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Working on a Sega Blast City

What Amp are you using? Did you ever try to just replace the blast city power supply with a different psu and keep current amp.
It's a cheap Parts Express amplifier and I posted the model number and other details earlier in this thread. Replacing or modifying the power supply to send more power to the audio amplifier would probably require modifying the amplifier. Have you tried using the speakers that other people are using in the Blast City? I like how my Blast City sounds but if I were to do it again I would try an easier solution first.
 
my issue is that my PS has crapped out. I recapped and still dead. I found a replacement psu I want to try, but I'm working out the internal wiring now. I want to keep the wiring in the stick ps box so I'm making a harness to convert everything to the original connections. the amp is the only place I'm struggling on
 
my issue is that my PS has crapped out. I recapped and still dead. I found a replacement psu I want to try, but I'm working out the internal wiring now. I want to keep the wiring in the stick ps box so I'm making a harness to convert everything to the original connections. the amp is the only place I'm struggling on
The Blast City amp is only for amplifying the line level stereo output from JVS hardware (or something like Mister or a console etc). If you only plan to use JAMMA hardware then you don't need an amplifier. If you plan to use something other than JAMMA then you'll need to figure out how to power the stock amplifier from your new power supply, or you can copy what I did with a Part's Express amplifier. I posted the full wiring diagram in a previous post in this thread. The Blast City manual also has a wiring diagram.
 
Happy AF here! Got my second Blast and is on its way from the US to Costa Rica.
This one will be restored, too.
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Love it 😍😎👍
 
Wow. I really like the color choice of the stick/buttons you used. They complement the color of the Blast City graphics so much better than the green/pink standard that was carried over from the Astro City. Will definitely be implementing those colors if/when I manage to get one.
 
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In all the photos I've seen online, the metal doors on both the Astro City and Blast City become darker and yellow compared to the resin body of the cabinet. Some worse than others. There are a few possible causes for this. The doors, control panel base, and cabinet body should all be the same color. Except the doors in the flyer for the Blast do appear to be a shade darker. Not as dark as mine were, and not yellow.

Flyer.jpg
Flyer.jpg
I think this is dues to
Cast body is gel goat
Metal work is painted
Plastic panels- control panel/speaker housing I believe are unpainted white plastic

So 3 different techniques paint/gel coat/unfinished plastic

And each one has different properties and give different results from elements

I know this is old now, but going through same task, this was very helpful and a good read
 
The new speakers and new tweeters sound great and I'm impressed with how full the sound is with such tiny woofers. The Blast City's ported enclosure really helps to pull out some lower frequencies. But once again there is a little problem. A problem for me anyway. With both the game PCB and Blast volume turned to max, the sound level is okay, but not loud. I want it LOUD. So I added an amplifier:

IMG_6983.JPG


This is the WONDOM AA-AB32189 2x100W TDA7498 Class-D Amplifier from Parts Express. And with 100 watts at 6 ohms it gives me exactly what I wanted. I'm only getting about a third of that power due to my 8 ohm speakers being connected in series but it's more than enough (the Peerless woofers are only rated for 10 watts each anyway). I have the amp set to medium level and with my volume knob at the front of the cabinet turned up less than half way it's very loud, and very clear. My Blast speakers were wrecked when I got the cabinet so I don't know how they sounded and can't make a comparison. But I can say that these new speakers and amp sound much better than the Logitechs in my Astro City. I plan to add one of these amplifiers to the Astro for improved sound and stereo. I expect it still won't sound as good since the speakers aren't in a proper enclosure like the Blast has.

I pulled the original Blast amplifier out, bought some JST connector headers, and utilized the original connections for the new amp and a line output converter.

Original amplifier with JST connectors CN1-CN4:

IMG_6756.JPG



And here is CN2, CN3, and CN4 routing the JAMMA audio signal through a line converter, to the volume control under the control panel, to the new amplifier, then to the speakers:

IMG_6970.JPEG




The converter and JST connectors are mounted with adhesive Velcro in the spot where the original amp was. I routed RCA connections for the amplifier input and speaker inputs (amplifier output) through the opening of the power supply case where the 32 pin connector is:

IMG_6974.JPG



No wires were cut and everything can be unplugged and returned to stock condition if I want (not likely).

For power I utilized CN13 on the terminal board. I cut the end off of an AC power splitter and added an AMP UP 3 pin connector. I'm using a power splitter so that I have an additional AC power plug in case I ever add something else to the cabinet in the future that needs 120V AC. The ground wire is connected to the screw in front of the power supply where the other ground wires are connected:

IMG_6914.JPG
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I placed the new amplifier power supply behind the coin box and used adhesive Velcro to secure it in place.

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And since I was buying these connectors I bought one to bypass the door switch:

IMG_6909.JPG
IMG_6911.JPG
Do you happen to have a list of all the parts you used for this upgrade? I'd love to do the same audio upgrade and any help would be greatly appreciated.
 
Do you happen to have a list of all the parts you used for this upgrade? I'd love to do the same audio upgrade and any help would be greatly appreciated.

