pots and wiring issue

[lurksalot]

I wonder if you techies out there can offer a bit of advice ,

I have a Spector legend4 and love it , however , I have recently been aware of a lot of hiss/general noise through the amp when I touch the strings, and also that the neck pickup volume pot is behaving more like a switch with little sweep in volume more of a sharp cut in/out .

So , off with the backplate and out with the multimeter.

first off the volume pots have 500K stamped in , but across the terminals I can only measure 105K on both, this seems a touch odd but will await confirmation.

The both vol pots sweep from 0 - 105K from the centre terminal to one of the outside ones , in a pretty linear fashion , but when swapping to the other outside terminal expecting a simple reverse measurement , I can only get the numbers to go from 0 - 7.5K (or 7.5K -0)

This all seems very odd and would love any input that is available

thanks in advance

[KiOgon]

Next to impossible to say from here - & I've never seen inside a spector - but, have you still got the pickups connected to the pots? Is it an active circuit? If so is the battery connected/does it switch through the jack plug?

A decent photo or 2 of internals might help.

EDIT: After a quick google, does any of this apply to yours?
"[color=#000000]The Legend Classic basses have been upgraded recently w/ better electronics, to make them an ever better piece. - - , - - - active Spector TonePump Jr. boost only active tone controls w/ EMG-SSD passive humbuckers, "[/color]

Edited May 19, 2012 by KiOgon

[lurksalot]

everything is still hooked up , active eq I believe , not active pups,

I will try some pics later if it helps, but would external influences have an effect on the resistance measurement across the pot terminals ?

[mart]

[quote name='lurksalot' timestamp='1337430536' post='1659797']... would external influences have an effect on the resistance measurement across the pot terminals ?
[/quote]
Oh yes, most definitely!
To take a silly example, suppose you had a 500k pot, and then soldered a 10k resistor across the terminals. The resistance is going to be a lot less than 500k now, isn't it! So whatever else is wired up to them will affect the reading on the pots.

Anyway, I don't think the pots are likely to be a problem - hiss and noise that comes when you touch the strings is usually a sign of earthing issues. The casing of each pot should be connected to the ground on the jack socket - check those wires, and maybe resolder them.

[LukeFRC]

[quote name='lurksalot' timestamp='1337428234' post='1659755']
I wonder if you techies out there can offer a bit of advice ,

I have a Spector legend4 and love it , however , I have recently been aware of a lot of hiss/general noise through the amp when I touch the strings, and also that the neck pickup volume pot is behaving more like a switch with little sweep in volume more of a sharp cut in/out .

So , off with the backplate and out with the multimeter.

first off the volume pots have 500K stamped in , but across the terminals I can only measure 105K on both, this seems a touch odd but will await confirmation.

The both vol pots sweep from 0 - 105K from the centre terminal to one of the outside ones , in a pretty linear fashion , but when swapping to the other outside terminal expecting a simple reverse measurement , I can only get the numbers to go from 0 - 7.5K (or 7.5K -0)

This all seems very odd and would love any input that is available

thanks in advance
[/quote]

they are still wired up! of course it will not be what it says on it.
Hum is more likely to be something touching something it shouldn't or some grounding error

[lurksalot]

Electrical diagnosis was never my strongest point , but then neither is bass playing ...... bum tish.
I think I will have another look at this to get my head around the i humm issue , but what would be the cause of the volume being like a switch?

[lurksalot]

[quote name='LukeFRC' timestamp='1337434024' post='1659897']
they are still wired up! of course it will not be what it says on it.
Hum is more likely to be something touching something it shouldn't or some grounding error
[/quote]

Cheers Luke , I have cut the cables and guess what the pots are reading like they should now
Even the hum seems to have gone aswell so we a top result .........

Only thing is I can't hear anything through the amp, I will have to takes that apart now to fix it










only kidding ........TAXI ,



Having done a bit searching , I see mention of audio log pots , can I tell what the originals are by the markings? when I meaured the resistance it seemed linear , but could that be due to them still being wired in?
sorry for the numptiness

[mart]

[quote name='lurksalot' timestamp='1337443988' post='1660148']....Having done a bit searching , I see mention of audio log pots , can I tell what the originals are by the markings? when I meaured the resistance it seemed linear , but could that be due to them still being wired in?
sorry for the numptiness
[/quote]
You should be able to tell from the markings - if there is an "A" or a "B" next to (or near) where it says 500k then that tells you whether it's audio (A) or linear (. Or if you google a bit more you may find a circuit diagram for your bass, which will also tell you.