[AngelEyes]

Hi Chaps,

I have bought a few new toys recently and realise I may have issues with my power requirements.

I have 4 wall sockets and previously had the power hungry items such as the Cinepro and Onkyo on a wall socket and then all the other gear on two 'supermarket' 6 way distribution boards.

I now have 4 more power amps and at east one is going to be reasonably hungry.

Is it safe / sensible to put power amps on these kind of cheap distribution boards or should I invest in something better and if so what?

Or am I simply asking for trouble?

Thanks,

Adam

[Tone-uk]

If the power strip is 13 amps then the maximum wattage possible is 2990 watts @230 volts. (230v x 13amps).

I would add up the total power consumption of each of you components and see what the totals are. I have always kept things at around 2000 watts - don't really know why!!

(Watts/volts = amps and watts/amps = volts)

[AngelEyes]

Ok, that doesn't sound as bad as I thought then, thanks.

Adam

[lbstyling]

a amplifier that has a 400w output per channel doesnt usualy draw anything like 400w when turned up to the max most of the time because of the duty cycle. during the 'dead time' a amplifier charges capacitance banks giving a averaged power consumption from the wall- typically from music this is less than 30% of peak delivery.

in short--no worries

of interest- this is why class A amplifiers generate so much heat, because the transistors draw large amounts of power even when not in use, because they dont switch off inbitween cycles- they use double the energy -this stops switching noise and transient distortions, giving a good square wave in bench tests.

[alexs2]

Originally Posted by lbstyling

a amplifier that has a 400w output per channel doesnt usualy draw anything like 400w when turned up to the max most of the time because of the duty cycle. during the 'dead time' a amplifier charges capacitance banks giving a averaged power consumption from the wall- typically from music this is less than 30% of peak delivery.

in short--no worries

of interest- this is why class A amplifiers generate so much heat, because the transistors draw large amounts of power even when not in use, because they dont switch off inbitween cycles- they use double the energy -this stops switching noise and transient distortions, giving a good square wave in bench tests.

The peak efficiency of most Class A amps is less than 25%,and for a single ended Class A,even less than that.

The end result is that a 100W Class A amp can easily draw over 400W at idle,and obviously this will not rise,until the Class A level is exceeded and the amp enters Class A/B(as with the old Krells and Levinsons).

As an example,my KMAs draw around 500W each,and dissipate around 400W of heat,but at switch on,the current draw is not far short of 13A transiently,when the PSU caps charge initially.

[lbstyling]

Originally Posted by alexs2

The peak efficiency of most Class A amps is less than 25%,and for a single ended Class A,even less than that.

The end result is that a 100W Class A amp can easily draw over 400W at idle,and obviously this will not rise,until the Class A level is exceeded and the amp enters Class A/B(as with the old Krells and Levinsons).

As an example,my KMAs draw around 500W each,and dissipate around 400W of heat,but at switch on,the current draw is not far short of 13A transiently,when the PSU caps charge initially.

this actually agrees with my post.-but- im not talking about a test bench situation, please read it carefully.

[severnsource]

If you're being pedantic the maximum efficiency of a push-pull class A amplifier is 50%, 25% for single ended. That is only into the designed for impedance and in practice will be less owing to various unavoidable voltage drops.

And as there are no commercial amplifiers that are actually class A it is of theoretical interest only.

[paulst10]

Originally Posted by AngelEyes

I now have 4 more power amps and at east one is going to be reasonably hungry.

Do tell more what have you bought ?

[stevefish69]

Originally Posted by alexs2

As an example,my KMAs draw around 500W each,and dissipate around 400W of heat,but at switch on,the current draw is not far short of 13A transiently,when the PSU caps charge initially.

Adam - Have you not noticed your lights dimming when you first fire up the Cinepro until the caps are charged. Once it's it's on, i've never noticed my energy meter go through the roof though and certainly nowhere near its 2400w input as stated on the side

I've personally always tried to get the power amps and Sub's on dedicated sockets but did have my two Parasounds briefly hooked up on a 8 way anti-spike thingy with no problems. This was along with the Plasma, Processor, CDP, EQ1, PS3, Sky HD and XE1. Still never blew the 13amp fuse even at reference.

