Modifying powercords

[Jurgenvanes]

Hi,

I’m thinking about modifying the standard powercords of my NAD C370 integrated and my NAD C270 poweramp. I want to remove the original cords and mount a suitable socket so I can connect decent quality powercords.

Does anyone have tips or suggestions?

Cheers.

[Resident Loser]

...There is not a single shred of credible evidence that IEC-type power cords contribute anything whatsoever to a systems' sound.

The IEC cord was adopted solely for economic reasons and as a result a new cottage industry was spawned based on the gullibility and the never-ending search for the grail among audiophile types.

You could seek out sites to obtain retro-fit female connectors, but most will require extensive modifications to back panels at the very least and possibly to the PCBs within the units to be modified; say goodbye to any warranties. Safety issues may also arise.

And of course we have the requisite question: how do you think six-feet of powercord will undo any gremlins unleashed by the powerplant itself, line transformers and un-shielded service feeds that supply your mains? Think about it.

jimHJJ(...expensive snake oil IMO...)

[gonefishin]

Hi Jurgenvanes,


Funny you should mention that...I was thinking of doing the exact opposite in my system. I've seen a good number of audiophiles swap in and out power cords...and even some add IEC sockets to the component so they can swap power cords in and out. But man...I just keep thinking that the weak link will now be the socket. I'd much rather prefer hardwiring.

have fun!

[E-Stat]

And of course we have the requisite question: how do you think six-feet of powercord will undo any gremlins unleashed by the powerplant itself, line transformers and un-shielded service feeds that supply your mains? Think about it.

You've got it bass ackwards. It is the first six feet, not the last. The interference is caused by computers, appliances, and a range of other digital devices found in the home that you filter out.

rw

[mtrycraft]

You've got it bass ackwards. It is the first six feet, not the last. The interference is caused by computers, appliances, and a range of other digital devices found in the home that you filter out.

rw

With the power cord? Are you serious? Didn't think so.

[E-Stat]

With the power cord?

Brush up on UL / EN 60950 RFI standards. The Europeans take this more seriously. Don't worry about noticing such things with your boombox.

rw

[skeptic]

If the Europeans take a technical issue seriously, you can be sure it is worthless. I lived in Europe, specifically the southwest of France for nearly two years. The power distribution system there stinks. Like everything else I saw, it was designed and built on the cheap. They transmit at 230 volts because they can use lighter gage wire to transmit a given amount of power. The price is that if you get a shock, you have a much better chance of dying. Every time there was an electrical storm, power went out with every lightening strke. My French made Thompson television set failed several times in electrical storms. Once a capacitor across the AC line input exploded. Another, a fuse for the flyback transformer popped. Each time, a technician fixed it under warranty. He had special parts to jury rig a quick fix and knew exactly what had happened having fixed the same problem on these sets again and again. My friend was nearly burned to death with a defective electric blanket. He returned it to the department store (Nouvelle Galleries) which sent it back to the factory. After about 6 months, the factory said they had determined that it had been used improperly as they had decided that it must have been folded. No appology, no refund, not credit, no nothing. In Britain, if you buy an electrical applaince it comes without a plug. You have to buy your own and it's always the same one. It's designed for an appliance which can draw up to three kilowatts. And that's the one you use even if the appliance is a two watt alarm clock. Somebody from Britain, please say it ain't so. At least not anymore.

Do you know what IEC is about? After the second world war, American engineers working in Atlanta set up cheapo standards to be used in Europe. They needed a uniform standard to built equipment to, could not afford to build to American standards, and the risk of successful lawsuits with big payouts to victims of defective items was non existant. That's how they got it. Now some Americans want it too. Anything to save a buck. At an industrial level, I instinctively hate it because equipment built to that standard is invariably flimsy compared to what I am used to. As a consumer, I don't like it any better.

By the Way, the FCC sets standards for RF emissions from all electrical appliances sold in the US. Just look at the back or inside of any remote control or any cordless telephone or the beginning of any operations manual for an appliance. Certificaton of compliance will be there.

[Resident Loser]

...did you catch the bass or did the bass catch you?

First...last...who mentioned a pecking order? Not me!

But let's not get into an argument over semantics...let's get into one re: your misconception.

