Re-wiring active bass guitar / pickups

[sonicyouth]

Not really sure if this fits any other topics, or even this one. But im getting pretty stuck on this one, just repaired my old ashdown bass amp, easy job, some cracked solder joints and some new jack sockets, onto my bass guitar, inside is an incredible mess of wires and dodgy solder from whoever owned it originally...
Does anybody know the basics of wiring active guitars? It has:
Two active pickups
One volume pot
One tone pot
One three way selector switch
a 9v battery
a capicitor

Next week im buying new components including a new 0.40uF capacitor to hopefully give a brighter sound on the tone pot, however no wiring diagrams seem to fit exactly my specs, and being somewhat of an amateur I cant really transpose those to suit my needs.
Any help appreciated! I can upload photos or more info.
Cheers sparks

 

[nickblake]

most guitar wiring is a mess , what you want to do is before you replace the wiring is get a piece of paper and draw where each wire goes inc the capacator this way you are not going to get it wrong , in most i have worked on the battery is connected when the jack is inserted also some operate via a switch .to help reduce noise do all the connections in screened cable and earth the screen

 

[nick182]

i dnt have any info to add but id just like to say that sounds like an awesome project. Id love to see how it all pans out. Can you include some pics on your next post?

cheers
Nick

 

[sonicyouth]

Thanks Nick(s), that sounds like a good idea. NickBlake... Nick Blake fan? Pink Moons a great album.
Ive found a load of wiriing diagrams, its just a trip to maplin and ill show some photos, it looks more complicated than it is I think!
ta

 

[sonicyouth]

Well I left my shopping list at home and didnt manage to get all the components from maplin, my bass amp is now absolutely screwed, attached are photos, if anyone knows anything about amplifiers give me a shout, I dismantled it and resoldered some cracked joints on the PCB, but it made no difference it doesnt detect any input at all now, still turns on.
Heres some initial photos of my bass, not going to rip it up just yet until I know what im doing.... (any comments/advice welcomed)

 

[nickblake]

RS will have the parts you need or CPC maplin tend to be very limited on components these days , so what wrong with the amp then . easiest way to test them is by using an oscilloscope ,oscillator this will inject a sine wave into the input of the amplifier , and a dummy load and work your way through the circuit looking at what the amps doing rather than listening

 

[sonicyouth]

RS will have the parts you need or CPC maplin tend to be very limited on components these days , so what wrong with the amp then . easiest way to test them is by using an oscilloscope ,oscillator this will inject a sine wave into the input of the amplifier , and a dummy load and work your way through the circuit looking at what the amps doing rather than listening

I never knew that, my knowledge extends only to resoldering and checking for burnt/damaged components, that sounds great but I lack the funds to buy an oscilloscope as much as id love to have one! I will try RS mail order once i know exactly what bits I need. Would you recommend any literature or knowledge bases for amateurs (attempting) to service this type of gear?
thanks for your advice

 

[nickblake]

scopes always sound expensive but you can pick up cheap ones on ebay i used to repair amplifiers years ago i then had an expensive scope these days ive got one that cost £15 off ebay , you can get service manuel for most amplifiers these have the schematic diagram , you are right to look for burnt components and dry joints as these are very common especially with modern lead free solder ,always start with the power supplies and check you have the right supplies depending on the amplifiers some can use plus and minus 55 volts , other common faults are blown output transistors , the bits that work hard ,basically an amplifier is a pre amp then power amp all on the same board there are some books on the market basic amplifiers and power amplifiers worth a look