The Mudcat Café TM
Thread #116640 Message #2505773
Posted By: GUEST,Tom Bliss
02-Dec-08 - 08:51 AM
Thread Name: Acoustic Guitar Pickup
Subject: RE: Acoustic Guitar Pickup
Hi Richard - that's very strange, the I-beam is usually very reliable. There may be two reasons. The first would be some fault in the unit itself, which is unlikely as there's not much to go wrong, just a transducer in a case and the pre-amp (though that could be dodgy - is the power form the battery getting through properly? I don't have any with the volume control, but maybe there could be a crack in the resistor, or perhaps a dry joint?
The second possibility is more likely - that the i-beam is not seated properly on the bridge plate. You could check this by removing it if you wanted to. Do you have the special jig that comes with it? For locating the i-beam under the bridge? And do you have some spare double-sided tape? (It has to be the stuff they supply I think - normal tape is not sticky enough). If so you should be able to take out the i-beam by rocking it very gently until it comes loose. Then remove the tape, apply new and re-fit. Does the Hagstrom have a peg bridge (sorry, not familiar with that model)? I-beams can be fitted to floating bridge guitars (and Richard Bridge guitars, obviously), but they're much harder to fit, as you can't apply force to the jig by heaving on the bolts through the peg holes, to seat it firmly on the bridge plate. The other issues might be a bridge plate that's not completely planed flat, or one that's too small for the i-beam - it has to make good contact along its full length.
The I-beam is so clever because, being a transducer, it faithfully reproduces the vibrations of the sound board without the feedback issues associated with open mics (which amplify the sound travelling through air), or the thickness of magnetic pick-ups, or the lack of contact of 'contact' bugs - yet because it's not trapped between bridge and saddle it doesn't bark or quack, is not prone to damage through compression, and also does not interrupt the transmission of vibrations from string to saddle to bridge to soundbaord (top).
It sounds to be like yours needs looking at.