[jules]

I know this has been dealt with before but despite trying various "search" options I can't dig up a specific thread ....

What is the best option for a power cord [for an AKSA 55N+]? I know there are $500+ options out there and people who swear by them but I'm not going to go anywhere near that.

Given that single strand copper wire is highly favoured for signal wiring would there be any virtue to the same approach to power cords. the most basic approach could be to use the sort of single strand wire that is used for house electrical wiring [the fixed, hidden in the wall stuff]. The stiffness would be a bit of a pain though. edit 2: In Australia the std. form for this cable is a flat form with three parallel strands individually insulated as well has sharing a common outer jacket.

Is there an ideal length? Are there any known principles here or is it in the same class as sat speaker wiring ie don't ask why this works but it does. If DIY is ok, what sort of wire/plugs are best?

edit: how about hardwiring [at the amp end]? One less source of poor connection chances but any drawbacks?

Heap of Q's here but I thought I might as well try to get it all in one.

jules

[Seano]

Occam recommends what he calls the Sara Lee solution and there is a sticky post about in the Technical section of AudioCircle.  Basically he suggests a Volex(?) power cord which I figured could be landed in Oz for about 20 bucks from www.carlton-bates.com (which is a supplier that Hugh also uses).

I'd have bought one before now but I don't actually care enough at this point since the zipcord I have at the mo from a computer was obviously good enough for a delicate piece of electronics so it should be just fine for an AKSA - maybe later though. After dinner.

[andyr]

What is the best option for a power cord [for an AKSA 55N+]? I know there are $500+ options out there and people who swear by them but I'm not going to go anywhere near that.

Given that single strand copper wire is highly favoured for signal wiring would there be any virtue to the same approach to power cords. the most basic approach could be to use the sort of single strand wire that is used for house electrical wiring [the fixed, hidden in the wall stuff]. The stiffness would be a bit of a pain though. edit 2: In Australia the std. form for this cable is a flat form with three parallel strands individually insulated as well has sharing a common outer jacket.

Is there an ideal length? Are there any known principles here or is it in the same class as sat speaker wiring ie don't ask why this works but it does. If DIY is ok, what sort of wire/plugs are best?

edit: how about hardwiring [at the amp end]? One less source of poor connection chances but any drawbacks? ...

Hi, Jules,

Power cords ... I reckon the best thing to do is try a few different DIY ones and see whether they make a difference in your system.  I did try comparing some at one stage but now I simply work from a few basic theories - however, I'm quite open to the idea that there is a commercial cord out there that's does the "power cord" job better than mine (trouble is, I probably wouldn't be able to afford it!)  

As far as I'm concerned, the ideal requirement of a PC for a power amp is that it should impose ZERO impedance to the current coming from your wall socket.  Of course, if you have old house wiring, or a thin supply wire in from the telegraph pole ... etc, then your "power delivery capability" is compromised anyway!    

But you may as well try to have a PC which does a good job of it.  You can't produce one with zero impedance to the current but, by using a couple of basic rules, you can get close:

Rule #1 is maximum copper ... for lowest resistance.

Rule #2 is minimum inductance ... so as to let the current run umimpeded when it wants to (remember current in a PC flows in milli-second bursts of high current, not a constant low-current flow, as the filter caps charge and discharge).  This means braiding!

Add a rider to these basic rules ... the ideal PC will act as a HF filter, to remove HF hash from your AC.  Braiding also helps with this.

Whether using solid-core wire for a PC is better than using stranded is probably a "religious" matter but I suggest it can't hurt.  But you can't get very thick solid-core cable so you have a trade-off!

Now you asked about hard-wiring ... yes, just like with ICs, hardwiring the PC will remove a contact (which is good) but makes it difficult to experiment or get something better!

Secondly, plugs ... for the wall-socket end, I use HPM side-entry plugs, simply because you can get a heavy-duty version which has a deeper body to take thicker wire.  At the IEC end, I lashed out many years ago and bought a stack of Marinco IEC plugs, however, these are expensive and I suspect the normal IEC plugs you buy at a hardware store are really just as good.  (US folks go mad about "power jewellery" because, with their 110v supply, they have to ... as they operate on more than double the current we do here.)

Finally the wire itself - and Seano, you might well use computer PCs for source components but they are not built to carry heavy currents so I suggest they are "starving" your AKSA!  

You have several options:

1.  The "quick and dirty" is to make friends with the nice men at Lawrence & Hansen so they will cut lengths of cable for you instead of making you buy a roll!     I use six thick stranded cables about 1.2m long for my AKSA monoblocks; overall the cable is 12mm thick and each core is probably 12awg (3.3mm sq).

These six PCs plug into two DIY "power strips" - the cord from the wall to each 4-outlet power strip is made from three lengths of RG213/U, braided (I stripped off the jacket and shield).  Each of the cores is stranded but 10awg.

