This early 70s P bass was producing a very weak and very noisy signal. The challenges started with simply trying to get the scratchplate off - the screws were choked with rust, both in their threads and heads.
The wiring had been replaced at some point, but had been done by someone without great soldering skills - there were some poor solder joints in there. The pickup also had a problem - one coil showed very high DC resistance when measured on the multi-meter. I don't have the experience or equipment to start digging into a vintage pickup, so after consulting the owner I sent it off to Armstrong pickups in Kent. They rewound the coil and got it back to me in just over a week. I replaced all the wiring again and put the bass back together. All the scratchplate screws had a cleanup, apart from three that I replaced with new, aged screws. This bass had obviously had a life, with quite a bit of natural wear, and also some corrosion to metal parts. It was very satisfying to see it working properly again.
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A customer contacted me, asking if I could cut down the nut slots on his 'Partscaster' Stratocaster. The guitar was made up of a 1980's Squier body to which he had recently added a Fender neck that he bought via eBay. The nut slots on the neck gave the guitar a very high first fret action. On inspecting the guitar, I realised that it really needed a full setup. This involved:
1. Adjusting the truss rod, 2. Shimming the neck/body joint to allow a good action to be obtained within the adjustment range of the bridge saddles, 3. Adjusting the bridge saddles to give a comfortable 12th fret playing action, 4. Cutting down the nut slots to give a comfortable 1st fret playing action, 5. Adjusting the intonation. Additionally, the customer asked for a couple of Tusq string guides to be fitted to the headstock and the earth wire solder joint onto the vibrato claw needed repairing. The customer had a Yamaha RBX375 bass, which has active circuitry. The pickup pan control and tone control didn't appear to be working properly. Active circuits can be tricky to work with as there are usually quite a few components, circuit boards and wires crammed into small spaces in the control cavities. The complexity of the circuits also makes them quite difficult to understand and diagnose without a circuit design diagram. Fortunately with this one I was able to find a service manual on the Internet, for a similar Yamaha bass. This helped me to home in on the part of the circuit which might be at fault. By doing some meter tests and physically inspecting the circuit (with a torch and magnifying glass) I found a solder joint which had been badly made in the factory and which had subsequently come apart. This was easily fixed, but is a good example of how this type of problem can take a lot more time to diagnose than to fix.
The customer had made a bass guitar some years ago, while at school. It had been unused for several years, but he had recently tried to play it. Unfortunately he found that the electrics weren't working and he had no recollection of how it should have been wired. He came to me to get it working.
I was slightly surprised when he turned up with just the scratchplate with the pickups and controls attached - no guitar! Anyway it didn't stop me doing the work. On examination, the wiring was a bit strange, plus one of the pots was broken. I suggested that I would get three new pots and wire it up as a Fender Jazz Bass, with a volume control for each pickup and a common tone control. In addition to this, the coil wire of one of the pickups was not properly soldered to the hookup wire, so this needed repair. Final testing was done by holding the scratchplate close to the vibrating strings of one of my basses and checking that a signal was being generated! The customer followed up with a text message: "Works like a dream. Thanks Duncan". |
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