> Robin, one thing that I miss a lot, are block diagrams describing
> recorders. It would, for example, improve my understanding where, in
> the chain, that self noise is produced.
> Dan, as a Nagra service man, can you get such diagrams over Nagra
> recorders, if you want to? Even more detailed?
I could, but I don't think it would be very helpful. On the recorder end things
are pretty simple. If the noise in the recorder's signal chain isn't dominated
by the noise of its mic preamp, its broken. You'd have to turn a recorder's
gain down below 30% or so to get into that condition; but when you have a loud
source, input noise is inconsequential.
Digital gain control after the converters the way some recorders do adds a
complication; it's like what you might do in post processing but in the
recorder before the file is written. I can see that as being useful if you
wanted to end up with a finished production level in the box, like if you were
producing a podcast that you would edit in your recorder or smart phone and
post directly to the web. But it's much better to record at conservative levels
in the recorder and do post work in post, when you are in a predictable
environment.
It would be very useful for those who do technical tests on field recorders to
discover, in recorders with digital gain controls, what the unity gain setting
is; that is, the gain setting that makes the converters' clipping point match
full scale code.
-Dan
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