pickups - maybe paul can help

i57dwun4yb1pt8

weird issue on bass .

I have two bass humbuckers , connected to a blend pot - forward position is full neck / back is full bridge / middle position is both pups at 50 % each .

issue is forward and back position seem ok but middle - no sound - im thinking may be the bridge is 180 out of phase with the neck so cancelling
but both pups are wired the same way and are supposed to be / appear to be indentical pups ?

wiring digram for a blend pot is here

http://studio1031.info/BlendPot.html

top digarm , neck is source b bridge is source a

all connections are fine .

has me baffled.

anders

I can't believe you could get a 100% cancelation, it's just not possible. Even if you would have one of them inverted you would still hear something.

What's the sound like with a 80/20 or 20/80 blend?

i57dwun4yb1pt8

all you get if you go off center towards either end , is more of the pick up assocaited with that end and none of the other pickup , so its in effect behaving like a volume control forward or volume back with nothing in the middle

its sounds fabulous at either end , but in the middle , nought !


HISTORY

i bought this bass from a guy who refurbed it as a home project - he called around and i checked it out , and it sounded ok , ,
seemed to be lacking in growl and top end a bit . but i thought it might be the strings - so i bought it .
looked good , hed done a great job on the body and neck

so I changed the strings , and it sounded the same , a little better maybe - but still not what i expected .

I decided to have a look inside , and my jaw dropped at the mess inside . - dry joints , bad soldering .
and the pickups were badly wired as well-,

decided to strip it all out and rebuild the electronics - had to figure out all the circuitry and signal paths ( its active )
I knew there was a killer sound in this thing somewhere.

took me all weekend - but now it sounds fcuking amazing - all the top end and growl is there and then some !

it sounds like its worth 4 times what I paid for it - so im not to p1ssed anymore at the electronics botch job he sold me .

( I think he'd actually be p1ssed if he heard what it sounds like now TBH - its a real find )

but the only issue is the blend pot - its doing this weird thing
( I have wired the neck to the top of the pot and the bridge to the bottom -
he had it the other way around - i might change it to that and see )

anders

Just a thought... You say the bass is active, right? This means the pickups would be fairly low output compared to passive pickups. The blend pot wiring seemes to be ment for passive pickups.

Could it be that the pot is to heavy for the application when used with active pickups so that the centre possition actually attenuates the signal too much and lets nothing trough? Anyway of putting in the blend pot after the active circuit?

PMI

anders wrote: »

Just a thought... You say the bass is active, right? This means the pickups would be fairly low output compared to passive pickups. The blend pot wiring seemes to be ment for passive pickups.

Could it be that the pot is to heavy for the application when used with active pickups so that the centre possition actually attenuates the signal too much and lets nothing trough? Anyway of putting in the blend pot after the active circuit?

Follow this route.....im thinking the same....

i57dwun4yb1pt8

ahh , i did some searching , and it looks like i need to reverse the hot and ground on the pot ( at moment its centering to ground = o out ) when it should be centering to hot .

dunno how the last guy got it to work - as i think he had it wired as i have
to hot and ground - but i may be wrong ;_)

will swap em and report back ..still cant believe how good this bass sounds now though compared to when i bought it - fcukin hell .

120_Minutes

interested in seeing a pic of this bass!

i57dwun4yb1pt8

here you go , now ive fixed her innards , shes a killer .
the pickups are superb .

http://www.adverts.ie/showproduct.php?product=101179&cat=16


the one thing ive learned is - make sure you check the electronics when buying refurbs .
lucky im handy with solder and circuits.

he did a great job on the neck though , really nice - Id never manage it .

PaulBrewer

anders wrote: »

I can't believe you could get a 100% cancelation, it's just not possible.

I'd agree here

anders wrote: »

Just a thought... You say the bass is active, right? This means the pickups would be fairly low output compared to passive pickups.

I'm not sure of this though. Certainly the output of the bass itself would generally be higher on an active as opposed to passive. I see no reason why the pickups themselves would be lower.

If it was a passive bass (does it have a passive mode?) one would think the selector switch was the problem however being active it could be a million things.

PaulBrewer

anders wrote: »

I can't believe you could get a 100% cancelation, it's just not possible.

I'd agree here

anders wrote: »

Just a thought... You say the bass is active, right? This means the pickups would be fairly low output compared to passive pickups.

I'm not sure of this though. Certainly the output of the bass itself would generally be higher on an active as opposed to passive. I see no reason why the pickups themselves would be lower.

If it was a passive bass (does it have a passive mode?) one would think the selector switch was the problem however being active it could be a million things.

i57dwun4yb1pt8

fixed it by swapping the hot and ground around , sounds even better , this thing just keeps on giving !


gonna sell me other basses now , this one does the lot .

120_Minutes

ahhhh its that bass! that caught my eye over on the GS board. i'm very surprised that the doc did a bad job on the wiring.

ya lucky baxtard. i wanted that bass.

i57dwun4yb1pt8

not as suprised as i was after forking out for it ,
alot of people think they can solder and put electonics togehther , but its not as easy as you think,

still the work he did on the neck was very nice.

i guess it was fate , cos once i fixed her , she came alive .

tis a little gem

120_Minutes

DaDumTish wrote: »

not as suprised as i was after forking out for it ,
alot of people think they can solder and put electonics togehther , but its not as easy as you think,

still the work he did on the neck was very nice.

i guess it was fate , cos once i fixed her , she came alive .

tis a little gem

I think i may be calling you for a wiring job in the future then! check my thread on the gs board bass section about the bass i'm building....

anders

PaulBrewer wrote: »

...Certainly the output of the bass itself would generally be higher on an active as opposed to passive. I see no reason why the pickups themselves would be lower...

To my knowledge active pickups have lower output due to a smaller coil. This is compensated by a built in pre amp which brings up the level.

i57dwun4yb1pt8

120_Minutes wrote: »

I think i may be calling you for a wiring job in the future then! check my thread on the gs board bass section about the bass i'm building....

sure , if oyu want to

takes bout two days , quicker if you have full circuit digrams .
we can work out a deal

Seziertisch

If you really want to get it sounding good I recommend wiring (at least in part) with Evidence Audio Monorail. Great sounding all purpose instrument cable at a very attractive price (around 2 yo-yos a foot).

PaulBrewer

anders wrote: »

To my knowledge active pickups have lower output due to a smaller coil. This is compensated by a built in pre amp which brings up the level.

Why would they have a smaller coil?