2.  So, a better PC IMO is made from braiding these RG213 cores.  You get a sexy, pearlescent looking PC with immense current-carrying capacity as the braiding reduces inductance AND you have an immense amount of copper!  

3.  I agree this might be overkill so a cheaper, more conventional PC can be made using normal electricians solid-core single wire which L&H sell by the 100' roll.  The thickest you can get is 2.5mm sq (a bit less than 13awg).  If you braid this you will get an excellent PC.

Is there an optimum length?  IMO, if you just use normal thick stranded cable like 1. above then the best length is the shortest!  If you are braiding the cores, like in 2. & 3., then the optimum length depends on whether you believe the braiding is also acting as a hash-filter (as well as reducing inductance).  It SHOULD but I can't prove it!  However, if it is, then 3m is probably what you need for the hash-filtering to do its job.

Happy braiding!    

Regards,

Andy

[gonefishin]

Hi Jules,

  Here's the cord I use with a strain relief connector.  However...I just cut off the IEC.  The Volex is supposed to be the same as the Belden 17604.

    take care,

  dan

[jules]

Thanks Sean and Andy,

Aside from carrying capacity, my original question came out of wondering if there is somethng akin to a tuned length here given that the power cord is part of the whole circuit. On the face of it the AC to DC step along with the smoothing by capacitance would seem to isolate power cord influence effectively and make it a non-issue but ...... ?

I'm in the unusual position of being able to hardwire my amp directly to the source of my AC [a sine wave inverter] if I choose so, theoretically I could have 1m between the place the AC is made and the place it's used. Also, living in the middle of nowhere, interference of various sorts is not a factor.

I have to make the observation that running at 50% my Aksa 55 uses less than a light bulbs worth of power so I can't see the point of using very heavy wiring.

All in all I think I might leave it till after dinner myself and make my speaker cables my first priority in this area.

jules

[Seano]

Finally the wire itself - and Seano, you might well use computer PCs for source components but they are not built to carry heavy currents so I suggest they are "starving" your AKSA!

Too easy. I'll use the lead from my electric kettle instead.  That draws heaps of current.

The thing is.......if the amp is using a 10 amp fuse that costs less than 20 cents.....why use a 15 amp rated power cord?  

[andyr]

Finally the wire itself - and Seano, you might well use computer PCs for source components but they are not built to carry heavy currents so I suggest they are "starving" your AKSA!

Too easy. I'll use the lead from my electric kettle instead.  That draws heaps of current.

The thing is.......if the amp is using a 10 amp fuse that costs less than 20 cents.....why use a 15 amp rated power cord?  

Absolutely correct, Seano ... you will notice an improvement in your sound if you re-wire your AKSA to take the fuse out of circuit!  

However, if your house burnt down (eg. from some other cause) if the assessors saw what you'd done inside the melted AKSA, they could well decide to renege on paying you!  

Regards,

Andy

Regards,

Andy

[ginger]

Brushing of the Fairy Dust (not to mention the Bull Dust).

The mains transformer is a step down transformer. The impedances in the primary reflect into the secondary according to the SQUARE of the turns ratio. Impedances in the primary are INSIGNIFICANT when reflected into the secondary, compared to secondary wire resistance etc. (An extra 0.1 ohm in the primary will reflect into the secondary as about an extra 0.01 Ohm).

Its bunk - those who spend $100 on a "flash" power cord report improved sonics because they expect to hear improved sonics and are therefore convinced that they do so, NOT because the were any.

The thing that does give you some improvement is keeping mains noise out of your amp. So chuck that cheap IEC mains socket and replace it with a filtered socket - the one with the most agressive filter you can find.

Do NOT under any circumstances remove the mains fuse(s) - this is BAD advice and in worst case conditions is DANGEROUS advice.

I suppose I should appologise to those that I offend with this post and I probably would - if I gave a rats.

Cheers,
Ginger

[PSP]

Ginger,
Thanks... I'm just going back to re-work the chassis on a '55 (and eventually, a '100).  I've looked longingly at filtered IECs, and always worried that I'd end up with an anemic amp... not a problem?

Can one go too far, in any realistic sense?

Many thanks,
Peter

[Jens]

Ginger,
Thanks... I'm just going back to re-work the chassis on a '55 (and eventually, a '100).  I've looked longingly at filtered IECs, and always worried that I'd end up with an anemic amp... not a problem?

Can one go too far, in any realistic sense?

Many thanks,
Peter

I've tried a number of mains filters, even fairly big ones that were supposed to have no detrimental effect on power amps. None of them worked well with power amps. The problem with most mains filters is that they incorporate some kind of coil(s). It would seem that when drawing fairly large currents through these - which happens all with power amps - you tend to get an undynamic and flattish sound image.

I suppose there is a logical explanation to this phenomenon, but I won't pretend I would be able to explain it.

