How to upgrade a nondetachable power cord?


Hi
My Conrad Johnson amplifier has a captive power cord.
I have bought a VH audio diy kit to make a new power cord. So, What do you recommend?
- Cut the original amp cable and put a female connector and then plug the new cord
or
- Open the amplifier and attach the new cord inside the amplifier. This would take a big hole to do it.
Please give some advice
Thanks
ALAN
alanbrain
what are you expecting a new power cord to do in terms of an upgrade ?

the cj amp has a captive pc for a reason,you will not be doing your amp a favor by hacking a hole in it for an aftermarket pc.
Either way you suggest would do the job, but if you want a really workmanlike solution, you need to install a IEC panel receptacle on the amp and plug your PC into it. That's how CJ would have done it.

Additionally, that'd allow you to try lots of different power cords. Oh joy!
I agree with Nsgarch, I've probably installed at least a dozen IEC panel receptacles on hi fi equipment, including my open reel tape machine, my AirTight ATM 3's and even a Pioneer Elite RPTV.

Is your CJ still under factory warranty? I ask because if it is, the factory may not approve of your mod.
Hi Allan.If your apprehensive about cutting a hole in the chassis. The only alternative is to cut the existing cord close to the chassis and solder the female receptacle to it,use a heat shrink to make it look a little more professional....kind of defeats the purpose though. Sounds like you have an older CJ. I installed one on a MV 52 some years ago. Best of luck
Hi
I think my CJ is way out of the warranty. ALbertporter, When you installed the iecs you made a hole in the chassis?
How did you do it to look fine?
Alan
I've done it both ways. Hard wiring the cable is by far the easier route but installing the IEC receptacle does allow more future flexability. Good luck and let us know how it works out.
probably best way to cut hole for novice is dremel tool.if you are not good with hand tools,you might want to have someone else do this.unit must be protected from debris,light air blast cleaned.does any one know where to buy high quality iec solder-in recp.i have replaced a few,but recp. where scavanged from other equip.thanks,bill.
Cutting the hole for an IEC is tricky and tedious - Albert or others may have better methods than I, but below is what I've done. If your back panel is extremely heavy, the nibbler may not work and you'll need a "plan b".

- You need a cutter - I bought a nibbler from Radioshack. After removing the old cord, decide how to place the IEC and draw an outline of the hole. You'll need to make a template for this unless your IEC comes with one.
- If the IEC hole is positioned over the existing hole, begin nibbling from inside the hole, and work out to your line - but not past it. You'll need to drill a hole if it's not there.
- Finish off the hole edges with a file. A dremel moto-tool may work better than a hand file, but I do it by hand because the last thing you need is metal shavings on your circuit. It's very tedious, and you'll want to try for fit as you go. The IEC has about 1-2mm trim tab which doesn't leave much room for error.
- Once your IEC fits, and tightly is good - place it and drill the fastening holes (unless it's a snap in model), fasten it, and wire it up.
- When you're done - make sure you get ALL of the metal cuttings out of the unit that may have gotten away. I use an air compressor to air it out.

Hi
Thanks for the advices.
My amp is a CJ MV50, and the original power cord is very simple. I think the upgrade will be worth.
Im thinking, the hole is now too dificcult and I will prefer to not harm the amp(for now). Because this new power cord will remain in the amp for some time. Then maybe I will try for the IEC.
So, the option is the female. But Do you think maybe the short original cable that goes from amp to female will reduce the overall effect of the upgrade?
or the upgrade will have his effect anyway?
Please let me know.Today I will make the upgrade.
Thanks
Don't bother, cj voiced their amp with the captive power cable and they feel you need to spend real money to improve on it.
if you feel the need to change something, change an interconnect or something.
Very well said Brad, measure twice, cut once !

You can always take it off, but you can't put it back on.

Alanbrain, look for a Furutech IEC, they are very nice quality and offer a coice of set screw terminals or solder-on tabs for the internal wiring.
I tried adding the female IEC to an existing cord - the kind that leave you a pigtail hanging out the back. I removed it and wouldn't do it again, at least not on a good piece of equipment. I think it looks cheap, and if you're leaving the old cord there for the final run to the PS, I'm not sure what you accomplish.

If you're going to do anything, install an IEC with good hookup wire to the PS, or replace the entire cord with a better one.

Finally, you can probably find a shop to do the work for you, but it will be expensive because of the labor involved. OTOH, compared to the cost of a good power cable, this charge will probably be nominal
sometimes the original dedicated cord is the best cord. i'm sure conrad-johnson knew what they were doing.
The last time I looked into the "how to" of this matter, it seems to me there were chassis punches available that accommodate either 15 or 20 amp IEC receptacles. I'm sure you can find them to purchase, or (even better!) a repairperson who has them, and would do it for you for a small charge.
I would contact CJ about them installing an IEC as they will give you better advice than anyone else can. Otherwise I am with downunder don't mess with it.

Chuck
Tomorrow I will finish the female instalation. I will tell you the results.
I understand that CJ put the captive power cord for some reason and in that time (mid 80s) it was the better option. But maybe today is not the better option to go.
ALAN
Alan, in the mid eighties, no one used detachable PCs except for portable or pro equipment. Certainly NOBODY used alternative aftermarket PCs, because there was no such animal.

If you needed a longer PC on your amp or whatever, you used an extension cord. And if the PC it came with was longer than you needed, why you coiled it up real tight and neat. That way you increased the broadcast range of the EMI it was radiating. Of course you had all your components grounded and were using coax-type single ended ICs because that's all that was available if you weren't in a recording studio and using balanced!
I am sure that manufacturers adopted detachable power cords for a practical reason...so that they could easily configure their products for sale in different countries that use different configurations of electrical outlets. This opened an oportunity for the "upgrade" business that has been thoroughly exploited.

If you think that the wire which the manufacterer used is somehow inadequate, a few feet of new wire should cost only a few dollars. The new wire should be soldered in place just like the original "captive" wire. A soldered connection is always better than any plug. (Besides, the captive approach discourages "PC rolling" that could bankrupt you!) While you have the chassis open you might like to count up how many "push on" connections there are between the power cord and the transformer. The power switch, the fuse holder and the transformer itself are frequent offenders, but some designs have many more. You might consider hitting these spots with the solder while you are in there.
Hi
Well, its been a long time. And I was inmersed in tons of job. But 2 weeks ago I did it. I put a female connector in the CJ cord. And then put my male-male Vh audio flavor 2 power cord. I have to tell you the background is dead quiet right now. I did put some heatshrink in the female and it looks good. The soundstage has become a little bigger and the highs are more present.
Thanks for all the help
Alan
sounds great Alan. Which CJ amp did you do this on? I recently acquired 2 MF2100's with light duty captive power cords.
I noticed while visiting the Aural Symphonics website the other day that they make a special (?) adaptor for just this purpose called the Power Inlet Mod. Go to:

http://www.auralsymphonics.com/power%20im.html

You cut the captive cord short and attach this adaptor. Don't know how much $$, and it's probably no better than Alan's solution.
I did it in a Conrad Johnson MV50.
Cable is still breaking in, Chris Venhaus from VH audio said it will take near 200 hours to get it cooked.
See you
Alan