The reason repair pros don’t like to be involved in changing out power cords for larger diameter units or adding in iec connectors to do power cord swaps..is that this entails messing with the AC power input to the given system.
And THAT is a legal issue, big time.
Any changes to power input requires, by law, a complete re-certification of the given equipment.
Otherwise the legal aspects lie solely on the shoulders of the person who changed it. It is a giant snail trail of ever enlarging legal liability for anyone who does it repeatedly.
The same holds true for doing custom parts modifications that have different values or specs from the originals. Liability. Big time.
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@ teo audio,
Wrong..... The owner/user of a piece of audio equipment can do about anything he wants to a cord and plug connected piece of equipment.
OP,
I had a response to your last thread that was deleted by the Moderator for some reason. I lost the post when I entered "Post Your Response". I will respond again later. That is, unless this one is deleted as well.
Jim
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Having been introduced to the laws of the land during my electronics training, and taking courses on such, I’d have to say with about as much authority as I can muster, that you are dangerously misleading people.
changing hard wiring or receptacles on equipment is flat our contrary to the law regarding AC power that comes into your abode or domicile.
This is doubly, triply, quadruply, exponentially true -- when it comes to commercial installs of any kind. ’Don’t ever go there’ in a commercial or professional environment.
an electronics tech who is professionally papered and has business insurance, can change out a captured power cord with one that is identical in spec and sizing and legally specified and certified qualities, and has to be identical in how it mounts to the chassis. The end.
Otherwise the gear requires, re-certification by UL or in Canada, CSA.
If one want to dick around and do it all on their own, go ahead, but consider that the full weight of the law and courts might come down on your head if ever a problem erupts during the entire potential lifespan of the given equipment, post change.
think of it as a gasoline kind of issue. We have become inured to playing with gasoline all day, every day. Gasoline is ~unbelievably dangerous~. This is why there are strict laws about containers for gasoline, which are taken very seriously by all involved. Or, taken seriously by those who have seen the catastrophic results for being careless and complacent.
Electricity is the same - AC power is the same. We handle it, we are near by it, it surrounds us..all day long..but...We have strict laws about how it is handled, when you actually go looking at the fine details. And that’s what is actually keeping more of us safe from when things go wrong.
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^ Not to mention, changing the original cord won’t improve performance unless it’s corroded or defective in some way. If your goal is the placebo effect, you can get one of those quantum, tychyon manipulating, unobtanium pronged noise supressors that plug into an adjacent outlet, or just install a Synergistic Research fuse. |
@toolbox149,
As for your old 2 wire zip cord with a non-polarized 2 blade plug.
I have read on other audio forums, where guys didn’t want to modify, or didn’t have the room, to install an IEC inlet connector on the back of their vintage equipment so they could use aftermarket power cords. It was suggested if the old 2 wire power cord is not cracked, hard, or brittle the last few inches where it enters the piece of equipment, in other words in good condition, you can cut off the old cord leaving about 4" to 6" and install a male IEC connector on the cord. With the male IEC connector you will be able to use 2wire with ground after market power cords. You will not be using the equipment ground of the power cord though.
If you decide to go this route it is important before installing, wiring, the new IEC male connector to the 2 wire zip cord of the audio equipment to make sure you have the correct proper AC polarity orientation feeding the primary winding of the power transfer of the equipment. The equipment will sound better if the AC polarity is correct.
The neutral conductor of the Zip cord is identified by either a ridge or ridges down the entire length of the cord, or, the neutral conductor will have printing down the entire side/length of the zip cord. You can check your cords for the identified, neutral, conductor.
That does not guarantee though the correct AC polarity orientation is wired correctly to the primary winding of the power transformer. It can be checked using a mulimeter, set to AC volts, reversing the old non-polarized plug 180 degrees at the wall receptacle outlet. (If you decide you want to check for the proper AC polarity plug orientation post back and I will give the procedure you will need to follow.)
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Things that can influence an aftermarket power cord other than the size, wire gauge of the power cord.
Type of wire used.
Solid core conductor/wire or stranded wire.
Geometry, construction, of the cable. (Capacitance? Inductance? How does the geometry, construction of the cable affect EMI? RFI?
