• Whitestar - Monopoly - Way too loud!

    From John Robertson@spam@flippers.com to rec.games.pinball on Thursday, April 08, 2021 22:24:03
    From Newsgroup: rec.games.pinball

    Anyone here looked into how WhiteStar board sets the audio volume? As
    near as I can figure out it is data buried in SD0 to SD7 data between
    the audio 6809E, the Basement 2K chip, and the DAC. Where I can't figure
    out is the steps in the audio - are they simply data or is one of the
    serial latches responsible?

    My problem is the game sound (while pretty clear) is WAY too LOUD! Only
    with one bar above zero is the sound OK, and that is loud for a small
    arcade. Add any bars to the volume and distortion kicks in and the
    volume goes up enough to be annoying/painful.

    So, I'm trying to figure out how audio volume is done digitally...I do
    have a request in to Stern tech, but not sure if they know these older
    (for them) games that well.

    By the way, audio is controlled between 3800h and 3BFFh on the main MPU.
    I worked that out with my Fluke 9010A today. Not exact memory locations,
    but the audio enable was active for most of the calls to memory in that
    range.

    Thanks!

    John :-#)#
    --
    (Please post followups or tech inquiries to the USENET newsgroup)
    John's Jukes Ltd.
    MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
    (604)872-5757 (Pinballs, Jukes, Video Games)
    www.flippers.com
    "Old pinballers never die, they just flip out."
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  • From Todd Scott@lostlumberjacks@gmail.com to rec.games.pinball on Friday, April 09, 2021 03:30:22
    From Newsgroup: rec.games.pinball

    John,

    I had the same problem with a game. I did this service update and it helped a lot. Todd Scott

    https://sternpinball.com/wp-content/uploads/2018/10/sb133.pdf
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  • From Kerry Imming@kcimming@pobox.com to rec.games.pinball on Friday, April 09, 2021 06:12:09
    From Newsgroup: rec.games.pinball

    On 4/9/2021 12:24 AM, John Robertson wrote:
    Anyone here looked into how WhiteStar board sets the audio volume? As
    near as I can figure out it is data buried in SD0 to SD7 data between
    the audio 6809E, the Basement 2K chip, and the DAC. Where I can't figure
    out is the steps in the audio - are they simply data or is one of the
    serial latches responsible?

    My problem is the game sound (while pretty clear) is WAY too LOUD! Only
    with one bar above zero is the sound OK, and that is loud for a small arcade. Add any bars to the volume and distortion kicks in and the
    volume goes up enough to be annoying/painful.

    So, I'm trying to figure out how audio volume is done digitally...I do
    have a request in to Stern tech, but not sure if they know these older
    (for them) games that well.

    By the way, audio is controlled between 3800h and 3BFFh on the main MPU.
    I worked that out with my Fluke 9010A today. Not exact memory locations,
    but the audio enable was active for most of the calls to memory in that range.

    Thanks!

    John :-#)#


    The audio data is written in parallel to U23 and U24 and then serially
    shifted into U26, the digital-to-analog converter (DAC). I can't
    imagine a problem in SD0-SD16 that could corrupt the audio data without causing other problems on the CPU.

    The service bulletin that Todd pointed out decreases the gain of the
    main amplifier (TDA2030) and seems like a good thing to try.

    U30 is a low-pass filter and probably set to a gain of 1 (no
    amplification). If something went wrong with it or the R16, R17
    resistors it could amplify the signal and probably cause distortion but
    I would suspect that to only affect the left or right channel.

    - Kerry
    --- Synchronet 3.18c-Win32 NewsLink 1.113
  • From John Robertson@spam@flippers.com to rec.games.pinball on Friday, April 09, 2021 08:24:09
    From Newsgroup: rec.games.pinball

    On 2021/04/09 4:12 a.m., Kerry Imming wrote:
    On 4/9/2021 12:24 AM, John Robertson wrote:
    Anyone here looked into how WhiteStar board sets the audio volume? As >> near as I can figure out it is data buried in SD0 to SD7 data between >> the audio 6809E, the Basement 2K chip, and the DAC. Where I can't
    figure out is the steps in the audio - are they simply data or is one >> of the serial latches responsible?

    My problem is the game sound (while pretty clear) is WAY too LOUD!
    Only with one bar above zero is the sound OK, and that is loud for a
    small arcade. Add any bars to the volume and distortion kicks in and
    the volume goes up enough to be annoying/painful.

    So, I'm trying to figure out how audio volume is done digitally...I do
    have a request in to Stern tech, but not sure if they know these older
    (for them) games that well.

