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Thread: Centaur "Say it Again"

  1. #1
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    Centaur "Say it Again"

    I have been looking into getting the echo back on my Centaur.
    It had the original board in it, so I replaced many of the caps and then came to the conclusion that the SAD4096 was probably faulty.
    The sound still worked but with no echo.

    Original Sound


    Original "Say it Again" board
    IMG_1667.jpg

    The coloured wiring is just for testing as the connections were really bad.

    I found some info on BigClives site that linked to a smaller replacement board instead of the SAD4096.From that sites schematics I made up a circuit that would plug directly into the SAD4096 as below :-

    IMG_1671.jpg IMG_1672.jpg

    This still didnt work so I went back to BigClives site and downloaded the two files to make my own circuit board.

    Yes I know it still needs tidying up
    IMG_1674.jpg

    This is the end result, it sounds so much better standing next to it.



    I know I could have gone and bought one from the US but what would be the fun in that....
    Things I have learnt in doing this:-

    1. I can now create a circuit board from a schematic, and get it made.
    2. I can now print and etch my own circuit boards.
    3. I now own a set of mini drills for drilling circuit boards
    4. I have enough stuff to do a few more boards.

    All up a nice little learning curve with a reasonable result.
    Also this board cost me about $50 to make so I saved money as well

    Oh yes, dont look at the playfield as I have a new CPR to go in it

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    Nicely done. Did you use the "press and peel" sheets to make your PCB? Also I wouldn't mind getting the circuit /pcb layout off you as i also have a Centaur with a dead Say It Again board, so will have to make one, one day. Good work, well done. Good Move Human !

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    Congrats and soooo much better with the echo!
    I was a slacker and bought the one off ebay for $150 .... Works great
    Nice work and Enjoy

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    Quote Originally Posted by thegrunta666 View Post
    Nicely done. Did you use the "press and peel" sheets to make your PCB? Also I wouldn't mind getting the circuit /pcb layout off you as i also have a Centaur with a dead Say It Again board, so will have to make one, one day. Good work, well done. Good Move Human !
    I actually ordered some transfer sheets off eBay as jaycar prices are ridiculous for one sheet, however they haven't arrived yet so, going back to google I used 120gsm photo paper, laser printed the image and ironed it onto the copper. The first attempt was patchy so I just cleaned it up and did it again.

    The images are at http://www.bigclive.com/centaur.htm

    All the photos are missing from that site at the moment but the files are still there.

    I have a spare Holtek chip as I had to buy a couple, not sure if I have a spare dram.

    More fun to make the board yourself but they are available to buy

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    Quote Originally Posted by raysco View Post

    More fun to make the board yourself but they are available to buy
    I'm building the battle Pinny, so have been having a great time doing Acid in the Shed !!!! But I hate drilling all the bloody holes ! I use the press and peel, but yes, pricey per sheet , thats for sure....

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    Quote Originally Posted by raysco View Post

    I found some info on BigClives site that linked to a smaller replacement board instead of the SAD4096.From that sites schematics I made up a circuit that would plug directly into the SAD4096 as below :-

    )
    Any idea why the piggyback version did not work? I have got the components and my first effort did not work either...

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    Quote Originally Posted by Ballywannabe View Post
    Any idea why the piggyback version did not work? I have got the components and my first effort did not work either...
    That's interesting, no I don't know and I didn't investigate any further.
    If I get chance I will revisit it. My minimum order for the pcbs was 5 so I have spares
    When it didn't work I just did the big Clive board.

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    Quote Originally Posted by Ballywannabe View Post
    Any idea why the piggyback version did not work? I have got the components and my first effort did not work either...
    Good question, that board should have worked - and sounded perfect. I made one, it worked & it sounded exactly as a good SAD4096 does. It is possible the MN3205 was a fake or faulty. I bought two from ebay seller polida & both didn't work (remarked). I found a genuine one & that was fine.

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    I actually bought mine from the same place on ebay so that might be the issue.
    Where did you get the original?

    Sent from my SM-N9005 using Aussie Arcade mobile app

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    Quote Originally Posted by raysco View Post
    I actually bought mine from the same place on ebay so that might be the issue.
    Where did you get the original?

    Sent from my SM-N9005 using Aussie Arcade mobile app
    Here is a pic of the fake MN3205 (at the top) & the genuine at the bottom. The fake has had the top sanded painted & re-stamped. The original has a matt finish & a polished border around the edge which is how I could tell. Pins were a slightly different shape too.

    IMG_6755.jpg


    The originals were from smallbearelectronics.com but are no longer available, however their is a new clone they sell of the MN3205 which will work as a substitute & are readily available elsewhere also. V3205.


    http://smallbear-electronics.mybigco...mn3205&x=0&y=0


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