Annoying Buzzing sound

[duaplex]

Hi Guys,

So I managed to get another scart switch (Hama) and now I can switch consoles no problem and the sync is in tact.

Now I have a different problem - I cant seem to eliminate the buzz sound coming out of my PC speakers when connected to the Female Scart BNC. I have tried the following:

Taking the Audio form the scart switch - No difference
Using a ground loop isolator - No effect
Testing PC speakers with another device - No buzz from other devices
Moving speakers about - no effect
Removed ground wire from extension cable - no effect

Speakers in question

http://www.logitech.com/en-gb/product/s ... ystem-z623

The Phono cables I have are of the expensive variety and have double shielding. This Buzz occurs on both my PVM monitors 20M4E and 20L5

Has anybody else got this problem? Was this always part of retro gaming and I have just forgotten?

[Ed Oscuro]

Removed ground wire from extension cable - no effect

Why would you do this?

Does the system to SCART plug (or whatever you're using) have the grounds wired up?

[duaplex]

In the uk we are grounded from the power station itself (so an electrician tells me)

Removing the grounds cable almost certainly removes buzz/humming from audio equipment so it was the last resort.

As for the scart cable being grounded - no idea? How would I know?

The cables are from retrogamingcables

Females scart to BNC

http://www.retrogamingcables.co.uk/fema ... itors.html

Snes cable

http://www.retrogaming cables.co.uk/super-nintendo-pal-rgb-av-scart-cable-av-lead-cord-for-sale.html

Megadrive

http://www.retrogamingcables.co.uk/sega ... -lead.html

Thanks

[duaplex]

Removed ground wire from extension cable - no effect

Why would you do this?

Does the system to SCART plug (or whatever you're using) have the grounds wired up?

Do you mean the switch?

The buzz is there with or without it.

[Ed Oscuro]

First of all, removing grounds is removing the safety potential provided by that means.
Nothing is grounded unless you have a ground hooked up! What your electrician said doesn't contradict this fact; he assumes you'll be using that ground. If you remove the ground willy-nilly then your device is floating, or your devices are floating with respect to each other.

I suppose you can eliminate some hums by eliminating grounds, but it seems like a messy makeshift fix that doesn't fix the issue safely or repeatably. Additionally, grounds can eliminate hum. (Another nice piece, which has perhaps the best layman-friendly explanation of the problem, is this 20 year old piece from Sound On Sound, which also has some practical advice.) It's worth preserving them if you can.

ePanorama hosts some decent guides on resolving hum in audio systems. One key thing to remember is from the opening of this linked piece: Disconnect everything and then reconnect things until the hum appears again. At the point the hum appears, you will have a better idea how to solve the problem.

To save you some time, I'll give you a few ideas that hopefully can point you in the right direction - though there is likely just one simple cause to be corrected, and you should have a better idea where to start after finding the point of entry for hum into the system.

1.) The cables you use might carry audio signals physically too closely to video. Many forum members suggest splitting audio off a multi-input connector as soon as possible, if not taking the audio from another source entirely. Additionally, shielding of the cables might be inadequate. That "expensive double shielded cable" you mention probably isn't the source of trouble, but it's worth mentioning that shielding standards can be improved well beyond a braid/foil shield combination (these issues are actually more remarkable with video cable, if you look at the table there, but thankfully RGB is pretty well suited by most good cable types). There's a hint in the first link from Blue Jeans Cable about what to do when you get hum: Improve shielding!

2.) The cables you use probably use the SCART connector. There's a lot of different ideas out there about how to wire these up properly for audio. A quick fix might just be to peruse this thread's supplier mentions and see about getting a different SCART cable. It might be good to share the design, or the maker, of your cables.

