the site is slightly kludgy to use, but I added the Asteroids mainboard and AR to the database and submitted my fixes.
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Please post all monitor technical topics in the Technical - Videogames - Monitors section, not in the General Help section.
Another Asteroids Loud Hum Post
- Thread starter rknucklez
- Start date
the site is slightly kludgy to use, but I added the Asteroids mainboard and AR to the database and submitted my fixes.
Arcadenut
Well-known member
Well, let me know what you don't like and I'll work on making it better. I've had pretty much zero feedback at this point.
DarrenF
Well-known member
Anyhow, YMMV here as the TL084 requires minimum 7v input supply to operate or it's outputs suddenly go high, so in certain analog (likely non-audio) implementations this may not work for you. For audio, I don't ever see anybody having a problem unless it's in low-voltage setup, then you'd be better off using something like an MC33079.
As always, thanks for bringing this up Darren. There were some considerations I didn't think of before, Re; TL084 vs. LM324. Granted, now I'm just going to recommend the MC33079 in those cases.
Yeah, my point was to be careful subbing. For example, OutRun uses Lm324s in the audio output, powered by 5v (and GND). Subbing a TL0x4 here wouldn't meet the 7v supply requirement you mentioned.
Personally, I'll sub in a TL part if it operates on a split supply, but replace with an LM324 for those on a single supply. They're always socketed when I'm done, so anyone can swap out easily in the future.
And as you point out, arcade games aren't exactly generating quality audio in the first place, so the whole discussion is mostly academic.
I'd like to figure out what's causing the hum in my Asteroids. Replacing the LM324 did nothing. In my case, the sound effects are still loud and crystal clear, but there is an annoying buzzing through the speaker that comes and goes; it's almost as if the vector chatter is causing feedback in the speaker or something, because it gets worse when there's a lot of crap being drawn on the screen.
WindDrake
Well-known member
Pretty much, yeah. I'd forgotten about the 7v min VCC on the TL084, so it's good you jogged my brain.
I just don't trust them anymore, and when I really need something that can get down under the 7v supply requirement, I'll opt for OnSemi's MC33079. The LM324 just makes me feel dirty. Haha.
Vector chatter is completely normal. It shouldn't be very loud, but it is loud enough to notice it. The hum from the LM324 was LOUD and increased significantly with volume increase.
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Yes, faint vector chatter on the speaker is normal. Might help to make a video of what yours is doing if you think you've got something else going on.
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