robolobo
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Post by robolobo on Sept 10, 2011 20:24:35 GMT -5
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Post by newey on Sept 10, 2011 21:15:58 GMT -5
RL-
Hello and Welcome to G-Nutz2!
To answer your questions directly- yes, it matters what gets wired to where, both for switches and potentiometers.
But in order for us to help you, we're going to need to know what you want to do with the switch and the pots. Do you have a diagram from which you are working?
So far, you have a switch, a Dave Mustaine pickup (or is it more than one of these?), and some pots. . . . Some further information is needed.
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robolobo
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Post by robolobo on Sept 10, 2011 23:44:27 GMT -5
Thanks for a speedy response. The wiring diagram was in the link, but here is a more convenient picture. This is the official diagram.  It is a set of two pickups. I would like only one Volume and one Tone, so I'm looking to this second diagram except for the extra battery.  Do I just connect to both tabs for each switch position? Edit: Aside from the switch, I will still need the 1uf on the Tone ground, right? What's that for anyway? I'm full of questions. |
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Post by JohnH on Sept 11, 2011 7:29:09 GMT -5
The diagram is a bit curious. Although it clearly states that an on-off-on switch is to be used, this seems like the wrong switch to me. On-off-on switches are completely disconnected in the central position, so instead of getting both pickups you would get no sound at that setting. A normal three way toggle on a guitar has the centre lug connected to both in the centre position.
john
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robolobo
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Post by robolobo on Sept 11, 2011 14:51:24 GMT -5
It does seem unusual.
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robolobo
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Post by robolobo on Sept 13, 2011 13:43:07 GMT -5
The double tabs are because it's DPDT instead of SPDT, I guess. I could still use it by just picking one of the two tabs to solder to for each switch position. I liked the idea of the switch being center off, but I've changed my mind. So, I won't be using this switch anyway. Here is the answer to my question about the 1uF capacitor. acapella.harmony-central.com/archive/index.php/t-1234570.html |
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Post by newey on Sept 13, 2011 20:56:31 GMT -5
I've looked at whether this switch can be wired so as to give the 3 combos of two pickups, and concluded that it can't be done with the on-off-on. At least, if it can be done, it's a mystery to me. Adding the second pole doesn't change anything, the center position is still not connected to anything.
My thought was that it could be done, provided one didn't insist that the N+B setting be in the center position. But I've convinced myself that's not workable either.
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robolobo
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Post by robolobo on Sept 13, 2011 21:54:12 GMT -5
I think you are right. Thanks for the help.  Any ideas why on-off-on is specified? There is no technical reason for this is there? Only preference? |
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Post by thetragichero on Sept 14, 2011 13:14:28 GMT -5
kill switch?
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Post by ashcatlt on Sept 14, 2011 13:50:32 GMT -5
The only thing I can think is that they didn't want you combining the two pickups in parallel. We generally don't "mix" two active devices via a straight wire connection like that. If the outputs of both are low enough impedance, then one pickups's output will find it easier to complete its circuit through the other pickup's output, rather than whatever pedal/amp you've got it plugged into. This will cause loss of volume and tone, and possibly even smoke. (!)
...But, the second diagram illustrates what looks like a standard Gibson-style toggle switch, which would do just that. I can't imagine that SD would not have designed their circuits to allow combinations of pickups. So I think the first diagram is just plain wrong. The only way to know for sure would be to email SD directly. Considering that there is at least some potential for permanent damage in this situation, I think maybe you should.
Anyway, you could use that second pole to interrupt battery power to the unused pickup, and save some small amount of battery life.
With passive pickups you could use the on-off-on to wire it with the center position as a series combination of the two, rather than the standard parallel, but I'm not sure how that would work with this type of active pickup.
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Post by newey on Sept 14, 2011 18:29:57 GMT -5
Yeah, I saw how to do the series but was assuming parallel was the goal. The active issue never crossed my mind, I keep forgetting these are active.
