Kramer guitar - tone control wiring help.

musicalstash

Any ideas on what's going with the tone controls on this Japanese kramer, it all works as it should except for the tone controls. 

I've opened the guitar up and cannot see any loose wires or dry joints, the wiring diagrams I have seen online don't match this one so a bit stuck . 

Hss with coil tap.  Tried to show on the photos but the cap from the volume control runs to the end leg of the 5 way switch  

https://ibb.co/j4Vrtmm

https://ibb.co/6JcN2Zh

https://ibb.co/Xb8q566

https://ibb.co/d5wChHN

https://ibb.co/QJvFqyn

https://ibb.co/565MN4D

Any input would be appreciated 

Funkfingers

Your selector switch and tone controls are wired correctly. The only weak link is that the tone control grounding path is via the pickguard screening foil. This works but hard wire between all three pot cases would be preferable.

The cap on the volume pot is a treble bypass between two of the terminals. The grey/black continuation wire is the normal connection between the switch and the volume pot.

So far, so normal. Textbook vintage Stratocaster, in fact.

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The disadvantage of the traditional circuit is that there is no tone control for the pickup nearest the bridge. Is this what is "wrong" with your Kramer?

If so, the solution is to add a wire on the selector switch. Add a new link between the unused terminal and the next one along. i.e. The one connected to the lower tone pot.

musicalstash

Thanks for in depth answer,  the issue is that both controls don't seem to work on any of the pickups, the volume works as it should as does the coil switch. 

musicalstash

Just plugged the guitar into a larger
amp and  turned he gain  all the way up and without touching the strings turning each tone control it does have an effect on the amount of "hum" . This happens in the correct position but cannot really here a difference when the string is struck. 

Funkfingers

Each of the capacitors in your circuit should have some letters and numbers printed on it. 

Please specify what is printed and which cap is which.

FelineGuitars

You ought to daisy chain an earth wire from the back of the two pots to the back of the volume pot .

If you don't have an earth in place and the contact with the foil on the pickguard is compromised then the tone controls can't bleed the high frequencies away to earth as they are not connected to earth

the cap on the volume control is simply a treble bleed 

ICBM

Can't add much to what's been said already - the first thing I would do is connect the backs of the volume and neck tone pots together - you don't need to worry about the other tone pot since the cap isn't connected to it.

Everything else looks OK, so if that doesn't fix it the remaining possibilities are either a faulty switch - the rotor on the tone side not making proper contact with the terminals - or a faulty cap... very rare but not impossible. It looks the right physical size to be the correct value, although it won't hurt to check it.

Funkfingers

FelineGuitars said:

the cap on the volume control

My thought is that the bypass cap value is too close to that of the bleed cap on the Tone Control part of the circuit. They might almost cancel each other out.

ICBM said:

remaining possibilities

One other.

How old/corroded are the strings? Passive treble roll off controls can not subtract frequencies that are not there to begin with.


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FWIIW, the humbucker mode switch is configured for series/parallel. True coil split would only be available if the mini switch is a DP3T on/on/on.

musicalstash

Just soldered a wire from the volume to the tone control and the tone controls have come back to life.

https://ibb.co/6y84bBB

out of interest why would they not  have done this from the factory ?

Thanks again to you all for taking the time out to respond,  I spent the whole of the morning going through various amps trying to persuade myself I could hear a difference. 

ICBM

musicalstash said:

out of interest why would they not  have done this from the factory ?

Cheapness/quickness - relying on the contact between the pots and the shielding foil to make the connection - or a mistaken belief that doubling the ground connection causes a ground loop.

Omitting a shakeproof washer between the pot and the foil makes the connection less reliable. Sometimes it's not the one between the pot and the foil which fails, it's between the pot casing and its bushing part - which is held by four little bent-metal tabs. Surprisingly, it's possible for enough oxidation/corrosion to get in that all four cease making an electrical connection.

Funkfingers

musicalstash said:

why would they not have done this from the factory ?

Cheepnis - as Frank Zappa would put it.

If a previous owner had upgraded the pickups, it might have been necessary to unfasten everything on the pickguard prior to altering any of the holes through it. Unfastening and refastening the pots a few times can be enough to wear through the screening foil. This, in turn, weakens the grounding path for the tone pots.