Wire a 4 strand bass humbucker to a blend pot, help

[billybigbass]

Have tried all ways of hooking my 2 KA soapbar humbuckers to a new active eq wiring harness's blend pot. 

Multimeter tell me the pots all work. 

Black wire from pups is the live, red and green are tied off, soldered and taped off. This worked fine onto the former passive circuitry Vol pot.

White and bare get earthed onto pot side( blend pot back is open). 

The blend pot is wired as it arrived. 

Frustrated. 

Where am I going wrong? No sound at all. The 9v battery is good, jack is good. 

TY

[BassBunny]

There are some wire straps missing off the blend pot.

Google "blend pot wiring", I'm on a mobile at the moment and can't find the image I downloaded to add.

[Geek99]

Agree

 

https://www.stewmac.com/video-and-ideas/online-resources/learn-about-guitar-pickups-and-electronics-and-wiring/blend-pot-wiring.html

Edited July 10, 2021 by Geek99

[Geek99]

I’d say the two crossing strappers were missing 

[billybigbass]

There is a short wire crossing the 2 pan levels, 1st pic didn't show it. 

[paul_5]

That joint in the bottom left looks dicey at best.

 

solder joints should be bright and shiny- are you using rosin cored solder or flux? 
 
Your iron might need the temperature adjusting too if possible - dull joints can be a sign that your iron is too hot.

Best thing to do is remove all of the solder from the pot lugs, cut fresh ends on the wire, then twist and tin them. Insert both ends into the solder lug, then solder them both to the pot at the same time.

 

Also, it’s worth putting a crocodile clip across on the lug you’re soldering as a heat sink so you don’t damage the pot with heat. 

Always turn pots to full counterclockwise before soldering them too - this reduces the risk of damaging the track inside with the 200 degree iron..

sorry if that’s a lot, I’m just sharing the wisdom of my years of building, and the stuff that I learnt the hard way when I was starting out.

Edited July 10, 2021 by paul_5

[billybigbass]

26 minutes ago, paul_5 said:

That joint in the bottom left looks dicey at best.

 

solder joints should be bright and shiny- are you using rosin cored solder or flux? 
 
Your iron might need the temperature adjusting too if possible - dull joints can be a sign that your iron is too hot.

Best thing to do is remove all of the solder from the pot lugs, cut fresh ends on the wire, then twist and tin them. Insert both ends into the solder lug, then solder them both to the pot at the same time.

 

Also, it’s worth putting a crocodile clip across on the lug you’re soldering as a heat sink so you don’t damage the pot with heat. 

Always turn pots to full counterclockwise before soldering them too - this reduces the risk of damaging the track inside with the 200 degree iron..

sorry if that’s a lot, I’m just sharing the wisdom of my years of building, and the stuff that I learnt the hard way when I was starting out.

thanks for advice.

that dodgy solder was me i think, removed some solder by mistake.

the solder i have is a lead free a 0.7mm alloy sn99% cu 1%. stuff from Rapid. Says 22SWG on it. The soldering gun is 15 watts.

my experience is clearly limited, have done some simple  passive p bass 2 control repairs sucessfully but never dealt with a blend pot, that's why i bought the whole harness. Living in the back of beyond i dont have easy access to guitar techs, 3 hour trip down to glasgow. Can usually work things out myself but am wasting a lot of time on this job.

per the stewmac link schematic should i put an earth wire across the top left to bottom right tabs? Then put the 2 black pup wires back to the middle tabs?

Edited July 10, 2021 by billybigbass
error

[Woodinblack]

Yes. A blend pot is effectively two volumes in reverse

[Geek99]

1 hour ago, billybigbass said:

There is a short wire crossing the 2 pan levels, 1st pic didn't show it. 

Yes, but you need two 

that single wire is not obvious in your first image, but you do need two 

[billybigbass]

11 minutes ago, Geek99 said:

Yes, but you need two 

that single wire is not obvious in your first image, but you do need two 

Like this? 

Short black wire added across. 

Still not working. 😕

Edited July 10, 2021 by billybigbass

[Geek99]

Maybe continuity test those strap wires ? Is either one of the pot tracks burned perhaps ? 

[Woodinblack]

Needs to be something like this - assuming if that wire is earth, and the red wire is out.

[Geek99]

Yes he is right, pickup feeds go on the two middle tags, output bottom left tag 

 

 

 

[billybigbass]

That's how it is wired now but nada. 

[Geek99]

Did you check continuity on straps?

suggest you post a face-on image and detail the connection colours and purposes 

[billybigbass]

45 minutes ago, Geek99 said:

Did you check continuity on straps?

suggest you post a face-on image and detail the connection colours and purposes 

continuity seems fine both straps, getting reading to 0 ok so not a poor connection.

the connections are a bit of mystery, the kent armstrong sheet doesn't label each wire just gives different wiring for dpdt switch, vol pot and jack, nothing for blend pots.

the harness wiring paper is of little help because it shows connection for 2 wire pickups only and a single row of tabs on the blend pot image rather than 2 rows. Chinese i expect.

attached both with the image of the wired blend pot again.

 

warman have a wiring guide online but not sure if KA follow that same wiring.

