Pin 1 problem Revisited For Amatuers

[Trdat]

Considering I have read about the Pin 1 problem I can't manage to turn the understanding into a solution. I am aware that the Hypex NC modules have the ground from the module to the male clip on the XLR, while Pin 1 is connected to Chassis ground. Does this now mean that the XLR cable coming into the Hypex Amplifier doesn't need to be altered?

Now, for other amplifiers that do not have a connection based on the new standard (AES48 not that I can say I fully comprehend the schematic) do I change the XLR cable going into the amp or is it better to change the amplifier channels wires going into the XLR socket inside the amp? If its changing the wiring of the XLR socket then I can do the same as the Hypex module. But if its the XLR cable coming into the amplifier can someone tell me what needs to be changed?

And lastly just so I understand the whole topic better. When articles mention shield needs to be wired to chassis ground rather than Signal ground I get the shield its the part(wire) that wraps around the XLR cable but what is chassis ground compared to signal ground? I am guessing signal ground is the Pin 1 if that is so then what is chassis ground?

 

[Speedskater]

XLR pin#1 is the shield not audio common (aka ground) it is connected to the chassis that also is a shield. While audio common (aka ground) is also connected to the chassis, it's not part of the shield.

 

[Trdat]

XLR pin#1 is the shield not audio common (aka ground) it is connected to the chassis that also is a shield. While audio common (aka ground) is also connected to the chassis, it's not part of the shield.

So when you say XLR Pin 1 are we talking about the XLR cables shield?

When you say connected to Chassis do you mean anywhere on the chassis?

Audio common (aka ground) what is this exactly? What part of the cable or the amplifier?

I know this is basic stuff but its a point of confusion and all texts presume we know what these are. Once this is untangled further reading will become more understandable.

 

[boXem]

... I am aware that the Hypex NC modules have the ground from the module to the male clip on the XLR, while Pin 1 is connected to Chassis ground. Does this now mean that the XLR cable coming into the Hypex Amplifier doesn't need to be altered?
...

Wut?

Audio common (aka ground) what is this exactly? What part of the cable or the amplifier?

I know this is basic stuff but its a point of confusion and all texts presume we know what these are. Once this is untangled further reading will become more understandable.

Ground is a reference point for everything electrical in the amplifier. Like ground is the reference for everything you do in your daily life.
Maybe you should spend some time learning the very basics of electricity, there are many online courses available that are very well done.

 

[Trdat]

Wut?

Well if the Pin 1 problem is fixed on the amplifier according to the white paper by Hypex. Which I am confident I have understood right thanks to the Buckeye teardown post. Does that mean we can use a standard cable without altering it? I ask this cause many DIY forums and the RANE articles on the Pin 1 problem mentions that the shield needs to be connected to chassis ground and not signal ground(with other recomendations) which is an alteration of the cable right? Or have I misundertood this concept as well...?

Ground is a reference point for everything electrical in the amplifier. Like ground is the reference for everything you do in your daily life.
Maybe you should spend some time learning the very basics of electricity, there are many online courses available that are very well done.

I am working on it. But will a basic course teach me the difference between chassis ground and signal ground? I thought this is a audio topic...

 

[sergeauckland]

Well if the Pin 1 problem is fixed on the amplifier according to the white paper by Hypex. Which I am confident I have understood right thanks to the Buckeye teardown post. Does that mean we can use a standard cable without altering it? I ask this cause many DIY forums and the RANE articles on the Pin 1 problem mentions that the shield needs to be connected to chassis ground and not signal ground(with other recomendations) which is an alteration of the cable right? Or have I misundertood this concept as well...?



I am working on it. But will a basic course teach me the difference between chassis ground and signal ground? I thought this is a audio topic...

My view is that chassis ground is safety ground. It's connecting any exposed metalwork to the mains earth (ground). That way, if there are any faults in the insulation anywhere on the mains side, there is no possibility of touching any live point. looking back at some vintage equipment, Quite a few amplifiers etc had metal cases, but were double insulated so didn't have a separate chassis earth (ground). That's fine when they were new, but now 40-50 years later, can one be sure that the insulation is still as good as it was, or indeed meets current regulations rather than those of 50 years ago? For that reason, I prefer to change the two-core cable for three-core and properly ground the metalwork.

Signal ground can be the same potential as chassis ground, indeed should be, but doesn't have to be. In the case of an amplifier, say, especially one with balanced inputs, XLR pin 1 should always just go directly to the chassis and nowhere else. Signal ground can be connected directly to the chassis somewhere else in the box, can be connected to the chassis through a resistor, say 10-100 ohms, can be connected to the chassis through a low value capacitor and or the resistor, or indeed left floating. If it has balanced inputs and loudspeaker outputs, then where audio ground goes doesn't much matter. A lot of Pro equipment has a 'ground lift' switch which will connect audio ground to chassis ground either directly or through a resistor, but NEVER EVER should disconnect the chassis ground which is there for safety reasons only.

S.






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[JSmith]

I thought this is a audio topic...

G'day mate... have you seen this video yet?

https://www.audiosciencereview.com/...understanding-grounding-in-audio-video.21360/



JSmith

 

[Trdat]

G'day mate... have you seen this video yet?

JSmith

Hey Buddy, no not yet. I got some catchng up to do on Amir's youtube videos. I'll take a look. Thanks.

 

[JSmith]

I'll take a look. Thanks.

No worries, all sweet ol' cobber.



JSmith