Shielded, non shielded.
The quality of the plug and IEC connector. Contact pressure of the female IEC connector. Type of plating material if used.
Jim
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jea48 wrote,
"Things that can influence an aftermarket power cord other than the size, wire gauge of the power cord.
Type of wire used.
Solid core conductor/wire or stranded wire.
Geometry, construction, of the cable. (Capacitance? Inductance? How does the geometry, construction of the cable affect EMI? RFI?
Shielded, non shielded.
The quality of the plug and IEC connector. Contact pressure of the female IEC connector. Type of plating material if used."
>>>>Ah, hem, you forgot one thing: wire directionality.
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If that older equipment is Class II double insulated then no service tech is going to play around with changing power cords unless the new cord fits into the existing grommet and the cord has no grounding conductor. So if that lamp cord on your unit is 18/2 then maybe you can find someone to replace it with 16/2. Not sure what benefit that would be. |
Correct. The owner/user of a piece of audio equipment can do about anything he wants to a cord and plug connected piece of equipment.
Anyone claiming otherwise can cite to the relevant law, statute, or regulation.
That doesn't mean that a repair facility can do it, or wants to assume any liability, and besides, as per the above post, it does nothing for SQ.
Reverse the plugs if you have noise. |
If it’s been working all these years? Why mess with it! Upgraded old technology with new power cord seems like a waste. |
And you can tear the tag off your mattress, too! |
OK Uncle, uncle!
I just had some great sucess with two cord upgrades for my Bryston amps and I thought my good, 60 year old, McIntosh C-20 preamps and a few of my old signal processors might also benefit from a cord upgrade, if there was a new type of cord out there that might provide an improvement.
I have to admit I'm a bit befuddled by the fact that the cords have a, "Do not touch" policy attached to them (legal-wise), when I've had capacitors replaced in the power supply in many of my components.
Nevertheless, I was hoping someone would say, "Try this new, oxygen-free copper plus silver, stranded, twisted, cooked, directional cord from So-and-so Supply Co.
Since there doesn't seem that anybody has ever built a better lamp cord, and techs might not be willing to replace the cord anyway; this idea will just have to go on the Not Feasible pile.
Thanks for all of the responses.
Toolbox
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I have to admit I’m a bit befuddled by the fact that the cords have a, "Do not touch" policy attached to them (legal-wise), when I’ve had capacitors replaced in the power supply in many of my components. You can believe what you want. And yes you could more than likely hear the difference changing out the old 2 wire power cord and plug on your old McIntosh C-20 preamps . Search the archives on the Steve Hoffman forum. You’ll find several guys that have changed out the old power cords on vintage audio equipment and were happy with the results. Can't recall anyone asking if they would be arrested for doing it though. . |
I have added an IEC receptacle to several of my older components with great success! It is fairly easy, and the vast array of powercord tech is then at your dispense. As a matter of fact most of the gear was mid fi and it responded very well. Just order a couple of receptacles, get a dremel tool with some cutoff disc. Make a pattern for the opening , mark tht rear panel and take your time. It usually takes me about 1.5 hours, then used canned air to clean out debris and connect. This process has now been made easier with the new IEC receptacles which have screw connections. Give it a try it is WELL WORTH the time and the older powercords are very inexpensive here on Audiogon. |
Installed a 20 amp (C20) IEC on a Krell TAS so I could use a Shunyata PC.
Not sure if it sounds any better but easy enough to do. Local audio repair guy wouldn't touch it. Now I know why.
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Local audio repair guy wouldn't touch it. Now I know why.
Or possibly he didn't have the confidence in installing the IEC power inlet. What if in the process of cutting the hole for the IEC inlet he screwed something up? How many "repair guys" cut holes in the outside panels of audio equipment? Did the "repair guy" specifically tell you he was prohibited from installing the IEC power inlet? |
JEA
Bingo. I think you just hit the nail on the head. The two times I broached this topic with audio techs the excuse for not doing the conversion was they didn't want to drill/cut into the back of the unit. (We wouldn't want to drill holes in your Mc C-20. That would diminish it's resale value.")
It was never a question of legalities. Otherwise, if a tech couldn't legally work within/on the power supply, you'd have to junk any piece of equipment that ever developed a problem with the power supply.