Have you considered making your own (cheap) distribution panel using a few MK unswitched sockets mounted on a board with some 4mm cable making a mini ring main within. This could either be hooked up direct to the rear of an existing socket, connected using a nice 13amp plug or better still have the two ends of the ring running direct back to a dedicated MCB if near the fuseboard.

[lbstyling]

Originally Posted by severnsource

If you're being pedantic the maximum efficiency of a push-pull class A amplifier is 50%, 25% for single ended. That is only into the designed for impedance and in practice will be less owing to various unavoidable voltage drops.

And as there are no commercial amplifiers that are actually class A it is of theoretical interest only.

my post was structured around duty cycle- ie, if you get transient peaks of 400w, the caps absorb this and average it out, with the actual draw remaining several orders of magnitude less.
most musical information is at 1 or 2 watts at a highish playback level- the rest is all dynamics.

[IWC Dopplel]

Reading other posts and experimenting with dedicated earths I am about to have a dedicated spur to each unit in my cinema room totally seprarate from the rest of the house. Cabling will be 35mm sq to distribution board and 6mm sq 40 amp cable to each unit. Very low impedence, power supply to the units is as important as power supply in them

You will see a picture of the cabling ready for install compared to stock

[Nic Rhodes]

I have a dedicate ring main to a separate distribution board, note ring. I never have any issue wrt to power loading specs (and not 3kw limited for the ring) and have a huge number of devices on local 8 way Belkin distribution blocks (something like 8 of them). More importantly the noise on the mains (even before the Belkin distribution blocks) is VERY VERY low. In fact so low sniffers had to be returned to manufacturers for checking. It makes a difference

[Medrep1]

I have a dedicated spur, going to unswitched M&K sockets.

I recently had an isotek sigma on loan. I found it took away some slight harshness to the top end, which was a good thing, but it really took away the dynamics from the music. This was only really noticeable when using it on the class D amp?

Could the fact that the main power supply was good enough to warrant the isotek unnecessary, to the point of having a negative impact?

[IWC Dopplel]

Originally Posted by Nic Rhodes

I have a dedicate ring main to a separate distribution board, note ring. I never have any issue wrt to power loading specs (and not 3kw limited for the ring) and have a huge number of devices on local 8 way Belkin distribution blocks (something like 8 of them). More importantly the noise on the mains (even before the Belkin distribution blocks) is VERY VERY low. In fact so low sniffers had to be returned to manufacturers for checking. It makes a difference

Nic, those that have done the experiments have found sonic benefits from not operating rings but using separate spurs. But a difficult one to test. This could be from the better earthing potential from spurs.

I will be able to see if a dedicated supply with star earthing to each component and very low impedance makes a big difference. Most domestic mains uses 2.5mm sq cabling I will be using 35 to the board and 6 to each unit with equal length cables.

I have tried a lot of power supply conditioners, transformers and recently spent a weekend with the big Isotek. All conditioners I have tried slug dynamics (I am told this is related to mains impedance) and some do improve the isolation from mains junk. If you have a dedicated mains supply and separate earthing this will be a 'cleaner' solution.

[Medrep1]

I have tried a lot of power supply conditioners, transformers and recently spent a weekend with the big Isotek. All conditioners I have tried slug dynamics (I am told this is related to mains impedance) and some do improve the isolation from mains junk. If you have a dedicated mains supply and separate earthing this will be a 'cleaner' solution.

Interesting. Could this mean then that people are better off spending a few hundred getting a dedicated spur, as opposed to spending silly money on conditioners etc?

Im about to embark on setting up a new listening room in the house, albeit a bit smaller, but I am looking to do the seperate spur again?

I will follow your posts with interest IWC..........

[IWC Dopplel]

Originally Posted by Medrep1

Interesting. Could this mean then that people are better off spending a few hundred getting a dedicated spur, as opposed to spending silly money on conditioners etc?

Im about to embark on setting up a new listening room in the house, albeit a bit smaller, but I am looking to do the seperate spur again?

I will follow your posts with interest IWC..........

The 'best' set up is a variation on a big incomer ( 100amp ) then with big tails to a dedicated hifi consumer unit and each plug is fed by 6mm sqrd cable from a separate spur. The spurs should be as close as possible to equal length. From what I have read people have tried bigger with little advantage but smaller shows compromised performance. Then each unit fed by at least 4mm sq cable from plug to IEC. The best is 6mm sq

My compromise is to mount the consumer unit in my cinema room but I have fed it with a very serious 35mm squared cable (I did need a commercial metal clad distribution unit as the cable was too thick for a domestic !)

