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Spectral Morn
06-12-2009, 11:01
Hi guys


Anybody know which might be Live and Neutral on a two core mains cable. I recently got an item from American which dates from 1975 its mains cable looks like speaker cable (think QED 79 strand but black). One cable has a ridge on it the other is smooth. There is no colour coding at all.

Anyone able to say which cable is which? There is no third earth cable.

Photos

http://i549.photobucket.com/albums/ii364/davros124/Marant125Tuner003.jpg

http://i549.photobucket.com/albums/ii364/davros124/Marant125Tuner.jpg

http://i549.photobucket.com/albums/ii364/davros124/Marant125Tuner001.jpg

http://i549.photobucket.com/albums/ii364/davros124/Marant125Tuner002.jpg

http://i549.photobucket.com/albums/ii364/davros124/Marant125Tuner004.jpg

http://i549.photobucket.com/albums/ii364/davros124/Marant125Tuner006.jpg

http://i549.photobucket.com/albums/ii364/davros124/Marant125Tuner007-1.jpg




Thank you in advance.


Regards D S D L

anthonyTD
06-12-2009, 11:09
Hi guys


Anybody know which might be Live and Neutral on a two core mains cable. I recently got an item from American which dates from 1975 its mains cable looks like speaker cable (think QED 79 strand but black). One cable has a ridge on it the other is smooth. There is no colour coding at all.

Anyone able to say which cable is which? There is no third earth cable.


Thank you in advance.


Regards D S D L

hi neil,
see PM...
A...

anthonyTD
06-12-2009, 12:12
hi neil,
i presume this piece of equipment has already been running on our mains supply YES? so no need to swap over the jumper leads inside? if so, then just wire it up to a three pin plug [live and neutral cconnections only] and have a listen, then swap the wires over in the plug and see if you can hear a diffrence, all you will be doing is swapping the wires around on a floating primary winding on the mains transformer that should not be refrenced to anything, so no harm should come of wiring it up either way around, although as stated, it may sound better one way than the other.
just make sure it is set for OUR voltage first!
hope this helps.
A...

Spectral Morn
06-12-2009, 12:21
hi neil,
i presume this piece of equipment has already been running on our mains supply YES? so no need to swap over the jumper leads inside? if so, then just wire it up to a three pin plug [live and neutral cconnections only] and have a listen, then swap the wires over in the plug and see if you can hear a diffrence, all you will be doing is swapping the wires around on a floating primary winding on the mains transformer that should not be refrenced to anything, so no harm should come of wiring it up either way around, although as stated, it may sound better one way than the other.
just make sure it is set for OUR voltage first!
hope this helps.
A...


Yes its previous owner was running it on 240 volts.


Regards D S D L

anthonyTD
06-12-2009, 12:24
hi neil,
forgot to mention, the other quirky thing you may come across in this equipment is one of the live wires maybe conected to chassis via a cap, in some older equipment, [mainly musical instrument amplification] they have a switch that refers either of the mains live leads to chassis,this is because they dont have a bonded chassis earth like us so they earth either of the lives to chassis via a cap so that you can set the swith either way the amp sounds quiter! [some people refer to this as "the death cap" mainly because if the cap goes dead short then the chassis becomes live!] remember,,, their mains is only 110v to 120v and have two lives not a live and neutral, so in theory you can only be subjected to a shock from 55v to true ground earth in the states, if this is the case, remove the cap and bond an earth straight to the chassis, ie rewire this piece of equipment with three core mains lead, job done!
A...

Spectral Morn
06-12-2009, 13:27
hi neil,
forgot to mention, the other quirky thing you may come across in this equipment is one of the live wires maybe conected to chassis via a cap, in some older equipment, [mainly musical instrument amplification] they have a switch that refers either of the mains live leads to chassis,this is because they dont have a bonded chassis earth like us so they earth either of the lives to chassis via a cap so that you can set the swith either way the amp sounds quiter! [some people refer to this as "the death cap" mainly because if the cap goes dead short then the chassis becomes live!] remember,,, their mains is only 110v to 120v and have two lives not a live and neutral, so in theory you can only be subjected to a shock from 55v to true ground earth in the states, if this is the case, remove the cap and bond an earth straight to the chassis, ie rewire this piece of equipment with three core mains lead, job done!
A...


