I used them in the power connectors for the Class D amp kits I built. Not sure if there was an audible improvement, but that's definitely a place for them.
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Thank you Eric!
Can anyone else chime in? I do have a Audioquest power cable for my headphone amp and it came with a choke positioned near the the connection to the amp. I have also viewed photographs inside some higher end pieces of equipment that had every power tap out of the transformer choked. One area of my system is my Streamer/DAC, a Cambridge Audio AZUR 851N with no power supply chokes and would have no problem popping the lid and applying chokes to it's transformer, unless for some reason this would be a bad idea. I would appreciate any thoughts - thank you!
I still use some on my large AC Power cables. I had them, at one time, on each end of most of my interconnect and digital cables.
I was reading an article about these "tweeks" and the author stated not to over do it. I went back and started removing some and found out that they were sucking the life out the music.
So through my experimentation, I found a few work really well, but don’t over populate them!
BTW, I have a ton of them in all sizes if anyone wants to buy them :-)
Ferrite beads/clamps roughly act as a transformer where the primary is the cable or wire in the clamp and the secondary is shorted. The end result is that high-frequency current is converted into heat. Since the high-frequency (EMI) currents are fairly low unlike 50/60Hz mains currents, the amount of this heat is minuscule. Absolute majority of ferrite materials are targeting high-frequency spectrum (tens of MHz and up). They don't address low-frequency (tens of kHz to few MHz) conducted noise that is prevalent on AC power. The main purpose of ferrite beads/clamps is to reduce radiated emission (30MHz and up) for EMC test - any cable is an antenna and these ferrites introduce losses making what would be a good antenna a bad antenna. One should expect perhaps 10dB attenuation which may be just enough to pass CE/FCC radiated emission test. If you are looking to reduce conducted noise on AC mains, ferrites would be of very little help - you would need to have an AC EMI filter for that.
Thanks all, I appreciate the description of how a ferrite choke works.
I have noticed that certain electronics in my home such as some HDMI cables, computer system cables, and power cables came from the manufacturers with chokes molded right into the cable or clamped on such as my Audioquest power cable. What is it that these manufacturers are trying to accomplish by installing the ferrite chokes on all of these different types of cables? Are they trying to reduce radiated noise or are they trying to stop something from entering the equipment from the AC mains or something in the signal chain? Thanks!
You can destroy the transfer rate of a digital cable with the benign placement of a ferrite to lower RF. Maybe on the output cable of a switching power supply. However most manufacturers already have them. Bottom line it's a lot easier to do harm than good. RF is a real problem. The FCC is supposed to test all electronics for excessive RF, but that is little comfort to audiophiles who own sensitive gear. Think of the RF inside a desktop PC.(At least laptops run on batteries.) This is why a whole new component has emerged: AC filtering devices. They all have their pros and cons. There is many different technologies with every designer saying theirs is best. There is a good paper on Audioquest's site with the engineer eventually pushing his own.(I have a discontinued PS Audio Duet.) But don't put a ferrite or choke on your USB, coaxial, HDMI, etc. Toslink isn't a problem, but they have their own issues. Audioquest's Jitterbug and iFi's Silencer 3+ are good products for USB.