New Astro city. New power supply and jamma harness

[djsheep]

Do you have them wired as mono? In series? That would mean it equals to 16ohm on your amp!

That would explain why they sound so muted

Not at all. They’re wired in exactly the way the cab came from the factory. My other NAC is the same.

I was talking about the Mono signal from the PCB. I am unsure if the Sega PSU amplifies the signal from the PCB in any way? Or perhaps the volume control is just directly controlling the volume output from the PCB?

Would be good to hear feedback from @jepjepjep about how he found the LG speakers on his NAC.

 

[PascalP]

Stock NAC is wired in series, so dual 4ohm acts as a single hm mono speaker.
So for you it would mean a single 16ohm mono speaker.

I know @Sp33dFr34k has wired them as stereo L/R to the NVS4000

 

[jepjepjep]

Do you have them wired as mono? In series? That would mean it equals to 16ohm on your amp!

That would explain why they sound so muted

Not at all. They’re wired in exactly the way the cab came from the factory. My other NAC is the same.
I was talking about the Mono signal from the PCB. I am unsure if the Sega PSU amplifies the signal from the PCB in any way? Or perhaps the volume control is just directly controlling the volume output from the PCB?

Would be good to hear feedback from @jepjepjep about how he found the LG speakers on his NAC.

The LG speakers sound pretty "good" to me. I put "good" in quotes because they're still 3" speakers, so the sound isn't really comparable to a good setup but I feel like the sound is pretty good for an arcade cab.

I played a game of Raiden II this morning and I'm able to get plenty of volume, although I never really have a need to crank the sound too high, since I'm in an apartment.

As far as sound quality and volume level, I'm happy with the setup, but I don't like the idea of running out-of-spec speakers. The main concern is that I want to avoid any unnecessary stress on my game PCBs.

 

[tiff_lee]

Has anyone seen inside a AC/NAC psu, is there any amplification circuit or is it just a pot between the board and speakers?
If it's the latter I find that quite odd given that the Astro City has 2 x 8 ohm speakers in parallel for a 4 ohm load and then the NAC has 2 x 4 ohm speakers in series for a 8 ohm load. So dependant on which cab you put your jamma board in you are going to have a speaker impedance mismatch somewhere.

 

[djsheep]

I’ve seen the insides of the NAC power supplies a few times, but can’t remember what the sound section was like @tiff_lee

My google searches allude to just a pot to control the volume from the PCB and nothing else. So having the pot set on 10 would essentially be the volume of the PCB. I too find it strange that certain Astro City PSU are found in NAC cabs.

I’m going to order a some new speakers and will report back when I find something good that’s actually 4ohm/30w/3”

 

[jepjepjep]

I've opened up my New Astro power supply and it looks like it's just a potentiometer in there to adjust volume. @djsheep, I measured the resistance of my LG speakers to verify and they are indeed 8 Ohm speakers just like yours.

 

[djsheep]

I've opened up my New Astro power supply and it looks like it's just a potentiometer in there to adjust volume. @djsheep, I measured the resistance of my LG speakers to verify and they are indeed 8 Ohm speakers just like yours.

Thanks for checking @jepjepjep, so theoretically, turning up the pot on my PSU to 10 won't do any damage. That's good to know. I'll adjust from my board and keep the pot on full tilt from now on.

Also good that you checked the LG speakers too. Pretty peeved at the seller for misleading people. I wonder if it caused any harm for anyone. I wonder if they're even 45 watt.

If anyone on the forum has use for hm, 45w, 3" speakers, drop me a line.

 

[lolo-san]

I recently took apart 2 NAC PSUs that have different issues and thought I could share the pictures in this thread which seems to be the NewAstroCity main thread.

I have 2 NAC cabs that came with 2 different PSUs:

The Tate one has the 400-5198-01Y (JQA JQ10011), mono and one of the weakest stock PSU for the NAC (it can't run some PCBs like Cave SH-3)
The Yoko one has the NVS-4000-01, no need to present that one I guess.

Just a quick comment about the Stereo / Mono speakers inside the cab, I found this wiring schematic of the cabinet on the web :



It looks like on a stock cabinet the speakers are not mounted in series inside the cab and that they are independent from each other however a small connector on the wiring side (the one that connects to "CN1" on a stock mono PSU) will set them in series (the one with the white cable loop):



On a cab with a NVS-4000 this connector should be left unused. I learned this the hard way when a friend of mine blown is spare NVS-4000 PSU audio amp (we were trying to swap the original one in my Tate cab with his NVS-4000) most likely because we left the speakers connector there plugged into DC1...



Anyway this will be for another thread as I think it can be fixed however I'm an absolute beginner with soldering and troubleshooting electronics..

Here are the PSU pictures for the 400-5198-01Y:







And the NVS-4000-01 (power supply part):





and the stereo amplifier part (Sega Model-3):





As you can see the lm1876tf amplifier has seen better days

 

[lolo-san]

I was limited by the number of attachments in my previous post so here are 3 other pictures that are relevant for the NVS-4000:

The audio power transformer that is sitting underneath the audio amp (which is upside-down inside the PSU):





And the pinout description on top of the PSU:



I outlined the DC OUT1 connector pinout (green rect). I highly suspect that the 2 connectors inside the red rect are in fact connected contrary to what one could understand from "NC" (not connected ?) and that having the mono speakers wiring plugged-in like for a standard mono NAC PSU is prone to the failure we had on the NVS-4000 stereo amp.

