Bad sid sounds and parasite

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Don't Panic. Please wash hands.
  • Hi ! I have a big problem with the sound quality. When I turn on the c64 r mk2, there is like a snap. When there is music, the sounds seem to be muffled and there is noise. I tried with 3 different sids (two 6581 and one 8580) and no change! I used several different power supplies 12v 1.6A and 12v 3A but no change either.


    Do you know that issue ?


    Olivier

  • There should be no noise. We did have a problem with noise being coupled in during development, but that was fixed by separating the audio-input with additional circuitry that is now in every C64RMK2 board. It should definitely not sound "muffled", as that points to higher frequencies being cut off. We don't have additional filters installed that could accomplish that.


    What does the remote control menu show for chip recognition, and what voltage to you measure on pin #28 of the SID?

  • Hi !

    In fact the problem came from the protective envelope that wrapped the motherboard.

    I had put it on for the first use. There was like a bad mass noise. And when I removed this protective envelope, no more problems!

    It's rather strange because this envelope is made of plastic!


    So All is fine ! The c64 reloaded mk2 works perfectly !

  • Interesting report anyway, as it shows that the antistatic bag does a good job. I certainly wouldn't have expected to get an audible difference from the board being placed on such a relatively bad conductor ("bad" in terms of transporting energy at low voltage levels that are found in the C64RMK2).