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View Full Version : Strange Noise and wavelength shape in Logic while recording


Chuchi
11 Oct 2009, 07:45
Ciao a tutti,
My system

Microphone Gefell UM 70S → Preamp Mercury M76m → Studio Konnekt 48 (Tc Electronic→ TC near → Logic 9 on Imac).
I would like to understand..for not to make twice the same errors :o


To test the microphone I switch on the Preamp 1h and plug the UM70 on
Cardioid ( file cardio.onmi.eight). The shape was great (1st dark blue)
Then I move the microphone button on the Omni (O) and there was immediately a signal that appeared as the Light blue shape on logic and that reached a level of about – 24 db flashing. The phenomenon occurred in alternation on both the TC Itself and on The soft TC Near. ( zero level – zero level) (file Cardio, omni, eight) and when I went back on the cardio the wave was similar (file Eight Cardio).

This signal continued to persist even when I turned of the phantom power.
Same applies with the position on (OO) and again ON cardioid….
I’ve tried this with 3 new cables !

Then I’ve tried and tried…The only thing that I haven’t done is to set the Pot of the preamp gain and the Phantom power at zero before making the microphone selection ?:confused:

I did later on and it seems that this phenomena occurred a little with the (OO) microphone position…until I reduced gain:(

At the beginning at all steps Gain level was set between was 36-48, level noon-one and level attenuation at noon..
Turning pot of attenuation or level din not have had any influence…

Any information on how to fix it will be more than welcome…

I would also appreciate if someone could tell me the steps to do before changing a microphone setting from cardiod, O, and OO without any damage risk..:eek:
:confused:
Ciao a tutti and thanks again for your kind reply and attention

albert
11 Oct 2009, 15:13
Hey there Chuchi,

Although I have no experience with that specific microphone, I looked it up and understood it does not have an external power supply and that it uses phantom power with an onboard pattern selector.

My questions so that someone more familiar with the mic or myself may help you:

When did you acquire this microphone?
Did you acquire it brand new?
Had it been working always without a problem?
Did you ever try connecting directly into one of the preamps on the TC? (I believe that interface comes with an integrated preamp with phantom?)
Have you tried a different preamp if you have access to one?
Have you also made sure that it's not the drivers or some issue that only has to do with the conversion on the TC?
Oh, also, did you try the second channel on the 76m?

Others will probably have other questions, or might take a different approach, but whatever it is, I am sure someone will be able to help you. And worst comes to worst, I have a feeling Gefell can help!

Best of luck, and don't let one microphone get between you and recording music!