 

[PascalP]

Just a quick comment about the Stereo / Mono speakers inside the cab, I found this wiring schematic of the cabinet on the web :



It looks like on a stock cabinet the speakers are not mounted in series inside the cab and that they are independent from each other however a small connector on the wiring side (the one that connects to "CN1" on a stock mono PSU) will set them in series (the one with the white cable loop):

looking at your schematic (which is the same I use from the NAC manual), the speakers are mounted in series.
See the bridge that gaps - of the left speaker to the + of the right speaker?

Yes with the NVS4000 they are wired in stereo, but with the ‘normal’ NAC PSU it is in series resulting in a 16ohm load in @djsheep’s case

 

[digitron]

@djsheep curious if you found a good pair of speakers, I think I'm going to purchase a better pair of hm speakers for my Astro City (not NAC) and forget the amp.

 

[djsheep]

Found some locally at an Electronics Store. But they’re not hard to find if you follow the recommended ohms and wattage. The NAC speaker are a pain in the arse being 4ohm.

 

[digitron]

Found some locally at an Electronics Store. But they’re not hard to find if you follow the recommended ohms and wattage. The NAC speaker are a pain in the arse being 4ohm.

These look to be a good gamble, size is right, 8 ohms, 5 watts more than factory (15w vs 10w) but I think they should be fine.

https://www.amazon.com/gp/product/B01IN8YI4Y/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[hardyhell]

And the pinout description on top of the PSU:



I outlined the DC OUT1 connector pinout (green rect). I highly suspect that the 2 connectors inside the red rect are in fact connected contrary to what one could understand from "NC" (not connected ?) and that having the mono speakers wiring plugged-in like for a standard mono NAC PSU is prone to the failure we had on the NVS-4000 stereo amp.

@loloC2C you are saying the the Information on the psu is wrong and blew up your amp?

i am trying to get this Setup done properly with a Stereo mvs but still have some probs thatleft is not as loud as Right channel and also somehow in the test menu i dont get the channels seperated.for example if i do test tone on left it also Comes out of the Right Speaker a bit. what i am wondering is why the in port of Audio for L Sound is Twisted compared to the Sound out port.
has somebody a good guide how to wire this propperly?

and the second Thing i am trying to find out is if ist possible to just run Mono pcb as well by just using the cable with the one loop or is there another trick?

thanks guys

 

[lolo-san]

I blew my amp because the cab's speakers were still wired to the main 18 pins AMP UP connector (through the 4 pin connector with the white loop) when I connected it to the NVS-4000 (green rect on my picture). Both the inline fuses on the stereo amp card were blown as well as the amp. Replacing these parts fixed the issue so at least it could be repaired.

The cabs speakers must be connected to the NVS4000 Audio Out (4 pins AMP connector), in the end what happened for me was more about forgetting to remove the speakers connector from the "main" AMP rather than being mislead by the informations on the PSU.

 

[hardyhell]

Did use both connections with non stereo boards. Only thing that happens to me is no sound. Nothing blown up jet. How the hell do I get mono out. Have to follow the traces there tomorrow

 

[segasonic91]

It just dawned on me that I have this Stereo Amp in my New Astro. I was wondering if anyone could break down how to wire up the input. I believe the power / sound out cables are already present.

I guess I'd like to try out CPS-2, CPS-3 and Neo Geo...

Did you ever get this wired up? I bought one but of course, no wires. The power and sound out cables you mentioned, are they on the 001 loom? I can't picture mine at the moment to think if it has them or not.

 

[djsheep]

Bumping this thread with information about the Astro City 2 speakers.

The cab I bought came with some nice aftermarket 4ohm/15watt speakers, whereas the AC2 takes 4ohm/40watts. The upgrade to these are amazing. Definitely the loudest and boomiest sound out of any traditional candy.

The speaker boxes are marked with the model speaker inside the box, these three are "302", the other one (not pictured) was a totally different number.

I swapped the boxes around from this set from China with the ones originally in the cab as they were rust free.

I guess it is safe (and sad) to assume that this set of speakers is rotting away from age/being on site? Or it could be dust? I didn't want to pry any further in case I started doing damage to the cone. The sound doesn't seem to be affected at this point (as compared to my Blast City speakers which are toast).

Apparently, the status quo is that these speakers are Bose, however I couldn't find any markings to suggest so, and a google search shows up empty with the model number.

One of the best things about AC2 is that it's just the red and black wire to install, no need for having to pull out the soldering iron or crimp some wires.

Hope this brief insight is helpful to someone. My AC2 is a dedicated DoDonPachi machine, now my "Power Up" comes with a lot more punch and bass.

 

[twistedsymphony]

Apparently, the status quo is that these speakers are Bose, however I couldn't find any markings to suggest so, and a google search shows up empty with the model number.

a bit of a secret about Bose... most of the drivers they use are cheap/lower quality than other name brands. what you're paying for is the engineering work that went into designing a finely tuned enclosure and equalizer design that is capable of making up for the shortcomings of the crappy drivers.

the result is that their products sound great and have an enormous profit margin, but if you put those drivers in something else it's going to sound like dog-shit.

 

[Sp33dFr34k]

Apparently, the status quo is that these speakers are Bose, however I couldn't find any markings to suggest so, and a google search shows up empty with the model number.

a bit of a secret about Bose... most of the drivers they use are cheap/lower quality than other name brands. what you're paying for is the engineering work that went into designing a finely tuned enclosure and equalizer design that is capable of making up for the shortcomings of the crappy drivers.
the result is that their products sound great and have an enormous profit margin, but if you put those drivers in something else it's going to sound like dog-shit.

While that's true, I didn't think this was a secret