Stereo Amp/Power Supply

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emperormax
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Stereo Amp/Power Supply

Post by emperormax » Mon Oct 12, 2020 3:44 pm

Hi,

I want stereo sound on my machine and understand that I would need my own amplifier. I found this inexpensive one on Amazon, would this work?
"Bluetooth 5.0 Audio Amplifier/Receiver Board Stereo Sound TPA3116 Kits, 50W x2 DC 5-27V"
Or something as simple as this?
"! Hot Sale 12V Mini Hi-Fi PAM8610 Audio Stereo Amplifier Board 2X10W Dual Channel D Class Lowest Price"

The next question is, what kind of power supply comes with the raspberry Jamma? Is it a power brick that plugs into the wall, or do I need my own P/S?

Max

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Re: Stereo Amp/Power Supply

Post by dee2eR » Tue Oct 13, 2020 12:19 am

RaspberryJAMMA just uses the cabs JAMMA power supply, I don't really recommend trying to use extra power supplies while it's plugged in via JAMMA.

That said if you are using an external amp you won't need the RJs onboard mono audio amp and therefore won't need 12v to the board. At that point you could power the system via a Pi power supply (assuming you don't have a JAMMA power supply hooked up - do not try to use 2 power supplies at once).

Any stereo amp you want to use that is matched to whatever speakers you're going to use and whatever power you plan to run the amp by should work. I wouldn't bother with bluetooth, it would be pretty pointless. If you're modding an existing cab you will want to check the specs of any existing speakers to match the amp.

Finally, a lot of older games don't actually have stereo sound anyway... depending on what you want to play you may never notice the difference from mono to stereo.

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Re: Stereo Amp/Power Supply

Post by emperormax » Tue Oct 13, 2020 2:07 am

I guess I don't know anything about Jamma since I didn't know it had its own power supply. I'm planning to convert a cabinet for Jamma and bought a Jamma harness but I guess I need to buy a power supply as well. Any suggestions there?

The speakers in the cabinet are computer speakers, since the cabinet is currently set up to be run with a PC running MAME. I hacked some computer speakers and installed them in place of the speakers that were originally in the cabinet. I don't know how to figure out what amp would "match" the speakers. Do you mean the impedance?

I wanted stereo for certain games like Super Sprint.

EDIT: Never mind about the audio amp/speakers. I found a kit that includes the amp, p/s, speakers, cables, etc. Also, I guess I would just need a 5V p/s for the RPi, correct?

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Re: Stereo Amp/Power Supply

Post by dee2eR » Tue Oct 13, 2020 7:33 am

you could use your hacked PC speakers, assuming they have an amp built into them. Normally computer speakers do. If you already ordered new stuff, nevermind...

If you don't need the JAMMA audio and don't already have a power supply and don't plan to use iother JAMMA boards just get a RPi power supply. They need a 5.1v 2.5A supply. A basic 5v phone charger won't work well and will limit the Pis performance (if it works at all).

If you want to run other JAMMA boards too get a JAMMA power supply.

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Re: Stereo Amp/Power Supply

Post by emperormax » Mon Nov 09, 2020 5:48 pm

I forgot that I already had a set of hacked PC speakers, and it has an amplifier with its own power supply, so I will use that. My new question is where to plug in the audio cable (the 3.5 mm jack that plugged into the PC audio out). I see there is "audio out" written reeeeeealy tiny on the raspberry jamma, but that has a cord plugged in that wraps around a few times and goes back into another port on the card. Do I unplug that from the audio out and plug in my speaker cord?

The other question is about powering the raspberry pi. I think I got the wrong thing because it plugs into the wall and has a USB-C jack on the other end, but I don't see a corresponding port on the raspberry pi. What do I need?

Max

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Re: Stereo Amp/Power Supply

Post by dee2eR » Tue Nov 10, 2020 6:39 am

Yes, to use a stereo amp just unplug the 3.5mm cable that is currently there and either reroute it to your amp or use another cable. The location for audio output marked on the DAC sticker is the right place to use (the really tiny writing).

