Noise after shielding

[Simon Barden]

A higher ohmage is acceptable as shielding still works (supposedly) up to about 1 megohm, but I always feel that lower is better. And with copper, you should be looking at a very small reading.

[fender3x]

A higher ohmage is acceptable as shielding still works (supposedly) up to about 1 megohm, but I always feel that lower is better. And with copper, you should be looking at a very small reading.

That's good to know. I usually get a reading that is not 0 but very close. Never higher than 2 ohms, and usually less than 1 even using aluminum HVAC tape.



Sent from my ONEPLUS A3000 using Tapatalk

[Simon Barden]

Most low-cost multimeter leads have a reasonable resistance, and often just touching the probes together can give a 0.1-0.2 ohm reading. For a good, accurate, low resistance reading, you need a more specialised meter; but these often use a higher driving voltage so aren't ideal for delicate electronics.

[Booooooom]

I'm sure my multimeter isn't one of the best that China has ever produced but here are some sample readings... (Some took a few seconds to settle down)

test probe to probe 0.1 - 0.2Ω
Isolated foil to foil (probes about 10mm apart) 0.5Ω
Isolated oil to foil (probes about 60mm apart) 0.7Ω

With the jack socket removed from the body:
Jack ring to switch 0.4Ω
Jack ring to Bridge tone pot body 8.46Ω
Jack ring to Bridge volume pot body 8.46Ω
Jack ring - Neck tone pot body 8.46Ω
Jack ring - Neck volume pot body 8.46Ω
Bridge body - jack ring 0.8 - 0.9Ω
Bridge body - jack ring (ring connected to cavity foil) 0.7Ω
Bridge volume pot body - neck volume pot body 0.5Ω
Bridge tone pot body - neck tone pot body 0.6Ω
Bridge body - control cavity foil 0.7 - 0.8Ω
Bridge body - neck volume pot body 0.5 - 0.6Ω

all of the above registered a connectivity beep

With the guitar still open I plugged it in with a loose jack socket - still quiet with both tones zeroed, still noisy (although not as bad as before) when opening the tone pots.

Any alarm bells?

[Booooooom]

Reassembled and to recap the scenario...

Neck pup selected, tone off - ok

Neck pup selected, tone open in any position - noise

Bridge pup selected, tone off - ok

Bridge pup selected, tone open in any position - noise

Both pups selected, both tones zeroed - ok but slight volume drop. Zero either volume kills all volume (in last 10% of pot travel).

Both pups selected, either tone open in any position with the other zeroed - ok

Both pups selected, bridge tone fully open, neck tone zeroed -ok. Decrease neck volume - noise

Both pups selected, bridge tone zeroed, neck tone fully open - ok. Decrease bridge volume - noise

For all above scenarios, touch any pot spindle and get noise (no knobs fitted so far)

???

[Simon Barden]

Your jack ring to pot body readings are high, indicating a poor solder joint somewhere. Those readings should be right down in the 0.4Ω region. But it's hard to understand why as the jack ring to switch reading is low when the switch is grounded from the neck tone pot, and that is reading 8.46Ω!

Can you take and post a picture of the wiring with the scratchplate off and showing all the connections so we can see exactly how it's wired now. I've been going by the build picture on the cardboard template, which obviously is missing a couple of connections.

[Booooooom]

Thanks Simon, here you go. When I originally wired it I used the colours supplied and as the Pit Bull wiring diagram but have replaced the hot wires with red ones.




For clarity, the end of the red wire connected to the switch is not touching the switch body tab.

[Simon Barden]

Something's gone wrong with the photos. Can't see or link to them.

[Booooooom]

Also for info, the vol pots (nearest straight edge on scratchplate) are As and the tone pots Bs.

[Marcel]

Going by the photos I can see and the description of the fault it looks like the signal and ground connections on the jack are reversed.

Nil sound when either volume is at less than 10% would be normal with this wiring scheme.

It's personal preference for every builder but for consistency and clarity on all my builds I prefer to use Black or Green or bare wire for all earths/grounds, with Reds and Yellows and Oranges as signal wires. And White and Blue wires for DC voltages when they enter the scene. Obviously there are plenty of times where this just can't happen or it simply doesn't matter.