Heavy Duty IEC AC Power Cable

[agedhorse]

None of my power amp gear had any molded plugs. It was all custom wired. For example, on my Apogee rig (which I kept because it was obsoleted by the gear the sound company replaced it with), the power amp was wired to the back of the Apogee controller for power (the Apogee had power control built in) with a 1-foot 12AWG hand-made plug to jack. It had to be made a certain way so it didn't get in the way of the plug-in audio transformers on the back of the power amp.
We always had boxes of spare custom made cables like that as they retired the systems that used them. Then the power cable coming off the Apogee controller was a 150 foot 12AWG with custom ends. I believe they were made by Rapco for the guy who owned the gear.

The QSC PLX units I have for an EV rig had all of their molded power cables swapped out for custom short cables with industrial plugs. Nobody wanted a mess of 6-foot loop cables back there.
Only the Driverack had a computer-style molded power cable. This was all pre-PowerCON. I rarely ever saw computer power cables on amps unless it was stuff like those power mixers or amps made by ABI for a tiny TOA speaker-on-stilts PA setup.

Oh and Bose... All the Bose stuff had its plugs changed because their power cables used to wear out at the stress-relief "boot" or "flex".

My own QSC GX5 amp does have a molded plug cable.

All the distro stuff was multi-phase and I never had to connect any of that - it was all done for me. Straight out to a breaker panel.

All of that custom work on the power cables voids that equipment's UL safety listing. If you were to be inspected by a hard-ass, you might get shut down with no valid argument in the world to justify it.

I believe EVERY QSC and Crown power amp uses IEC cables (not counting the really big stuff, though I believe even for them most are IEC... it becomes 208V-240V on an IEC).

If you go back far enough, sure that was before IEC was the standard, line cords were hard wired to the equipment. IEC inlets were a game changer for the industry, about 25 years ago, because it allowed for a safe and convenient way to manage multiple AC power system standards. It also made things safer because it discouraged inexperienced people from monkeying with the standard, while making it easy to replace damaged power cables.

I designed pro audio amps and processing during both eras, no way would I ever consider going backwards. If the equipment needed locking connectors, PowerCon is an option but not all jurisdictions (globally) have accepted it yet.

Rapco doesn’t make high quality. I used to be a dealer for them.

That's not true. Rapco made different grades, some of which were as good as anything available. For example, their venue series transformer isolated splitter snakes with mulit-pins were a great product (though expensive) as well as their Belden 8412 series cable with Neutrik or Switchcraft connectors. They built a LOT of national tour product, but many dealers didn't have access to that side of the business. I became a contractor dealer the first year they started, I often used them for when I built out installations or built up systems for touring clients. Never had an issue, but I never used their music store grade products either.

 

[frankie5string]

All of that custom work on the power cables voids that equipment's UL safety listing. If you were to be inspected by a hard-ass, you might get shut down with no valid argument in the world to justify it.

The way I understood it was that in 1984 or 1985, BGW supplied 750Cs to Apogee for their rigs. Those 750c amps came with short power cables. They came to Apogee with the custom length power cables. Dunno if they had different approval for that. But the cable was just long enough to reach up to the processor - an A-4 or something of that vintage. It wasn't a bi-amp rig. Apparently some A-4 processors had weird 4-conductor "Canon" style speaker connectors - but mine had SpeakONs.

I used to have a 750c that had a regular power cable, though - but I bought that years later, used, obviously.

Right now it's in storage with a note taped to the power cable that says "do not power up before bench-testing" ...

 

[Jim C]

I always wanted to leave them out on the asphalt drive on a 100 degree day and see what happens. Maybe I’ll try your cooking method.

It's not a night and day difference but it definitely helped.
I've started posts before asking for suggestions for a flexible IEC cable but never got a good suggestion.
Back in the day, electric drills came with super flexible rubber cords that also had very good abrasion resistance.
I assume they were no longer offered due to cost but that is just speculation.

I just looked up a spec for some cables I made in the 90's that were for a mil spec project that were made from SJOOW cable. I don't think the material is a s flexible as it used to be but will have to buy a piece and see for sure.

