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Sega Model2/3 - JAMMA Adapter Thread

Whew, look at that last reply, 10 months ago, well, I feel like I should update all of you.

Friends, this little adventure I started was a bit of a mind strain. As people wanted the product, I began to panic with impostor syndrome, and on top of fatigue from crimping, I had taken a break to help recover my financial assets and to decide how I should handle all this. I've been trying to keep costs to pretty much a bare minimum in a spreadsheet, but every little thing I did added up.

A lot of my time away when thinking about this project involved amp substitution and power delivery. Discovering that the "mono" circuit installed didn't work on the original board after I already spun clones was a big mistake on my part and I could have redesigned the clone differently based on that. However, now I'm at a point where I'd just like to finish this build, let people have the original design should they want it, and move onto the next revision and again letting financial assets recover.

The first finished adapter will got to Tailsnic, as they were gracious to sell me the original board provided I would provide them a clone plus extras. I very much appreciate their lax attitude as they have generously let me go at my own pace with so much a single poke about it. As for the rest, I haven't really formed a queue anywhere, as it's hard to tell who from the many of you still want one at this point.

Currently, there is one major constraining factor in finishing these PCBs, and that's the JST-NH crimp connectors. My seemingly endless supply has been cut short due to all the COVID nonsense, and there's currently a 34 lead week time for them. There is a supplier I have ordered from to finish the first adapter to test it, and should everything work fine, finally send it off to Tailsnic, but if I were to order more to finish the other 4 adapter boards I have, let's just say it's unlikely anyone would buy the adapters at the additional cost those connectors would add.

Once the connectors do arrive, I will finally finish up the first adapter and keep you all informed of how it works. I don't anticipate any problems, however.
 
Three days ago, Digi-Key, my normal supplier of JST-NH connectors, got in 115,000 connectors. There were over 100.000 by the time I clicked the email. 3 days later, there are none. I should have ordered 1,000 for $30 oops...
 
In a stroke of brilliant luck, I had signed up for the JST-NH connectors "in-stock notification" but did not get it, but decided to look at the page anyway. I assume an big order got cancelled and a lot of the stock got replenished in the system, so I ordered 1,000 which should satisfy for maybe 3 adapters LOL (no more than that)
 
I haven't forgotten this, and I'm finally ready to tackle and be done with the first wave of boards. I am still salty from not having tested the adapter before reverse engineering it, but that's how the cookie crumbles sometimes.

There has been quite the interest over the last year and a half, and many people inquired about these boards and what their final prices might be. I will try to reach out to everyone who's expressed interest and list them in a future post as a type of queue. If they no longer want an adapter or the price is out of their budget, the person below them gets a slot until all the adapters are sold.

I have an idea of how to tackle the next iteration of this board and it involves using the Fingerboard of @Frank_fjs Jamma Extension Cable :D
 
Thanks for the update, would you be so kind to share some pictures / drawings of what the final design looks like ?
 
rtw said:
Thanks for the update, would you be so kind to share some pictures / drawings of what the final design looks like ?
Click to expand...
Well the final design from the JLPCB preview is here and the design with all components minus a few connection headers is here. I haven't finished making the cables yet and I still need parts to make the summing cables as everyone wants mono lol.
 
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A friend just pointed me to this thread and I really can't wait to see how this progresses! Been wanting to dive into a model 2 for a while now.
 
Shentok said:
A friend just pointed me to this thread and I really can't wait to see how this progresses! Been wanting to dive into a model 2 for a while now.
Click to expand...
I think people should keep in mind this was supposed to be a general resource thread and not my specific project thread :P

That said however, cleanup of my work area has begun and I plan on cranking out 5 total adapters and putting them on Tindie.

Spoilers:
I'm going to have to sell them at a loss :facepalm:
 
biggestsonicfan said:
I think people should keep in mind this was supposed to be a general resource thread and not my specific project thread :P

That said however, cleanup of my work area has begun and I plan on cranking out 5 total adapters and putting them on Tindie.