The total cost for me has been something like £650 on commercial distribution units, 32amp MCB's and cables (including enough to make 12 4m cables for equipment leads) £600 or so on labour and fitting a big incoming fuse, new tails and cleats etc. There were three electricians one afternoon and one builder to fit the monster 35mmsq cable. Oyaide IEC's account for £400 for 12, a very good deal and they are superb. So it will be some £2k all done I suspect including three dedicated earth spikes.

So this is something like £150 per mains lead all done. Look in the catalogues and anything with Oyaide connectors is more than this........ Then people plug it into a 2.5mmsq ring main with poor earthing and lots of RF dumped on it from everything else in the house.

Drop me a PM if you need any more info MOD COMMENT email address removed.

[Medrep1]

Fantastic, that sounds like a serious rig there. I dont have the level of kit you have, so my power requierements are 'a little less'

Thanks for taking the time to reply. I will take a look into this further later in the week.

[Nic Rhodes]

Originally Posted by IWC Dopplel

Nic, those that have done the experiments have found sonic benefits from not operating rings but using separate spurs. But a difficult one to test. This could be from the better earthing potential from spurs.

I will be able to see if a dedicated supply with star earthing to each component and very low impedance makes a big difference. Most domestic mains uses 2.5mm sq cabling I will be using 35 to the board and 6 to each unit with equal length cables.

I have tried a lot of power supply conditioners, transformers and recently spent a weekend with the big Isotek. All conditioners I have tried slug dynamics (I am told this is related to mains impedance) and some do improve the isolation from mains junk. If you have a dedicated mains supply and separate earthing this will be a 'cleaner' solution.

Not everyone agrees with that spur theory though, I have astonishing clean PS and I use a ring (with no dedicated earth needed), in fact pros who have seen it say they have never come across anything as quiet electrically by a long way (but I have high voltages). I just do the basics correctly with no filtering.

[IWC Dopplel]

Originally Posted by Nic Rhodes

Not everyone agrees with that spur theory though, I have astonishing clean PS and I use a ring (with no dedicated earth needed), in fact pros who have seen it say they have never come across anything as quiet electrically by a long way (but I have high voltages). I just do the basics correctly with no filtering.

I did read a very interesting Hifi News technical article some 10 years old that showed poor internal earthing could easily show a measured drop of 30+db some units from memory where 50 db in signal to noise ratio when potential differences seen in systems between earthing points. I summised this might lead to advantages from dedicated star earthing with the supply.

I have certainly found sonic differences from fitting a dedicated earth spike to a ring main.

[Avi]

Originally Posted by IWC Dopplel

I did read a very interesting Hifi News technical article some 10 years old that showed poor internal earthing could easily show a measured drop of 30+db some units from memory where 50 db in signal to noise ratio when potential differences seen in systems between earthing points. I summised this might lead to advantages from dedicated star earthing with the supply.

I have certainly found sonic differences from fitting a dedicated earth spike to a ring main.

How does this relate to complete systems or items of equipment that are designed not to require an external earth ?

AVI

[Welwynnick]

Originally Posted by IWC Dopplel

Drop me a PM if you need any more info **********@mac.com

Hi Adrian,

I REALLY wouldn't post your email address on the internet.

Nick

[alexs2]

Originally Posted by welwynnick

Hi Adrian,

I REALLY wouldn't post your email address on the internet.

Nick

I've removed it...thanks

[IWC Dopplel]

Originally Posted by welwynnick

Hi Adrian,

I REALLY wouldn't post your email address on the internet.

Nick

Tks

[IWC Dopplel]

Originally Posted by Avi

How does this relate to complete systems or items of equipment that are designed not to require an external earth ?