 

[Playbyear]

18 gauge, 3 wire cord is rated 7 amps. 7 x 120 = 840 watts.
16 gauge, 3 wire cord is rated 10 amps. 10 x 120 = 1200 watts.
14 gauge, 3 wire cord is rated 15 amps. 15 x 120 = 1800 watts.

Spec a cord that will handle the maximum load of the device (amp)

The wire will handle more than that, especially intermittently, but if used above the rated ampacity continuously, it will heat up and there is voltage drop.

A bass amp does not spend much time at full power.

 

[crankypants]

Wow! 5 pages!!!

 

[agedhorse]

The way I understood it was that in 1984 or 1985, BGW supplied 750Cs to Apogee for their rigs. Those 750c amps came with short power cables. They came to Apogee with the custom length power cables. Dunno if they had different approval for that. But the cable was just long enough to reach up to the processor - an A-4 or something of that vintage. It wasn't a bi-amp rig. Apparently some A-4 processors had weird 4-conductor "Canon" style speaker connectors - but mine had SpeakONs.

I used to have a 750c that had a regular power cable, though - but I bought that years later, used, obviously.

Right now it's in storage with a note taped to the power cable that says "do not power up before bench-testing" ...

BGW was one of the last companies to switch to IEC, but that was not the original company but a follow-up successor. I believe BGW came with an LA County safety approval. The 750C was fairly early in the amp's long history, IIRC they went to G or H. I used to do warranty service for BGW back in the 1980's, mostly for the cinema industry. It's a pretty nice amp circuit.

18 gauge, 3 wire cord is rated 7 amps. 7 x 120 = 840 watts.
16 gauge, 3 wire cord is rated 10 amps. 10 x 120 = 1200 watts.
14 gauge, 3 wire cord is rated 15 amps. 15 x 120 = 1800 watts.

Spec a cord that will handle the maximum load of the device (amp)

The wire will handle more than that, especially intermittently, but if used above the rated ampacity continuously, it will heat up and there is voltage drop.

A bass amp does not spend much time at full power.

This isn't helpful for audio equipment, because audio equipment carries a different type of power draw rating so the load is calculated differently. By the safety agency's regulatory requirement, they test and specify everything (including the requirement for AC cordset size) at a minimum of 1/8 - rated audio power into the lowest rated load, which is equivalent to just clipping the amp under normal dynamics. If the amp is designed for and intended to be driven into either clipping or limiting, the manufacturer is allowed to alter this duty cycle to whatever they feel is representative. For example, I do all my specifying and testing at between 1/4 and 1/3 rated audio power, which is pretty stringent by MI industry standards (and even pro audio standards).

So, for an 800 watt bass amp that's 80% efficient, they would be roughly (800 x .33 duty cycle) x 1.2 = 320 watts of rated AC draw. Clearly this is a small load, even for an 18 gauge power cable. The voltage drop for a 6' cable would be trivial.

Now, saying that a 16 gauge 3 wire AC power cord (cordset) is only rated for 10 amps is also wrong. For SVT and SJT type cable used in most IEC cordsets, The UL ratings are:
18 gauge: 10A
16 gauge: 13A
14 gauge: 15A
12 gauge: 20A

IEC also has a smaller cable size than our 18 gauge which is good for ~6 amps, but it's rarely used internationally because it's not as durable.

There's a whole lot behind a manufacturer's choice of power cable. This is a good example of why engineers are focused on the details... they matter when designing products for the global market.

 

[byacey]

It's not a night and day difference but it definitely helped.
I've started posts before asking for suggestions for a flexible IEC cable but never got a good suggestion.
Back in the day, electric drills came with super flexible rubber cords that also had very good abrasion resistance.
I assume they were no longer offered due to cost but that is just speculation.

I just looked up a spec for some cables I made in the 90's that were for a mil spec project that were made from SJOOW cable. I don't think the material is a s flexible as it used to be but will have to buy a piece and see for sure.

