Electric Piano output connection rewire!

Discussion in 'General Electronics Chat' started by Thecheapguy, May 18, 2011.

  1. Thecheapguy

    Thread Starter New Member

    May 18, 2011
    Unfortunately, I purchased a casio privia Px- 120(electric piano) with the understanding that I would not be connecting it to a sound system but rather only be using the speakers provided. I have recently changed my mind and I have the desire to rewire. I have tried using a 1/8 TRS adapter out of the jack to a XLR connection but there is nothing but static and crackling. The only two audio outs on the piano are midi out and two 1/8 TRS (female, headphone jacks). I want to rewire the 1/8 TRS to an XLR male connection but I don’t know where to start. There are six wires going to the 1/8 TRS’, one is red and the other five are grey. oh yeah and I can't find a wiring diagram anywere.
    Questions :confused:
    1) Are there voltage changes between different connections? 1/8 TRS compared to XLR’s
    2) Do I need to know if the piano is sending a balanced signal
    3) There are two jacks would I be able to leave one connect and use the other jack for the XLR connection.
    4) How do I know if the piano is sending mono or stereo
    5) Is it better to use a three prong or a two prong XLR
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    XLR are three prong connectors. to change from 2 pin audio to XLR leave pin 2 as the 'hot' connector, 1 and 3 can be wired together and connected to the ground portion of the audio jack.

    Hot is the tip of the 1/8 connector, ground is the shaft of the 1/8 connector

    The six wires will be DC +, DC -, Left ch+, Right ch+, Left ch-, Right ch- Trace them out on the circuit board to see which is which. Right away you can assume the red wire will be DC+
  3. KJ6EAD

    Senior Member

    Apr 30, 2011
    The manual indicates that the phone jacks are standard ⅛" stereo:

    If you want to connect to a monophonic system, you'd need to sum the channels together. The Hosa XVM105M cable will do it. It probably has a simple resistive summing circuit in the connector housing: http://www.americanmusical.com/Item--i-HOS-XVM1XXM-LIST. You might be able to find such a thing at a local music store but it needs to have the summing included.

    The passive summing network in the connector will be something like the left side of figure 2 going to the right side of figure 3 in this note: http://www.rane.com/note109.html.
    Last edited: May 18, 2011