Players will spend money on expensive pickups and leave the rest of the circuit untouched. Sometimes that works. Sometimes the new pickup only reveals how weak the rest of the electronics are.
The pickup is not the whole signal path
The signal still passes through pots, caps, switches, solder joints, grounding, and the output jack. Cheap or worn parts can make a guitar scratchy, dark, intermittent, noisy, or unreliable even when the pickup itself is good.
Symptoms that point past the pickup
- Scratchy controls
- Signal cutting in and out
- Noise that changes when touching hardware
- Weak output from one switch position
- Tone controls that behave like on/off switches
- Loose jack nuts or rotating pots
Upgrade the circuit, not just the name on the pickup
A good electronics job is clean, solid, serviceable, and quiet. Sometimes the best upgrade is not the most expensive pickup. It is making the circuit around the pickup worthy of the guitar.