I use SJOW for all my stage AC U-ground drops. The cable insulation is a neoprene rubber that is very flexible, but I have noticed after a number of years (25 years or so), it starts hardening up and becomes crumbly.

 

[agedhorse]

I use SJOW for all my stage AC U-ground drops. The cable insulation is a neoprene rubber that is very flexible, but I have noticed after a number of years (25 years or so), it starts hardening up and becomes crumbly.

Me too, I had to scrap a couple hundred pounds of old cables. There is a newer synthetic material than many now use for SJOW

 

[2tonic]

This! Victor Wooten's personal choice:
Victor Wooten Signature MusicCord-PRO Power Cord
You're Welcome!


Kiddin'

Don't do that.

Oh for cris sakes

Yep
He's a good player and all but his knowledge on gear, I don't know

And at $26+shipping. That still seems unnecessary.
Although it's far better than $250

Those snake oil cables are such a racket and it’s mystifying to me that people are naive enough to fall for it.

I know, I know.......but.....but......but if you buy 3 you get a 10% discount!
That brings 'em down to a much more reasonable $225 each. Who can't spring for that?
I mean really, how can you resist?
Especially with all the test data showing that putting one of these on your '73 Univox combo will make it sound just like a WD800!
Just think what they could do for that Kasino head buried in the back of the closet!
Brilllllllllllliant!!!

 

[bbh]

All of that custom work on the power cables voids that equipment's UL safety listing. If you were to be inspected by a hard-ass, you might get shut down with no valid argument in the world to justify it.

I believe EVERY QSC and Crown power amp uses IEC cables (not counting the really big stuff, though I believe even for them most are IEC... it becomes 208V-240V on an IEC).

If you go back far enough, sure that was before IEC was the standard, line cords were hard wired to the equipment. IEC inlets were a game changer for the industry, about 25 years ago, because it allowed for a safe and convenient way to manage multiple AC power system standards. It also made things safer because it discouraged inexperienced people from monkeying with the standard, while making it easy to replace damaged power cables.

I designed pro audio amps and processing during both eras, no way would I ever consider going backwards. If the equipment needed locking connectors, PowerCon is an option but not all jurisdictions (globally) have accepted it yet.


That's not true. Rapco made different grades, some of which were as good as anything available. For example, their venue series transformer isolated splitter snakes with mulit-pins were a great product (though expensive) as well as their Belden 8412 series cable with Neutrik or Switchcraft connectors. They built a LOT of national tour product, but many dealers didn't have access to that side of the business. I became a contractor dealer the first year they started, I often used them for when I built out installations or built up systems for touring clients. Never had an issue, but I never used their music store grade products either.

Thank you, I stand corrected. We seem to have only sold mid to low range Rapco products to our customers.

 

[Rockbobmel]

And at $26+shipping. That still seems unnecessary.
Although it's far better than $250

If you are worried about economy, just grab a computer cord from a dumpster or roadside.

 

[Playbyear]

BGW was one of the last companies to switch to IEC, but that was not the original company but a follow-up successor. I believe BGW came with an LA County safety approval. The 750C was fairly early in the amp's long history, IIRC they went to G or H. I used to do warranty service for BGW back in the 1980's, mostly for the cinema industry. It's a pretty nice amp circuit.



This isn't helpful for audio equipment, because audio equipment carries a different type of power draw rating so the load is calculated differently. By the safety agency's regulatory requirement, they test and specify everything (including the requirement for AC cordset size) at a minimum of 1/8 - rated audio power into the lowest rated load, which is equivalent to just clipping the amp under normal dynamics. If the amp is designed for and intended to be driven into either clipping or limiting, the manufacturer is allowed to alter this duty cycle to whatever they feel is representative. For example, I do all my specifying and testing at between 1/4 and 1/3 rated audio power, which is pretty stringent by MI industry standards (and even pro audio standards).

So, for an 800 watt bass amp that's 80% efficient, they would be roughly (800 x .33 duty cycle) x 1.2 = 320 watts of rated AC draw. Clearly this is a small load, even for an 18 gauge power cable. The voltage drop for a 6' cable would be trivial.

