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Thread: LiveWires problem low output, big hum

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    Default LiveWires problem low output, big hum

    Installed some livewires last night following this diagram:
    http://www.seymourduncan.com/support...ire_1v_1t_3way

    I am using a stereo jack, for which I thought the wiring was different than the schematic. After reading through the forums, I found this post which suggests the same thing:
    http://www.seymourduncan.com/forum/s...d.php?t=144429
    The picture is actually right, if looked at as if looking into the entrance as opposed to looking out from inside.

    I have guitar plugged into mackie onyx 1620i. I have to crank the gain up 3/4 of the way to even hear guitar. I have a constant hum that is fixed by touching instrument cable, input jack, or pot knobs (didn't put plastic covers back on yet. If I touch any hot lead, the hum gets real loud (the volume I'm expecting to hear my guitar at). I get the same results from a DI box or an effects box. I am using a mono cable.

    These are installed in an Ibanez Iceman ICX120. It has a bridge ground, which I have to the attached to the jack sleeve along with a ground cable from the solder pool on back of volume pot. I wasn't sure if that is the correct place for the bridge ground, of if it should go to volume pot.

    I am using 100k pots and a 50V .047uF cap as recommended in schematic.

    Thanks in advance.

    Sam

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    Butterball speed2dirt's Avatar
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    Default Re: LiveWires problem low output, big hum

    Any pics, Iceman?

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    Default Re: LiveWires problem low output, big hum

    Not until I get home. Even then, I dont' know how helpful they'll be. I literally took every wire out last night and started from scratch. The only reused part is the jack and the bridge ground wire. New wire, new pots, new cap, new toggle.

    I originally installed these pickups in 2003 on top of all original gear. They worked fine, but I noticed recently when recording that I was getting something similar to a plosive "p" on the bridge pickup when hitting the string hard. Now, when I first bought these pickups, I had to redesign the paper schematic that came with them to work for 1 volume and 1 tone, instead of 2 of each. I was surprised to learn that the schematic was now available on the site.

    So, I thought, I'm going to replace the (500k?) pots and stock larger capacitor with what SD recommends and hopefully get rid of that nasty spike. Whoops.

    The original pots were connected with an extra wire wrapped around the lead and grounded to the backs of the pots. The hot wire sent to the jack was also wired this same way. I also didn't mimic this. I wired exactly as the diagram depicts.

    I'll take some pics when I get home, but not sure it'll help. Also, I'll have a multimeter, if anyone has any recommendations.

    Thanks,

    Sam

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    Slam Dunk da Funk Funkfingers's Avatar
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    Default Re: LiveWires problem low output, big hum

    I agree that the SD schematic drawing is misleading (although, the legend around the jack socket is correct).

    Hold the jack socket sideways on. You should see a succession of layers - metal contact parts with insulation spacers between.

    The system ground connection is circular, furthest from the threaded barrel of the jack socket. It may even have the word Switchcraft stamped into it.

    The next metal contact layer is the one to use for the battery ground. It connects to the shorter of the two sprung contact points.

    The metal contact closest to the threaded barrel section of the jack socket connects to the longer of the two sprung contact points. This carries the signal.

    It may help that, on a Switchcraft TRS jack socket, the soldering lugs are positioned directly opposite the contact to which they relate.
    Esperanza Spalding - "You have to have something to say; chops don't matter. If you have nothing to say on your instrument, I'll just go home and listen to albums with people better than you."

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    Default Re: LiveWires problem low output, big hum

    Quote Originally Posted by Funkfingers View Post
    I agree that the SD schematic drawing is misleading (although, the legend around the jack socket is correct).

    Hold the jack socket sideways on. You should see a succession of layers - metal contact parts with insulation spacers between.

    The system ground connection is circular, furthest from the threaded barrel of the jack socket. It may even have the word Switchcraft stamped into it.

    The next metal contact layer is the one to use for the battery ground. It connects to the shorter of the two sprung contact points.

    The metal contact closest to the threaded barrel section of the jack socket connects to the longer of the two sprung contact points. This carries the signal.

