[TECH] Zaxxon sound
- Thread starter LukeWells
- Start date
Re: [ukvac] Re: [TECH] Zaxxon sound
Use the edge connector pins for sound, there should already be a
connector covering those 6 pins IIRC, you do have the big heavy
interlink cable near the edfe connector right? Maybe I'm thinking of
another set..
Anyway, as for the common sound faults (I've had the problem detailed
below on EVERY Zaxxon hardware PCB I've owned) - here you go:
>From http://home.san.rr.com/rbarnes/Arcade/fix.txt:
****Zaxxon (+Super Zaxxon)
==Problem: Sounds of ship flying, explosions, etc. may be there when
the game is first turned on, but slowly fade over several minutes. Will
not return until the game has been left off for a while. [COMMON]
-Solution 1 (easy): Replace all 2.2 uF/50V caps C69, C68, C29, C28,
C38. Only use basic cheap-o polarized electrolytics (e.g. Mouser
140-XRL50V2.2). Don¹t get fancy, as the circuit relies on the leakage
through this cap.
-Solution 2 (better): Replace C69, C69, C29, C28, C38 with non-polar
electrolytics (e.g. Mouser 140-NPRL50V2.2). Next, strap the ³output²
side of each cap to the +6V common though a 100kohm resistor. Refer to
the circuit diagram to find the best place to install each resistor.
-Discussion: These caps are used as DC blocking caps in the audio
section. As the feed a high-Z load without any tie-down resistor, they
do not really work as high-pass filters as planned. The capacitor can
build up a charge which eventually biases the OP amp to the point of
clipping. When the caps are fresh, leakage through the cap
can prevent the run-away bias. But if fresh caps are installed that do
not have enough leakage, they will not work.
On Tue, 2003-02-11 at 10:52, arcadeukcom wrote:
> So what are the common faults causing sound problems? amp?
>
> And where are the speakers meant to be connected? Edge connector or
> 6pin connector?
>
> Thanks
>
> Luke
>
>
Use the edge connector pins for sound, there should already be a
connector covering those 6 pins IIRC, you do have the big heavy
interlink cable near the edfe connector right? Maybe I'm thinking of
another set..
Anyway, as for the common sound faults (I've had the problem detailed
below on EVERY Zaxxon hardware PCB I've owned) - here you go:
>From http://home.san.rr.com/rbarnes/Arcade/fix.txt:
****Zaxxon (+Super Zaxxon)
==Problem: Sounds of ship flying, explosions, etc. may be there when
the game is first turned on, but slowly fade over several minutes. Will
not return until the game has been left off for a while. [COMMON]
-Solution 1 (easy): Replace all 2.2 uF/50V caps C69, C68, C29, C28,
C38. Only use basic cheap-o polarized electrolytics (e.g. Mouser
140-XRL50V2.2). Don¹t get fancy, as the circuit relies on the leakage
through this cap.
-Solution 2 (better): Replace C69, C69, C29, C28, C38 with non-polar
electrolytics (e.g. Mouser 140-NPRL50V2.2). Next, strap the ³output²
side of each cap to the +6V common though a 100kohm resistor. Refer to
the circuit diagram to find the best place to install each resistor.
-Discussion: These caps are used as DC blocking caps in the audio
section. As the feed a high-Z load without any tie-down resistor, they
do not really work as high-pass filters as planned. The capacitor can
build up a charge which eventually biases the OP amp to the point of
clipping. When the caps are fresh, leakage through the cap
can prevent the run-away bias. But if fresh caps are installed that do
not have enough leakage, they will not work.
On Tue, 2003-02-11 at 10:52, arcadeukcom wrote:
> So what are the common faults causing sound problems? amp?
>
> And where are the speakers meant to be connected? Edge connector or
> 6pin connector?
>
> Thanks
>
> Luke
>
>