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oopwah
6 posts 10-28-2017 7:46am
I have added an IEC receptacle to several of my older components with great success! It is fairly easy, and the vast array of powercord tech is then at your dispense. As a matter of fact most of the gear was mid fi and it responded very well. Just order a couple of receptacles, get a dremel tool with some cutoff disc. Make a pattern for the opening , mark tht rear panel and take your time. It usually takes me about 1.5 hours, then used canned air to clean out debris and connect. This process has now been made easier with the new IEC receptacles which have screw connections. Give it a try it is WELL WORTH the time and the older powercords are very inexpensive here on Audiogon. I have read many posts on Audio Asylum where guys have asked others how to cut the hole for the male IEC power inlets. The Dremel tool seems to be the preferred method. For any one interested they can search the AA archives. First you made sure you had room for the IEC power inlet. Sometime there is not room on the back panel to install the power inlet. I imagine you considered how it might affect the resale value of the piece equipment. Especially if the equipment has appreciated in value as it has aged over the years. oopwah, If I may ask. Was any of the equipment you installed the IEC inlets older 2 wire cord and non polarized plug audio equipment? If yes did you install a 2 wire male IEC power inlet or a 3 wire grounding type power inlet? If 3 wire did you connect the equipment ground pin of the power inlet to the metal chassis of the equipment? Did any of the equipment have an AC line noise capacitors connected from one AC power line to the chassis? Did you remove the cap? Sometimes a resistor is connected from one AC power line to the chassis. Did you remove the resistor? I assume you made sure the HOT pin of the power IEC inlet connector was connected to the inline fuse and power on/off switch of the equipment. By chance did you take the time to check for the proper AC polarity orientation of the power transformer? Thanks in advance for you response, Jim . |
Volex Home Depot extension cord |
Put snap-on ferrite beads on them. Very inexpensive. Can help clean out EMI/RFI clutter. Check the internal diameter: http://amzn.to/2Dig2Pc |
As for resale value generally no change in resale value for components with a nice job IEC on back in place of hard wired zip cord.
I agree the liability for a professional would stop a lot of this being done by them.
SO many folks are lawsuit crazy.. It is just not worth it to take any chance for a customer. (do them a favor and they bite you in the arse with a lawsuit)
I own an Audio Research SP-15 I wish I could get in gear and swap the wired in AC for a IEC. Lazy.
If anyone knows of a little box to place the IEC dangle mod..
Cutting the hardwired AC cord just outside the cabinet, then adding a IEC.. if only someone made a small plastic box to place the IEC into, which just covered the back of the IEC and screwed the IEC into. With a hole just big enough in back for the zipline AC wire..
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Here are some cable mount IEC connectors http://cpc.farnell.com/c/cable-leads-connectors/connectors/power-connectors/iec-connectorsAlso I just spent 15 minutes looking for the legal aspect of this issue and could not find a single case of having to re-certify either UL or CSA for components with the power cord is changed by a technician or owner Having said that - CSA and UL really only applies to companies making devices for sale in the respective domains and not after sales mods made by customers However, If a technician changes the power cord they immediately become liable for that repair - and as we all know, power supplies can catch fire - whereas changes to an internal circuit board will probably only fry that board, which is why most technicians will not touch a power supply - except the really competent ones Also - if your insurance company discovers you tinkered with a piece of electronics after it’s purchase - and it actually caused a fire - you would probably not be covered. Hopefully the fire would destroy all evidence :-) Realistically - the number of components in the world that are constructed by DIY enthusiasts must be huge and with the right due diligence they are probably completely safe. Using the connectors in the link above is comparable to replacing a switch or plug on a table lamp. If the plug is polarized - for sure, care must be taken to get the polarity correct - otherwise there may be a risk of electric shock As for UL and certainly CSA - I have encountered cable products having both of these certifications where the polarity was incorrect - which makes me wonder exactly how stringent they are at enforcement. Next time you purchase a power cable from Home Depot - check the polarity - it might just surprise you :-) Regards - steve |
Never had good results with ferrites on Audio Equipment whereas I always had good results with ferrites on appliances such as fridge, TV, computer, etc.
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