! measuring resistances from the switch at this point to ground - ??! Apologies for complete muppetry!! Disconnect whichever end of that red wire is easiest Your meter will not be affected by capacitors, its as if the capacitor has infinite resistance, which it does. So having separated that red wire, just measure through the jack like you were before, which should be the same as from ground (=jack barrel) to volume centre lug (-jack tip). It should be 0 at 0 rising up to the full pot value 500k at 10. Then the rest of it, lets say you disconnected that red wire at he switch end (I'm thinking that might be easiest). Put one meter probe to the switch lug that you disconnected from, the other to ground. Measure resistance for all the pickup settings, which should be I eh range as noted above (if you had all 7k pups, they would be about 3.5k, 7k or 14k)
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carter
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Post by carter on Jul 31, 2015 17:18:33 GMT -5
Cool, should manage to get to grips with that OK - hopefully get some time to pull it apart tomorrow and see what gives... Have a great weekend
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carter
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Post by carter on Aug 2, 2015 17:10:28 GMT -5
OK, here are my results just now obtained :-
With 'red wire' detached at the switch lug (Vol Pot) :
Volume Pot readings -
10 - 473 9 - 454 8 - 354 7 - 241 6 - 142 5- 113 4- 79 3- 45 2 - 26 1 - 07 0 - 0
Bridge Pup:-
Unsplit - 11.4 Split - 9.0
B + M:-
Unsplit - 4.1 Split - 3.7 Series - 17.6 Series Split - 15.1
B+N:-
Unsplit - 3.9 Split - 3.1 Series - 17.2 Series Split - 13.6
M+N:-
Unsplit - 3.1 Split - 2.7 Series - 12.2 Series Split - 11.0
Neck:-
Unsplit - 6.0 Split - 4.7
As soon as the 'red wire' was re-attached the 119.5 reading returned for bridge pup at Volume 10....?!
Measured the resistor while at it with a reading of 113.9
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carter
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Post by carter on Aug 2, 2015 18:41:04 GMT -5
Well guys, thought you'd be interested to hear I finally got to the bottom of this and ironically it appears to be exactly what I was querying as a possible issue back when I posted my first results after initial wiring up :- the hot lead to the jack was indeed wired to the leg of the treble bleed cap/resistor, NOT the actual lug of the Volume pot - as soon as I rectified that, boom! Job done yay Measuring virtually exactly as described in your hypothetical scenario for a 7k pup John! Checked other combos too, all looking good to go - time to put it all back together and see how it all sounds
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Post by JohnH on Aug 2, 2015 23:36:41 GMT -5
Thats great, it sounds like good news. Im curioys as to why the split B or N pickups are such a high proportion of the unsplit values instead of being about 50%. Is that what youd expect for those pickups?
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carter
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Post by carter on Aug 3, 2015 2:30:01 GMT -5
That was going to be my next question (as if I hadn't asked enough already)! I really have no idea/answer re: those particular pickups, maybe someone else has more knowledge on the Dimarzios. I wondered if this was down to the specific way Dimarzio make these noiseless, but that doesn't seem to make much sense to me. Certainly the values are so close that there is hardly any audible difference when they are switched. The only other thing I can think of is the how thick the 22 AWG wire is which the MUCH tinier pickup wires were connected to, but you seem sure this is not a factor... ...apart from this though, got 10 minutes quick test in last night and what a wicked system! Major thanks are due John (and newey!)
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Post by JohnH on Aug 3, 2015 2:55:09 GMT -5
Ah yes..they are noiseless singles. Brain fade on my part..that was why we did it that way...all good. The noisecanceling coils that we are cutting off are designed to collect anti-hum with minimal impedance. Removing them presumably adds just a little extra edge and bite? Nice to have.
Have fun exploring...and comparing tone 23 to tone 37 etc!
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carter
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Post by carter on Aug 3, 2015 14:57:59 GMT -5
Hi John Now that I've been able to plug into my 50w combo and crank it a bit, I've got to hand it to you sir - this is one seriously impressive, indeed kickass switching arrangement! The coil split switching doesn't become noticeable until you've got a bit of volume on a quality amp, but once you do it delivers yet another really useful tonal flavour in many of the other switching positions, which of course are already extensive! I had an amazingly convincing cocked wah with fazing tone going on earlier in Switch position 2 with the addition of the phase switch engaged plus the coil split on and the tone turned quite low yet with a still bright overall tone - in fact the guitar retains incredible brightness (not the classic strat harshness or shrill treble, just strong bright tone) across almost all the many many switching combos, even with the volume and tone turned way down. Quite unexpected, making the full range of any setting you care to make useful. I can already say this guitar is unquestionably far and away the most versatile I've ever picked up. Knowing that it's not something you can buy off the shelf only makes it that much more satisfying So once again, huge thank you for all your patience and time - I owe you one!
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Post by JohnH on Aug 3, 2015 15:27:18 GMT -5
Carter that's great to hear and thanks for working through this. One day Ill build one of these myself. I might link this thread to the schematic thread so we can keep reference to it. cheers John
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