Gain channel and phantom power

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  • 2010/10/02 at 8:35 pm #22490
    Profile photo of Anonymous
    Inactive

    Hello :)
    I have one question. I have ilive T112 and IDR48. When i active the phantom power on any channel and quick change the gain on this channel i hear strange “noises” like “shot” few times. Why is this happend? When the phantom power is off then is silent on this channel.

    Best regard
    Mario from Poland.

    2010/10/03 at 12:11 pm #26555
    Profile photo of Mr-BMr-B
    Participant

    Mario I think you will find the noise you refer to is normal for most channel inputs on most desks, when you apply or remove the phantom volts for the first few seconds there are odd pops and click’s which I guess could be described as shots going off, usually accompanied by the peak light coming on for that channel. I believe this is due to the fact you are applying a DC bias voltage onto a predominantly AC circuit, things like blocking capacitors have to charge up and this causes the odd noise. I am sure Carey will give chapter and verse on this. Most people just wait a few seconds for it to settle down and the noises go away. If they persist it suggests you have some bad microphone leads causing intermittent phantom voltage to the pre-amplifier of the microphone.

    2010/10/03 at 12:27 pm #26556
    Profile photo of BiggsoundsBiggsounds
    Participant

    The obvious thing being – mute the channel while you apply or remove phantom! My Neumann KMS105’s take maybe 3 or 4 seconds to settle down, and if you leave the channel open it makes a horrible din, but as Mr B said that’s part and parcel of phantom (either on mikes or to a lesser extent on di’s).

    iDR32 mixrack
    Asus N61 Laptop (x2 wireless)
    Sennheiser IEM (for PFL)
    Dante card (soon!)

    2010/10/03 at 6:27 pm #26557
    Profile photo of Anonymous
    Inactive

    I know that first 3-4 second must wait. But later then the channel is alright make quick change in gain channel (not trim). Then you can hear again “shots” – there is no microphone. Try it in your ilive system.

    Best regard
    Mario :)

    2010/10/06 at 6:14 pm #26587
    Profile photo of Anonymous
    Inactive

    No one have tried this?

    Mario

    2010/10/06 at 6:27 pm #26588
    Profile photo of ryanlantzyryanlantzy
    Participant

    quote:

    Originally posted by aqstyk

    No one have tried this?

    Mario

    Mario,

    I had a similar problem with my iLive… though it was independent of phantom power. Did it sound like this? It was only on one channel though.

    https://www.youtube.com/user/bilitski#p/u/4/jm0kazG-_UM

    I had to replace one of the I/O boards in my mix rack.

    2010/10/14 at 3:56 pm #26622
    Profile photo of mumumumu
    Participant

    channels where phantom is being turned on or off have to be muted (ever since phantompower exists) PLUS wait a few seonds until the condenser is loaded /unloaded…

    did you try the same mic on another channel?
    if its not the mic it must be the preamp (or its phantom)

    cheers
    dave

    allen&heath iLive-144 /idr 64 / idr 48 (i am convinced there is a yamaha conspiracy against the release of the dante )

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