I take it you never did much troubleshooting...I have... 35yrs. worth...you have to know which end is up, so...since you mentioned it, the power cord IS the last six feet(or so) in the AC mains chain...the powerplant is the source and that expensive mamba snake merely an extension of it...go ahead, prove it to yourself...take a VOM and see if you don't have 110v or so at the IEC connector...does the amp(or other device) inject anything into the grid? NO, it surely doesn't, actually it's vice-versa. Therefore, logic dictates it is the LAST thing in the supply line before the AC gets to the device's power supply board. On second thought don't...I'd hate to be responsible for your getting shocked...I'm not completly comfortable with your level of expertise in such matters...

I'd take a guess you might not subscribe to the practice of choosing loudspeakers first and everything else afterwards...another error IMO...

Since I always like to be somewhat familiar with what I speak about, I took the time to peruse that UL/EN 60950 standard...on the face of it, it seems to be simply an upgrade of the previous 950 spec...dealing with safety issues, mechanical and electrical stresses and the like, with regard to computers, computing devices and telecom interfaces...not RFI/EMI issues with after-market powercords...in fact, doing a Google with the RFI-suffix shows only those safety standards as applied to the manufacture of lower voltage(-80vdc)switching supplies and nothing to do with their culpability in the whole RFI matter(although the standards-adherent manufacturers do claim low RFI/EMI levels, but that is a separate issue)...again, it was only a cursory search, so perhaps another one of those factoid acorns, from whence great oak tree myths blossom, may have escaped me.

The Europeans also instigated the ISO standards...a commonality for the economic union, again like the ubiquitous IEC-type connector, strictly an economic issue. ISO provides bragging rights and ensures that the procedures to be followed are easily accessible to anyone who needs them...the Bell System Practices did the same thing 80 or so years ago...no big whoop, nothing new under the sun...Judge Greene be damned...but I digress.

jimHJJ(...and this cord clears up digital hash how?...)

[skeptic]

You'll need to use a chassis punch to cut a clean hole of the right size and shape. You have to drill a pilot hole first. If you know someone with such a tool borrow it. It will make a nice clean cut. File off any sharp edges or any small pieces of sheet metal not cleanly removed with a rat tail file. You may also be able to use a hole saw drill bit to make the hole. Try Hubbell for an IEC chassis mount male plug socket to mate the female connector on the IEC power cord. Any good electrical supply house should carry them and several other brands. There is probably hardware available in some high end audio retailr store especially if they do repairs on site although their prices will undoubtedly be much higher. Choose a spot in the amplifier where there is plenty of clearance inside. This can be difficult or impossible depending on how tight it is in your amplifier. If you can get a socket where there are no live exposed parts that will fit in your amplifier, that would be best. If this is impractical because the internal layout is too tight, try to find a socket that will surface mount on the outside back of the chassis. Drill a large enough hole for a rubber gromment or bushing to protect the wire from being abraided and still let the cord through to the inside. If the socket requires being secured with sheet metal screws or machine screws and nuts, be sure you pick a spot with available clearance for that too. Again, try to be very careful to be certain that there are no live exposed parts, no stray strands of wire, and no short circuits to the chassis at either end. you may have to remove and replace the existing leads to the on/off switch and transformer primary because they are too short to reach the new socket. At that end, you will probably have to solder new leads on and at the other, you will solder or screw the leads to the socket depending on what it requires. Try to route the power cord away from any signal wires. If there are exposed live parts, you may want to insulate them. Plastic electrical tape is fair but not great. Wrap the exposed parts several times to be sure they are insulated. Heat shrink tubing is much better. Since most people don't have a heat gun, a high powered blow dryer will do just fine for shrinking it. If you use heat shrink, try to attach the wires to the socket before you install it in the amplifier. This way you will avoid accidentally heating and damaging other electronic components.

Personally I do not recommend that you do this. I don't think it will improve your equipment performance but many people are determined to experiment even thought they will learn an expensvie lesson. Also, be aware that you are voiding any manufacturer's warranty and probably the UL listing of the equipment. You assume full responsibility for any consequences. This is not like experimenting with speaker wire or interconnects. If you don't know what you are doing, are not handy with tools, or just plain careless, you have the possibility of severely injuring or killing yourself or someone else. If you are not familiar with working with hand tools and small electrical appliances, get help from someone who is or at least have someone check your work before you plug it into a wall outlet. You can also check your own work with an ohmmeter, continuity checker, or multimeter. both power and neutral leads should be open to the chassis ground. They should show continuity with each other when the power on/off switch is on and open when it is off. If there is a ground pin, it should show continuity to the chassis and open to both the hot and neutral legs always. As a final check, be sure there are no stray pieces of wire, solder or other foreign debris inside your amplifier. Turn it upside down and shake out anything loose before you put the cover back on. Good Luck.