I took out the bridge piece (which was very tight) and cleaned it, then gently rubbed the sides on some floor tiles (I had no sand paper). (I've done this before, although not on this guitar.) The pickup gives me an even volume on all strings, despite being about 1/32" shorter than my existing pickup. All I needed was to measure the width of my pickup so the replacement would fit in my saddle slot (1/8" in my case), and I was in business I ordered this part and it arrived in a few days, despite my choosing the option for cheapskate shipping.Īfter a few dicey moments soldering the pickup's wire onto the mini-jack that plugs into the guitar's internal preamp - you have to do this with the pickup already installed, since you can't get the jack through the pickup hole in the bridge - the installation went smoothly. So I decided to take a chance and order the pickup. I realized that the last time I had changed strings, the bridge had popped out, and I might have damaged things by putting the bridge back in carelessly. I couldn't see any breaks in the foil on my pickup, although a small enough tear could be difficult to notice.
The email went on to suggest a seller for the part I needed. Usually if you touch the endpin jack and the hum goes away, it is a shielding problem within the pickup element. It sounds like the under saddle pickup element may be faulty. (There was no shielding on the endpin jack at all, something that some web sources suggest can cause hum.)Īccording to Fishman when I emailed them about this: In the past, I've fixed similar problems in electric guitars by shielding the inner cavity with copper tape. It's entirely possible that there was some sort of shielding problem on the previous wire, as this answer suggests, but I can't say for certain. I didn't have time to shield the wire - I can't get my hand all the way into the cavity of the guitar, and I don't have tools to work inside a guitar (outside of some skinny pliers and a small inspection mirror), so I elected to simply replace the pickup. The problem turned out to be either the pickup or the wire to the preamp. (I don't want to order a pickup, only to find the problem is the preamp or the wiring.)Įven better, could this simply be a shielding issue? Can the problem be corrected by shielding the electronics? How does one even do that with an acoustic guitar, by sheilding the interior cables? How I can go about diagnosing the problem? I'd like to replace as little of this system as I can.
I've swapped the battery and made certain it's connecting solidly, neither made a difference. None of the wires inside are loose (I tightened up a cable that screws into the preamp, and that didn't make any difference), and all the soldered connections inside seem solid. So I've narrowed the problem down to the guitar electronics. (Or, if there were such marks, they've long since been worn off.) But here are pictures of the preamp and of the pickup: The preamp has no identifying marks, other than saying "Fishman Equipped". The guitar was subjected to no unusual stresses in that time, aside from being carried in the trunk of a car in the cold (but it was very well protected, in a hard case with nothing on top of the guitar). It's also worth mentioning that the problem came upon me quite suddenly, in-between two gigs about two weeks apart. Changing cables, mixers, amps - none of this makes a difference, the hum is still present. There's a continuous hum coming from the guitar, that mostly goes away when I grab the metal end of the cable jack, making me think that this is a grounding issue.
I haven't been able to identify the type of pickup or preamp, although I have emailed both Fishman and Cort in an attempt to get more information. I have an acoustic guitar - a Cort MR750 dreadnought, from about 1998 - with a Fishman pickup system that came pre-installed in the guitar.
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