Hi friends
I was tempted to build this interconnect: DIY Silver RCA Interconnect Cables
fun and simple to build. It seemed.
But when I started to source the parts, I found that I couldn't just blindly "get parts". The required ferrite-core does not tell much, my source lets me select specific impedances @ frequencies...
So I tried to find out about those details, but found nothing.
Gosh, where could I learn about it!
david
I was tempted to build this interconnect: DIY Silver RCA Interconnect Cables
fun and simple to build. It seemed.
But when I started to source the parts, I found that I couldn't just blindly "get parts". The required ferrite-core does not tell much, my source lets me select specific impedances @ frequencies...
So I tried to find out about those details, but found nothing.
Gosh, where could I learn about it!
david
DIGI-KEY or other suppliers
search ferrites or cable ferrites
Review data sheets
example
https://content.kemet.com/datasheets/KEM_E5005_ESD-SR.pdf
ESD-SR-S10 KEMET | Filters | DigiKey
search ferrites or cable ferrites
Review data sheets
example
https://content.kemet.com/datasheets/KEM_E5005_ESD-SR.pdf
ESD-SR-S10 KEMET | Filters | DigiKey
You need to determine what frequencies are to be attenuated, ferrites have different properties and attenuation curves.
Multiple turns of your cable through the ferrite core will improve the attenuation.
The alternative approach is to use shielded cable.
Multiple turns of your cable through the ferrite core will improve the attenuation.
The alternative approach is to use shielded cable.
Well, the op may be surprised that it makes no audible difference since the ferrite converts RF energy into heat.
Indiglo, thank you for the direction.
You got to my weak point—what frequencies to attenuate. What are the parameters? Does it depend on the environment (how quiet it is) or on the gear (what devices get connected)?
I vaguely remember something about hf interfering with the signal, but there must be more, but what?
And yes of course, shielded cable. I wanted to see (well, hear) what it was about those claims about the shield (some inductance or something) interfering with the signal.
I’m pretty sure I won’t hear any difference, but as long as I haven’t heard it I don’t know.
It's good that you ask these questions, typically cable clamp-on ferrites are used to attenuate RF energy for either ingress or egress type arrangements, as an example you may see round cylindrical mouldings on consumer products like these to reduce EMI radiating from the cable.
An another example which would be more appropriate if you had a radio amateur with a high powered HF radio transmitter living close by and when transmitting may induce RF energy into your audio inputs via the interconnect cables. Fitting a ferrite clamp to the cable will reduce the amount of RF energy entering the audio device by converting it to heat.
I suggest if you are not experiencing any type of radio interference in your audio devices all you really need to use is good quality shielded cable. No need to spend large sums of money, do a search for Belden shielded audio cable.
Capacitance and inductance in cables is mostly negligible for most devices except for connecting a phono turntable to a preamplifier where you want low capacitance cable.
An another example which would be more appropriate if you had a radio amateur with a high powered HF radio transmitter living close by and when transmitting may induce RF energy into your audio inputs via the interconnect cables. Fitting a ferrite clamp to the cable will reduce the amount of RF energy entering the audio device by converting it to heat.
I suggest if you are not experiencing any type of radio interference in your audio devices all you really need to use is good quality shielded cable. No need to spend large sums of money, do a search for Belden shielded audio cable.
Capacitance and inductance in cables is mostly negligible for most devices except for connecting a phono turntable to a preamplifier where you want low capacitance cable.
Last edited:
From an interference prospective that's about as poor of an RCA interconnect as you can get, so a ferrite will be helpful.
Go back to a manufactured coax cable with a heavy braided shield.
Go back to a manufactured coax cable with a heavy braided shield.
The op didn't state they had interference, there's absolutely no need for coax unless you live next door to a 10kw radio transmitter and then the ingress of RF is probably via another mechanism in any case.
Belden shielded audio cable is all is required anything else is a extravagant waste of money.
Belden shielded audio cable is all is required anything else is a extravagant waste of money.
Jim Brown an AES EMI/RFI expert thinks that there are about 30 RFI sources in a typical modern home.
All RCA interconnects should use a coax cable.
Mostly what Jim discusses relates mostly to AM broadcast and Ham HF radio transmitter RFI into microphones at close range, its unlikely the average suburban home will see any RF signal levels of that magnitude.
My advice to the op is to avoid the audiophile fad of silver cables and just use some decent shielded cable and connectors.
My advice to the op is to avoid the audiophile fad of silver cables and just use some decent shielded cable and connectors.
Last edited:
Thanks for all these inputs.
I understand both the pro and contra (not technically, but "conceptually")...
When I was thinking about making those cables, it was about finding out wether the use of shielded cable has an audible influence... (of course, the silver conductor is tempting too... :roll eyes:
BTW, I already went very low and used twisted 0.3mm enameled copper wire, no shields, and ugly, cheap rca-plugs. It worked and was fun, but I didn't went very far into it...
I understand both the pro and contra (not technically, but "conceptually")...
When I was thinking about making those cables, it was about finding out wether the use of shielded cable has an audible influence... (of course, the silver conductor is tempting too... :roll eyes:
BTW, I already went very low and used twisted 0.3mm enameled copper wire, no shields, and ugly, cheap rca-plugs. It worked and was fun, but I didn't went very far into it...
Ummm... no. Always, always, always use shielded "microphone" cable for RCA interconnects. Well, unless you want your system channelling the local CBer... "Breaker Breaker Any Taker"...
The snap on ferrite beads won't hurt your audio response at all. Most have no effect under about 2 mhz. But when deployed at your amp inputs they can help keep that pesky CBer out... When I make interconnects, I put them on as a matter of course. They're cheap and they're not going to make anything worse, so why not.
Recent phone call: "Why is my stereo humming?" ...
Me: "Because it doesn't know the words."
Last edited:
Mix 77 ferrite is good from 100 kHz to 50 MHz
Mix 75 ferrite is good from 150 kHz to 30 MHz
While ferrite mixes 31, 43, 52 & 61 are all for much higher frequencies.
Mix 75 ferrite is good from 150 kHz to 30 MHz
While ferrite mixes 31, 43, 52 & 61 are all for much higher frequencies.
Thank you, speedskater
Since I don’t know of any specific frequencies to shield the signal from, a wider bandwidth (100kHz - 50mHz) would be a better choice I presume?
Randomly suggesting ferrites is not the appropriate method.
You need to determine what frequency range, how much attenuation you require, how many loops of cable need to pass through the ferrite, what is the appropriate ferrite material, what core size or cable diameter is needed.
If you use shielded cable and not experiencing any RF EMI then you don't need ferrites.
Ferrite 77 is mainly used as a toroid in switchmode power supplies.
You need to determine what frequency range, how much attenuation you require, how many loops of cable need to pass through the ferrite, what is the appropriate ferrite material, what core size or cable diameter is needed.
If you use shielded cable and not experiencing any RF EMI then you don't need ferrites.
Ferrite 77 is mainly used as a toroid in switchmode power supplies.
I totally understand that this should be a „targeted approach“
No way am I able to achieve this.
So I‘ll go the killall-way and use shielded wire [emoji41]
If you want the expensive audiophile look you can always fit some fancy cable sleeving over the top and nobody will know the difference 🙂
Cable Sleeving
Cable Sleeving
Last edited:
I could use a vacuum-tube for sleeving to get a reeaallly hefty look. [emoji851]
(Actually, I prefer stuff like that: Google-Ergebnis für https://i.ebayimg.com/images/g/pygAAOSwol5Y0ecD/s-l400.jpg )
