jaybyname Posted January 2, 2013 Share Posted January 2, 2013 Hi, hope all is well. I recently purchased a concentric stacked pot (6 terminals) which Im going to use as a pickup blend. Top knob is neck pickup volume and bottom knob is for the bridge. My question is, in the simplest of explanations, can someone tell me/show/diagram how to wire the pot. Ive actually wired it up already but only the bridge pickup works yet both tiers are wired the same. Pickup-middle pole, power and earth both sides. Ideas? Quote Link to comment Share on other sites More sharing options...
mart Posted January 2, 2013 Share Posted January 2, 2013 Need a few more details to work out what's going wrong. Is the volume control for the bridge pickup working perfectly? And the neck pickup isn't coming through at all, no matter what settings the knob is on? And the two "power" tags on the pot are linked together, are they? If so, then either there's a bad solder joint somewhere, or the pot isn't wired up the way you're expecting. In that case, disconnect everything and play about with a multimeter. Quote Link to comment Share on other sites More sharing options...
jaybyname Posted January 2, 2013 Author Share Posted January 2, 2013 (edited) Yes to the first question. Yes to the second too although there is a seperate wire for the tags to the power source. (not bridged). Forgive the diagram below. It looks like this. [url="http://i685.photobucket.com/albums/vv215/hondog/Pot_zps5de36586.jpg"]http://i685.photobucket.com/albums/vv215/hondog/Pot_zps5de36586.jpg[/url] Edited January 2, 2013 by jaybyname Quote Link to comment Share on other sites More sharing options...
mart Posted January 2, 2013 Share Posted January 2, 2013 That diagram looks right, at least for how I would guess the pot should work. So at this point I would check the joints carefully - either the pot is faulty, or you've somewhere shorted out the neck pickup. If you're confident that the joints are ok, then I'd unsolder everything and get a multimeter to measure the pot in various settings to check that it is behaving as you would expect. Btw, it's kind of irrelevant, and forgive me if this comes across as patronising, but when you talk about "power" and "the power source", I'm assuming you mean the output jack socket. If so, that's really not appropriate terminology, as no power comes from the amp to the bass - the power actually goes the other way! If, on the other hand, you really do mean "power" and this is some kind of active bass, then do say whether its just an active preamp, or active pickups too, since that complicates things! Quote Link to comment Share on other sites More sharing options...
jaybyname Posted January 2, 2013 Author Share Posted January 2, 2013 My apologies, I actually ,mean the power from the preamp. It has an 18v Active Preamp. During the hours of dismantling, I discovered the lives, the earths, the negatives etc. Ill have another look tonight when I get in Quote Link to comment Share on other sites More sharing options...
brensabre79 Posted January 2, 2013 Share Posted January 2, 2013 I think from what I can gather you have to reverse one of them. It is basically two volume controls stacked on top of each other, so for a blend control, you'll want one to work in reverse. i.e. when you are turning the neck PU volume up, you should be turning the Bridge PU vol down at the same time (and vice versa). So you need to wire one of the rows of 3 tabs back to front (swap the earth and live over on your diagram). Usually it would be the Bridge pickup wired opposite to a normal vol control so as you turn the knob up (towards the neck) the bridge pickup will turn down. Neck stack: LIVE : PU-Hot : Earth Bridge stack: Earth : PU-Hot : LIVE Quote Link to comment Share on other sites More sharing options...
brensabre79 Posted January 2, 2013 Share Posted January 2, 2013 [quote name='jaybyname' timestamp='1357144451' post='1918080'] My apologies, I actually ,mean the power from the preamp. It has an 18v Active Preamp. During the hours of dismantling, I discovered the lives, the earths, the negatives etc. Ill have another look tonight when I get in [/quote] The preamp should not come into it at all. LIVE in my explanation above should go to the input of the preamp, or the master volume control - or straight to the output jack if you are bypassing the other two. If you have a volume control for each pickup this should go before the blend control. The Preamp should be last in the chain before the output socket. Quote Link to comment Share on other sites More sharing options...
mart Posted January 2, 2013 Share Posted January 2, 2013 [quote name='brensabre79' timestamp='1357146647' post='1918166'] I think from what I can gather you have to reverse one of them. It is basically two volume controls stacked on top of each other, so for a blend control, you'll want one to work in reverse. ... [/quote] I would have though that's a matter of taste; you could wire it that way, or the way the OP has done. I think I'd find a backwards volume control pretty confusing personally. Of course, if the pot is log/log, then it will work best wired one way round and not the other. In any case, that doesn't explain why the neck pickup isn't coming through. Finally, I agree with brensabre about the preamp - it shouldn't affect the wiring on this pot. (But again, the live wire from this pot to the preamp is really an output, not a power - there is no power going from the preamp to the pickups, but that's by the by). Quote Link to comment Share on other sites More sharing options...
