Buzzing Twin Famicom

Started by Famicom.In.My.Blood, July 15, 2021, 10:10:43 am

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Famicom.In.My.Blood

Hello, new here.

I have a Twin Famicom AN-500B modded NESRGB and recaped, but I have a buzzing from the sound.

When the game hasn't music, or when I pause it, it's not a complete silence, but a buzzing is here. The buzzing is also when there is music, but it's hidden by that.
This happen on both Famicom and Famicom Disk System games.

I saw Twin Famicom could have sound problem, but it's not exactly the same things than me....

So, it's normal, or should I fix it (if it's possible) ?

Thanks for your help.

adori_12

Audio buzz is indeed normal and should be there, but it should be barely audible. Usually it's caused by a faulty and/or third-party AC Adapter, is you PSU official?

If so, then check your cables. Composite always has audio buzz although it should be a bit less noticeable when using official cables. RGB cables (the ones I am assuming you are using since you modded your system) usually nearly eradicate buzzing, but only if they're good quality. Cheap RGB cables have poor shielding and are very prone to buzzing, color bleed, checkerboard patterns, etc.

If your cables are properly shielded, then your house's voltage may have something to do. My electrical connections used to be subpar and that sometimes made audio buzz on my consoles super loud.

Famicom.In.My.Blood

Quote from: adori_12 on July 15, 2021, 04:38:37 pmAudio buzz is indeed normal and should be there, but it should be barely audible. Usually it's caused by a faulty and/or third-party AC Adapter, is you PSU official?

If so, then check your cables. Composite always has audio buzz although it should be a bit less noticeable when using official cables. RGB cables (the ones I am assuming you are using since you modded your system) usually nearly eradicate buzzing, but only if they're good quality. Cheap RGB cables have poor shielding and are very prone to buzzing, color bleed, checkerboard patterns, etc.

If your cables are properly shielded, then your house's voltage may have something to do. My electrical connections used to be subpar and that sometimes made audio buzz on my consoles super loud.

On my other consoles, no buzz at all (same sound system for each, on the same electric installation).

On Famicom, there is a permanent barely audible buzz, that's what you mean ?

I can't say it's barely audible in my case, it's clearly noticeable.

Unfortunately, if I can say, all my cables are high quality : fully shielded RGB and premium AC adapter.

The power supply of the console has been converted/replaced to 230V one, to avoid a tension converter, so it's a direct plug.
The problem could be here ?

P

My AV-modded Famicom (composite video only) had a permanently audible buzz. Though it was the most audible on silent screens in games (like when pausing some games and in the Everdrive menu) it was quite audible when there was sound as well. So yes noise on the audio-line is indeed a thing even on a normal Famicom with just a (good quality) AV-mod.

I tried other RCA-cables that came with my MSX and looked to be of a bit better quality than the cheap ones I had been using with the Famicom, and these seemed to make it a little better but not by too much as the buzz was still audible on silent screens. Then I tried the RCA-cables that came with my stereo computer/bookcase speakers I bought for the TV, and now the buzz is only audible on silent screens if volume is turned up real high and not at all when playing at a normal volume on screens with or without a BGM. So these RCA-cables was clearly of much better quality.

I know that Viletim's NESRGB has problems with audio noise, that's why he uses a special variant of the Framemeister-pinout RGB cable with audio in its own separate cord.

Does it buzz even when using composite video on the same Famicom?
And what power supply do you use? Replacing the original one is not a problem as long as the new one is at least as good and has all the correct values. The NESRGB might draw more power though, so you might want one with a little more juice than the original one. And by juice I mean more current (ampere) output and not voltage (volt) output. If you also use an Everdrive or Powerpak, that will draw even more juice.

Famicom.In.My.Blood

Quote from: P on July 16, 2021, 04:25:30 amMy AV-modded Famicom (composite video only) had a permanently audible buzz. Though it was the most audible on silent screens in games (like when pausing some games and in the Everdrive menu) it was quite audible when there was sound as well. So yes noise on the audio-line is indeed a thing even on a normal Famicom with just a (good quality) AV-mod.

