Speaker wire, CCA vs OFC

[SIY]

The tubed phono stage would be one of the situations as it has high gain and high internal impedances more likely to pick up EMI. For most instances if you play music at 120 db SPL, you would still find EMI to be below the threshold of audibility. And if you are worried about it the smart thing to do as a first step is go balanced in your wiring.

Zero issues with either tube phono stage that I have here. This is purely someone repeating stuff he doesn't understand, or understands it well and is trolling (IMO).

 

[Blumlein 88]

Zero issues with either tube phono stage that I have here. This is purely someone repeating stuff he doesn't understand, or understands it well and is trolling (IMO).

I agree, but I've had issues with more than one tubed phono. I don't mean to imply they are all this way or they need to be abandoned. Often it was a matter of moving it two feet in some other direction if it picks up interference. I've had a few tubed phonos myself. Don't have any now.

 

[SIY]

I agree, but I've had issues with more than one tubed phono.

Telling you something you already know: most tube phono stages are terrible.

 

[Speedskater]

The recommendation is for minimizing the radiation of EMI interference that may affect operations of your other electronic devices. Not for sound quality.

Loops may also receive interference from other electronic devices.

 

[NTK]

Loops may also receive interference from other electronic devices.

It is not an issue here as we are talking speaker cables carrying speaker level signals. For other applications, yes.

 

[March Audio]

I'm sure @March Audio will want to be educated.

View attachment 31548

Mmmmm...... Sounds to me that ICE should do some further work on reducing their amps RF emissions if they are recommending shielded speaker cable.

Hypex recommend twisting the speaker cable inside the amp but not beyond. My measurements show virtually no additional RF (switching frequency) present externally from the amp.
Copied from another post elsewhere:


Below is the RF spectrum of one of my P252 amps. The Hypex NC252MP board is sat on the desk, not in a case and connected by a couple of meters of speaker cable.

The antenna is 1 m away. The scope is measuring the switching frequency as 405 kHz.

You can very nicely see the AM radio stations, our local ABC Radio Perth being the strongest at 720kHz.

Amp off

Amp on

No 405kHz or harmonics of.

 

[Speedskater]

It is not an issue here as we are talking speaker cables carrying speaker level signals. For other applications, yes.

The speaker cables can be interference receivers from other applications. Jim Brown EMI/RFI expert sometimes warns about this problem.

 

[sajunky]

Mmmmm...... Sounds to me that ice should do some further work on reducing their amps RF emissions if they are recommending shielded speaker cable.

Hypex recommend twisting the speaker cable inside the amp but not beyond. My measurements show virtually no additional RF (switching frequency) present externally from the amp.

Perhaps one should ask a simple question 'why?'

The only reason for not using twisted cable would be RLC values exceeding maximum. FFRC cable with 4 twisted pairs represent moderate capacitance, it should not give a problem under a typical home setup..

Copied from another post elsewhere:


Below is the RF spectrum of one of my P252 amps. The Hypex NC252MP board is sat on the desk, not in a case and connected by a couple of meters of speaker cable.

The antenna is 1 m away. The scope is measuring the switching frequency as 405 kHz.

You can very nicely see the AM radio stations, our local ABC Radio Perth being the strongest at 720kHz.

Amp off

View attachment 31587

Amp on

No 405kHz or harmonics of.

View attachment 31588

You did post it to the science-aware audio community and nobody picked it up? Strange...

Unless graph shows calibrated absolute energy values, comparison to the AM radio station doesn't mean anything. Otherwise we should see lot of details of the radio station, your location, radiation figures, etc.

Meassuring few hundred meters long waves with the antenna, just 1 meter away? It can be in the area of near-zero field.

On another thought, maybe a Bluetooth antenna? .LOL.
It looks to me a material coming out from a marketing department.

 

[SIY]

Perhaps one should ask a simple question 'why?'

Because it's not necessary. If one ignores FUD and Dunning-Kruger, the simple solution is the simple solution- and works.

 

[sajunky]

Because it's not necessary. If one ignores FUD and Dunning-Kruger, the simple solution is the simple solution- and works.

Works well for EMI.

 

[SIY]

Works well for EMI.

You misspelled "FUD."

 

[sajunky]

You misspelled "FUD."

Nope. It is engineering term, not many people understand.

 

[SIY]

Nope. It is engineering term, not many people understand.

Clearly.

 

[March Audio]

Perhaps one should ask a simple question 'why?'

The only reason for not using twisted cable would be RLC values exceeding maximum. FFRC cable with 4 twisted pairs represent moderate capacitance, it should not give a problem under a typical home setup..

You did post it to the science-aware audio community and nobody picked it up? Strange...

Unless graph shows calibrated absolute energy values, comparison to the AM radio station doesn't mean anything. Otherwise we should see lot of details of the radio station, your location, radiation figures, etc.

Meassuring few hundred meters long waves with the antenna, just 1 meter away? It can be in the area of near-zero field.

On another thought, maybe a Bluetooth antenna? .LOL.
It looks to me a material coming out from a marketing department.

As SIY said above.

That's absolute nonsense. It does not need to be calibrated to show there is no significant Rfi issue.

So you would measure the Rfi from a device hundred's of metres away. Nope.

What do you mean by "see a lot of detail of the radio station etc"? What a meaningless statement.

The major non audio output from the device is the switching frequency (although there are some higher frequency components created at device switching point) which it clearly does not radiate at any significant level.

 

[sajunky]

Clearly.

Actually you 'liked' that post, so I assume you accepted everything there.

 

[sajunky]

So you would measure the Rfi from a device hundred's of metres away. Nope.

It means you can't measure it properly, so why did you try?

 

[SIY]

As SIY said above.

That's absolute nonsense. It does not need to be calibrated to show there is no significant Rfi issue.

So you would measure the Rfi from a device hundred's of metres away. Nope.

What do you mean by "see a lot of detail of the radio station etc? What a meaningless statement.

The major non audio output from the device is the switching frequency which it clearly does not radiate at any significant level.

I think at this point it's clear we're being trolled. @Thomas savage may want to weigh in.

 

[sajunky]

I think at this point it's clear we're being trolled. @Thomas savage may want to weigh in.

In that case I have nothing more to say.

 

[Thomas savage]

And as if by magic I appear...

I'm being paid like a NHS dentist now , by the tooth so you better watch out .

 

[March Audio]

It means you can't measure it properly, so why did you try?

The measurement is fine and appropriate for the intended purpose. i.e. a simple demonstration that properly designed class d amps don't need shielded speaker cable to prevent Rfi.

Btw I used to represent Keysight products (amongst others such as freedom communications) including RF spec ans. A typical application would be pre compliance testing, so let's not go there.