Sure, list is below. If you haven't already tried some of the replacement speakers recommended in the Blast City speaker thread, I suggest doing that before doing what I did.


I think this is nearly everything:

WONDOM AA-AB32189 2x100W TDA7498 Class-D Amplifier Board
DC 36V 5A 5000mA 180W Switching Power Supply AC Adapter - 2.5 x 5.5mm Center Positive Plug 100~240V
Peerless TC2X4FB00-08 1-3/4" x 4" Rectangle Full-Range Woofer 8 Ohm
Dayton Audio ND20FB-4 Rear-Mount 3/4" Soft Dome Neodymium Tweeter
Dayton Audio DMPC-6.8 6.8uF 250V Polypropylene Capacitor
Dayton Audio DNR-3.0 3 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-0.33 0.33 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-1.0 1 Ohm 10W Precision Audio Grade Resistor
Hosa YRA-105 Female RCA to Dual Male RCA Y-Cable 6"
Rean NYS373-2 RCA Plug Connector Black with Red Indicator
Rean NYS373-9 RCA Plug Connector Black with White Indicator
25K Audio Taper Potentiometer 1/4" Shaft
White Perforated Large Hole Crossover Board Pair 3.5" x 5"
JST NH 5 pin, 455-4185-ND, BE5P-SHF-1AA, CONN HEADER VERT 5POS 2.5MM
JST NH 6 pin, 455-BS6P-SHF-1AA-ND, BS6P-SHF-1AA, CONN HEADER R/A 6POS 2.5MM
JST VH 4 pin (looks like I broke a 10 pin in half to make it a 4 pin), 455-B10P-VH-FB-B-ND, B10P-VH-FB-B, CONN HEADER VERT 10POS 3.96MM
AMP Universal Power 3 pin, A106282-ND, 176272-1, CONN PLUG HSG 3POS 3.96MM
AMP Universal Power 3 pin, A122360-ND, 176283-1, CONN RCPT HSG 3POS 3.96MM
JST Connector, A107106CT-ND, 175151-1, CONN SOCKET 22-26AWG CRIMP TIN
JST Connector, A100484CT-ND, 175152-1, CONN SOCKET 16-20AWG CRIMP TIN
JST Connector, A100481CT-ND, 175149-1, CONN TAB 22-26AWG CRIMP TIN
JST Connector, A100483CT-ND, 175150-2, CONN TAB 16-20AWG CRIMP TIN
Cable Leader Power Cord Splitter Cable for 2 NEMA 5-15R to 1 NEMA 5-15P (14 inches / 14 AWG)
PAC SNI-35 Variable LOC Line Out Converter 1.2x6.25x5.9
YABEDA RCA Female to Dual RCA Male Y Splitter Cable,Gold Plated RCA (1 Female to 2 Male) Stereo Audio Y Adapter Cable - 1.6feet/50cm


Last year I added a mute switch to the amplifier. I don't want to make the speakers pop when powering off the cabinet, and toggling a mute switch is easier for me than unlocking and opening the control box to turn the volume down then back up to exactly where I had it set. The amplifier already has this mute function built in but you need to add your own switch or button to utilize it. I don't have a part number for the switch. It's just a basic switch that I bought many years ago.

IMG_9303.JPG
IMG_9305.JPG
 
Sure, list is below. If you haven't already tried some of the replacement speakers recommended in the Blast City speaker thread, I suggest doing that before doing what I did.


I think this is nearly everything:

WONDOM AA-AB32189 2x100W TDA7498 Class-D Amplifier Board
DC 36V 5A 5000mA 180W Switching Power Supply AC Adapter - 2.5 x 5.5mm Center Positive Plug 100~240V
Peerless TC2X4FB00-08 1-3/4" x 4" Rectangle Full-Range Woofer 8 Ohm
Dayton Audio ND20FB-4 Rear-Mount 3/4" Soft Dome Neodymium Tweeter
Dayton Audio DMPC-6.8 6.8uF 250V Polypropylene Capacitor
Dayton Audio DNR-3.0 3 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-0.33 0.33 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-1.0 1 Ohm 10W Precision Audio Grade Resistor
Hosa YRA-105 Female RCA to Dual Male RCA Y-Cable 6"
Rean NYS373-2 RCA Plug Connector Black with Red Indicator
Rean NYS373-9 RCA Plug Connector Black with White Indicator
25K Audio Taper Potentiometer 1/4" Shaft
White Perforated Large Hole Crossover Board Pair 3.5" x 5"
JST NH 5 pin, 455-4185-ND, BE5P-SHF-1AA, CONN HEADER VERT 5POS 2.5MM
JST NH 6 pin, 455-BS6P-SHF-1AA-ND, BS6P-SHF-1AA, CONN HEADER R/A 6POS 2.5MM
JST VH 4 pin (looks like I broke a 10 pin in half to make it a 4 pin), 455-B10P-VH-FB-B-ND, B10P-VH-FB-B, CONN HEADER VERT 10POS 3.96MM
AMP Universal Power 3 pin, A106282-ND, 176272-1, CONN PLUG HSG 3POS 3.96MM
AMP Universal Power 3 pin, A122360-ND, 176283-1, CONN RCPT HSG 3POS 3.96MM
JST Connector, A107106CT-ND, 175151-1, CONN SOCKET 22-26AWG CRIMP TIN
JST Connector, A100484CT-ND, 175152-1, CONN SOCKET 16-20AWG CRIMP TIN
JST Connector, A100481CT-ND, 175149-1, CONN TAB 22-26AWG CRIMP TIN
JST Connector, A100483CT-ND, 175150-2, CONN TAB 16-20AWG CRIMP TIN
Cable Leader Power Cord Splitter Cable for 2 NEMA 5-15R to 1 NEMA 5-15P (14 inches / 14 AWG)
PAC SNI-35 Variable LOC Line Out Converter 1.2x6.25x5.9
YABEDA RCA Female to Dual RCA Male Y Splitter Cable,Gold Plated RCA (1 Female to 2 Male) Stereo Audio Y Adapter Cable - 1.6feet/50cm


