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Scott Dorsey Scott Dorsey is offline
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Default Comparing two audio interace mice pre's for self noise.

In article , Tobiah wrote:
How would you do it? I have one of those 150 Ohm terminators
that you guys told me how to make. Given two USB audio interfaces,
what would be your procedure for comparing the two units (like
deciding which one to keep) with regard to the mic pre's, mostly
for noise figures.


Set the gain the same way, put the terminator in, read the noise floor on
the meters.

If you don't trust the gain settings, put in a tone, set the gain, then
replace the tone source with a terminator. So that way you know the gain
is the same on both.

I have a pair of NT1A's, and am looking for low noise and transparency.


Low noise isn't always transparency... often people will do tricks to
bring noise down at the expense of coloration.

Since most of the mike preamp noise is at low frequencies, if you design
it to roll everything off at 60 Hz or so the preamp seems a lot quieter...
but it isn't.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."