Powering the Power Amp

I've tried a few blocks in the past and they've never been much good. Plugging into that wall has, by definition, got to be better as you are removing a load of gubbins from the loop. One of my reasons for choosing the system that I have is because it only needs two mains leads. I have a double socket on the end of a 10mm spur, into which the two Powerlines are plugged. It's harder with bigger systems of course, but the answer is to get an electrician to add more sockets. Of course, one doesn't get the cryogenic treated eddy current defeating circuitry and wiring made from single stands of extra virgin copper that of course fully justify the mumbo jumbo spin around expensive blocks.

And going from a single radial circuit to one for each piece of kit was a huge upgrade, as was the upgrade from 6mm to 10mm mains cables. Then there was the consumer unit, and that gave the biggest surprise of all, that different makes of consumer unit affected the sound quality.

i must admit this surprises me a bit, although i can understand that a mains block may introduce its own problems -- but it would do so for all components and not just the power amp (NAP500 in this case). i dont know whether John or Michael tried to plug the 500 to another socket on the block? 

i know for sure that plug sequence on the block has a fundamental influence on sound -- well, it did so, disastrously when i got it wrong - when i was using a high quality Olsen block.

Now i have 5 double sockets connected to the 10mm radial and i dont have to worry about sequence issues as each socket is electrically more or less the same because of the way its wired. Well, theoretically anyhow... :-)

enjoy

ken

I think the issue is that you still need to have a 'sequence' to the plug-in, as the 'problems' with mains are not so much to do with what is getting into your HiFi from outside, but what your HiFi power supplies does to the mains. Being aware of this issue for a few years and also the origin of Mike and JN's experience, I have a few views on it I've previously posted, so will not go through it all over again here in detail, but will sum-up essentials below.

Essentially the most noise is injected into the HiFi by the equipment demanding the most dynamic power - the power Amp - the rectifiers essentially presents a short-circuit across the mains and 'bites' into the waveform distorting it for everything else seeing it. If you have some inductance (proportional in part to lead length) presented in the way of leads between the power amps and the other equipment mains plugs then the high-frequency parts of this get some rounding-off, so do not presume smallest leads will sound best. Many years ago I tried ultra-short mains leads direct into directly-wired sockets and it was awful.

There is in fact a low-frequency resonant circuit set-up between all the linear supply transformers that become open when the rectifiers are 'on' and conducting and it has an impact on the sound. Many will get rather animated at this explanation as it makes the theory that all you need to consider is resistance of the mains partial at best - but real life has reactive components that are modeled by inductance and capacitance.

It took me a long while before I could accept what I heard was actually the case, as I wanted it to be different and simple, but it isn't. Empirically I found putting the Power Amp(s) on the wall, then grouping all other items off on their own 'quieter' block and sequencing them on that worked best, so that is what I use - and demonstrated it to Mike on his system - to his liking, now John's as well it seems.

Others have found other solutions work better for them - since it is easy to try it is easy to find what you prefer.

DB.

Power Amps, because they operate mainly in class B, impart the speaker drive current back into the main current drawn for that - and onto any leads that have resistance (all leads), so not having it run through the mains-block power lead that feeds the rest of the class A equipment (sources and Pre), means that does not incur that problem.

It is surprising it works, but experiment shows it does - for some people anyway.

DB.

very interesting. i dont doubt for a moment that you are hearing the difference that you describe but i am not sure i fully understand the explanations - but hey, what do i know?...

enjoy

ken

DB,

Thanks for this. I am goingto be addressing a v.mild ground loop over the next few days and I will also keep your observations in mind.

M

ken c posted:

very interesting. i don't doubt for a moment that you are hearing the difference that you describe but i am not sure i fully understand the explanations - but hey, what do i know?...

You know about as much as me. 
My opinion is more a possible hypothesis based on empirical results I've heard to date. It may work for other reasons, but it does seem to work.