I tried other RCA-cables that came with my MSX and looked to be of a bit better quality than the cheap ones I had been using with the Famicom, and these seemed to make it a little better but not by too much as the buzz was still audible on silent screens. Then I tried the RCA-cables that came with my stereo computer/bookcase speakers I bought for the TV, and now the buzz is only audible on silent screens if volume is turned up real high and not at all when playing at a normal volume on screens with or without a BGM. So these RCA-cables was clearly of much better quality.

I know that Viletim's NESRGB has problems with audio noise, that's why he uses a special variant of the Framemeister-pinout RGB cable with audio in its own separate cord.

Does it buzz even when using composite video on the same Famicom?
And what power supply do you use? Replacing the original one is not a problem as long as the new one is at least as good and has all the correct values. The NESRGB might draw more power though, so you might want one with a little more juice than the original one. And by juice I mean more current (ampere) output and not voltage (volt) output. If you also use an Everdrive or Powerpak, that will draw even more juice.
« Unfortunately », if I can say, my RCA cables are very high quality ones, and are the same for all my consoles.
So, I don't think it's the problem.

I made other sound tests today : it appears the buzzing is louder with FDS games, compared to « classic » Famicom games. In fact, I could almost say the buzzing with Famicom games is normal, or acceptable.
But with FDS games, no.
Also, the buzzing is even more louder if the second controller micro is activated, and it increases if I push the micro volume high.

The buzzing is exactly the same if I use the original mono output instead of the « double » mono of the two RCA from RGB (I have a BVM, so I use a scart/BNC converter, and I can unplugged the two RCA from the converter).

I haven't tested this Twin Famicom in Composite yet.

I don't know what power supply is in actually, I don't make it myself, it's my modder guy who has made all the modifications. I'll see with him what he can do (if it's possible).

P

I see, in my experience a SCART->BNC adapter doesn't to introduce any noticeable noise (and even with additional adapters needed to connect to the speakers), so that's probably fine.

If there is noise on the microphone line it's usually because of a dirty or oxidized slider potentiometer on Controller II. Even if you set the slider to volume 0, a faulty potentiometer could still let through a current and cause noise which is mixed in with the audio output (as that's how the mic is designed).
You can try disconnecting the Controller II PCB connector from the main board and see if you still have noise.

Testing composite might be the easiest test you can do now though, unless you don't have an RCA->BNC adapter to use composite video with your BVM. Make sure to use a good quality one (possibly gold-plated), not a cheap one.

Famicom.In.My.Blood

August 17, 2021, 08:14:51 am #6 Last Edit: August 17, 2021, 08:33:50 am by Famicom.In.My.Blood
My modder finally analyzed the Twin Famicom buzzing. After his test, he told me it's a « 50Hz sound ». He tested another Twin Famicom : same noise.
He also tested the second controller micro, it works perfectly and isn't oxidized inside or something else.

After heard some recording of 50Hz sound to be sure we talked about the same thing, it's clearly what I hear.
50Hz sound is a common thing on all consoles, but it's most audible on my Famicom than on all my other consoles.

My question is : for those who have Famicom, or especially a Twin Famicom, does this console is less good than other for the sound ?

This 50Hz sound could be attenuated with a Stereo Mod or something else, or it's just normal for a Famicom/Twin Famicom ?

I know some persons told me there is also a buzzing for them, but now it's clearly identified as a 50Hz sound, maybe other advices ?

P

The Twin is quite a bit different sound-wise (in recorded comparisons it sounds notably more muffled than other Famicoms), so I don't find it too surprising if it would turn out that it's noisier than other consoles. My AV-modded Famicom isn't too noisy as I said above, and I don't have a Twin. I don't know how to make it better though, it might be possible to make some kind of frequency filter but I can't help with that, sorry.