Sega Astro City: Best Practices Plugging into US 120V Receptacle

[sam jam]

Hi all,

I have what appears to be a basic question but I've overcomplicated it in my brain after reading so many threads/forums.

What is the "best" practice (most ideal setup) when plugging in a Sega Astro City to a US receptacle? Below is my train of thought... not sure if there is a definitive answer.

I see a lot of different approaches, and the most popular/recommended one seems to be replacing the stock power cord from the standard JP 2-prong connector (JIS C 8303 / NEMA 1-15P) to become a standard US 3-prong connector (NEMA 5-15P). This has the benefit of grounding the cab when plugging into a US receptacle with ground, of course. With a surge protector in place, most seem to call it a day and move on at this point.

But assuming I've replaced the stock power cord with a US 3-prong type, my subsequent concern is the incoming voltage. I've measured and verified the receptacle where I plan to plug in the cabinet is 120V. I understand the PSU allows for a range of incoming voltage (AC90-132V per the wire diagram); however, the cabinet is manufactured for an ideal incoming voltage of 100V and has had 100V all of its past operational life in Japan.

Is it considered best practice to condition the incoming voltage to be 100V in lieu of 120V? I don't see a lot of US individuals mention or suggest this as necessary. Keep in mind I want to do everything in my power (excuse the pun) to protect this expensive cabinet and extend the lifetime of the electrical components. This might be an overkill step which is why I don't see it suggested or required unless I lived in a country with 240V or something.

If it is best practice to step down from 120V to 100V, I've been searching for a product that fits the bill but there are so many options online. I was hoping for a product recommendation. I came across the LiteFuze JP-1000 but using this product only confuses me... For example, the 100V output only has the standard JP 2-prong connector! Does this mean that using this product could negate the need of replacing the stock power cord altogether? And the SAC wiring diagram mentions 300W at 100V, so I followed the manufacturer's advice in doubling the wattage when sizing the converter which leads to the 1000W version, not the 500W version, even though the sticker on the back of the cabinet says 140W at 100V. Furthermore, how would I actually ensure the cabinet is actually grounded if using the aforementioned device?

So it would appear an ideal setup consists of a surge protector at the 120V receptacle, then 120V step down to 100V transformer, and plug in the stock 2-prong power cord?

I'd be more than happy to spend some money on a quality setup to ensure longevity of the cabinet, but I don't want to buy things that might ultimately be redundant or just plain unnecessary. This cabinet is like my grail collection piece so I am probably overanalyzing all of this.

Thanks for your time!
Sam Jam

 

[streetfighterken]

I've been running 9 Astros 40 hours/week in a public arcade for 8 years just plugged into 120. I didn't even read your post lmao.

 

[sam jam]

I've been running 9 Astros 40 hours/week in a public arcade for 8 years just plugged into 120. I didn't even read your post lmao.

Haha that is very reassuring and about what I expected. But yea, just overanalyzing the most basic things. Thank you!

 

[Crunch]

The NAC (unsure about Astro) has a grounding point on the back of the cab where the power cable comes from. If you haven't already swapped it for a 3 prong cable, you would use it with the grounding point as shown on the product you linked.

Whether all of this is necessary or useful remains to be determined. In my experience in owning a NAC I had to remove a grounding point in the cab to get rid of a ground loop and clean up the monitor's image.

I'm in the same camp as @streetfighterken and ran in without a 3 prong cable for 15+ years with no issues. Just changed it very recently.

 

[sam jam]

The NAC (unsure about Astro) has a grounding point on the back of the cab where the power cable comes from. If you haven't already swapped it for a 3 prong cable, you would use it with the grounding point as shown on the product you linked.

Whether all of this is necessary or useful remains to be determined. In my experience in owning a NAC I had to remove a grounding point in the cab to get rid of a ground loop and clean up the monitor's image.

I'm in the same camp as @streetfighterken and ran in without a 3 prong cable for 15+ years with no issues. Just changed it very recently.

The SAC does have a similar grounding point location on the back. That makes sense and thanks for clarifying how the cab would be grounded in connection with that voltage step down product!

 

[jcmorrisii]

So it would appear an ideal setup consists of a surge protector at the 120V receptacle, then 120V step down to 100V transformer, and plug in the stock 2-prong power cord?

Yes this is the ideal setup if your wall voltage is ~120. I personally like to use VCT VT-500J that I modified to fit our needs in NA on anything that has a native voltage of ~100. I would be happy to discuss the easy mod if you decide to go this route.