In my opinion, the small IEC filter units are not suitable for power amps, but they would be fine for low consumption components.

I do use mains filters on low-consumption components, such as preamp and CD-player. No problems there. It does clean up sound somewhat.

And just for the record - I've heard power cords that made one heck of a difference to the sound. And yes, they were (very) expensive, and I haven't bought any of them, so I'm not biased because of that.

Cheers,

Jens

[jules]

Thank you everyone  

Looking back over the collected wisdom here, there's been a great deal of divergence of opinion.

One factor hasn't had much attention so maybe I can add this to the mix. At various times in the past I've gone to the trouble of driving an earth stake into the ground for improved radio reception. The argument is made that it isn't good enough to attach an earth to the nearest hot water pipe [copper] or to use the existing house wiring earth because the first option can be too indirect, pass through too many poor connections and finally not even earth all that well. The second option has the same problems with the additional risk of some sort of feedback from the AC system.

It's certainly very noticeable with poor radio reception that an earth stake made from a few feet of copper rod and driven into a carefully selected damp spot, makes a big difference to reception. Ok, so this is not the same situation [as radio signal reception] but if the best form of earth is a dedicated earth stake then there might be several useful options:

    * earth the case to a dedicated earth stake and forget the power cord earth. [is this legal?]

    * earth the power cord shield to a stake [if shielded]

    * work out all the other permutations and combinations of single end/both end, shield/earth connection involving stakes, the amp and the wall plug.

Sometimes the obvious is overlooked.

jules

[kyrill]

powercords are antenna's too
So if the rest of the system equals or passes the transaparency of the AKSA..., and if your power is made clean, don't expect clean pwr out of the wall, no way, you better shield them or braise them into themselves.

If you have not cleaned the power out of the wall, well don't bother  

[econ]

Many years ago I was advised never to use water pipes as an earth. Actually thats the polite version. The person doing the explaining (not an electrician but a physicist ) became rabid with me when I asked him about this possibility. He used terms that made me think he was familiar with female genital anatomy.

             
The explanation went something like this:
The earth wire  is there  to carry  stray return currents which should under normal circumstances be carried by the neutral wire. Its a kind of sink hole  for electrons  that stray away from the active to neutral path. He was talking about mains here and neither of us then knew anything about hifi and the mystical effects earthing systems have on music.

lets imagine I own an old transistor radio and its internals are crumbling and the active lead has become unsoldered and during loud, head banging music, the vibration within the tranny makes the live wire occasionally touch    the metal casing  of the radio. During these times the casing is live . The earth will save me if its properly connected to the case because it will carry this stray current into the earth somewhere near your switchboard.  And A modern well maintained switchboard will trip with the smallest of such leakage currents.

If the  earth from this faulty radio is connected to the house waterpipe system  and a person with a few cuts (which lowers the normal dry skin resistance)  on his hands takes a shower when the music is playing he   is going to get a shock ....maybe .  That rigidity   that suddenly develops will have nothing to do with the water temperature  when he touches the taps or is under the unbroken water stream   . That person may become the path of least resistance to earth for said stray electrons. Its a matter of probability.  The odds  of electrocution  shorten with such a system , when there is a faulty appliance or wiring in the system

I imagine the big desk sargeant on Hill Street Blues would say  to "Be careful out there "  and Fifty Cents the rapper would remind us not to F##K with the earth bro'   .  Ive seen his pictures on his latest album cover  and listened to his songs at modest volume and I agree with anything he says even if I dont want to.


So now I approach mains earthing with something like religious  zeal.

Is it safe ?  Will this system/wiring  preferentially carry any stray unwanted  current (no matter how excellent my soldering is )   to earth and not through a person touching the equipment.

And a remote second: what effect will it have on the sound. ?

Having a separate stake sounds like a very interesting suggestion . It sounds like it would satisfy the requirement for carrying away stray current  in the event of a equipment becoming live.

off my soap box now. Any electricians who can tell us about the legals ?

[andyr]

... Any electricians who can tell us about the legals ...

Hi, econ,

This idea of an earth stake with a separate ground wire from each component's chassis earth screw to it has been expounded by Ben Duncan (see: http://www.britishaudio.co.uk/proaudioaccessoriesbd.html) - he's even come out with a kit for it!

His prose is very believable ... I just worry what will happen if you happened to get a lightening strike hit the ground near the spike!  

Regards,

Andy

[ctviggen]

According to the NEC, you can only have one earth ground.  If you use another ground, it has to be tied to the first ground using large gauge wire.  Pipes are a valid way to ground your house's electrical system.  However, the ground is to be within a certain few inches of entering the house (to prevent someone from replacing metal pipe with non-conductive).  If you don't tie together the earth grounds, you'll get grounding loops.  You can pick up the NEC (or more easily readable versions thereof) at Amazon.