    It may help that, on a Switchcraft TRS jack socket, the soldering lugs are positioned directly opposite the contact to which they relate.
    You are exactly right. Unfortunately/fortunately, that's the way I currently have it soldered. Any thoughts on the bridge ground and where it should be connected. Also, to mention, none of the wires that I added have the bare ground wire built in under the insulation. I notice that my original signal wire from the original volume had that...

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    Question Re: LiveWires problem low output, big hum

    Now comparing my tone pot to the original, looking at the back of the pot with all three contacts pointing up, the left has the cap attached and grounded to back. The middle is the signal to the right post of the volume pot and the right is open.

    On the SD schematic and the way I have it soldered. The MIDDLE on the tone pot has the capacitor, the LEFT connects to the RIGHT of the volume pot, and the right is open.

    Basically the left and middle are flip-flopped between the old configuration and the new one. Also, it isn't grounded in any way unlike the original.

    Could this be the issue? Which is correct?
    Last edited by IcemanCometh; 05-03-2012 at 03:29 PM.

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    Default Re: LiveWires problem low output, big hum

    Okay, one more update tonight.

    I ran a ground from volume to tone. No change.

    I attached multimeter to one ground and tested every spot that was supposed to be ground (ground on selector, back of other pots, string, sleeve on jack) and there was continuity. Then I did the same for hot route and for selector switch, and got continuity everywhere I expected. I tested between ring on jack (battery ground) and contact 3 on volume (signal from selector/to tone) and got 17V, not 18V, but I can't imagine that would cause a difference.

    Only other thing I haven't mentioned is I took the strings off last night and only put the low E back on so far. Could that have ANYTHING to do with it?

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    Default Re: LiveWires problem low output, big hum

    Okay, more info. With volume pot open, 17.14 V output between ring and tip and 0V between sleeve and tip. With volume pot closed, 0V between ring and tip, 0v between sleeve and tip.

    With instrument cable plugged in and volume pot open, 0V between ring and tip, 0V between ring and sleeve.
    With instrument cable plugged in and volume pot closed, 0V between ring and tip, 0V between ring and sleeve.

    So testing continuity from the tip to sleeve (main ground), there is continuity with pot open, none with pot closed. This originates back at the volume pot, where continuity between contact 2 and back of pot reflect the same (ground on back flows to sleeve, contact 2 flows to tip). Doesn't seem right to me, but hey, what do I know?

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    Default Re: LiveWires problem low output, big hum

    Hello, again. (Sorry for the delayed reply. I am in Europe.)

    Three things that you have not mentioned;
    1) How old are the batteries?
    2) What sort of instrument cable are you using between the guitar and mixer?
    3) Is the mixer's +48v phantom power switched on?

    Photographs of your wiring are essential to get any further in answering your problem. It is probably a simple oversight. Spotting the oversight is a visual activity.
    Esperanza Spalding - "You have to have something to say; chops don't matter. If you have nothing to say on your instrument, I'll just go home and listen to albums with people better than you."

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    Default Re: LiveWires problem low output, big hum

    Quote Originally Posted by Funkfingers View Post
    Hello, again. (Sorry for the delayed reply. I am in Europe.)

    Three things that you have not mentioned;
    1) How old are the batteries?
    2) What sort of instrument cable are you using between the guitar and mixer?
    3) Is the mixer's +48v phantom power switched on?

    Photographs of your wiring are essential to get any further in answering your problem. It is probably a simple oversight. Spotting the oversight is a visual activity.
    I took photographs this morning and will put them up soon. Answers to the questions:
    1) Not sure how old batteries are. Again, they are registering an output voltage of 8.74 a piece, as measured on the disconnected battery. Give a nice tingle on the tongue, too.
    2) Mono instrument cable. Tried known working cables, bunch of different ones. Also tried a stereo cable as well.
    3) Phantom power is off on the port I'm trying. Pulled out the guitar amp last night, got the same exact results: Have to crank it to hear any guitar, but if I touch the hot lead, it pushes loud signal out of amp more at the volume I'm expecting to hear guitar at.

    Thanks!

