(Topic ID: 73066)

Funhouse audio board, system 11 vs. WPC A-12738


By BestShot31

7 years ago



Topic Stats

  • 14 posts
  • 8 Pinsiders participating
  • Latest reply 6 months ago by Gaston
  • Topic is favorited by 2 Pinsiders

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#1 7 years ago

Does anyone know if I can switch out my Funhouse system 11 audio board (it was one of the initial 200 units), for the main production audio board (WPC AUDIO board A-12738)?

I would like to take advantage of the most updated ROM, but that's only compatible with the U18 sound chip, which in a system 11 board is integrated on the board.

#2 7 years ago

I can't say for sure - I'm guessing yes unless they wired up the prototypes differently and that the aux power board would need to be removed, you'd need a new cable to go from the CPU to the audio board as well as the new board and ROMs.

I do know that the tricky part in all of this is the A-12738 sound board. In the WPC boardset that's one of the more difficult to come by and you would likely have to pay over $200 for one if you don't have it already.

Good luck!

viperrwk

#3 7 years ago

You'd have to change out the transformer. If you're gonna do that, for the love of history, just trade your proto FH for a really nice production machine. I don't think you'd have any problems setting something up with someone.

#4 7 years ago
Quoted from Barron:

You'd have to change out the transformer. If you're gonna do that, for the love of history, just trade your proto FH for a really nice production machine. I don't think you'd have any problems setting something up with someone.

I don't have a proto FH and have never done this mod. So take what I'm saying with the usual caveat.

Having said that, looking at this photo:

http://ipdb.org/showpic.pl?id=966&picno=30741

J501 and J502 look like the standard plugs that would go into the A-12738 audio board with 501 carrying the AC voltage which normally gets rectified to +/-12v on the audio board and 502 carrying the logic voltage. If the voltages check out no reason they couldn't be used with the WPC audio board. The wires look long enough to fit.

Also this page - http://www.flippers.be/funhouse_prototype_guide.html - does not mention the xfmr being different on the FH prototype. Doesn't mean it's not but given everything documented here would have thought it would be mentioned.

viperrwk

#5 7 years ago
Quoted from viperrwk:

...does not mention the xfmr being different on the FH prototype. Doesn't mean it's not but given everything documented here would have thought it would be mentioned.
viperrwk

I just assumed the ones with the sys11 board were running off of a sys11 transformer. Just taking a stab in the dark there.

#6 7 years ago

http://mirror2.ipdb.org/files/966/Williams_1990_Funhouse_Prototype_Manual_Addendum.pdf

This indicates the sound board, sound roms and transformers are not compatible.

WPC-89 sound is run off of 18 volts.

I can't tell from the IPDB schematic, but sys11 sound boards operate off of +12, +5 and -12. If the 18 volt transformer is used on a 12 volt sound board, damage usually occurs. If the 12 volt xformer is used to operate the 18 volt sound board, it probably won't work.

#7 7 years ago
Quoted from johnwartjr:

http://mirror2.ipdb.org/files/966/Williams_1990_Funhouse_Prototype_Manual_Addendum.pdf
This indicates the sound board, sound roms and transformers are not compatible.
WPC-89 sound is run off of 18 volts.
I can't tell from the IPDB schematic, but sys11 sound boards operate off of +12, +5 and -12. If the 18 volt transformer is used on a 12 volt sound board, damage usually occurs. If the 12 volt xformer is used to operate the 18 volt sound board, it probably won't work.

Ah - there's your answer. Good find John.

The A-13502 "Sound Interface board" provides the +/-12v to the Sys11 sound board. The input to that board is 9.7VAC according to the schematic (and now I see that on the IPDB photo.) The WPC sound board needs 18VAC input. Unless you also change the xfmr it won't work.

Props to barron on the right call!

viperrwk

#8 7 years ago

I had a set of those schematics at one time, when I had a sample FH. I included them when I sold the game, so I don't have a copy to reference.

I do have an extra A-13502 board in a box of parts that I acquired along the line.

#9 7 years ago
Quoted from viperrwk:

Props to barron on the right call!

My guesses like this have lead to too many problems for me to ever deserve props.

But, seriously, don't desecrate the sample game. There are plenty of rarity hoarders out there to get a nice FH from. Most protos didn't come along at such a transitional period as Funhouse did for Williams. Makes it such a cool prototype to own!

#10 7 years ago

All good points made. I'm going to live with the sample/prototype FH and either trade or sell it eventually to someone that will appreciate the nostalgic value more than I.

3 years later
#11 3 years ago

I know this is a old thread but has anyone successfully upgraded the prototype soundboard in Funhouse to the WPC-89 soundboard?

I have the new soundboard and if all at need is the transformer I would like to do it. Thanks for any input.

#12 3 years ago

It's probalby going to be wired for the system 11 sound board, rather than the WPC sound board. You may have to rewire things in addition to finding a transformer.

Honestly, I'd keep it original. It's a fairly rare find.

If you don't care about it all that much, see if someone might want to trade for a standard WPC funhouse.

1 year later
#13 1 year ago

Hi all,
I did change the sys11 sound board on my funhouse to a WPC sound board from the getaway. I also changed to the latest ROMs for sound (L3) and game (9.05H).
Changes as follows:
-Removed old sound and interface board
-Moved W2 to W1 on the CPU board
-New game ROM, 4 Mbit
-New ribbon cable between CPU and sound board
-New ROMs for the sound board, 1 x 2 Mbit and 2 x 1 Mbit needed
-And most important: Made an adapter cable so that the 10 VAC from the sys11 transformer is changed from being full wave rectified to half wave rectified on the sound board. This gives the correct voltage to the sound board.

The connection from the transformer to the sound board has to be changed in the following way (this is done using my adapter cable in the attached photo):
Transformer <-> Sound board
1 <-> 1 and 4
2 <-> 2 and 5
4 <-> 6
5 <-> 7
6 and 7 <-> not connected

This is not a how to, do it at your own risk. I just wanted to show that it is possible. The half wave rectification stresses the components (mainly diodes and capacitors) a bit more but should not be a major issue for home use.

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10 months later
#14 6 months ago
Quoted from pellew:

Hi all,
I did change the sys11 sound board on my funhouse to a WPC sound board from the getaway. I also changed to the latest ROMs for sound (L3) and game (9.05H).

pellew, did you keep a copy of your original PA-1 CPU and sound ROMs, and would you be willing to share them with us?
We would like to integrate them into MAME / PinMAME, for once...

Cheers,
Gaston

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