Last year I added a mute switch to the amplifier. I don't want to make the speakers pop when powering off the cabinet, and toggling a mute switch is easier for me than unlocking and opening the control box to turn the volume down then back up to exactly where I had it set. The amplifier already has this mute function built in but you need to add your own switch or button to utilize it. I don't have a part number for the switch. It's just a basic switch that I bought many years ago.

IMG_9303.JPG
IMG_9305.JPG
Thank you! I appreciate your sharing, it will make my life much easier. Also, thank you for the information on the new modification.

I posted the 3D print file for everyone in the speaker thread. I was able to refurbish the additional speakers and am currently using those.

Did you add the same sub you used in the Astro City mod to your Blast City?
 
Did you add the same sub you used in the Astro City mod to your Blast City?

No sub for the Blast. The ported speaker enclosures provide enough low end. My Blast City sounds better than my Astro City, even without a subwoofer.
 
No sub for the Blast. The ported speaker enclosures provide enough low end. My Blast City sounds better than my Astro City, even without a subwoofer.
Another question for you.

Do I need the following items if I'm keeping the original speakers?

Dayton Audio DMPC-6.8 6.8uF 250V Polypropylene Capacitor
Dayton Audio DNR-3.0 3 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-0.33 0.33 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-1.0 1 Ohm 10W Precision Audio Grade Resistor
 
Another question for you.

Do I need the following items if I'm keeping the original speakers?

Dayton Audio DMPC-6.8 6.8uF 250V Polypropylene Capacitor
Dayton Audio DNR-3.0 3 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-0.33 0.33 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-1.0 1 Ohm 10W Precision Audio Grade Resistor

Those components were chosen specifically for the amplifier, woofer, and tweeter combination that I am using and if any of those three components change, you need to change the components too. So the answer is no, you don't need them. But if you connect the same amplifier that I'm using directly to the stock speakers, you will likely damage them. The stock speakers (woofer and tweeter together) are something like 5W at 8 ohms? I can't remember. You could buy a different model amplifier with less power but I don't expect you will notice any improvement in sound. I only added an amplifier because the woofers I installed are higher impedance and weren't quite loud enough for me being powered directly from a JAMMA game board.
 
Those components were chosen specifically for the amplifier, woofer, and tweeter combination that I am using and if any of those three components change, you need to change the components too. So the answer is no, you don't need them. But if you connect the same amplifier that I'm using directly to the stock speakers, you will likely damage them. The stock speakers (woofer and tweeter together) are something like 5W at 8 ohms? I can't remember. You could buy a different model amplifier with less power but I don't expect you will notice any improvement in sound. I only added an amplifier because the woofers I installed are higher impedance and weren't quite loud enough for me being powered directly from a JAMMA game board.
So you would not recommend this upgrade if I plan to keep the restored (original) speakers?
 
Do you recommend upgrading the speakers or keeping the refurbished OEM speakers? Just wondering since I'm working on this restoration now anyway.

Thank you for all you advice and support.
 
Do you recommend upgrading the speakers or keeping the refurbished OEM speakers? Just wondering since I'm working on this restoration now anyway.

Thank you for all you advice and support.
My OEM speakers were completely ruined so I never had a chance to hear how they sound. My guess is that they sound fine. That's assuming the refurbishment you did brought them back to their original condition. If it sounds bad, try different speakers. But not the speakers I'm using. Find something with lower impedance so you don't need to add an amplifier.
 
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My OEM speakers were completely ruined so I never had a chance to hear how they sound. My guess is that they sound fine. That's assuming the refurbishment you did brought them back to their original condition. If it sounds bad, try different speakers. But not the speakers I'm using. Find something with lower impedance so you don't need to add an amplifier.
Excellent.

Thank you for the sage advice.
 
Edited my last post to delete the lower impedance comment. That's not quite right. Different speakers need different amounts of power to drive them. The sensitivity rating is more important than the impedance. You should stick with the original speakers unless they sound really bad or have absolutely no low end.
 
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