Spoilers:
I'm going to have to sell them at a loss :facepalm:
Click to expand...
Please don't sell them at a loss! It's just not worth it.
 
biggestsonicfan said:
... this thing does produce stereo sound! It sounds like one channel is slightly louder than the other, but that could just be my speakers...
Click to expand...
Guess who figured out they were using a shitty audio cable and that the stereo output is fine from the HA13001? ||

Also guess who's preparing 5 adapters for sale :thumbup:
 
Here's how all this is going to go down:
  • These 5 adapters will be the only 5 adapters of this kind produced. I've grown not fond of them for multiple reasons: HA13001 chip should be bought and used to replace in boards with actual failing HA13001s, I don't like the idea of taking these chips away from someone who could use them just so a Model2 can have an amplifier; the stereo audio requires a modified JAMMA harness to use the COINCOUNTER2 pin as it's 2nd channel, which is an absolutely unlikely circumstance anyone would have this normally. The point (imho) of a JAMMA adapter is plug and play, so if you have to modify your setup in any way, that defeats the purpose.
  • More than 5 people have wanted these, and I don't think it would be fair to message and wait on the replies of each individual who expressed interest in order. Therefore, to the victor go the spoils, these will be put up for auction on ebay and I will message everyone who has expressed interest a link to the store. There will be 5 adapters, so you can choose which one you want to try to bid on (snipe lol).
  • A new JAMMA adapter is in the works and I will post a thread about it in Project Showcase when it's ready (I've already started work on it). This thread was originally to generate discussion about the adapters (which there has been) but the need for adapters themselves seems to be greater, so I will cross-link to that thread when it's ready. I will also let the people I message know there will be a different and new adapter coming in the ebay link message, so they don't have to feel obligated to miss out. If you're a die-hard who wants authentic arcade components in your arcade (HA13001) then maybe you will want to jump on one of these adapters, otherwise you can wait just a bit longer for a (most likely) cheaper adapter with options to suit your needs.
  • The first adapter I built will both have multi-colored wires and stereo output to the COINCOUNTER2, a 1:1 replica of the originally reverse engineered adapter (aside from the service button passthrough traces). All the other adapters will be properly configured for mono and use black wires. If a buyer wants something special done (both adapter types) I can see if I can accommodate with my extra parts but I can't guarantee anything.
All in all I think that's a fairly reasonable way to handle things given how long it's taken to get to this point.
 
Very cool. Thank you for doing this
I hope I'm not outbid too terribly as I been wanting this adapter since day one. 😅
But this seems fair to me.
 
Okay, so using a datasheet of the HA13001, I'm able to only populate the area that goes to the SPEAKER +/- channel, and as COINCOUNTER2 was shorted to GND, I've cut that trace so if a 2nd coin counter is hooked up, it will be safe. Coin counters wouldn't easily be hooked up via this adapter anyway, the original adapter didn't have them and most adapters I've seen don't come with them either as the counters hook to CN15.

This first experimental mono adapter I accidentally cut the SPK- trace thinking it was the COINCOUTNER2 trace. I've bodged it, but the sound just isn't as loud as first adapter with stereo output. That may be be due to the bodge, or it may be the HA13001 being not as good. I will begin work on adapter 3 before finding that out. I'm hoping I just need a better bodge.

EDIT: Figured it out. Cap 6 (100uF 16V) was going to go to COINCOUNT1 and was soldered in, but the rest of the components for COINCOUNT1 weren't, and conversely Cap 4 (also 100uF 16V) was supposed to connect HA13001 Pin 5 to GND. Swapped the cap from 6 to 4 and the volume is fine! Resuming work on the summing (MONO) aspect of the adapter!

EDIT2: Taking inventory on parts I still need to complete the 5. Also it looks like I will be able to test these on the supergun. I didn't think I would be able to but I figured out a way to get them to work.

[twitter] biggestsonicfan—2023.02.22—1628467574941057024—Fpl6WxUaAAETjh9.jpg


EDIT3: Jesus Christ I forgot how much wire this is gonna take...

EDIT4: The cost of 48 wires per board has increased the cost per board by a bit sadly. I'm not sure how I forgot to take that into account initially, but the cost of colored wires per board would have increased the costs substantially.
 
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*SCREAMS INTERNALLY*
PXL_20230307_034806890.jpg

So, I'm making an adapter to make sure the mono audio works, because just soldering resistors onto the board, as-is, or trying to solder resistors to wires, isn't working.

Screenshot_20230306_195103.png


:S

EDIT: *SCREAMS EXTERNALLY*
I didn't double check my schematic vs my footprint, accidentally wired this this wrong, OOPS! It's already gone into production so I can't cancel it, but when this batch of bad board arrives I will confirm they will fit and modify if they don't.
 
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