> However, many recorders have converters (e.g. sigma-delta converters) and
> noise shaping algorithms that produce an increase of noise with frequency=
.
> Probably we need first to check if the noise produced by the converter is
> flat or not. How to do this ? By shortening the input ? or by lowering th=
e
> gain to zero ?
Gianni,
I'm using a pro quality SQN mixer which feeds into a cheap Tascam recorder=
at line level and the recorder noise level is around the digital dither
level in the bottom three bits. This is around 72dB below peak and well
above natural sound and mic noise levels in practice.
If you are using mic level inputs, check the recorder noise levels with a
dummy load across each input around 1000 Ohms. Otherwise just short out the=
inputs. Turn off PIP powering. Lowering the gain to zero will not include
the input preamp stage noise but try that as well.
David Brinicombe
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