Now, saying that a 16 gauge 3 wire AC power cord (cordset) is only rated for 10 amps is also wrong. For SVT and SJT type cable used in most IEC cordsets, The UL ratings are:
18 gauge: 10A
16 gauge: 13A
14 gauge: 15A
12 gauge: 20A

IEC also has a smaller cable size than our 18 gauge which is good for ~6 amps, but it's rarely used internationally because it's not as durable.

There's a whole lot behind a manufacturer's choice of power cable. This is a good example of why engineers are focused on the details... they matter when designing products for the global market.

I looked it up and I was incorrect. The ratings you quoted for cord-sets are indeed the higher number.

My day job is EPG, I'm used to conductor ratings for that purpose.

 

[lug]

The confusion with power cables is understandable. The truth is you're getting bad power and you want to blame the cable itself. The real culprit is the cheap house wiring and the dirty power supplied by lazy power company employees who do not give 2 hoots about the kwality of you precious sound. This is why I've developed the Lug Power Systems 5000. This ultra-clean power source will allow you to transparently broadcast your own unique sound to the audience and allow them to understand and appreciate your true genius.

ONLY $19,999 and if you purchase within the next 20 minutes, there is an extremely generous 2% discount! Order yours TODAY!

 

[Playbyear]

The confusion with power cables is understandable. The truth is you're getting bad power and you want to blame the cable itself. The real culprit is the cheap house wiring and the dirty power supplied by lazy power company employees who do not give 2 hoots about the kwality of you precious sound. This is why I've developed the Lug Power Systems 5000. This ultra-clean power source will allow you to transparently broadcast your own unique sound to the audience and allow them to understand and appreciate your true genius.

View attachment 3720429

ONLY $19,999 and if you purchase within the next 20 minutes, there is an extremely generous 2% discount! Order yours TODAY!

Awesome, but is it endorsed and signed by Victor Wooten?

 

[lug]

Awesome, but is it endorsed and signed by Victor Wooten?

Sorry, Victor didn't meet our high standards to achieve endorsement status.

 

[BurningSkies]

I generally follow @agedhorse 's advice in this range. My preamp is a 10' 16g IEC. My power amp is a 14g, but it's also powercon rather than IEC and I'm not terribly worried about the mechanics failing (also, it's fairly beefy power amp (2500w RMS). My pedalboard is a 18g IEC.

People should also remember that because a cable looks heavy and honkin' thick it isn't always the case...sometimes they've just given it a super heavy jacket. Sort of like ethernet cables...CAT5 is lighter weight than CAT7 but the internals are the same. Depending on your use, CAT5 may be a better option.

 

[seamonkey]

Sort of like ethernet cables...CAT5 is lighter weight than CAT7 but the internals are the same. Depending on your use, CAT5 may be a better option.

 

[joel the bass player]

N-Series IEC F - US NEMA 5-15P M Power Cable

I was searching for a longer cord a while ago and came across this on Amazon. For some reason they had it marked down to $5 at the time, so I grabbed one. It is way more flexible than any of my other power cords, and being a bit longer than all the rest at 10' made it handy to have.

 

[DJ Bebop]

If you are worried about economy, just grab a computer cord from a dumpster or roadside.

Not me, I have this:
Victor Wooten Signature MusicCord-PRO Power Cord
NOT!

 

[DJ Bebop]

The confusion with power cables is understandable. The truth is you're getting bad power and you want to blame the cable itself. The real culprit is the cheap house wiring and the dirty power supplied by lazy power company employees who do not give 2 hoots about the kwality of you precious sound. This is why I've developed the Lug Power Systems 5000. This ultra-clean power source will allow you to transparently broadcast your own unique sound to the audience and allow them to understand and appreciate your true genius.

View attachment 3720429

ONLY $19,999 and if you purchase within the next 20 minutes, there is an extremely generous 2% discount! Order yours TODAY!

I'm still using last years the Lug Power Systems 4500 version