Since these have preamps internal to the pickups, it would seem that daisy-chaining them might burn something up . . .
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robolobo
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Post by robolobo on Sept 14, 2011 22:52:00 GMT -5
Ok. Immensely helpful. Thanks very much newey and ashcatlt. ;D
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Post by gumbo on Sept 15, 2011 6:40:43 GMT -5
...it always helps if you don't let the smoke out....  |
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robolobo
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Post by robolobo on Sept 15, 2011 17:32:15 GMT -5
I posed this question to Seymour Duncan: I have Livewireâ"¢ Dave Mustaine Model LW-Must. The diagram calls for an on/off/on SPST switch. Will a traditional Gibson-style switch, allowing both pickups in parallel with the center switch position, damage the pickups in any way? Response: This setup will definitely not hurt the pickups. You'll be good to go. Best, Scott Marceau Sales / Customer Service Seymour Duncan 5427 Hollister Ave, Santa Barbara, CA 93111-2345 805-964-9610 x 1028 www.seymourduncan.com |
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Post by sumgai on Oct 4, 2011 2:35:13 GMT -5
Ye Gawds! I buy you guys books, and I send you to school, and whaddya do......  Two active/low-impedance devices in parallel that are roughly the same output impedance will not short each other or harm the tone in any way - they're the same, just as if they were passive/high-impedance devices. Les Paul's original Low Impedance Pickups for his Recording model were an amazing 100Ω - kein scheiße! On-off-on controlling the selection of pups? Again, how many times to I have to hammer on you: Think Outside The Box!! Short the output of the unwanted pup. In the center, neither pup is shorted, so both sound out. Next time I'm gonna stay home for my vacation, and keep an eye on youse guys..... And robolobo, Hi, and  to the NutzHouse! sumgai |
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Post by JohnH on Oct 4, 2011 5:00:04 GMT -5
I would hope that active pickups are designed to be combined - probably by having some passive resistance at the output, after the output circuits. But without that, two active circuits with outputs shorted togther will definately fight and both lose! I have heard the consequent distortion very clearly when combining the stereo output from Mp3 players down to mono, to go into a mixer. Its much better if both channels have a resistor in line before they mix.
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Post by sumgai on Oct 4, 2011 20:42:30 GMT -5
John,
Yes, active circuits must be isolated from each other before they are summed (mixed) together. I was referring solely to low-impedance passive pickups.
sumgai
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Post by ashcatlt on Oct 5, 2011 9:31:08 GMT -5
Ummm...sg? Ummm... "Short the output of the unused pickup"? I can see how this works in series, but can't make it work in parallel. Shorting one shorts both. We end up with two "off" positions and one "both". I'd be happy to see a picture that proves me wrong. Edit (since nobody's replied, so as not to annoy ijws  ) - Was thinking about the series thing. I can't see any reason why this would hurt anything. It's just two boosters connected in series with an inductor in between. I stack boosters all the time, and never burned anything up. The main issue I see here is that the second preamp would be trying to find its battery ground through the output of the first. It won't be able to find it, because there's a cap at the end of the preamp circuit. It's there specifically to block DC current from flowing via that path. If you can actually get into the circuit board, it might not be too difficult to run a seperate battery ground wire. I've never held one of these active pickups, but I'd be surprised if they let you in that far. Once it's done, though, it should work just fine. How it will sound is another question. I wouldn't expect quite so dramatic a difference between the series and parallel combos, but I've been warned about expectations a whole lot lately. |
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Post by sumgai on Oct 6, 2011 23:58:40 GMT -5
ash, "Short the output of the unused pickup"? I can see how this works in series, but can't make it work in parallel. Shorting one shorts both. We end up with two "off" positions and one "both". I'd be happy to see a picture that proves me wrong. Forgive me, you're correct of course. I can only think that my fingers must have thought I was through, and stopped typing before I got around to telling them to use the word 'series'. I hate it when that happens!  sumgai |
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