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    Default Re: LiveWires problem low output, big hum

    Green goes from 3 on volume to 1 on tone. Red from middle (3&4 together) of switch to 3 of volume, and 2nd red from 2 of volume to tip on jack, 3rd red from battery meets the two reds from pickup. Blacks are ground, minus the ring on jack (one wire) to battery ground. Whites from pickups to 1 and 4 of to respective pickups.
    Last edited by IcemanCometh; 05-04-2012 at 12:31 PM.

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    Default Re: LiveWires problem low output, big hum

    Is the 3-way selector grounded to volume?

    The big piece of black tape covers a lot of your wiring. Any pics with it removed or at least wrapped tightly? Sorry! I'm just trying to follow the flow but miss a crucial piece behind the tape.

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    Default Re: LiveWires problem low output, big hum

    I am detecting two oversights.
    1) The problem description makes absolutely no mention of the battery portion of the circuitry. Check all the solder joints. Also check the physical condition of the clips. These can corrode or the terminal connections can be broken if excessive force is applied to remove either battery.

    2) The plosive sound intermittently heard is consistent with the 18v power cutting on and off.
    Esperanza Spalding - "You have to have something to say; chops don't matter. If you have nothing to say on your instrument, I'll just go home and listen to albums with people better than you."

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    Default Re: LiveWires problem low output, big hum

    Sure you don't have the battery and audio wires backwards on the jack?
    LTD M-50 W/ AHB-1 Blackouts.
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    Default Re: LiveWires problem low output, big hum

    Quote Originally Posted by speed2dirt View Post
    Is the 3-way selector grounded to volume?

    The big piece of black tape covers a lot of your wiring. Any pics with it removed or at least wrapped tightly? Sorry! I'm just trying to follow the flow but miss a crucial piece behind the tape.
    Sorry, didn't wrap it tight after I pulled tape off to check connections. I can take a few more pics.
    Yes, the lone terminal on the one side of selector runs to back of pot.

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    Default Re: LiveWires problem low output, big hum

    Quote Originally Posted by Funkfingers View Post
    I am detecting two oversights.
    1) The problem description makes absolutely no mention of the battery portion of the circuitry. Check all the solder joints. Also check the physical condition of the clips. These can corrode or the terminal connections can be broken if excessive force is applied to remove either battery.

    2) The plosive sound intermittently heard is consistent with the 18v power cutting on and off.
    1) checked the solder joints. The battery terminals are fairly new, and as I said, my voltage across batteries is as expected.

    2) that was happening before rewire, had some bad solder joints.

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    Default Re: LiveWires problem low output, big hum

    Quote Originally Posted by Bfeeney View Post
    Sure you don't have the battery and audio wires backwards on the jack?
    Not sure of anything. Black cable from 9v connector connects to the shorter of two jack connections. The red cable from that same 9v connector runs to the black of the next, and that red joins the two reds from the pickups. The taller of the two jack connectors is the red cable that runs to the middle terminal of the volume pot. The two black wires on the middle terminal of the jack run to the stock. Ridge ground and to the main ground on back of volume pot.
    Last edited by IcemanCometh; 05-04-2012 at 06:05 PM.

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    Default Re: LiveWires problem low output, big hum

    Okay, everyone, thank you so much for your insight. Turns out my volume pot was bad. It was making a weird sound when turning. I happened to have another 100K pot laying around, swapped it out and voila.

    Anyway, thanks again everyone. It's awesome that this community exists.

    Sam

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    Default Re: LiveWires problem low output, big hum

    Here's the jack wiring on my LTD with 2 AHB-1's. The white wire on the right goes to the post that does your AUDIO (the longer of the 2 contact points (at the other end of the jack), like a passive jack). The middle wire is the AUDIO ground, the center ring (I guess) on the jack, like a passive. The left wire is the battery wire, Should be red but I didn't have any red to splice in, only black. It goes to the shorter of the contact points. On my jack the audio and battery wire is connected to the post on the opposite side of the long/short contact points mentioned earlier. I wired my EMG's backwards and got a WTF? sound out of it. Spent like $75 to have a guy switch them, I felt like an idiot. Hopefully you can get your answer without having that experience!
    Last edited by Bfeeney; 07-07-2012 at 04:34 PM.
    LTD M-50 W/ AHB-1 Blackouts.
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