    By the way, audio is controlled between 3800h and 3BFFh on the main
    MPU. I worked that out with my Fluke 9010A today. Not exact memory
    locations, but the audio enable was active for most of the calls to
    memory in that range.

    Thanks!

    John :-#)#


    The audio data is written in parallel to U23 and U24 and then serially > shifted into U26, the digital-to-analog converter (DAC).  I can't > imagine a problem in SD0-SD16 that could corrupt the audio data without
    causing other problems on the CPU.

    The service bulletin that Todd pointed out decreases the gain of the
    main amplifier (TDA2030) and seems like a good thing to try.

    U30 is a low-pass filter and probably set to a gain of 1 (no amplification).  If something went wrong with it or the R16, R17
    resistors it could amplify the signal and probably cause distortion but
    I would suspect that to only affect the left or right channel.

    - Kerry
    I had done the resistor change from the SB133 already, no improvement.
    I agree it is hard to see how a data error would not cause serious
    distortion too, but it is the volume that is simply way too high.
    I'll try my logic comparator on U23, 24, and 26 just to be sure.
    Weird!
    Thanks,
    John :-#)#
    --
    (Please post followups or tech inquiries to the USENET newsgroup)
    John's Jukes Ltd.
    MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
    (604)872-5757 (Pinballs, Jukes, Video Games)
    www.flippers.com
    "Old pinballers never die, they just flip out."
    --- Synchronet 3.18c-Win32 NewsLink 1.113
  • From John Robertson@spam@flippers.com to rec.games.pinball on Friday, April 09, 2021 10:49:11
    From Newsgroup: rec.games.pinball

    On 2021/04/09 4:12 a.m., Kerry Imming wrote:
    On 4/9/2021 12:24 AM, John Robertson wrote:
    Anyone here looked into how WhiteStar board sets the audio volume? As >> near as I can figure out it is data buried in SD0 to SD7 data between >> the audio 6809E, the Basement 2K chip, and the DAC. Where I can't
    figure out is the steps in the audio - are they simply data or is one >> of the serial latches responsible?

    My problem is the game sound (while pretty clear) is WAY too LOUD!
    Only with one bar above zero is the sound OK, and that is loud for a
    small arcade. Add any bars to the volume and distortion kicks in and
    the volume goes up enough to be annoying/painful.

    So, I'm trying to figure out how audio volume is done digitally...I do
    have a request in to Stern tech, but not sure if they know these older
    (for them) games that well.

    By the way, audio is controlled between 3800h and 3BFFh on the main
    MPU. I worked that out with my Fluke 9010A today. Not exact memory
    locations, but the audio enable was active for most of the calls to
    memory in that range.

    Thanks!

    John :-#)#


    The audio data is written in parallel to U23 and U24 and then serially > shifted into U26, the digital-to-analog converter (DAC).  I can't > imagine a problem in SD0-SD16 that could corrupt the audio data without
    causing other problems on the CPU.

    The service bulletin that Todd pointed out decreases the gain of the
    main amplifier (TDA2030) and seems like a good thing to try.

    U30 is a low-pass filter and probably set to a gain of 1 (no amplification).  If something went wrong with it or the R16, R17
    resistors it could amplify the signal and probably cause distortion but
    I would suspect that to only affect the left or right channel.

    - Kerry
    Hi Kerry,
    Thanks for the clue! It turned out to be a bad DAC - the TDA1543 was
    putting out too high a reference voltage. Normally this is -1.7VDC, but
    here it was at +2.5! Now the reference voltage does not change depending on the volume, but - of course - it does set the gain on the L&R Op Amps U30A/B.
    Volume is normal now, and regular adjustment range.
    John :-#)#
    --
    (Please post followups or tech inquiries to the USENET newsgroup)
    John's Jukes Ltd.
    MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
    (604)872-5757 (Pinballs, Jukes, Video Games)
    www.flippers.com
    "Old pinballers never die, they just flip out."
    --- Synchronet 3.18c-Win32 NewsLink 1.113
  • From John Robertson@spam@flippers.com to rec.games.pinball on Friday, April 09, 2021 12:03:17
    From Newsgroup: rec.games.pinball

    On 2021/04/09 10:49 a.m., John Robertson wrote:
    On 2021/04/09 4:12 a.m., Kerry Imming wrote:
    On 4/9/2021 12:24 AM, John Robertson wrote:
    Anyone here looked into how WhiteStar board sets the audio volume? As
    near as I can figure out it is data buried in SD0 to SD7 data between
    the audio 6809E, the Basement 2K chip, and the DAC. Where I can't
    figure out is the steps in the audio - are they simply data or is one
    of the serial latches responsible?

