Electronic Repairs on Hollowbody Guitars
This beautiful Collings I30 guitar came to us with a non-functional neck pickup tone control. While this is likely a simple repair electronically, as with most wiring repairs on semi-hollow and fully hollow-bodied guitars, the more time consuming task will be accessing and reinstalling the electronics before and after service.
As we have previously mentioned in our article about replacing hollow body output jacks, Hollow-bodied guitars typically do not have and easily accessible control cavity. Rather than a removable pickguard like a Fender Stratocaster or a control plate such as a Fender Jazz Bass, the electronics on these guitars must be fed in and out through either the pickup cavity or the instrument’s F- hole.
After removing the mounting nuts and washers and unscrewing the bridge pickup, we carefully pull the wiring harness out for examination.
Since the pickups and string ground wire are still attached, the work will have to be performed on top of the instrument’s body. Here we are using a retired polishing cloth to protect the top from damage.
After observing that all the connections appeared visually solid, we tested the Jupiter “vintage tone” capacitor and found that it was defective. If within spec, this particular capacitor should read about 20nF on the meter; A reading of 0.18 is way out of range.
After a quick bit of soldering, we’ve got the new capacitor installed and the tone control is working great! Now, before we can call this done, the electronics must be carefully reinserted through the pickup cavity and mounted in their former position.
Reinstallation can be a bit fiddly since there is limited space with which to manipulate the parts back into position and one must take care not to damage the instrument body or any of the wiring work, which would then require its re-removal. There are a few different techniques for this; For us, nimble fingers and curved tipped forceps are the tools of choice.
Jupiter Condensers Tone Capacitors
Erik Salomon - Calico Guitarworks Owner / Head Technician
Tech Talk articles are part of an ongoing effort to provide clear and detailed answers to common questions about guitar maintenance, modifications, and repairs.
While not intended as a step-by-step guide to servicing your own instrument, we hope that you will find value in the information provided.
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About Calico Guitarworks
Calico Guitarworks is the area’s premier destination for fretted musical instrument care and maintenance. Owned and managed by Erik Salomon, the shop is dedicated to providing quick, honest and reliable service. The staff at Calico Guitarworks has a combined 25+ years of professional guitar repair experience. Sharing the knowledge that we accumulate in this focused pursuit is at the core of what we do. Learn more About Calico Guitarworks, explore our Frequently Asked Questions, or Contact us with a specific request.
