John Lundsten wrote:
> and found a pretty smooth response curve that began
> | to roll off at about 1K and extended to about -20dB @20KHz. The
> | low-impedance source and balanced line didn't maintain a particularly
> | compelling response with such a long cable, but it was substantially
> | better and quite useable in our application.
>
> As i say I don't know what your UPA-1 is (or the out Z of the mic you used)
> but that seems a pretty dam poor performance to me.
>
>
Yikes! My little gizmo placed in the same sentence as "pretty dam poor
performance" kind of stings a little. Herein lies the problem of trying
to interact with the group while having commercial interests. I should
have been either more or less vague, rather than mentioning a part
number without detail.
As John mentions, the signal degradation is a function of cable
capacitance and source impedance. Input impedance of the preamp matters
too. Our preamp is driving a pretty unrealistic length of little 24
gage cable in that test. And while I admitted that it wasn't great
response, my point was that the response curve that I did have was
pretty smooth, so it could be compensated for to a large degree with EQ
or post processing--probably not best practice for high-fidelity
recording, but many applications are more about detection.
The UPA-1 is a little weather-resistant mono mic preamp (more detail at
www.aqaud.com/product.php?productid=25). It only draws about 10mA, and
has screw terminals for power and output. So with two resistors and two
capacitors, it can be configured to work as a balanced line driver and
powered by phantom power. Output impedance as wired is about 50 ohms.
The mic is irrelevant in this test.
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