The fact of the matter is, any time you apply a voltage higher than what a circuit is designed for, you are prematurely aging every component in line. The life expectancy is typically rated based on the current and temperature over time. Could they run like that for the foreseeable future and not have any failures? Sure, of course! But if you have the option to prevent that and actually run the devices at the voltage which the manufacturer recommends, why wouldn't you? Im a big proponent of setting things up correctly and doing things right the first time; rather than having to go back and fix things that could have been prevented.

Im sure 95% of the people will disagree with me because of their personal experiences of NOT running any sort of step down and not having issues; ultimately its something you will have to decide for yourself.

I've been running 9 Astros 40 hours/week in a public arcade for 8 years just plugged into 120. I didn't even read your post lmao.

Statements like this are dangerous. I could say that Iv lived in Florida my entire life and been outside in thousands of lightning storms and never been struck, but it doesn't mean it cant happen that that its a safe/smart thing to do. Not to mention the disrespect to the OP laughing about not taking the time to even read what your commenting on.

 

[SailorLodestar]

I agree with @jcmorrisii.

An electrical engineer I knew advised me to run everything on step-down transformers, so I've been doing that since I started collecting six years ago.

I'll also add, it's good practice because even if an astro or blast may appear to work normally, once you start collecting other Japanese machines, they will start acting wonky with the wrong voltage. If you get in the habit of using the step-down transformers for this grail, you can hopefully avoid damaging your future, more sensitive grails.

 

[sam jam]

Yes this is the ideal setup if your wall voltage is ~120. I personally like to use VCT VT-500J that I modified to fit our needs in NA on anything that has a native voltage of ~100. I would be happy to discuss the easy mod if you decide to go this route.

The fact of the matter is, any time you apply a voltage higher than what a circuit is designed for, you are prematurely aging every component in line. The life expectancy is typically rated based on the current and temperature over time. Could they run like that for the foreseeable future and not have any failures? Sure, of course! But if you have the option to prevent that and actually run the devices at the voltage which the manufacturer recommends, why wouldn't you? Im a big proponent of setting things up correctly and doing things right the first time; rather than having to go back and fix things that could have been prevented.

Im sure 95% of the people will disagree with me because of their personal experiences of NOT running any sort of step down and not having issues; ultimately its something you will have to decide for yourself.



Statements like this are dangerous. I could say that Iv lived in Florida my entire life and been outside in thousands of lightning storms and never been struck, but it doesn't mean it cant happen that that its a safe/smart thing to do. Not to mention the disrespect to the OP laughing about not taking the time to even read what your commenting on.

This is great information and thank you very much for taking the time to elaborate on your setup! It's great to hear real human feedback on a voltage converter device because I have a hard time trusting Amazon reviews.

Right, if I could provide the cabinet with 100V input like it has been during its entire past operational lifetime in Japan, then that is something I would like to try and achieve. I suppose I just needed to make sure I wasn't totally crazy or alone in my thought process.

Do you mind sharing the mod you mentioned? Is this a mod to effectively ground the cab with the noted voltage converter?

 

[leonk]

I shared this about 5 years ago. Been running my NAC cab like this since about 2010. I converted my cab to this universal mode (using a power strip) so I can swap what's inside. Anything from stock PSU and JAMMA PCBs, to Naomi 2 with its own SUN PSU to a MAME arcade setup with its own PSU. My cab came with a 110V to 100V isolation transformer. You don't need it. I have it so I just use it (felt bad throwing it out) I consider it there more for backup safety (isolation part) than the 100V.

The MS8/MS9 monitor in your Astro has its own isolating switching PSU. You are safe to connect it directly to 120V. The big assumption here is that it's an MS8/MS9 and it's the original chassis. When I used to have American wood cabs in the early 2000's, those ran old school Wells Gardner K7000 arcade monitors and they required an isolation transformer for your safety. So using an ISO on all monitors for me is an old habit.

 

[sam jam]

I shared this about 5 years ago. Been running my NAC cab like this since about 2010. I converted my cab to this universal mode (using a power strip) so I can swap what's inside. Anything from stock PSU and JAMMA PCBs, to Naomi 2 with its own SUN PSU to a MAME arcade setup with its own PSU. My cab came with a 110V to 100V isolation transformer. You don't need it. I have it so I just use it (felt bad throwing it out) I consider it there more for backup safety (isolation part) than the 100V.

