Aero City headphone kit

[geekmiki]

Hi,

I have in mind to add the headphone connectors + volume knob + stickers to my Aero City panel. I've seen a couple of pictures here from @Ziggy Cheetos Dust Aero CIty restoration project, that was very well executed, but the repro board by JNX for the headphones isn't connected. From what I've understood, another board is needed that filters the JAMMA audio output to bring it down to a decent headphone level. There is no repro of that board and I haven't found any info on that either.

Up until a few months ago, there was a kit sold on eBay by Overcome Arcade that seemed to include everything needed, even the stickers: https://www.ebay.com/itm/313902525960
More detailed info on the package contents here: https://www.neo-arcadia.com/forum/viewtopic.php?p=1402363#p1402363
(Also, make sure to check the pictures below of a few installed kits)

Feedback on Neo Arcadia wasn't great though. Several users' kits had issues, others stopped working after a few months, quality was not that great and Overcome Arcade wasn't responding.

I guess this could be an interesting addon for Aero City owners that just want a plug&play kit that includes everything needed.
Is there any interest at all?
And the most important question: Does anyone with the right skills and knowledge want to make and sell this?

 

[Ziggy Cheetos Dust]

I started researching on how to make the board. - but got sidetracked with life. It’s not that complicated a circuit. I need to do a bit more research on how to bring the levels down to headphone level and not line level. But it’s not a fixed value as some headphones can handle levels that others can’t. There are plenty of cheap speaker to line level devices out there for inspiration. I’ll see if I can do a test with the level reducing device I have in the aero already. If i got it to work it would be mono only - and I have the benefit of already having the amp and volume knob setup already in place. I think to make a kit would take hours each one. Maybe three of four hours.

 

[KaPH33n]

I have the JNX PCBs in two of mine. If I recall they don't need any other additional hardware? Maybe I needed to make some harnesses or 3D print some standoffs? I don't know if he's still selling or making them.

Here's his thread https://www.arcade-projects.com/threads/jnx-sega-839-0158-repro-headphone-board.2256/

 

[Big_P Big_p]

I started researching on how to make the board. - but got sidetracked with life. It’s not that complicated a circuit. I need to do a bit more research on how to bring the levels down to headphone level and not line level. But it’s not a fixed value as some headphones can handle levels that others can’t. There are plenty of cheap speaker to line level devices out there for inspiration. I’ll see if I can do a test with the level reducing device I have in the aero already. If i got it to work it would be mono only - and I have the benefit of already having the amp and volume knob setup already in place. I think to make a kit would take hours each one. Maybe three of four hours.

You want to reduce the speaker level voltage to about 1v (anywhere between 1.5v and 0.7v should be ok). To do this wire a series resistor and a parallel resistor into the circuit.
I have used 3.3k and 300R as well as 2.7K series and 100R parallel to get a line level but it really depends on the speaker output so play with those values untill you get close to 1v, reduce the series down to 1K if your running at low volume. You probably should add a 1uf high grade cap for good measure.