    My problem is the game sound (while pretty clear) is WAY too LOUD!
    Only with one bar above zero is the sound OK, and that is loud for a >>> small arcade. Add any bars to the volume and distortion kicks in and >>> the volume goes up enough to be annoying/painful.

    So, I'm trying to figure out how audio volume is done digitally...I do

    have a request in to Stern tech, but not sure if they know these older

    (for them) games that well.

    By the way, audio is controlled between 3800h and 3BFFh on the main
    MPU. I worked that out with my Fluke 9010A today. Not exact memory
    locations, but the audio enable was active for most of the calls to
    memory in that range.

    Thanks!

    John :-#)#


    The audio data is written in parallel to U23 and U24 and then serially
    shifted into U26, the digital-to-analog converter (DAC).  I can't
    imagine a problem in SD0-SD16 that could corrupt the audio data without

    causing other problems on the CPU.

    The service bulletin that Todd pointed out decreases the gain of the
    main amplifier (TDA2030) and seems like a good thing to try.

    U30 is a low-pass filter and probably set to a gain of 1 (no
    amplification).  If something went wrong with it or the R16, R17 >> resistors it could amplify the signal and probably cause distortion but

    I would suspect that to only affect the left or right channel.

    - Kerry

    Hi Kerry,

    Thanks for the clue! It turned out to be a bad DAC - the TDA1543 was
    putting out too high a reference voltage. Normally this is -1.7VDC, but
    here it was at +2.5! Now the reference voltage does not change depending
    on the volume, but - of course - it does set the gain on the L&R Op Amps U30A/B.

    Volume is normal now, and regular adjustment range.

    John :-#)#

    Forgot to mention the problem was solved in my previous post...
    John :-#)#
    --
    (Please post followups or tech inquiries to the USENET newsgroup)
    John's Jukes Ltd.
    MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
    (604)872-5757 (Pinballs, Jukes, Video Games)
    www.flippers.com
    "Old pinballers never die, they just flip out."
    --- Synchronet 3.18c-Win32 NewsLink 1.113
  • From Kerry Imming@kcimming@pobox.com to rec.games.pinball on Friday, April 09, 2021 20:59:14
    From Newsgroup: rec.games.pinball

    On 4/9/2021 12:49 PM, John Robertson wrote:
    On 2021/04/09 4:12 a.m., Kerry Imming wrote:
    On 4/9/2021 12:24 AM, John Robertson wrote:
    Anyone here looked into how WhiteStar board sets the audio volume? As
    near as I can figure out it is data buried in SD0 to SD7 data between
    the audio 6809E, the Basement 2K chip, and the DAC. Where I can't
    figure out is the steps in the audio - are they simply data or is one
    of the serial latches responsible?

    My problem is the game sound (while pretty clear) is WAY too LOUD!
    Only with one bar above zero is the sound OK, and that is loud for a
    small arcade. Add any bars to the volume and distortion kicks in and
    the volume goes up enough to be annoying/painful.

    So, I'm trying to figure out how audio volume is done digitally...I do

    have a request in to Stern tech, but not sure if they know these older

    (for them) games that well.

    By the way, audio is controlled between 3800h and 3BFFh on the main
    MPU. I worked that out with my Fluke 9010A today. Not exact memory
    locations, but the audio enable was active for most of the calls to
    memory in that range.

    Thanks!

    John :-#)#


    The audio data is written in parallel to U23 and U24 and then serially
    shifted into U26, the digital-to-analog converter (DAC).  I can't
    imagine a problem in SD0-SD16 that could corrupt the audio data without

    causing other problems on the CPU.

    The service bulletin that Todd pointed out decreases the gain of the
    main amplifier (TDA2030) and seems like a good thing to try.

    U30 is a low-pass filter and probably set to a gain of 1 (no
    amplification).  If something went wrong with it or the R16, R17
    resistors it could amplify the signal and probably cause distortion but

    I would suspect that to only affect the left or right channel.

    - Kerry

    Hi Kerry,

    Thanks for the clue! It turned out to be a bad DAC - the TDA1543 was
    putting out too high a reference voltage. Normally this is -1.7VDC, but
    here it was at +2.5! Now the reference voltage does not change depending
    on the volume, but - of course - it does set the gain on the L&R Op Amps U30A/B.

    Volume is normal now, and regular adjustment range.

    John :-#)#


    Wow... nice find John. I don't know why I find it so strange that the
    Vref failed but I'm glad you found it.

    - Kerry

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