All I can say is is the hum must definately be the result of the pickup. I haven't recording directly using any amplification devices. I can understand how a harp would present difficulties using mics ... as mentioned an accoustic guitar, mandolin, harmonica record with no problems ... the djembe comes in a bit weak and is difficult if not impossible to get the full resonance ... banjo came in with some high peaks (surprised) but was able to do some sound editing to remedy that issue.

sorry for all the posts I made here .. but those interested in recording .. do check out that World Studio website!

sIx