Headphone output to power amp

Discussion in 'The Projects Forum' started by andyhof, Jun 23, 2011.

  1. andyhof

    Thread Starter New Member

    Jun 22, 2011
    5
    0
    I know the title sounds silly.

    Looking to connect:
    Yamaha YDP-v240 piano stereo headphone output jack to the input of a
    Crown D75a power amp.

    I have no specs on the piano headphone output.
    Crown D75a is as follows:
    Input Impedance: Nominally 20 k ohms, balanced.
    ominally 10 k ohms, unbalanced.
    nput Sensitivity: Confi gurable for 26 dB gain
    or 0.775 volt sensitivity.

    So I have taken a stereo 1/4" TRS connector, red to tip, blue to ring and shield to sleeve. I would like to wire this to either 2 mono 1/4" plugs or 2 x XLR plugs.

    Would a 4k7 resistor work on each 1/4" mono plug end?
    or am I missing something?

    thanks in advance
    Andrew
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,118
    3,042
    You want to put a headphone signal into a line-in input? A resistor in series with each channel's input wouldn't hurt, but I think most folks just connect directly. Turn the volume of the source quite low to avoid clipping, from overloading the input. Then turn up the power amp to adjust volume. Usually you need to play around a bit. For instance you can change the volume of the source to give a volume similar to other line-in sources you might have, such as a radio tuner.
     
  3. #12

    Expert

    Nov 30, 2010
    16,283
    6,795
    Like wayneh said, it will work, just turn way down so you don't throw the speaker cones out in the floor when the "plug in" click happens.
     
  4. Man_in_UK

    Senior Member

    May 13, 2008
    132
    0
    Once upon a time I was doing something along the same lines and things went wrong.

    I was using the headphone output of a guitar amplifier to feed into a multitrack recorder. I think I managed about half an hour before the headphone output gave up and has never worked since.

    No help at all. I can't give an answer on how to prevent any damage but I found a matching problem, if your not carefull you might find the same one.
     
  5. #12

    Expert

    Nov 30, 2010
    16,283
    6,795
    With the Crown input impedance of 10k, there is no reason why the headphone driver should fail. The multitrack recorder shouldn't have damaged the headphone output either.

    I think it was just a coincidence.
     
  6. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,788
    945
    Professional Audio power amps are very capable pieces of equipment. I have driven mine(Carvin 400W) with the 8 ohm output of a small desktop radio and occasionally connected my old HP audio oscillator directly to it.(high impedance output). If it has an input attenuation knob then you are golden. Like others have said, don't turn up the headphone output to much and use the attenuation pad on the amp to set a max volume level, then you can use the headphone output adjust(if you have one) to turn the volume lower,not higher.

    Planning on doing some live performance practice?
     
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