Usage of ferrite clamps

[Baka]

I have recently noticed the picture of the internals of the very expensive MARANTZ SA-10 Reference Series SACD/CD player.

I have counted 7 of them with a possibility of being even more.

I would like to learn about positions on which these are used in this player and for what particular reason.

Marantz SA-10 Silver Gold - Lecteurs CD sur Son-Video.com

 

[DF96]

They may be shown on the circuit diagram. They will be there either to ensure correct operation of the circuit by stopping RF getting to where it should not be, or to comply with EMC regulations.

 

[Mooly]

Ferrites raise the apparent impedance of the cable at specific frequencies and can be useful both to stop interference radiating from the leads and also to stop the leads picking up interference radiated from elsewhere.

Where they are added and why is a design consideration... Marantz must have thought the cost outweighs the benefit (edit... or the other way around even), or perhaps it was more mundane and a simple fix to enable the unit to pass any required tests relating to emission of RF interference.


An in depth article is here:
http://audiosystemsgroup.com/SAC0305Ferrites.pdf

 

[Baka]

They may be shown on the circuit diagram.

I could find a bunch of other Marantz free service manuals (SA11, 12, 17...) but not for this particular one...

The above mentioned models have typically two or three clamps inside.

 

[Baka]

An in depth article is here:
http://audiosystemsgroup.com/SAC0305Ferrites.pdf

Thanks.

 

[AIM65]

Find here a video explaining ferrite bead behaviour made by a Youtuber with great pedagogy skills !



YouTube

 

[Speedskater]

Jim Brown at Audio Systems Group remains the go-to expert on all things related to EMI/RFI.
About 50 of his papers and Power Points at:
Audio Systems Group, Inc. Publications