|
Post by 2knowtalent on Oct 26, 2007 21:16:19 GMT
If NEC code in the states calls out 14 guage wire for a 15A service, would (could?) a powercord, made up of conductors collectively smaller than 14 guage, create a current bottleneck that somehow "starves" the transformer? I remember that V=IR and have vague recollections on series/parallel handling of caps and resistors but much beyond that and electrical circuit design/theory is largely voodoo to me so be nice
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 26, 2007 21:26:02 GMT
Not unless the amplifier is so powerful that the lights dim momentarily when you switch it on. O.K. I was being facetious, but you see what I mean ? (big toroidal transformers, for example, have a high initial inrush current) SandyK
|
|
rowuk
Been here a while!
Pain in the ass, ex-patriot yank living in the land of sauerkraut
Posts: 1,011
|
Post by rowuk on Oct 26, 2007 21:41:20 GMT
The reason a certain gauge is required is to keep the wire from getting too hot when the full current is flowing through it. Back in the days when microwave ovens were new, there were quite a few reports of brown stripes on the wall. They were caused by too small wire heating up when having to handle the 1500 watt power requirement of the MW. I am not aware of any powercord meltdown
|
|
|
Post by 2knowtalent on Oct 26, 2007 22:04:36 GMT
Not unless the amplifier is so powerful that the lights dim momentarily when you switch it on. O.K. I was being facetious, but you see what I mean ? (big toroidal transformers, for example, have a high initial inrush current) SandyK I almost had that.... last house I built I had a dedicated 20A circuit run for audio. The breaker was 20A and I'm "assuming" there was NEC coded 12awg(?) in the wall. Anywho, at the time I had the BIGASS Rotel 11XX 2 channel rated at 385wpc with peak current of either 80 or 85A (can't remember now) that came with a 14 gauge power cord. When I replaced it with a boutique cord of 10 gauge equivalance the soundstage grew drastically. Unfortunately I had to get rid of it because it would trip the 20A breaker on a cold start, then after resetting the circuit breaker and restarting the amp, the amp began to make popping sounds and emit strange smells. So you're saying the relatively piddly draw of a 1W headphone amp will not benefit by at least having a power cord with a wire diameter that, at minimum, matches what is in the walls?
|
|
|
Post by 2knowtalent on Oct 26, 2007 22:08:57 GMT
The reason a certain gauge is required is to keep the wire from getting too hot when the full current is flowing through it. Back in the days when microwave ovens were new, there were quite a few reports of brown stripes on the wall. They were caused by too small wire heating up when having to handle the 1500 watt power requirement of the MW. I am not aware of any powercord meltdown The old toaster element in the wall!!!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 26, 2007 22:37:58 GMT
"Unfortunately I had to get rid of it because it would trip the 20A breaker on a cold start, then after resetting the circuit breaker and restarting the amp, the amp began to make popping sounds and emit strange smells." That is poor amplifier design ! Most well designed high power amplifiers have a "soft start" circuit built in. This limits that huge inrush current for several hundred milliseconds, or more. It is often achieved by putting in series with the primary winding of the transformer a suitable value 10Watt,( or more) power resistor, then having relay contacts short circuit the resistor(s) after a predetermined time. As far as a 1W headphone amplifier is concerned, many would be powered by a wallwart. Just look at the thickness of their output lead. Not very thick are they ? SandyK
|
|
rowuk
Been here a while!
Pain in the ass, ex-patriot yank living in the land of sauerkraut
Posts: 1,011
|
Post by rowuk on Oct 29, 2007 11:09:03 GMT
............. As far as a 1W headphone amplifier is concerned, many would be powered by a wallwart. Just look at the thickness of their output lead. Not very thick are they ? SandyK Yeah, your 1W headphone amp needs a 1000 quid, 10 pound power supply with 1000 quid connectors to make the soundstage wide enough............ Why can't DC just be DC?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 29, 2007 11:32:37 GMT
"Yeah, your 1W headphone amp needs a 1000 quid, 10 pound power supply with 1000 quid connectors to make the soundstage wide enough............ " Rowuk Unfortunately, there is so much rubbish posted these days, and accepted as gospel, that many newbies get confused. Let's hope that Graham Slee and John Cadman are able to help dispell a few more myths, further down the track ! SandyK
|
|
|
Post by 2knowtalent on Oct 29, 2007 17:42:19 GMT
"Yeah, your 1W headphone amp needs a 1000 quid, 10 pound power supply with 1000 quid connectors to make the soundstage wide enough............ " Rowuk Unfortunately, there is so much rubbish posted these days, and accepted as gospel, that many newbies get confused. Let's hope that Graham Slee and John Cadman are able to help dispell a few more myths, further down the track ! SandyK I'm sticking with the 18awg shielded IEC and maybe I'll add one of those fancy ferrite emi blockers
|
|
mrarroyo
Been here a while!
Our man in Miami!
Posts: 1,003
|
Post by mrarroyo on Oct 29, 2007 18:46:59 GMT
I recently purchased four (4) 14 Gauge power cords for about $7.50 each. At that price I do not have a problem splurging.
|
|
|
Post by 2knowtalent on Nov 5, 2007 16:14:46 GMT
I recently purchased four (4) 14 Gauge power cords for about $7.50 each. At that price I do not have a problem splurging. Where did you buy them...and what model #? I can only find 18 gage and would prefer something a little thicker
|
|
mrarroyo
Been here a while!
Our man in Miami!
Posts: 1,003
|
Post by mrarroyo on Nov 5, 2007 21:13:32 GMT
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Nov 5, 2007 21:28:08 GMT
I wish you guys would talk in Amperes instead of wire guage ! Most common IEC type ,and extension leads would have ratings of 7.5A, 10A, or 15A. This would mean more to most people ? We are talking about equipment power leads that are used to supply gear with a much lower current draw than ANY of those typical sizes, aren't we? Let's face it, most people with an entertainment unit with TV , tuners, amplifiers etc, would have a power distribution board or 3 behind their unit, with , if lucky , a 15A lead supplying several pieces of gear. These leads would be better used for direct to a power point ? SandyK
|
|