Where to get shielded 3 core power cables

mbhangui

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I want to replace each and every power cord that goes to a SMPS in my music room. Reason is to eliminate any EMI that these cables could be generating because of switching regulators. There was this site theaudiocrafts.com where you could buy these cables at a moderate price. But the site has been showing 'under maitenance' for almost 2 weeks now. Any other site where shielded 3 core power cables are available?
 
I too was recommended Lapp, but such expensive power cables make a difference?
That's a difficult question to answer. Lapp is definitely no uber expensive and feedback that i heard from Chikpet market is that lapps quality is unparalleled.
2.5 awg 3 core shielded cable is about 350 rs per meter. Cheaper than or at par with entry level terminations. Only problem with online store is that it would need a minimum order of 5 or 10 meters.
 
I too was recommended Lapp, but such expensive power cables make a difference?
It depends on what you want to believe. In any cable, shielding serves 2 purposes:
- to mitigate outward EMI
- to mitigate inward EMI

All of the below statements are theoretical and should be taken in the spirit of science.
- a power cable is more likely to produce some outward EMI; it is less susceptible to inward EMI
- next set of cables that may exhibit this behavior are speaker cables, although they carry far less energy compared to power cables
- ICs are more prone to inward EMI
- Since ICs generally carry small signal voltages, even a smidge of EMI can "affect" them electrically
- Digital ICs more than analog since they are at the top of chain

Whether it makes a difference sonically, is debatable.
Let's assume back of your rack cabling is a mess with ICs/speaker-wire/power-cords crossing each other.
If you believe that power cables are the culprit, go ahead change them to shielded and try.
And please do let us know if you hear a difference.

Cheers,
Raghu
 
I too was recommended Lapp, but such expensive power cables make a difference?
This is a theory I want to check. I don't believe in power cables. They should absolutely making no difference. It defies common sense and logic and all laws of electricity and magnetism that the last 1 meter of cable after traveling bad wiring from the substation to your house should improve quaility. But recently I came across an article that the cables that feed your amps and devices are not shielded. These cables are suspended outside the walls and develop EMI in the audio range. This is possible because amps are basically your power supply getting modulated to deliver sound to the speakers ultimately. The current flowing through the cables will change as per the frequency of audio being delivered. So if you shield these hanging cables, these will not get picked up by interconnects that will be close to the power cables. So definitely shielded power cables should reduce noise. However the cost of the cable has nothing to do with this. But spending few Rs here and there will be worth it to prove the theory.
 
The other way to do it is use emi filters in the switchboard like the Barracuda that SoundFoundations use. I use a APC online UPS for the same which has active EMI/RFI filters and realised that when i moved from a direct connection to my HT versus via the house phase, there is an additional hum.
 
It depends on what you want to believe. In any cable, shielding serves 2 purposes:
- to mitigate outward EMI
- to mitigate inward EMI

All of the below statements are theoretical and should be taken in the spirit of science.
- a power cable is more likely to produce some outward EMI; it is less susceptible to inward EMI
- next set of cables that may exhibit this behavior are speaker cables, although they carry far less energy compared to power cables
- ICs are more prone to inward EMI
- Since ICs generally carry small signal voltages, even a smidge of EMI can "affect" them electrically
- Digital ICs more than analog since they are at the top of chain

Whether it makes a difference sonically, is debatable.
Let's assume back of your rack cabling is a mess with ICs/speaker-wire/power-cords crossing each other.
If you believe that power cables are the culprit, go ahead change them to shielded and try.
And please do let us know if you hear a difference.
I was typing my reply while you wrote exactly what I wanted to convey. It is the EMI thing that will definitely be there with unshielded cables. How much is of course debatable.
The other way to do it is use emi filters in the switchboard like the Barracuda that SoundFoundations use. I use a APC online UPS for the same which has active EMI/RFI filters and realised that when i moved from a direct connection to my HT versus via the house phase, there is an additional hum.
I too use CLC filters. They will reduce the emi that gets fed to the power supply of the units that are connected to these EMI filters. But these filters cannot remove EMI from the interconnect cables that are hanging close to the power supply cables. With careful routing of the power supply cables and interconnect it is definitely possible to mitigate the EMI. But in a typically setup the cables behind the units always become a mess and it may not be possible to keep the power supply cables and interconnects as far away as possible.

EDIT:
BTW the power distribution units made by @magma are very good and decently priced. I too purchased one with extremely good fit and finish (link posted below). Snake oil manufacturer sometimes pass of these as power condtioners. Recently I came across an Indian Power Conditioner attrociously priced, which was nothing but a single EMI CLC filter and few folks got pretty pissed off, got personal with me just for telling that.


The other reason why I want to have shielded power cables is because I have now replaced each and every interconnect in my system with twisted pairs taken out of cat6 ethernet cables. These cat6 cables (even cat5) have very low capacitance per foot. A typical 1 meter of branded interconnect have around 60 pF per meter and IIRC when I tested the twisted pairs they gave capacitance < 10pF per meter. A capacitor allows ac to pass through and the impedance reduces with increase in Frequency. This makes all interconnect cables non-linear wrt frequency and affects the HF quality of the audio.

Since I am now using unshielded twisted pairs (putting a shield would again increase capacitance), I need these cables to be far away from any emi radiation. The twisting of course helps in cancelling the emi picked up. But having shielded power cables becomes all the more important so that the unshielded twisted pairs I use don't pick up EMI.
 
