Shielding the control cavity can be useful, but it is usually more important to shield the pickup cavities first.
Most interference is picked up by the pickups themselves, especially single coils.
If pickup cavity shielding is added, connect each shield back to the instrument ground so the shielding is actually effective.
It’s possible to screw the terminal shut leaving a gap beneath the little plate looking pretty much the same as when the terminal is fully open. In other words, the screw terminal has been tightened up and you’re putting the wire in beneath the plate, and it won’t grip the wire.
See if you can unscrew it and have the little plate go down to the bottom.
Our pot threads are the standard 10mm length, same length that most use for rear mount.
Most bass bodies are 6mm or 1/4″ thick in the cavities.
Our nuts are ~2mm thick and one washer is 0.4mm
NOISE CANCELLING HUMBUCKERS
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+ Total noise cancellation is virtually impossible.
* For it to be perfect, the coils would need to be in exactly the same position, physically exactly the same size and construction, with mirror image coils.
* To call a pickup noiseless is rarely a truth, buyers are misled.
SINGLE COILS
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+ Often based on original vintage designs, they are the easiest to make/replicate and often sound really pleasing.
* This type is the most prone to interference but grounded copper foil screening in the pickup cavities can help massively, even just the on ‘floor’ of the cavity can make an enormous difference.
SCREENED HUMBUCKERS
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+ A combination of hum-cancelling coils and screening can help to create a virtually silent pickup.
* It is important that the pole pieces and/or magnets are grounded.
GROUNDED POLE PIECES
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+ Vintage pickups rarely had their magnets or magnetic pole pieces grounded.
+ Many modern pickups do have grounded pole pieces and magnets, but making an electrical connection with magnets can be an issue.
+ Where adhesive-backed copper foil is taped across the underside of magnets, it can work for a while but may eventually lose contact. The adhesive needs to be conductive but the conductivity is poor with many lower cost types of foil tape, that state conductive adhesive.
Crackling noises when turning knobs are typically not caused by dirty pots in East UK preamps, as the pots are sealed. The issue usually stems from the inner and outer shafts of the stacked knobs making and breaking contact as you rotate them. This is particularly noticeable with the treble knob due to the additional push-pull bright switch mechanism. While the pots are high quality and durable, this slight play in the shafts is a known characteristic.
To minimize the crackling, try grounding yourself to the plate, jack, or strings with one hand while rotating the upper knob with the other. If this reduces the noise, consider installing a spring between the upper and lower knobs to maintain ground contact.
If the issue persists or worsens, it could indicate a bent shaft, which might be carefully straightened. However, extreme caution is advised, as any sharp movement could break the shaft. For severe cases, returning the unit to East UK for pot replacement is recommended.
First, ensure that your pickup cavities are properly shielded. Use copper foil and connect the shields to the ground wire of your output jack. (see faq How to prevent buzzing… for more detailed info)
Next, check the height of your pickups. They should be adjusted close enough to the strings for a strong signal without causing interference.
If the noise persists, it could be inherent to single-coil pickups, which are known for their susceptibility to hum. Consider using hum-canceling pickups or explore further noise reduction techniques.