The MS8/MS9 monitor in your Astro has its own isolating switching PSU. You are safe to connect it directly to 120V. The big assumption here is that it's an MS8/MS9 and it's the original chassis. When I used to have American wood cabs in the early 2000's, those ran old school Wells Gardner K7000 arcade monitors and they required an isolation transformer for your safety. So using an ISO on all monitors for me is an old habit.

I had thought about having a power strip inside the cab as it would be super useful and convenient when modifying down the road. This is very helpful and thank you for sharing the diagram!

My SAC has the MS8 but you're right and, unless I'm misreading the SAC wiring diagram, I don't see an isolation transformer included within it but regardless this is still very useful information. I saw those isolation transformers online but didn't understand how they interconnected but now I see yours, so I appreciate you sharing your setup and in such detail! Beautiful cabinet!

 

[trashedcabs]

Everyone here is overthinking this or being borderline superstitious. Your cabinet has two major components in it which are powered by the wall: the monitor and the power supply. Ignore the sticker on the back of the cabinet, let's simply look at the ratings for each of these.

From the MS9's manual:

The MS8-29 manual is sparse, but the MS8-26 says this:

The sticker on an Astro power supply:

Just plug it into the wall, it's fine.

 

[sam jam]

Everyone here is overthinking this or being borderline superstitious. Your cabinet has two major components in it which are powered by the wall: the monitor and the power supply. Ignore the sticker on the back of the cabinet, let's simply look at the ratings for each of these.

From the MS9's manual:

The MS8-29 manual is sparse, but the MS8-26 says this:

The sticker on an Astro power supply:

Just plug it into the wall, it's fine.

Thank you for the MS8-29 snapshot, I must have missed that in my research. I'm only used to worrying about the incoming voltage for things like vintage high fidelity audio equipment from Japan which I understand is a bit of a different ballpark than this given its primary concern is preserving the audio quality which the voltage input can affect. So really that's where my concerns have largely stemmed from in my past experience working with vintage Japanese audio equipment.

I think this is great clarifying info and if anything I just needed this open discussion to better understand the approaches to plugging in a SAC based on all that I've read online.

I do trend towards overkill but I definitely feel much more comfortable plugging the cab to a US receptacle regardless of which approach I take, so I thank everyone here for their valuable time and input!

 

[streetfighterken]

Statements like this are dangerous. I could say that Iv lived in Florida my entire life and been outside in thousands of lightning storms and never been struck, but it doesn't mean it cant happen that that its a safe/smart thing to do. Not to mention the disrespect to the OP laughing about not taking the time to even read what your commenting on.

Flawed logic. Thumbs down? "DANGEROUS"? DISRESPECT! oh my! Come on now. If 150,000 hours of combined run time doesn't convince you it's safe, that's literally your problem. I'm telling you real world facts and you may choose to ignore if you want. I haven't even recapped the PSUs yet but I should probably get to it soon.

 

[leonk]

Everyone here is overthinking this or being borderline superstitious. Your cabinet has two major components in it which are powered by the wall: the monitor and the power supply. Ignore the sticker on the back of the cabinet, let's simply look at the ratings for each of these.

There are other things as well. Like light fixture and potentially a separate audio amp. I've personally experienced a poorly wired candy cab where when you touch the side of the machine, you can feel the tingling of electricity. Any electrician that worked around live outlets knows what I'm talking about.

I'm not advocating for 120V to 100V transformer. I'm advocating for proper grounding and a complete check of the machine. You never know how the thing was abused in its past life.

 

[notsonic]

My house voltage is pretty high. It can be as high as 129v. I got a 120->100 stepdown and the resulting output was like 110-115.

I had a lot of problems with my MS8 New Astro City so I tried the stepdown. All it did was change the pitch of the whine in my chassis and the light stopped working.

I run my Blast City on the stepdown out of superstition because the MS2931 is so finnicky and because my house voltage is so high. The reality is these components were sold in the US to use directly on the US power grid.

I do recommend using a 3 prong cable though.

 

[sam jam]

Well this is why I asked the direct question because I saw a lot of differing thoughts on it.

Of course my objective is to not fry anything, that would be the main goal lol. I assume if it worked in Japan on 100V then maintaining that here in the US would be the most ideal course of action. And as others have noted, the internal components are rated for a range of voltages. I didn't think any SACs were sold in the US but that is interesting to know.

This conversation does give me a lot of great insight!