Last edited by a moderator:
I was typing my reply while you wrote exactly what I wanted to convey. It is the EMI thing that will definitely be there with unshielded cables. How much is of course debatable.
Haha

Here is a pic of the mess behind the AV rack.
wire-mess-1-sm.jpg

Someone recently said that we tend to hear with our eyes too.
Since it is out of sight, I don't hear any gremlins or have willfully chosen to ignore them, if any.
Cheers,
Raghu
 
Haha

Here is a pic of the mess behind the AV rack.
View attachment 66894

Someone recently said that we tend to hear with our eyes too.
Since it is out of sight, I don't hear any gremlins or have willfully chosen to ignore them, if any.
Cheers,
Raghu

It depends on what you want to believe. In any cable, shielding serves 2 purposes:
- to mitigate outward EMI
- to mitigate inward EMI

All of the below statements are theoretical and should be taken in the spirit of science.
- a power cable is more likely to produce some outward EMI; it is less susceptible to inward EMI
- next set of cables that may exhibit this behavior are speaker cables, although they carry far less energy compared to power cables
- ICs are more prone to inward EMI
- Since ICs generally carry small signal voltages, even a smidge of EMI can "affect" them electrically
- Digital ICs more than analog since they are at the top of chain

Whether it makes a difference sonically, is debatable.
Let's assume back of your rack cabling is a mess with ICs/speaker-wire/power-cords crossing each other.
If you believe that power cables are the culprit, go ahead change them to shielded and try.
And please do let us know if you hear a difference.

Cheers,
Raghu
Thanks for explaining it so well. I was able to remember a few comments by in house physicist @Otpidus who explained the benefits of EMI rejection and why decluttering signal cables vs power cables well in some posts.
 
I too was recommended Lapp, but such expensive power cables make a difference?
With Lapp Ölfex - NO. Don’t know about others models. I bought a ready made Lapp cable with Lapp schucko plug. Only thing it did was strain my amps power plug socket due to its weight. There was no audible difference on my gold note s1 signature amp. Compared to the „generic“ cable It looks cool though.
 
The other reason why I want to have shielded power cables is because I have now replaced each and every interconnect in my system with twisted pairs taken out of cat6 ethernet cables. These cat6 cables (even cat5) have very low capacitance per foot. A typical 1 meter of branded interconnect have around 60 pF per meter and IIRC when I tested the twisted pairs they gave capacitance < 10pF per meter. A capacitor allows ac to pass through and the impedance reduces with increase in Frequency. This makes all interconnect cables non-linear wrt frequency and affects the HF quality of the audio.

Since I am now using unshielded twisted pairs (putting a shield would again increase capacitance), I need these cables to be far away from any emi radiation. The twisting of course helps in cancelling the emi picked up. But having shielded power cables becomes all the more important so that the unshielded twisted pairs I use don't pick up EMI.
https://e.lapp.com/in/p/1135403

I'm using these in my audio room drawn right from the Power Meter box on the ground floor. I definitely bought them at a much lower price over what's mentioned here. The problem is you won't find them at lower prices since the dealers won't give you shorter lengths from the 100m rolls it comes in. They are excellent as far as copper quality and sheilding is concerned.
 
One cannot buy almost anything on the lapp site without a GSTIN number. So finally went ahead and placed order with vashiisl (suggested by @k-pad ).

Order summary​

xDJI4btiTQEF0EcKSEgOiPc1hd7t4ZZdPI6hg3pGrlOieO9_yTQXiwPqRe3Dy1AJI-XJBROguGIXsrtfY8fNGy6GllUkIfKwm1SbVGC16XxZkBfLe1TLligHcxtMNC3f7CzEZJfCu-XEv4z0Wxt1Jg7l0uZr=s0-d-e1-ft
Finolex 2.5 SQMM X 3 CORE 2XWY COPPER XLPE INSU. ARMOURED CABLE 1.1 KV AS PER IS 7098(PART 1) 1988 × 2
Rs. 244.20​
jmZdHtbwvTMiH-WAQ9KD0ocmVotWjW583i1u0NzxFdZJzbO_g6vBzTPyNR0UAiev432sHLhWX2G5hFsYIexI-HmKu8aBISkvvbWkRqzqI9cXr0awsv4Gtzpeyr6tqyzvWNjpukzVvh2PPE6KSbCAwwesavfMg4eIt-2wW8P9NEjXLSH2V7D509V0fKdndbusQvE3V2shOHBF8NVwqcvxhepMDezFub-y5i8xdYoy=s0-d-e1-ft
Polycab 1.5 Sqmm, 3 core Overall Tinned Cu Braided Pvc Sheathed Flexible Unarmoured Cables × 10
Rs. 921.00​
Discount
tF3A35d40q_Y5EpPGJL_QKFDipFKdJESTGPMKW0UixEd2HyzFCEU7m9yGs4gepz1PLl44XYlk5NwbpnyVtO4-ZPlLF2kbJlwrSKW52GjgHoxrVhNCiVdWidEPc-6H2zQYcrLyerbgn4g4Xh-q32lBks78x39umGzm6pOcPgPOejqXCur-o2miBNJsgoBKLwqKZ_5-qZ-N97G771Zj7jNcddCicVd_xEaZo8TSOrgAH8kEfpPow=s0-d-e1-ft
VCARE
-Rs. 0.00
Subtotal
Rs. 1,165.20
Shipping
Rs. 0.00
Taxes
Rs. 209.74
Total
Rs. 1,374.94
 
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