triforce7770
Student
- Thread starter triforce7770
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300wins
Professional
Maybe it's this issue? https://www.arcade-projects.com/thr...-nvs4000-etc-no-jamma-sound-buzzing-fix.9228/
triforce7770
Student
Nope checked r1 and it's good at 10ohms out of circuit and in circuit. Also recapped the board as well. Sorry forgot to put this in main post.
triforce7770
Student
Ok so I found out about af+ and af-. Tapped those into speaker - and speaker + on the jamma end. but now on mono the audio is low but audible but sounds choppy. When I try stereo with my sega astro jvs loom i get nothing but hum. I recapped the sound board and changed both op amps and still nothing. only thing i see left on the board is the amp and another sound ic is M5283P which is a dual VCA IC for volume control.
triforce7770
Student
Update! Got another nvs4000 for my new astro city. Tried with the astro city and same issue. Mono is choppy/static and the amp on the game board gets hot to the touch.
Decided to put the new nvs4000 into my new astro and works good both mono and stereo. Originally had a 5198-01x psu only had to change one plug. Easy enough. Put the yellow jumper into sound in and works good. So what gives? I checked the pinout on sound in/sound out and dc1 for af +,- and it's matches and check continuity with cables as well. No difference.
Pics of the jamma wires going into af +,- and the others going into sound in.
Decided to put the new nvs4000 into my new astro and works good both mono and stereo. Originally had a 5198-01x psu only had to change one plug. Easy enough. Put the yellow jumper into sound in and works good. So what gives? I checked the pinout on sound in/sound out and dc1 for af +,- and it's matches and check continuity with cables as well. No difference.
Pics of the jamma wires going into af +,- and the others going into sound in.
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triforce7770
Student
triforce7770
Student
Been looking at the Astro City and New Astro City manuals and noticed something. Astro speaker wiring is wired in parallel. 2 8 ohm speakers.
Where as New Astro City speakers are wired in series with 4 Ohm speakers.
Astro on Left and New Astro on Right.
I wonder if the difference in wiring between the two cabs is causing me this issue. It sounds like an impedance issue from the sound coming out the cabinet.
I did make a mono jumper cable that should make the speakers into series that goes into sound in.
Where as New Astro City speakers are wired in series with 4 Ohm speakers.
Astro on Left and New Astro on Right.
I wonder if the difference in wiring between the two cabs is causing me this issue. It sounds like an impedance issue from the sound coming out the cabinet.
I did make a mono jumper cable that should make the speakers into series that goes into sound in.
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triforce7770
Student
Figured out my issue! Turns out I had my speaker (+) and (-) jamma l and pin 10 running to the top two pins on sound in! And also running it to af + and - !! So I cut my two wires on sound in and re ran them to af + and - . Now I get awesome mono! @opt2not
Here's a vid of it in glorious mono now! I do have a astro jvs for stereo so I'm all set!!
View: https://youtube.com/shorts/Cxa5BzeeiCg?feature=share
Here's a vid of it in glorious mono now! I do have a astro jvs for stereo so I'm all set!!
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Am I the only one who thinks it sounds like they sing the word "assholes" at least once during the attract mode song for TiT? I used to frequent this dollar theater's arcade with friends back in high school (mostly for a 4-slot Neo-Geo with a decent selection), they had that machine and it was turned up loud. All I ever heard was something something ASS HOLES something something ASS HOLES, ON THE EDGE OF YOUR MIND