Hi, I recently purchased a preowned 2013 Dupont MD60 on reverb and immediately noticed it had fret buzz, or so I thought. So I brought it to my luthier and refretted the whole guitar only to discover the buzzing persisted. After consulting builders, dealers, and forum posts, I discovered it was sympathetic vibration and not a fret buzz.
The guitar buzzes on the C and C# notes only on the G and D strings. If I tune those strings down a half-step the buzz will follow the note. I've checked the tailpiece, bridge, truss rod, and tuners. I purchase an LED luthier mirror to look inside the guitar and can't see anything abnormal. If i strike the note softly it doesn't buzz, but when I play at regular volume it does.
Has anyone encountered this type of sympathetic vibration before, or have any further suggestions?
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