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Post by dannyhill on Dec 1, 2011 9:09:02 GMT -5
Hi everyone, I'm considering a new guitar build Its an Aria Pro II TA61, sort like a Gibby ES355 complete with Bigsby and varitone, with stocks HBs swapped out for 4 lead GFS Memphis HBs. I would like to get a lot of tone variety out of it - split/series-parallel/phase a la Jimmy Page wiring although its not a hot PUP. At the same time, I wanted a real icepick/snappy sound which you get on shortscales like Jaguars. OK, so its 24 3/4" scale and not 24" but its the shortest I have. Now, Ideally I would 1MEG Ohm LOG DPDTs pots (dont want to put switches/drill etc). But can I find any, that have split/gnarled shafts? Nope. So it looks like regular 1M LOG Pots or 500k LOG DPDTs for JP switching? What would you do?
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Post by reTrEaD on Dec 1, 2011 9:52:41 GMT -5
Two volume and two tones, right? high resistance pots make "blending" difficult. I think 500k is better than 1 Meg for the volume controls in that case. And 500k linear (instead of log) would be a better choice (for the volumes) in a two volume arrangement.
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Post by asmith on Dec 1, 2011 10:41:02 GMT -5
Danny, I built Borsanova's "Mix" version of his go at a JP scheme using 500k Log long-shaft Push/Pull Pots. It works marvellously. 1 megaohm pots will be bright, but won't give as smooth a range of control as 500k. If you want an icepick sound perhaps you can incorporate a switchable small-value capacitor in series with your wiring scheme? This will passively cut bass, giving you a very trebley sound. Let us know if you're interested. rT, I'm curious as to your reasoning behind this. Cheers
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Post by reTrEaD on Dec 1, 2011 12:31:44 GMT -5
I'm curious as to your reasoning behind this. Cheers In a one volume configuration, a log pot does exactly what we expect a volume control to do. But in a TWO volume configuration, the game is changed when both pickups are selected. If one volume is at "10" and the other at "5", something bad happens to our division ratio. The pickup at "10" will still be at full volume, but the pickup at "5" won't be at half volume. It's more like 1/8 volume. The pickup at "10" is connected in parallel with the "bottom" part of our voltage divider for the pickup at "5". Because of the "loading" effect of the other pickup, even a small rotation from "10" makes for a large change in the voltage division. Even with linear volume pots, reducing the contribution of one pickup happens pretty quickly. With log pots, it's extremely abrupt. Gibson used 300k linear pots for their 2 volume guitars. This made blending a little better. But at the cost of a little more "dulling" of the tone. I don't think I'd make that trade, but it is an available choice.
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Post by JohnH on Dec 1, 2011 14:03:14 GMT -5
IMO, the best pot for humbuckers is a 500k log, with a treble-bleed circuit of 150k and either 1nF or 0.82nF. Apart from helping preserve the treble, the treble bleed (particularly the resistor) reduces the drop off in volume as you turn down from 10, making the pot effectively mid-way between log and linear, therefore helping set mixes when its a 2 volume set up. Without treble bleed, Id use linear.
J
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Post by asmith on Dec 1, 2011 14:56:00 GMT -5
Interesting. And - sticking strictly to theory and not sensible real-world application - when two volume-controllable pickups are in series, presumably this is an entirely different matter? 500k log pots across pickups would not affect each other in a series chain.
?
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Post by reTrEaD on Dec 1, 2011 16:27:38 GMT -5
I wouldn't go as far as to say "would not affect each other", but the interaction is definitely a different kind of mechanism. Instead of the full volume pickup loading the pot of the one that has the volume turned down ... the reduced volume pot adds resistance in series with the full volume pickup. So at first glance, you would expect a good bit of tone-dulling because of the capacitance of the guitar cable. Just like turning down the volume on a guitar with one volume control and no treble bleed cap.
But two pickups in series have twice the inductance. And when you dial back the volume control on one of those pickups, you remove half of the inductance, and replace it with series resistance. So decreasing the volume on one pickup makes the tone brighter by removing some of the inductance and duller by increasing the series resistance. So the effects tend to cancel each other out, to some degree.
When all is said and done, having the volume controls in series would definitely be less interactive than having them in parallel.
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Post by dannyhill on Dec 2, 2011 4:58:24 GMT -5
Wow, what response!