 

 

Edited July 10, 2021 by billybigbass

[Woodinblack]

It says in the pickup description "Black is pre - soldered to earth wire". Black is the earth, white is the output. If you tie the white to earth you have shorted out the whole pickup, you wont' get anything at all.

Seemed odd when you said black was output, black is almost always earthed.

Edited July 10, 2021 by Woodinblack

[billybigbass]

appreciate black is usually earth but there is a separate bare earth wire with these pups, 5 wires in total.

the way the pickup was wired to the former passive system volume pot, which worked fine, before i started is shown with black connected to vol pot tab with white and bare earthed to back of pot.

 

Edited July 10, 2021 by billybigbass

[Woodinblack]

Well, thats ok, although if you have another pickup (unless it is the same type wired the same) it will be out of phase..

I was confused as you showed that Warman pickup diagram, which show that green and red were one side, which you shorted together and black and white were the other phase which were also shorted, whereas the other diagram seems to show kent armstrong which have different wiring. So what pickups are they? I assume not those warman.

Have you buzzed out and made sure there is a connection between white and (one of green or red) and then (one of green or red) and black?

Also you should be able to buzz out between the Red output and the earth on that bass and have a value with the knob fully towards that pickup which is 1 / (1/(resistance of pot) + 1/(total resistance of your pickup))

 

[billybigbass]

57 minutes ago, Woodinblack said:

Well, thats ok, although if you have another pickup (unless it is the same type wired the same) it will be out of phase..

I was confused as you showed that Warman pickup diagram, which show that green and red were one side, which you shorted together and black and white were the other phase which were also shorted, whereas the other diagram seems to show kent armstrong which have different wiring. So what pickups are they? I assume not those warman.

Have you buzzed out and made sure there is a connection between white and (one of green or red) and then (one of green or red) and black?

Also you should be able to buzz out between the Red output and the earth on that bass and have a value with the knob fully towards that pickup which is 1 / (1/(resistance of pot) + 1/(total resistance of your pickup))

The pups I have are the Kent Armstrong HB5E3B model.

This diagram below is about all i can find for the kent armstrong bass pickup wire colours online and seems correct, their guitar humbucker pickups are different just to confuse.

Have hit up Flynn amps in glasgow who are good at this type of thing, see if they'll help. Losing the will to live, this is my 2nd day dicking about with it. 

Might be the jack is wrong, I had to take the jack socket off the new harness as it was the wrong type, mine has a long barrel jack, just wondering if I've done that re-wiring wrong now.

with a voltmeter and the 9v battery plugged in I get  near to 9v reading at teh jack terminal for battery wire, I dont however get any voltage reading on the hot terminal that the volume pot is wired to with my amp on and lead plugged in the bass. my logic tells me I should get a voltage reading there. I get voltage readings off the bass and treble pots but not the volume or blend pots. I do get resistance readings off the volume and blend pots though. Not sure of any of that is significant.

Electronics is a bit like double dutch to me, if there isn't a clear wiring diagram to follow I'm struggling.

 

57 minutes ago, Woodinblack said:

 

 

[BassBunny]

Can we backtrack a bit.

What pre-amp are you using? Is it installed in the bass? Have you tested it without any pickups/blend/ volume control?

It looks like an orangey/red wire that is the input to the pre-amp, touching that with bass plugged in should give you a low buzz.

[billybigbass]

28 minutes ago, BassBunny said:

Can we backtrack a bit.

What pre-amp are you using? Is it installed in the bass? Have you tested it without any pickups/blend/ volume control?

It looks like an orangey/red wire that is the input to the pre-amp, touching that with bass plugged in should give you a low buzz.

All I have is in this kit, that includes a preamp, does it not? 

https://www.gear4music.com/Guitar-and-Bass/Wilkinson-Active-Bass-EQ-System/36DF?origin=product-ads&gclid=Cj0KCQjwiqWHBhD2ARIsAPCDzamGlw2VAZVK4nn_ChOd19XcHWYqjPSAOsyl3eaCuOYh_-oC4YBQNUEaAgKEEALw_wcB

[BassBunny]

Yep, that's ball the gubbins.

Is it installed in the bass and have you done the "finger" test?

[Woodinblack]

So I was missing all the bit about the preamp. Simple way to follow what is going on, I am guessing the electronics are in the back and the bass is together with the strings on? if you ignore the preamp (take the battery out), ground the outside of a jack plug plugged into an amp (remember to turn it down), so the outside barrel touches ground, you should be able to touch the tip to where the red wire connects on the blend and get the sound of the bass. If you don't get that there is nothing you are going to get from the preamp.

Judging by the look of that kit, I assume it has everything you need once you get past the input.

Also when you say yours has a long barrel jack - was it active before this as there are a lot of barrel jacks you get that have 3 pins but aren't trs sockets (confused myself with that one before). It has to be a TRS socket or the switching wont work (on the plus side it will be always on, so at least it will work for a bit)!

[BassBunny]

Scratch everything I said.

I've just had a close look at the pre-amp and that isn't the blend that comes with the kit.

If you look at the picture on the gfm website, all the controls are wired to plugs that locate on the pins on the circuit board. I assume the pickups are wired to the small PCB that the blend control is fixed to and then plugged into the pcb. I've tried to find a wiring diagram on line, but nothing.

Is this a new pre-amp?