AVI

I will dig out the article, it was testing actual components and the real life impact of small differences in earth potential at various points of external earthing (mains, signal etc)

The reality seemed to be that most components don't deliver what they are capable of because of their poor internal earthing and lack of ability to deal with small external earthing potential differences (In a perfect world ofcourse it shouldn't matter) From memory the worst offender was a TAg processor

[lbstyling]

Originally Posted by IWC Dopplel

I will dig out the article, it was testing actual components and the real life impact of small differences in earth potential at various points of external earthing (mains, signal etc)

The reality seemed to be that most components don't deliver what they are capable of because of their poor internal earthing and lack of ability to deal with small external earthing potential differences (In a perfect world ofcourse it shouldn't matter) From memory the worst offender was a TAg processor

agreed.
this is true within the components themselves- its acceptable practice to use the chassis as a common earth net to connect all internal boards to- the problem is that steal realy isnt a good choice when your looking for the highest conductivity to increase the pd between the component board and ultimatly the ground.

this is the reason for the obsession with copper plateing the chassis on marantz gear.
balanced connectors are also of use here- but not the whole answer themselves.
im not suggesting it -but i have heard of companys silver plateing a chassis as a modification on high end equipment.
a easy improvment start would be to change the earth riing connectors with copper ones- at least you get a good connection then!!

iwc- have you looked into a balanced supply (2 transformers connected together) for a 'never connected' supply?

[IWC Dopplel]

I thought I would give an update

Well it's all been in for a few weeks now and I am very happy, the dynamics and fluidity and 'want to play more music' is in a different league than before.

I have gone back the the ring main to see how things sound and it has made a big and somewhat fundamental difference.

There is an effortlessness that isn't there on the ring main, the sound is cleaner and 'darker' in the sense that the music seems to come from nowhere in a very tangible and believable way. Voices on two channel have more projection and body, bass weight is improved and transients are much better. The foundation of the music is better. You notice the background 'hash' that has been removed or reduced and the clean transparency that was somehow veiled before. Have a look through this web site, it makes sense under 'mains stuff'

Just one thing about music - when it hits you feel no pain

It's a relatively cheap upgrade



I am going to dem it to AV friends this week, snow allowing.

[IWC Dopplel]

As my units all run on dedicated lines with iec connections I wanted to run one line for small plugs that are not suitable for an iec (eg the 8033 unit or the Dac magic).

I have managed to find an extention unit that is SUPERB, cheap and perfect for the job. I will connect it up from a 6mm2 dedicated line, and I will be able to star earth to the incoming earth and rewire the unit with 6mm cabling.

It comes with 2.5mm cabling, so ideal for those who simply want a good, no compromise low impedence extension unit.

I have a Russ Andrews 'low impedence' extension that is frankly noddy in comparison and I will sell, especially as this unit was £92........ See the inside, a thin printed circuit vs nice hardwired solid sockets for the Olson

Check this place out the unit you see was specced with no lead, in black, no switches and no light. It was about £40......

Standard Range

[AngelEyes]

Thanks for the very interesting discussion so far. I am certainly considering having a dedicated spur for my kit.

One thing that puzzles me is what happens if the supply arriving at your house is 'inferior'?

I live in a rural location and am second from last on this line. The last house is a farm and during harvest when the grain store starts up I notice the lights here dim a bit.

I also have the remnants of an economy7 system in the consumer unit and at midnight every night I hear a click and the lights dim for a second.

It may not be worth me going to the expense?

Adam

[IWC Dopplel]

Angel Eyes, hi

I really can't answer the question, but in term of context it's more than say changing speaker cable and interconnects. It seems more fundamental than that.

It does sound like a layer has been removed and their is more resolution, but this is done as well as adding body, weight and scale. All I know is if and when I move I will do it again. Dynamics are really superb

If your Consumer unit is close to the system (so you can wire internally then, the cost will be a lot less. Reading more on this it would seem 10mm2 from unit to back of socket, then 6mm2 from 13A plugs to unit.

Consumer unit's are £80 or so, MCB (circuit breakers £12-15), 6mm flexible cable for mains leads £2.50/m, 10mm2 twin and earth is £50 for a 50m reel.

To get the full install to the equipment sockets with a 100 amp incomer (if yours is 60) should be in the hundreds.

Some of the largest costs are termination of 6mm cabling into plugs and IEC's .....

[IWC Dopplel]

I have wired in the extension and replaced the internal wiring with 6mm2 and star earthed all fed through from a separate spur, this will be for DAC magic 8033 and non iec units

12 dedicated individual spurs with iec's plus one with 4 sockets