Let me see. Retread: Yep 2 and 2. I prefer log pots, as that is what I have and they seem to give a better, if not so easily controlable, range of sounds. Besides I don't play with both pups combined much.
asmith: I have the varitone in the circuit, which I guess just consists of switching across different capacitors instead of a fixed one across the volume pot? How would I put it in series? I'm interested in adding it to the circuit on the link you sent. That was the very same wiring I had already seen and so had in mind.
Separate to this I have other mods planned/underway:
Squier Tele custom II - I would like to get hold of a circuit for including series/parallel switch and phase change. I guess you will probably know it has 2 P90s, noise cancelling in the middle, 2 + 2 vol and tone control. Was thinking of using 500k P/P. Cap values?
Vintage V100WR - I'm fairly sure that the mini HBs are only two wire, which threw my JP wiring plans out of the window. So instead I thought about putting some 1MEG pots, gotta use these somewhere, to brighten the sound. Opinions? Cap values?
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Post by asmith on Dec 2, 2011 11:06:16 GMT -5
We're presuming that ground is at one end of a pot, hot the other, the output on the wiper, right? Top volume: V t | Bottom volume: V b | Top pickup: P t | Bottom pickup: P bLet's turn down V t - the top volume. To clarify: Instead of the full volume pickup loading the pot of the one that has the volume turned down ... the reduced volume pot adds resistance in series with the full volume pickup. Yes... Well, it's removing resistance in series with P b, and adding resistance in series with P t. Of course, the volume controls are signal splitters. Example: let's give V t a value of 500k, and P t a value of 5k. When V t is at 10, then after calc 99% of the P b signal heads through P t. As you turn V t down, obviously that percentage is going to drop, and the percentage of P b heading through V t will rise. Sort of. I'd certainly expect tone-dulling on P t from being turned down, just as normal - it's having resistance put in series with it, and of course with the cable capacitance... you get what I'm saying. I'd also expect the P b to be dulled as V t is part-way through its sweep, getting less dull as V t is turned down. You've got series resistance with P b's signal path through P t, and you've got series resistance with its signal path through V t. So at any point besides the two ends in any sweep of volumes in series, there's going to be some tone-dulling from the resistance combined with the cable capacitance... To some degree, I'd definitely agree with you there. However, my main point was on the sweep. Whether V t would produce the same sweep if P t was both on its own, or in series with P b. Why both doing calculations why 5Spice can do it for you, eh. I hope I've done this right... | Solitary Pickup | Pickup in series with another | Plain Ol' Volume | Sweep | Sweep | JohnH 'R+C' Treble Bleed | Sweep | Sweep |
Some difference towards the end I think, but not that much.
And so concludes my off-topic adventures. asmith: I have the varitone in the circuit, which I guess just consists of switching across different capacitors instead of a fixed one across the volume pot? How would I put it in series? I'm interested in adding it to the circuit on the link you sent. That was the very same wiring I had already seen and so had in mind. We'd have to know how it already operates in the guitar. Does the varitone change the capacitor value for both Tone Controls? That sounds like both Tone Controls use the same cap(s), like a Strat. Maybe not, depends on the way they've wired it. Could complicate things. Are you open to buying more parts besides the push/pull pots?
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Post by dannyhill on Dec 2, 2011 13:03:26 GMT -5
Hi asmith, Thanks for the electronics lessons. I'm always up for buying more parts although I have gone overboard buying 5 guitars this year to complement the one I have had for 15 years. Mine you they were all economic, until I started modding The varitone in the Aria? I don't know how it is wired but I do know that it works for neck, bridge and both together. It was tough enough just swapping the pots. Fortunately I had just taken up fishing, if you know what I mean This one will be the last mod. This w/end I plan to swap out the switch and pots on the LP Deluxe copy (V100) and finish that damn Tele mod that Newey and I have been going crazy over. Circuit looks good! Any idea for the Tele custom II (twin P90s, 2+2 pots) wiring? Hometime.....
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Post by dannyhill on Dec 3, 2011 20:15:26 GMT -5
Finally! Got the tele mod working. Thanks everyone. 1MEG pot threads were too short though for the V100 I guess I need to remove some wood or hunt for long thread 1MEG pots, do they even exist? Start the Strat lover's strat tomorrow! D
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Post by roadtonever on Dec 5, 2011 20:06:19 GMT -5
You can transplant shafts between pots if they're the same brand.
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Post by dannyhill on Dec 6, 2011 8:16:34 GMT -5
Hi roadtonever,
Its better than that. My current pots were actually standard 3/8" or 9mm. The ones I tried to fit were advertised as the same, I measured them, and they were half that. Refund and new order. Doh!
D
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