(Topic ID: 62686)

Bally/Stern AS2815-30/51 Soundcard redesign

By Zitt

10 years ago

Topic Heartbeat

Topic Stats

  • 15 posts
  • 6 Pinsiders participating
  • Latest reply 10 years ago by toddsvec
  • Topic is favorited by 5 Pinsiders


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    #1 10 years ago

    Is there any interest? I saw refurbs on Fleabay for a hundred or so... seems kinda silly to be throwing money at older EOLed components. Kinda surprised Rottendog or others haven't provided a replacement.

    I'm currently redesigning the AS-2815-3x/51 soundcard with modern replacements.
    I'm replacing the TTL PROM and 4bit counter which are both getting rare / expensive with a single MAX 3000 CPLD in 44pin PLCC. The CPLD cost 1.50 is single units... where the TTL PROM and 4bit counter are in the 5-6 range. The CPLD has just enough room to replace all the logic chips and house both sound PROMs for AS-2815-32 and AS-2815-51 designs. The -51 proms can be selected via a jumper wire. "In theory" it should work with any game listed with the AS-2518 boardset:

    I'm also adding hooks to include "background" and sound effects to switch shots on my Star Trek : Mirror Universe http://pinside.com/pinball/forum/topic/star-trek-mirror-universe-pinball
    project. The sound effects tie into the existing switch matrix and run off of a raspberry pi.

    The card should be a drop in replacement for existing card using mostly SMT components to keep PCB costs down.

    Is there any interest in seeing the design here? I haven't finished the PCB layout... so still need to work on product... build it, and then debug it.

    #2 10 years ago

    I wouldn't be opposed to spending money on a modern replacement for the S&T card.
    It just needs to have some form of output capability to the Say-It-Again board (and existing workarounds) for the game that uses it -- Centaur, in this case.


    #3 10 years ago

    You are better off coming up with a prom adapter for this board to allow for a common ROM be used. These boards are repairable it is just sourcing out the PROM is getting expensive. The PROM is dead quite often too. The stern speech card or some of the other bally sound boards with unobtainable parts may be a better candidate for repo.

    Also don't forget between the two PROMs there is components that need removed or added. Also there is a misprint on a resistor voltage divide circuit in the schematics / part lists that might throw you off (did to me once!). I wrote notes down about it somewhere if you need.


    #4 10 years ago

    You guys are missing the point. OR I wasn't clear.
    I'm not trying to repo a S&T board... or even replace the existing boards for money.

    I'm designing purely for my own needs on my specific project. If others can use it if desired. If not; no harm no foul.

    If you have some notes; would appreciate it. I think I got most of the data from the -51 schematics... but it doesn't hurt to have a second review.

    #5 10 years ago

    The component list for the -32 sound board incorrectly lists R28 as a
    4.7k resistor when it should be a 15k resistor. The schematic drawing
    is correct. R28 and R24 make a voltage divide. If you put a 4.7k
    resistor at R28 you will crap out the clock output and get no sound
    unless the clock is in a null state. With a 4.7k resistor at R28 you
    will see 6v at U9 P2 when you should see 2v when correct.

    A few months back I had a tough time with one of these sound boards
    and i had replaced an open R28 with a 4.7k resistor. It took me a
    while to find the mistake. In the last month i have gotten in for
    repair two of these boards where someone replaced R28 with a 4.7k
    resistor. So this misprint has messed up at least three people. I
    figured i would let everyone know.

    -51 PROM
    Remove C22 and R28

    -18 PROM
    Add C22 and R28

    #6 10 years ago

    Andrew - thanks.
    Luckily the Schematic I DLed from ipdb.org (Paragon) had these corrections on it.

    I'm going to do some more work on it tonight... maybe I'll be able to post some preliminary schematics later tonight.

    #7 10 years ago

    IF anyone is interested; I posted my rev-99 schematics here.
    Still need to take free gates and tie them up so they don't float.

    Also need to renumber components now that the layout is nearly complete. Then generate SilkScreen. I put a small prototyping area under the RazPi... just incase I need to do some rework.


    Hope to have the design committed to OSHPark by the weekend.

    #8 10 years ago

    I am interested in this. I'll try to understand your schematic.

    Am I understanding correctly that we would be able to order an unpopulated sound board through a company that does runs of boards? Then we order the components and solder them on ? Are those components typically surface mount?

    I could be a "beta" tester I guess, if you wanted one.

    #9 10 years ago

    I could make the PCBs available thru OSHPark.
    I placed the order last night for the PCBs; they are suppose to be on a panel going out Monday.

    Assuming I confirm the design is working; maybe I'll take the time update the design and/or write a blog about it at pinball-mods.com.

    #10 10 years ago

    Great. I'd be interested to hear more and try it out.

    1 week later
    #11 10 years ago
    Quoted from barakandl:

    You are better off coming up with a prom adapter for this board to allow for a common ROM be used.

    Check this out:


    The product works flawlessly.

    #12 10 years ago


    Did anything come about of that adapter, i am very intersted? I just spent a bunch of $ on PROMs because they are bad very often on boards that come in for repair.

    #13 10 years ago

    no worries about that. For me; it seemed silly to use a big eeprom with 1ks of wasted bits. That and those eeproms will eventually become scarce in another 50 years. I do; however, see the value of the product.

    For me I wanted to add in the RazPi for background music and added sound effects.

    #14 10 years ago
    Quoted from barakandl:

    Did anything come about of that adapter, i am very intersted?

    He has them listed on his products page for $15 (no EPROM).


    I've had the 'test' one he gave me installed in my Supersonic for 6 months now. It works great -- no difference from the stock chip.

    #15 10 years ago

    I'd be interested in distributing.


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