3.) There's also the source of the hum itself. If it's noise from within components being sent along due to a bad device design, and shielding doesn't correct that...that would be bad. Maybe RFI / EMI shielding tape...but that shouldn't be happening with our systems (details would be nice here). If it's a ground loop, then you should look carefully at your setup:

Do you have different devices grounded differently? (As suggested in one of the links above, a common power strip connection for all devices hooked into each other is helpful).
Is the source of the power itself noisy, serving many different devices and machines? In this case looking at a power conditioner or a transformer can be helpful. I haven't had hum-related problems of note myself, but I'm leaning towards thinking that power conditioners are a good investment, though you need not pay exceptional rates for them - finding good, spec-compliant affordable machines without audiophile hype and poor manufacture is a bit of a dark art, it seems. More relevant to this topic: Isolation transformers.

4.) Are you running equipment next to Big Transformers? The Sound On Sound article, again, does mention a few other sources of ground-related hum, though probably they aren't relevant to your situation they're still worth mentioning.

[duaplex]

No, not next to a transformer. I am using a power strip but now that you mention it, this is not a power conditioner, but a standard multiplug type device.

I'm going to try a few things first.

1. Power conditioner as advised
2. Different cables - I now suspect after reading that excellent post that it could be the cables and I have heard rumours about retro gaming cables before.

Thank you for the links and post, that made for some excellent reading!

Do you think adding an AV receiver into the mix would help things?

Thanks again and will report back

[duaplex]

Can anybody offer insight into retro console accessories. I read the forum above that was posted for me and they seem to be good. But I am worried about getting cables that are not earthed properly.

Retro gaming cables has seemingly not earthed the cables properly, although I am waiting on them to respond to my query regarding this before drawing this conclusion.

Anybody else have experience regarding this and using these cables as of late?

[Ed Oscuro]

I've tried to soft-pedal my criticism of Retro Gaming Cables, but I'm definitely not the only one who has been dismayed by their apparent unwillingness to ground the cables. They're UK-based, and Retro Console Accessories is US-based. There is another supplier listed in there from the UK, if that matters. I have a Retro Console Accessories cable - SNES wired up for Euro SCART - and I like it quite a bit, and mine was made just before RCA made an additional change in cables for the sake of quality. They definitely do have the grounds hooked up. They also have the cable shielded, which is a likely cause of your troubles.

I think, if I didn't make it clear, that a power conditioner is probably not the answer to your hum. If it carries an isolation transformer as well, then it should help, though; additionally the features it brings could be generally useful for you. But I'm getting along fine, as far as hum goes, with just hooking everything up to the same semi-cheap Belkin power strip right now.

[duaplex]

I've tried to soft-pedal my criticism of Retro Gaming Cables, but I'm definitely not the only one who has been dismayed by their apparent unwillingness to ground the cables. They're UK-based, and Retro Console Accessories is US-based. There is another supplier listed in there from the UK, if that matters. I have a Retro Console Accessories cable - SNES wired up for Euro SCART - and I like it quite a bit, and mine was made just before RCA made an additional change in cables for the sake of quality. They definitely do have the grounds hooked up. They also have the cable shielded, which is a likely cause of your troubles.

I think, if I didn't make it clear, that a power conditioner is probably not the answer to your hum. If it carries an isolation transformer as well, then it should help, though; additionally the features it brings could be generally useful for you. But I'm getting along fine, as far as hum goes, with just hooking everything up to the same semi-cheap Belkin power strip right now.

I definitely read between the lines there

I have sent an email over to RCA on eBay and waiting for them to tell me if they can make the female scart to BNC cable for me. RGC claim that all their cables are shielded, however I doubt its grounded, as you pointed out. Perhaps the Scart BNC one is but there is definitely none on the SNES and Megadrive cable.

I saw the other UK one in your review on the other post, but steered clear as there was no opinion on them thus far. Still it does not hurt to fire an email off to them and ask about grounding etc. If anything I can come back and contribute my findings to help others.

[duaplex]

Just made contact with daskrabs and he is going to send me the scart to BNC adapter

Now all i need is the SNES and Megadrive ones and I can send these back to retro gaming cables.