Hi Anthony


Crap:eek::eek::eek: A death Cap....oerrrrrrrrrrrrrrrrrrrrrrrrr !

As far as I know its been owned by 2 other people and been running fine so I should be okay ? However I may get Rodney (my engineer) to take a look at it some time.


Regards D S D L

DSJR
06-12-2009, 13:41
It's already been said Neil regarding polarity of the mains wire.

If you come across US black and white connectors as my Crowns have and the ARC SP14 had (green being earth in any case), the black should be connected to the positive IIRC. I used the SP14 with white to +ve with no issues, but the chap who bought it from me wired the thing the other way round and I'm sure it sounded sweeter toned with the black connector as positive...

Spectral Morn
06-12-2009, 14:06
It's already been said Neil regarding polarity of the mains wire.

If you come across US black and white connectors as my Crowns have and the ARC SP14 had (green being earth in any case), the black should be connected to the positive IIRC. I used the SP14 with white to +ve with no issues, but the chap who bought it from me wired the thing the other way round and I'm sure it sounded sweeter toned with the black connector as positive...

Thanks Dave

Sadly no coloured cables at all except inside the item ;). My Leak Troughline also came originally with one of these crap mains cables (I got Rodney to replace it) Why ? is the question I ask...why ? Would you make and sell something with confusing mains cabling...especially if it sounds better wired one way over another. Oh well.


Regards D S D L

REM
06-12-2009, 14:10
Designed in the USA, Made in Japan...how times change.

Cheers

DSJR
06-12-2009, 14:21
Neil, back in the seventies I don't think it mattered. In fact, it wasn't until the mid seventies or so that imported gear had to have conforming mains wires as I recall. My Yamaha CA1000-2, Technics ST-3500 (both from 1976) and my old Sony TC366 (from 1972 or thereabouts) all had captive fig-8 mains wires.

Could the ribbed conductor be the positive?

Finally, I bet the copper inside these wires is way off now. The TC366 conductors were almost black when I came to change the mains plug.

Spectral Morn
06-12-2009, 17:04
Neil, back in the seventies I don't think it mattered. In fact, it wasn't until the mid seventies or so that imported gear had to have conforming mains wires as I recall. My Yamaha CA1000-2, Technics ST-3500 (both from 1976) and my old Sony TC366 (from 1972 or thereabouts) all had captive fig-8 mains wires.

Could the ribbed conductor be the positive?

Finally, I bet the copper inside these wires is way off now. The TC366 conductors were almost black when I came to change the mains plug.

No...actually the cable is very clean, as is the rest of the item...it almost looks new. Heck it was new when I was 10 and it looks better than I do ;)

The ribbed cable could be the +....we shall see a bit latter.


Regards D S D L

Spectral Morn
06-12-2009, 17:05
Designed in the USA, Made in Japan...how times change.

Cheers

Indeed....:(



Regards D S D L

anthonyTD
06-12-2009, 20:05
It's already been said Neil regarding polarity of the mains wire.

If you come across US black and white connectors as my Crowns have and the ARC SP14 had (green being earth in any case), the black should be connected to the positive IIRC. I used the SP14 with white to +ve with no issues, but the chap who bought it from me wired the thing the other way round and I'm sure it sounded sweeter toned with the black connector as positive...

hi neil,
dave is right, black usualy relates to "live" in american three core wiring, with white being neutral, plain solid green being earth, it wont help on this occasion, but may help for reffrence in the future.
A...

Spectral Morn
06-12-2009, 22:31
Hi Anthony

Thank you for the help, its powering up and everything appears to be okay. Everything will be revealed soon.


Regards D S D L

anthonyTD
06-12-2009, 23:00
:)
A...