ali-stare Posted June 5, 2007 Share Posted June 5, 2007 does anyone know the standard wires going/out of into a 2 band preamp. my bass is a vintage v940 there is a brown and a black wire going into the preamp from the pickup blend knob i replaced the knob with a switch (long story) and now i cant get any tonal variety from the bridge pickup but still can from the neck pickup??!!??!! i shouldnt be saying this as have GCSE in electronics (A grade as well ) but this is beyond me as i cant see whats inside the preamp. HELP please Quote Link to comment Share on other sites More sharing options...
The Burpster Posted June 6, 2007 Share Posted June 6, 2007 Very difficult to say without seeing it..... maybe a quick and easy solution is to ring JHS on 01132 865 381 (I've found them to be very helpful) who are the inporters of Vintage and see if they can email or fax you a circuit diagram..... hopefully you should be able to use your GCSE from there???? JHS webby is [url="http://www.jhs.co.uk/contact.htm"]http://www.jhs.co.uk/contact.htm[/url] Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 6, 2007 Share Posted June 6, 2007 I'm afraid that the problem is there's no such thing as a "standard" 2-band preamp. They all use their own wire coding schemes. So unless you can identify the preamp model (which might be difficult as it could be Vintage's own brand) or someone else had the same bass/preamp and can describe where the wires go then we're stuck. Or contact the distributor as The Burpster suggests. Good luck. Quote Link to comment Share on other sites More sharing options...
neepheid Posted June 6, 2007 Share Posted June 6, 2007 [quote name='ali-stare' post='12730' date='Jun 5 2007, 10:54 PM']i replaced the knob with a switch (long story)[/quote] I hope you kept a note of how things were connected first before you did that. Quote Link to comment Share on other sites More sharing options...
ali-stare Posted June 6, 2007 Author Share Posted June 6, 2007 i did keep a note ill try and post some diagrams Quote Link to comment Share on other sites More sharing options...
ali-stare Posted June 6, 2007 Author Share Posted June 6, 2007 ok here are some wonderful diagrams hope they help the pot as it was [attachment=478:Pot.bmp] the switch as it is now [attachment=479:Switch.bmp] Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 6, 2007 Share Posted June 6, 2007 [quote name='ali-stare' post='12958' date='Jun 6 2007, 12:04 PM']ok here are some wonderful diagrams[/quote] What does that switch do ? (i.e. which contacts are connected to which when you activate the switch) And is the aim for the switch to operate as a selector switch for the pickups or is it something else ? Quote Link to comment Share on other sites More sharing options...
ali-stare Posted June 6, 2007 Author Share Posted June 6, 2007 its just supposed to be a selector for either bridge or neck pickup Quote Link to comment Share on other sites More sharing options...
The Burpster Posted June 6, 2007 Share Posted June 6, 2007 Bod, I'm off out for the evening, can you sort this one? I can do it in the am if you cant tonite.... Bob. Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 6, 2007 Share Posted June 6, 2007 [quote name='ali-stare' post='13156' date='Jun 6 2007, 05:17 PM']its just supposed to be a selector for either bridge or neck pickup[/quote] OK. This should be fairly esay to sort out but I need some specifics. Is it a 3-position switch ? i.e. 1. bridge pup only 2. both pups 3. neck pup only Do you know what contacts on the switch are made/broken when the switch is operated ? According to your diagram there are 12 contacts on the switch so I'd need to know what happens when you operate the switch. In principle, what you need to do is connect all of the earths to a common earthed point (usually the shell of one of the pots). This will include the earth wires from the pickups which were the wires connected to the top left connection on your "Pot" diagram. You'll also need to connect the black wire from the preamp to earth. Once you've done that all you should have left is a wire from each pickup and the brown wire from the preamp. All the switch needs to do is - Position 1. connect bridge pup wire to brown preamp wire Position 2. connect both pup wires to brown preamp wire Position 3. connect neck pup wire to brown preamp wire It [i][b]should[/i][/b] be fairly simple - much simpler than the original blend pot wiring. Does this make sense ? Quote Link to comment Share on other sites More sharing options...
ali-stare Posted June 6, 2007 Author Share Posted June 6, 2007 that does make sense but its only a 2 way switch with either bridge OR neck selected. but not both thats evne simpler than i thought so i could have a STDP switch and have the brown wire to the centre pin and the neck on one side and the bridge on the other. sweet one question the grounds just need to be all connected and connected to the blak preamp wire right?? cheers ali Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 6, 2007 Share Posted June 6, 2007 [quote name='ali-stare' post='13209' date='Jun 6 2007, 06:36 PM']that does make sense but its only a 2 way switch with either bridge OR neck selected. but not both thats evne simpler than i thought so i could have a STDP switch and have the brown wire to the centre pin and the neck on one side and the bridge on the other. sweet one question the grounds just need to be all connected and connected to the blak preamp wire right?? cheers ali[/quote] Yes. A two position switch will give you one pickup or the other but not both. On a simple three pole switch you would connect the brown wire from the preamp to the centre pole on the switch and the wires from the pickup to each of the other two poles. All the ground wires should be connected to the same earthing point, and this should be traced back to the earth side of the jack socket. The back preamp wire is just another ground wire too. The diagram below should do it (note any other wires from the preamp are not shown - only the two mentioned) [attachment=496:2pups.jpg] Quote Link to comment Share on other sites More sharing options...
ali-stare Posted June 6, 2007 Author Share Posted June 6, 2007 (edited) sweet. i have to wait to get my bass back from my mother (something about me having to do AS revision) before i can try anything but ill keep you informed cheers for all your help guys ali Edited June 6, 2007 by ali-stare Quote Link to comment Share on other sites More sharing options...
The Burpster Posted June 6, 2007 Share Posted June 6, 2007 Thanks Bod. Good luck with exams and the bass Ali ! Quote Link to comment Share on other sites More sharing options...
ali-stare Posted June 9, 2007 Author Share Posted June 9, 2007 Wooo. Cheers guys. new switch installed and works brilliantly cheers ali Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 9, 2007 Share Posted June 9, 2007 Nice one (breathing sigh of relief because the advice worked !) The wiring was actually very simple but I think you got confused because of the apparent complexity of the blend pot. Quote Link to comment Share on other sites More sharing options...
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