jaybyname Posted January 2, 2013 Author Share Posted January 2, 2013 Thanks for the advice. Ill try the reverse option. Just to clear things up if it helps. I have an 18v active circuit (Bass,mid,treb+active/passive switch). These then are wired to a concentric master volume(top) and tone (bottom).....then the 'new' pickup blend concentric knob. So, yeah all wires from this pot go to the master vol. Quote Link to comment Share on other sites More sharing options...
brensabre79 Posted January 3, 2013 Share Posted January 3, 2013 [quote name='mart' timestamp='1357149779' post='1918241'] I would have though that's a matter of taste; you could wire it that way, or the way the OP has done. I think I'd find a backwards volume control pretty confusing personally. Of course, if the pot is log/log, then it will work best wired one way round and not the other. [/quote] Yep, you're right, i missed the concentric pot bit, i thought this was a blend control (single shaft). Yes wiring one the opposite way around in that case would be rubbish. Ignore me, I'll get my coat! Quote Link to comment Share on other sites More sharing options...
KiOgon Posted January 3, 2013 Share Posted January 3, 2013 Which pot have you got? The Fender CTS Concentric PN 0019268000 is the usual & it's 2 different pots for a start, 500K nearest the mounting, for tone control & 250K on the bottom for volume. So not suitable for what you're trying toi use as a blend pot. Quote Link to comment Share on other sites More sharing options...
mart Posted January 3, 2013 Share Posted January 3, 2013 I kind of agree with where KiOgon is heading: it's an odd way to run a blend control if you already have a master volume on the bass - a single shaft blend pot would be more usual. Quote Link to comment Share on other sites More sharing options...
jaybyname Posted January 14, 2013 Author Share Posted January 14, 2013 (edited) Hi all. Following on from this thread, it appears that my ongoing electrical concern is still 'broken'. Having desoldered the wires Ive put in, Im now left with a a few questions. If I explain whats left in the cavity, can some fill in the gaps?...... I have in cavity - 1 bass pot 1 treble pot 1 mid pot 1 Preamp 1 active/passive switch. All wired together as normal. [b][u]Preamp [/u][/b] 5 wires come from this that need to be re-joined to 1 volume/tone (concentric pot) and 1 blend (centre detent pot) Originally 2 wires from the preamp went to 2 lugs on the tone pot and 1 wire went to the volume pot. The remaining 2 wires were earth from the preamp which were soldered to the can of the tone pot. [u][b]Pickups[/b][/u] Hot wire to ? Ground wire to tone pot can Can anyone supply a diagram or offewr some advice? Hope you can help. Jason Edited January 14, 2013 by jaybyname Quote Link to comment Share on other sites More sharing options...
mart Posted January 14, 2013 Share Posted January 14, 2013 Hmm, this is still a little confusing. Did your preamp originally have a separate tone pot in addition to its 3-band EQ? And is your blend (centre detent) pot different from the concentric stacked pot you were talking about in your first post? And it would be a great help if you could give us a model number for the preamp so we can know exactly what the connections to it are. In any case, to put your circuit together, you should probably first have a good look at this one: [url="http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=jazz_bass_blend"]http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=jazz_bass_blend[/url] The blend control there is probably what you need to begin with, and it's connected to the pickups in just the way you need. Note how there are two crossed wires on the blend pot; one side of the cross goes off to the casing on the tone control, i.e. to earth. The other is the live "output" from the blend. In that diagram it goes to the volume control, but you probably want it feeding into your preamp. And then you'll want the output from your preamp going to your master volume. Quote Link to comment Share on other sites More sharing options...
jaybyname Posted January 14, 2013 Author Share Posted January 14, 2013 Hi, thanks for reply. Preamp is visible but its just a plain black box. Turning it over reveals a multi plug and gain control. Tone control (which I was told it was at time of purchase) is the bottom knob and volume at the top. Next to it is the blend pot with crossed wires as explained above. I can locate where output wire and earth attach to the blend pot (centre detent) and middle poles for pickups. Earth from pickups originally went to the casing of the tone pot. Now....output wire from the blend pot- does this go to middle peg of vol or tone pot. Quote Link to comment Share on other sites More sharing options...
jaybyname Posted January 14, 2013 Author Share Posted January 14, 2013 To add- bass, treble and mid pots are 250k. New replacement ones I ordered for vol/tone and pickup blend are 2 x concentric 500k pots. (4 in total). At first I tried to replicate what was coming out and what was going back in the cavity but lost my way. The original 250k vol had a small capacitor on the earth peg soldered to the casing. Does this capacitor need to be attached to the new 500k vol pot. Thanks Quote Link to comment Share on other sites More sharing options...
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