anyone used a car audio amp like this in a game?

mc300baud

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i have a Sega Naomi Ninja Assault that seems to have a bad amplifier (lots of buzz, hum and noise.) it looks like it's the guts from a dedicated cabinet transplanted into an MKII, so the audio amp board is different from any other Naomi board i can find on-line. for those that may not have seen one, Naomi main boards output a line-level signal (RCA connectors, even) but don't have internal amplifiers to drive speakers of their own.

the game is on-location and making money. the location owner doesn't want the game to be down or the audio off; he'd rather have the messed up audio than none, so i don't have the time to spend to try to repair the current amp board, and the few i've seen for sale working aren't cheap.

i saw this amplifier on Parts Express and was wondering if it might work to replace the bad amp in my game:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=265-079

i should be able to pull 12-volts DC off of the PS and the speaker in the cabinet is 25 watt 8 ohm (or 35 watt 4 ohm if i decide to switch to a 6X9 car speaker.) anyone else tried this or see any reason why it wouldn't work?
 
I would think it would work. My only concern would be does the PS supply enough amperage to run it. Even a small amp at low volumes could pull 5 amps. Maybe it would be better with a dedicated PS. - Barry
 
I'm not familiar with that game. In fact, I've never heard of it.

It would appear that this car amplifier probably will work for your application. I noticed Parts Express says that amplifier is out of stock right now.
 
I think that the problem your going to run into is that you wont have volume control. Sega games usually output line level and then the amplifier has a volume control on it. If you built a line level volume control it would work or you could try this part from Happ (prepare for sticker shock).

http://na.suzohapp.com/amusement/jukebox/495140200k.htm
 
the Naomi amp boards (at least mine and a few others i looked at) don't seem to have volume control; the control is taken care of via the system menu on the main PCB. i went over it all with a fine-toothed comb looking for a secondary volume control as part of the problem with mine seems like it's simply turned up way too loud, but to no avail.

Parts Express says they don't expect new stock in until 2/3, which is why it's marked "unavailable."
 
You could also use an old home stereo receiver, using the aux RCA input/output jacks. Put it on the phono setting and it works as an amp for your input sound. You'll also get bass/treble, volume control. Just splice the power cord to wire up to the arcade PS. You can probably find one at your local thrift store for cheap.
 
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You could also use an old stereo receiver, using the aux RCA input/output jacks. Put it on the phono setting and it works as an amp for your input sound. You'll also get bass/treble, volume control. Just splice the power cord to wire up to the arcade PS. You can probably find one at your local thrift store for cheap.

i thought about doing something similar but most receivers are way too big. if i can find a cheap small Radio Shack-style amp i might do that. or if i can find a powered speaker that i can raid for parts...
 
You could use powered computer speakers they have amps inside them. You can get a converter for the mini-din to RCA type.

Good Luck.

Mark..
 

awesome! that's even better and cheaper can't hurt.

You could use powered computer speakers they have amps inside them. You can get a converter for the mini-din to RCA type.

i thought about this but with the placement of the speakers i'd be blocking the light for the marquee, assuming the powered speakers would even fit in that space at all. and since it's on location i can't leave anything external to the cabinet that a vandal might decide to rip off.
 
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