ossyrocks Posted February 3, 2022 Share Posted February 3, 2022 (edited) I’m the proud owner of a ‘73 Precision. I’ve only had it a couple of days, but yesterday I spent time with it through two different amps, my little Rumble 15 in the lounge, and my Markbass LM. I feel that the tone pot doesn’t have the sweep that it should have. It does work, but even backing it off completely doesn’t roll off the highs as I feel it should. The cheap Squire I have has a lot more tonal sweep than this does. I want to be able to really roll off the highs if I need to, and at the moment I’m using the bass with the tone pot rolled all the way back, and it’s just getting there. As I am unfamiliar with vintage Precisions, is this normal, or should I be taking a look at the pot and the tone capacitor? My feeling is that the cap might be way out by now. I can’t see the pot being at fault, it’s silent in operation, and I’ve got older pots in older equipment and they rarely fail. Any opinions and experience welcome. Cheers, Rob Edited February 3, 2022 by ossyrocks Quote Link to comment Share on other sites More sharing options...
ikay Posted February 3, 2022 Share Posted February 3, 2022 (edited) Have you looked to see what cap it has at the moment and check the pot (should be 250k audio taper) and wiring? Edited February 3, 2022 by ikay Quote Link to comment Share on other sites More sharing options...
ossyrocks Posted February 3, 2022 Author Share Posted February 3, 2022 39 minutes ago, ikay said: Have you looked to see what cap it has at the moment and check the pot (should be 250k audio taper) and wiring? I haven’t yet. But it is original, I’m told. Quote Link to comment Share on other sites More sharing options...
ossyrocks Posted February 3, 2022 Author Share Posted February 3, 2022 (edited) 250K Audio CTS pots, dated 1973 with a .05uf capacitor/ Looks ok, and original. I might just reflow the solder to start with and see if that makes a difference. Edited February 3, 2022 by ossyrocks Quote Link to comment Share on other sites More sharing options...
shoulderpet Posted February 3, 2022 Share Posted February 3, 2022 (edited) 55 minutes ago, ossyrocks said: 250K Audio CTS pots, dated 1973 with a .05uf capacitor/ Looks ok, and original. I might just reflow the solder to start with and see if that makes a difference. Yes maybe start with that and if that doesn't work then maybe try a higher value capacitor which should roll off more highs, when I had a pj Mustang the tone went from bright when on full to full on dub reggae with the tone rolled off so maybe try and find out what capacitor value the pj Mustang basses use Edited February 3, 2022 by shoulderpet Quote Link to comment Share on other sites More sharing options...
ikay Posted February 3, 2022 Share Posted February 3, 2022 (edited) 5 hours ago, ossyrocks said: 250K Audio CTS pots, dated 1973 with a .05uf capacitor/ Looks ok, and original. The only thing that doesn't look original is the fat white earth wire from the jack to vol pot. Looks like this has been added later. See pic below of original wiring on another '73. Soldering on the pot case is much tidier and the earth tag on the jack is unconnected (common with this era). One end of the tone cap goes to earth on the vol pot case so check that it's making a good connection. I'd be tempted to resolder that anyway and maybe dispense with the added earth wire. Or replace it with a black wire of the same gauge as the original wiring just to make it a bit tidier and consistent with black=earth. Edited February 3, 2022 by ikay Quote Link to comment Share on other sites More sharing options...
shoulderpet Posted February 3, 2022 Share Posted February 3, 2022 3 hours ago, ikay said: The only thing that doesn't look original is the fat white earth wire from the jack to vol pot. Looks like this has been added later. See pic below of original wiring on another '73. Soldering on the pot case is much tidier and the earth tag on the jack is unconnected (common with this era). One end of the tone cap goes to earth on the vol pot case so check that it's making a good connection. I'd be tempted to resolder that anyway and maybe dispense with the added earth wire. Or replace it with a black wire of the same gauge as the original wiring just to make it a bit tidier and consistent with black=earth. That's a great point, if the ground wire is not making good contact then that could explain the lack in tonal variation when the highs are not being bled to ground Quote Link to comment Share on other sites More sharing options...
ossyrocks Posted February 4, 2022 Author Share Posted February 4, 2022 @ikayThat’s really useful thanks. I can see why that earth wire was added, and I’ll probably wire another in, but better. Relying on the shielding under the guard to hold the earth to the jack isn’t the greatest, but there are probably thousands of P basses out there with exactly that. Quote Link to comment Share on other sites More sharing options...
ossyrocks Posted February 4, 2022 Author Share Posted February 4, 2022 I’ve had a look at it today. It was immediately apparent what the issue was. One leg of the cap was touching the wiper of the tone pot. I just gently moved the cap a bit and moved the leg away from the pot lugs. I did re-do that ground on the back of the pot, and I shortened and tidied up that added ground to the jack. All back together now with a new set of flats on it. Everything is as it should be now. Thanks for the input chaps. Rob 5 1 Quote Link to comment Share on other sites More sharing options...
Reggaebass Posted February 4, 2022 Share Posted February 4, 2022 11 minutes ago, ossyrocks said: All back together now with a new set of flats on it. Everything is as it should be now. Nice one ossy, glad it was something simple to sort out , it will sound superb with flats 👍 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.