bigjohn Posted October 7, 2008 Share Posted October 7, 2008 (edited) Hi, I've just replaced the electronics in a p bass for the first time. Well - actually for the second, but the first didn't count It sounds great. My one complaint is that the volume pot still has a bit of turn left after the volume is completely down. I actually don't mind this really - but... Does this mean that I'm missing some of the turn of the pot and cutting out some of the output when the pot is turned full up? Is the solder in the right place? Cheers for any advice. John Edited October 7, 2008 by bigjohn Quote Link to comment Share on other sites More sharing options...
neepheid Posted October 7, 2008 Share Posted October 7, 2008 Did you use a linear or a log (audio) taper pot? A linear pot will not seem like a uniform adjustment in volume whereas a log pot will. Quote Link to comment Share on other sites More sharing options...
bigjohn Posted October 7, 2008 Author Share Posted October 7, 2008 (edited) [quote name='neepheid' post='301351' date='Oct 7 2008, 02:10 PM']Did you use a linear or a log (audio) taper pot? A linear pot will not seem like a uniform adjustment in volume whereas a log pot will.[/quote] Both vol and tone are CTS 250k vintage back split shaft audio pots. I got them from Allparts and they only do audio pots with vintage backs. Weirdly enough, they also only do split shaft vintage backed pots too when I would have thought a solid shaft would be more "vintage" ( I know CTS make em as these were the ones I replaced). I was going to use a linear pot for the tone but they don't do em with a vintage back anyway... Anyway I digress... It's not like it's all or nothing with the volume, it's just that it hits "zero" before you stop turning the knob off, there's about another 10-15% of turn where the pot has no effect. Edited October 7, 2008 by bigjohn Quote Link to comment Share on other sites More sharing options...
BOD2 Posted October 7, 2008 Share Posted October 7, 2008 It could be that the resistance track on the pot isn't quite perfect (although probably within manufacturing tolerances). The only way to check this would be to put an ohm meter across the pot contacts and check the resistance at various points. With the meter across the two outer contacts you should get a reading of the full resistance of the pot of around 250k. With one meter probe on the centre contact and the other on one of the outer contacts you should see the resitance change as you sweep the control. The fact that the volume tails off early doesn't mean that the pot range has "shifted" at all - it's might just mean the the pot resistance reaches near maximum a little earlier than it should. With the volume control on "full" the pot is actually "bypassed" and it's resistance is not relevant. As you turn the volume down you introduce the resistance into the circuit. Quote Link to comment Share on other sites More sharing options...
bigjohn Posted October 7, 2008 Author Share Posted October 7, 2008 [quote name='BOD2' post='301439' date='Oct 7 2008, 03:30 PM']It could be that the resistance track on the pot isn't quite perfect (although probably within manufacturing tolerances). The only way to check this would be to put an ohm meter across the pot contacts and check the resistance at various points. With the meter across the two outer contacts you should get a reading of the full resistance of the pot of around 250k. With one meter probe on the centre contact and the other on one of the outer contacts you should see the resitance change as you sweep the control. The fact that the volume tails off early doesn't mean that the pot range has "shifted" at all - it's might just mean the the pot resistance reaches near maximum a little earlier than it should. With the volume control on "full" the pot is actually "bypassed" and it's resistance is not relevant. As you turn the volume down you introduce the resistance into the circuit.[/quote] Ah nice one. So long as I'm not doing myself out of output I can live with the volume being zero a little early. Thanks for the test though. I might have a play with it next time I've got it open. Cheers John Quote Link to comment Share on other sites More sharing options...
escholl Posted October 8, 2008 Share Posted October 8, 2008 [quote name='bigjohn' post='301387' date='Oct 7 2008, 02:42 PM']It's not like it's all or nothing with the volume, it's just that it hits "zero" before you stop turning the knob off, there's about another 10-15% of turn where the pot has no effect.[/quote] i have what sounds to be the same CTS pot in my bass, and i've got the same problem. I've checked and triple checked, and it's the right pot and in the right way....i think it's just something with those pots. Quote Link to comment Share on other sites More sharing options...
thepurpleblob Posted October 9, 2008 Share Posted October 9, 2008 Swap around the connections to the outer terminals of the volume pot and see what happens! Quote Link to comment Share on other sites More sharing options...
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