>> I have a hundred-foot 3.5 mm stereo extension that's .0075 uF from
>> one channel to shield. Assuming a 2 Kohm source, it would be a
>> gentle low-pass filter at about 10 KHz, if my slide rule technique
>> is right.
>>
>> -Dan Dugan
>>
>
> Hi Dan--
> Its a pleasure to use a rule isn't it?
Actually, it's the 1957 cardboard Shure Reactance Slide Rule. I'm not an
engineer, I just play one at work.
> Next time I install a long cable run, I'm going to record the test I
> did where I connected two Rode NT2000's (7dB[A] self noise)-- one to
> a 20' mic and the other to a 1000' role of cable and placed the mics
> side by side. Prior to this, I looked at all the charts and did the
> HF loss computations and then Richard Lee (miclist) suggested the
> obvious perception test. Result: to my aging ears (significant loss
> above 9-10Khz), I could not detect any loss of signal or HF. I use
> Symetrix SX202 Mic preamps.
An NT2000's output impedance is rated at 200 ohms, 1/10 or less than the
impedance of a PIP electret. So it could handle ten times the cable length for
the same amount of rolloff.
-Dan
|