If the mains socket were a perfect theoretical zero-impedance Voltage Source (none exist) then the problem would not exist. The fact it is a huge mesh of wiring with multiple taps, largely un-screened and with a finite complex resistance means there are effects. The Equipment 'talks' back into the mains to an extent that probably only really matters in any significant way for HiFi. The low-frequency bandwidth, dynamic range and noise floor of a good HiFi means there are more chances of these things getting through.
Otherwise all the DR Power upgrades would be unnecessary.
Nothing is perfect and if all the Power supplies were more perfect then there may be fewer problems - perhaps - maybe....

But in meantime I want the best from what I have - and it don't cost anything to try different mains plug-in, apart from pride and loss of satisfaction that you thought you understood the Universe. Usually I find the Universe always wins.

DB.

I went for individual radials to separate wall sockets as I wasn't keen on using a distribution block. Works for me.

Steve J posted:

I went for individual radials to separate wall sockets as I wasn't keen on using a distribution block. Works for me.

Steve,

i'm assuming your individual radials have a fuse each at the Consumer Unit, and you have [more than one] double-gang 13A MK unswitched sockets at other?, if so, are these sockets also connected to each other by a additional earth wire?

This looks like the way i'm going, very recently swopped out my trusty maplins delta plug for naim power-lines using the same double-gang socket for the 552 and 500. My radikal [which powers both Urika and LP12] is now plugged into the ordinary house ring main but this arrangement has brought nice benefits to the vinyl playing.

However, my CDS3 is presently plugged into my 2nd radial circuit which is separate from the 552/500 circuit, but this arrangement seems to have lessened the CD performance play - it just sounds slightly off, lacking it's usual natural ambiance and magic. My theory is that the CDS3 don't like the separation from the amp socket and the addition of an earth connection to join the CDS dedicated socket to the 552/500 socket should do the trick. Easy to do, the hardest part will be shifting all the components and fraim out the way to get to where the sockets are : )

Debs

Pleased to read that John has found moving the 500PS directly to the wall beneficial leaving the Pre and source equipment on the block. Thanks to Gary for suggesting this originally, it is definitely worth trying as it costs nothing.  Like you Debs, I  have gone one step further and removed the Linn Radikal (with its switched mode power supply)  powering the Urika  and LP12 from the block and plugged this directly into the main house ring circuit. So now I have the 552PS 2x 555PS and NDX in the Musicworks block. Ken in this order from the socket nearest the input of the block, 552PS, 555PS (Analogue), 555PS (Digital), Spare, Spare, NDX. I have found this combo to sound best in my system.. it may not be the same for others of course, but listening will tell... see what you prefer.

Michael posted:

... Ken in this order from the socket nearest the input of the block, 552PS, 555PS (Analogue), 555PS (Digital), Spare, Spare, NDX. I have found this combo to sound best in my system.. it may not be the same for others of course, but listening will tell... see what you prefer.

when i was using a block, thats more or less the order i had -- with power amps at the end -- furthest away from the block mains connection.

enjoy...

ken

Debs, 

I have multiple 10mm radials, one for each piece of kit, each on their own 32a mcb. When installing them I made sure each was identical in both length and cable direction. I also linked each together at the socket end with 4mm earth wire as I believe this gives the star earthing principle that seems important to naim kit.

Thanks for your confirmation Mr Happy,

The sockets are of course already earthed on the fuse box busbar but the nature of multiple radial circuits being used to supply each naim component individually may hamper the infamous star earthing principle if the individual sockets are not directly connected to each other with additional earth wiring.

It's funny how the Linn Radikal performs so well on the house ring main, i don't pretend to understand it : )

Debs

I had missed this in the past so thank you John for bringing it up again. I have given the 500 it's own dedicated spur plug this evening and I detect maybe a bit of increased air and clarity. Too early to say but what's to lose? I'll flip it back next week and see if I can hear a difference.