[Ed Oscuro]

Do make sure that you're selecting one wiring type for all cables - either JP-21 (the system to SCART cables will work for XRGB series upscalers, which is just about the only place this pinout is used outside Japan) OR Euro SCART (much more common), and label them all as such. So long as the system to SCART and SCART to BNC cables are a matching type, you are good (so theoretically JP-21 pinout should be fine on all cables would be fine if you were interested in an XRGB down the road).

Good luck.

[BuckoA51]

Honestly a tiny bit of buzz in the analogue audio seems par for the course on most consoles, the only way to 100% eliminate it in my experience is to use digital audio mods. I've tried SCART cables that separate audio but if the problem is already present when the AV signal comes out of the console that's not going to help.

Humming on the other hand is different and that can be caused by bad ground loop, but no way would I recommend removing grounds from anything.

I've tried to soft-pedal my criticism of Retro Gaming Cables, but I'm definitely not the only one who has been dismayed by their apparent unwillingness to ground the cables.

All their cables are now grounded. Some of their old designs were not. All their SCART to BNC cables are.

[Ed Oscuro]

I'm sure I was thinking of shielding there, not grounds.

[neorichieb1971]

I recently hooked up my consoles to a NOS 14" Sony Trinitron and that nostalgic hum was straight there. When the screen goes white it amplifies the hum twice over. I've always taken the hum as part of the package or used Svideo instead. I did use SCART cables on a PC 2.1 speaker setup before and that had hum as well.

Mind you, if the hum is possible to get rid of. Then custom cables are your best shot at it.

[duaplex]

I just had the cabless back from retro gaming cables.

I can confirm that they were not initially grounded, but they are now. The buzz is still present and perhaps, as you guys are saying, its normal and I forgot over the years.

What about adding an AV receiver in this, could this help filter the sound better maybe? Really clutching at straws there.

[CkRtech]

I made my own cables for the SNES and run the analog audio independently (separate shielded/insulated audio cables) from the video. The video goes to my switch, and the audio goes to a separate audio switch that I use for analog sound that I feed into a pretty good quality receiver. Both cables originate at the SNES multi-out. I still get a buzz.

The reason I didn't try to isolate analog audio even more (stop using the multiout, see if I can keep audio as isolated as possible from the rest of the board, etc) was because I planned on adding a SPDIF output to the SNES and using it. I ended up doing this, and the digital output has no buzz.

I would say that you are most likely going to have some sort of buzz in your analog audio unless you make internal changes to your systems and make an effort to isolate the audio. Even then, some of these consoles have fairly noisy circuitry.

[duaplex]

So is it even worth me trying different cables then? Are we saying no matter what this buzz will remain?

[CkRtech]

So is it even worth me trying different cables then? Are we saying no matter what this buzz will remain?

Some cables are a lot better than others, so it is still worth trying different cables. Still, I do not expect you to get buzz-free audio. The buzz might not be as pronounced in one cable vs. another, but it will most likely still be there.

Anyone else with buzz-free analog audio output from say a SNES is welcome to step in and say what they used for cables.

[Xan]

Something to consider is that 1st revision SNES consoles had the APU on a seperate daughterboard. Maybe this setup gives better sound quality compared to later revisions.

[Ed Oscuro]

Have another look at what I wrote earlier...I think the OP skipped all of the ground loop debugging hints and went straight for cables. It's an obvious place to start but it's not necessarily the only one.

FWIW, the SNES with separate sound APU has that in a metal box, so it'd naturally be better shielded.

So far I can't say I've noticed any buzz myself. I have a pretty simple setup though. One power strip, PVM and SNES hooked into that, SNES -> Euro SCART from Retro Console Accessories -> SCART to BNC from Daskrabs -> PVM and low-impedance headphones.

[evil_ash_xero]

Can anybody offer insight into retro console accessories. I read the forum above that was posted for me and they seem to be good. But I am worried about getting cables that are not earthed properly.

Retro gaming cables has seemingly not earthed the cables properly, although I am waiting on them to respond to my query regarding this before drawing this conclusion.

Anybody else have experience regarding this and using these cables as of late?

RCA make good shielded cables. If you still have problems with them, it's probably something else.

Retro Gaming Cables makes crap.