I've noticed in my last recordings (including Lisbon ones) a background annoying white noise.
After some tests I founded out that the issue comes from the microphones amplifier. I had to diminish this defect at editing proces by applying denoising filters.
I will replace that component as soon as possible.
Update (2011/11/03):
I've got the device:
Good news!!!
After some tests with this new set, the results are outstanding, so I hope the next recordings will have a pure crystal sound of hight quality.Later this month I expect to attend a good concert.
Keep in touch.