Pi3 uses a micro B(?) USB power port, the one that was the previous standard before the current one took over... This is the official one I think: https://au.element14.com/raspberry-pi/t ... dp/2945580

Alternately if you want to go the JAMMA power route, this is a good quality (assuming it's a genuine Happ) JAMMA power supply: https://www.ebay.com.au/itm/Happ-15A-Ar ... Swt55faiNn

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Re: Stereo Amp/Power Supply

Post by emperormax » Tue Nov 24, 2020 2:34 am

I installed my JAMMA harness, connected everything, powered everything, and everything mostly works. The only problems are the image has some strange artifacts that weren't there when I had the monitor connected to a PC.
sp_rpicd_2a.jpg
sp_rpicd_2a.jpg (63.39 KiB) Viewed 3867 times
The other problem is that the Ultimarc USB spinner isn't working. Maybe it's too old? I bought it for use with MAME back in 2007. Is there a way to reconfigure it so it will work? I don't know how to get to any setup menus or anything...

Max

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Re: Stereo Amp/Power Supply

Post by dee2eR » Thu Nov 26, 2020 5:21 am

Hard to tell from the pic about your monitor. Is it a low res CRT? If so are you running the default settings? It may not be very good at displaying interlacing, every monitor is different, it may be worth trying the '240p only' setting from the service menu.

Assuming your USB spinner uses the USB standard and not a custom driver it should be able to work. It's probably a config thing. Does it scroll the menu up and down at all? What have you tried it in so far? Also are you using a keyboard that also provides a mouse?

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Re: Stereo Amp/Power Supply

Post by emperormax » Thu Nov 26, 2020 6:24 pm

I have a wells-gardner 19K4900, which is "standard" resolution. I don't know if that is considered "low res" or not, but switching to '240p only' seemed to help, along with reducing the contrast. Everything looks normal now. (Except when playing certain games like Xevious or Donkey Kong, everything is squished into a narrow area in the middle of the screen.)
arpicade_xevious_1.jpg
arpicade_xevious_1.jpg (35.87 KiB) Viewed 3763 times
By the way, I really had to do some research to find the Service Menu. I found a post on another forum that said to press 'F4' on a keyboard, so I connected a USB keyboard and that worked. I hate to complain but none of that is in your FAQs or other documentation. What other keys or functions should I know about? I thought everything could be done through the control panel buttons/joysticks. Is there a way to get to the Service Menu from the game controls?

About the spinner: I have a Happ USB trackball, and that works partly. It scrolls the menu up and down but in games, it only moves up and down. The spinner, which is also USB doesn't work at all. I tried it on the menu and on Star Trek and Super Sprint, and it doesn't do anything. You said it might be a config thing, but I don't know how to configure anything. I see a reference in your installation guide to "/boot/config.txt" but how do I find that? Windows has a File Explorer, is there something like that? When I start the Arpicade, all I see is the front end game menu and no way to get out of it (except F4 to go to the Service Menu).

Also, I don't know how to get to the "System Select" menu. I was there once, because that is in the picture I posted in my last post, but I don't know how to get back to it.

Max

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Re: Stereo Amp/Power Supply

Post by dee2eR » Fri Nov 27, 2020 3:41 am

What emulator are the games that are squashed running in? I can see if I can improve the settings. 1920x240 is not going to have great results for most rotated games (not enough lines to draw on to display it all) but I can probably improve the width a bit.

To access the ARpiCADE service menu you can press either 'f4' (on a keyboard) or your cabs 'service' button. It is mentioned in the instructions under the 'FRONTENDS' bit, admittedly I'm not great at writing instructions... even I had to look twice to notice it there.

Trackball and spinner will almost definitely be emulator config. Sounds like the trackball is being picked up as the first mouse as it's working in the Attract-Mode menu. I'm not sure offhand which emulator you've been trying with it but it may be worth a look at this thread: viewtopic.php?f=9&t=2074&p=6256&hilit=t ... nner#p6256 - Also you may have some luck just trying to configure the trackball and spinner in MAMEs menus while the game is running (hit 'tab' or 'start+joy_right' while a game is running in MAME to open MAMEs menu).

System select menu is just 'b2' from any of the game select menus. B2 also acts as back in the Retroarch menus if you ever find yourself in them.

I hope that helps.

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