Any interest in a qbert sound amp kit?

Riptor

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I have the pcb drawn up and ready to order. These boards will replace the LM379S with a small pcb which uses a TDA2003 amp. The kit will include all parts required for the modification and instructions. Projected cost will be around $25. Let me get your yay nays or maybays.

Also works for Mad Planets, Krull, Reactor and possibly others.
 
I assume it removes +27V requirement? Does that one run on +12V or +5V?

Actually the original amp runs off 30v. There are some power supply modifications needed and if I remember right the upgraded amp will see around 18v. Im in the process of trying to dig up the documentation on this, I have it around here somewhere.
 
I have the pcb drawn up and ready to order. These boards will replace the LM379S with a small pcb which uses a TDA2003 amp. The kit will include all parts required for the modification and instructions. Projected cost will be around $25. Let me get your yay nays or maybays.

Also works for Mad Planets, Krull, Reactor and possibly others.

IAMIN! Hellz yes.
 
So this is just replacing the amp chip? Is that correct? I may be interested. I really would like a way to effectively do away with the power board in my qbert all together. That thing gets hot as hell.
 
With this modification, would the knocker still get 30V or would it get 15V?
 
Two components get changed on the power supply. There are a few componets that get removed from the sound board. Remove the original amp chip and install piggyback board.
The knocker will see a lower voltage just as the sound board. This was a factory revision made when the LM379S was discontinued. Im not sure if any machines actually shipped with it but it was sold as a replacment part. I have a couple originals here.
 
Two components get changed on the power supply. There are a few componets that get removed from the sound board. Remove the original amp chip and install piggyback board.
The knocker will see a lower voltage just as the sound board. This was a factory revision made when the LM379S was discontinued. Im not sure if any machines actually shipped with it but it was sold as a replacment part. I have a couple originals here.

Gotcha. I was just curious if there would be any noticeable difference when the knocker fires on a lower voltage. I have played around with a q bert knocker outside of a cab and gave it both 28 and 12 volts. I didn't really notice much if any difference in the sound produced to be honest.
Would love to see an original if you can snap a pic.
 
I have seen some on Mad Planets and all MACH 3s.

Maybe a version where no psu mods are necessary? Add a vreg?

Bill


Im not sure if any machines actually shipped with it but it was sold as a replacment part. I have a couple originals here.
 
I have 9 of these on the way. When I get these and verify everything looks good I will do a run of 30-50 more.
These should be much more reliable and the TDA2002/2003 amps are readily available and cheap. The first batch should be available in around 3 weeks.
 
I have seen some on Mad Planets and all MACH 3s.

Maybe a version where no psu mods are necessary? Add a vreg?

Bill

Well Bill, this is more of a power supply fix with the bonus of swapping out to a cheaper and readily available sound amp. I have seen, and have a few of the original power supplys with this update and all of them show no signs of burned traces like most QB power supplys do. With the modifications the 30v line becomes 16-18v. The power supply mod is simple, just remove the 30v zener and install the replacment zener in its place and one resistor gets swapped also....one cap and resistor get removed, thats it. Then on the sound board there are 5 components that get removed and the only part you reinstall is the piggyback board.
I have all the parts on hand to put these together except the pcbs. As soon as I get them I will assemble and start testing then they will be ready to ship. Price will be $25 +ship and will include piggyback board, the parts needed to mod the power supply and instructions.
 
I agree that the PS mods are the best way to go and that is what I do and recommend for Qberts to start - the only downside is that the modified sound card can only be used with a modified PS. My only suggestion would be adding two warning labels to the kit to be affixed to the PS and the sound board to help out the next owner of the game. Otherwise - this kit is a long time coming and I will buy a few.

Best, Bill

Well Bill, this is more of a power supply fix with the bonus of swapping out to a cheaper and readily available sound amp. I have seen, and have a few of the original power supplys with this update and all of them show no signs of burned traces like most QB power supplys do. With the modifications the 30v line becomes 16-18v. The power supply mod is simple, just remove the 30v zener and install the replacment zener in its place and one resistor gets swapped also....one cap and resistor get removed, thats it. Then on the sound board there are 5 components that get removed and the only part you reinstall is the piggyback board.
I have all the parts on hand to put these together except the pcbs. As soon as I get them I will assemble and start testing then they will be ready to ship. Price will be $25 +ship and will include piggyback board, the parts needed to mod the power supply and instructions.
 
Thats true and I wonder how many people have tried to mix and match PS and sound board types. Good call, I will make some labels to include in the kits.
 
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