Klas Strandberg <> wrote:
>
> Could be an overlooked thing...
>
> For the ones who don=B4't know about the principals of a pip circuit,
> have a look at telinga.com / whitepapers / this is plug in power.
>
> I wouldn't worry if, like in the old days, a resistor was used to
> give pip voltage. But it isn't, it seems: For some reasons, perhaps
> to increase input impedance, (?)
> a current generator is used.
> This may cause noise. On the other hand it could also lower the
> noise, compared to a battery and resistor...
>
> The tests I made last night with the LS-10 didn't show any
> difference. But I had some difficulties setting the reference tone
> because of insects.
>
> I'll be back when I know for sure.
>
> You noise measure people, Rod, Raimund, e.t.c. what do you think?
>
> I mean, - for the mic-fet it doesn't matter if it's running on pip
> voltage or a battery.
> So what could cause the recorder to start generating low freq. noise
> internally?
>
> Klas.
Hi Klas,
I also noticed the increased levels of noise caused by the activated PIP vo=
ltage option on the various recorders that I have tested (using a 150 ohm t=
ermination resistor).
I would also think that this additional (pink) noise is probably caused by =
a current generator inside the recorder.
However, I guess that this increased PIP noise is not relevant when using a=
typical PIP microphone, which itself usually also exhibits a higher inhere=
nt noise level that probably masks this current generator noise. This would=
most likely also apply for your quieter Telinga PIP mics as long as they p=
rovide a sufficiently high absolute output level.
In any case, it would be safe to switch off the PIP voltage option when usi=
ng self-powered microphones such as the Sennheiser K6/ME6x series models fo=
r instance.
Regards,
Raimund
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