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Does a separate mains spur for hifi make a difference?

I can definitely detect a change in sound quality after round 11pm on my system. Firstly it plays slightly louder and the resolution seems to improve. I think this is due to the mains voltage slightly increasing due to decrease in load.
This isn't actually going to make a significant difference, it's not physically possible. Mains voltage is fixed in law and has a tolerance that may not be exceeded. You then step this down inside your kit so any variation is multiplied down by the transformers converting 240V ac to (say) 40-0-40 Vac. This is rectified to dc and smoothed by the reservoir capacitors. You probably then have regulators that stabilise the voltage again, so even if there were a positive variation on the mains supply it would be ironed out by the regulators. In any case it's easy to test your mains voltage and establish whether you have indeed got any variation, a multimeter costing £10 will do it. I will stake money on it being within a couple of volts for the whole 24h. A 6 x stepdown transformer (240 to 40 is dividing by 6) will mean that a 1V variation at the input will be 1/6 of this on the secondary. Even an unregulated circuit is not going to notice this, if it were so sensitive to input voltage it would sound dreadful as the rail voltage will rise and fall by fractions of a volt on any amplifier according to amplifier load. Yours is a reasonable hypothesis but it doesn't stand up to any scrutiny. Don't just take my word for it, get a tester and measure it.
 
There's probably no definitive answer as if one person does this and thinks it's better and someone else does it, but doesn't they are both right in terms of their own experiences. I have tried it in two of my properties, but I could never hear the difference so I don't bother now. I understand more than many about mains supplies and I have to be honest and say that from a physics perspective I can't really see how it can make a difference given the quality of most supplies.
 
This isn't actually going to make a significant difference, it's not physically possible. Mains voltage is fixed in law and has a tolerance that may not be exceeded. You then step this down inside your kit so any variation is multiplied down by the transformers converting 240V ac to (say) 40-0-40 Vac. This is rectified to dc and smoothed by the reservoir capacitors. You probably then have regulators that stabilise the voltage again, so even if there were a positive variation on the mains supply it would be ironed out by the regulators. In any case it's easy to test your mains voltage and establish whether you have indeed got any variation, a multimeter costing £10 will do it. I will stake money on it being within a couple of volts for the whole 24h. A 6 x stepdown transformer (240 to 40 is dividing by 6) will mean that a 1V variation at the input will be 1/6 of this on the secondary. Even an unregulated circuit is not going to notice this, if it were so sensitive to input voltage it would sound dreadful as the rail voltage will rise and fall by fractions of a volt on any amplifier according to amplifier load. Yours is a reasonable hypothesis but it doesn't stand up to any scrutiny. Don't just take my word for it, get a tester and measure it.

I've always put a system sounding better late at night to a combination of alcohol and lower ambient noise.

Incidentally my system sounds louder - for a given volume setting - first thing in a morning after I've got up compared to later in the day.
 
Incidentally my system sounds louder - for a given volume setting - first thing in a morning after I've got up compared to later in the day.
+1. I very rarely enjoy listening to music early in the day. I put this down to the fact that this is when my ears are most sensitive to sound. My hifi kit INVARIABLY sounds it best late at night, this is when I'm most able to suspend my disbelief and become fully immersed in the music and forget that it's being replayed through a chain of electronic devices.
 
I've always put a system sounding better late at night to a combination of alcohol and lower ambient noise.
A glass of red is always going to help! I am prepared to believe that there is less crud on the mains late at night. In the early evening everyone is at home cooking, turning kettles and central heating pumps on and off, and so on. I have first hand experience of frdiges and CH pumps putting audible clicks and farts on the mains as they come in and out, and I do know a friend who lives down a long lane with only one supply cable in for about 20 houses and is into car DIY is cursed by his neighbours every time he fires up a welder or the compressor. It messes up their TV picture.

Incidentally my system sounds louder - for a given volume setting - first thing in a morning after I've got up compared to later in the day.
That makes a lot of sense. Ears are not the linear devices that we like to think. Brains even less so, after you have spent 8 hours in near silence it is bound to sound louder.
 
This isn't actually going to make a significant difference, it's not physically possible. Mains voltage is fixed in law and has a tolerance that may not be exceeded. You then step this down inside your kit so any variation is multiplied down by the transformers converting 240V ac to (say) 40-0-40 Vac. This is rectified to dc and smoothed by the reservoir capacitors. You probably then have regulators that stabilise the voltage again, so even if there were a positive variation on the mains supply it would be ironed out by the regulators. In any case it's easy to test your mains voltage and establish whether you have indeed got any variation, a multimeter costing £10 will do it. I will stake money on it being within a couple of volts for the whole 24h. A 6 x stepdown transformer (240 to 40 is dividing by 6) will mean that a 1V variation at the input will be 1/6 of this on the secondary. Even an unregulated circuit is not going to notice this, if it were so sensitive to input voltage it would sound dreadful as the rail voltage will rise and fall by fractions of a volt on any amplifier according to amplifier load. Yours is a reasonable hypothesis but it doesn't stand up to any scrutiny. Don't just take my word for it, get a tester and measure it.

Not quite true, it's 230V +10% to -6%, so does change. However, not sure if this will make much difference.
 
I'll repeat what I just said in a similar thread... EVERYTHNIG said about mains quality effecting sound quality is total bunkum and entirely a product of expectation bias.... like so many other things in hi fi. All the things that are important never get discussed outside of diy areas etc as they are too technical for the lay user and mainly of relevance at the design and testing stage.
I would very happily demonstrate any of my amplifiers using an extension lead, plugged into another extension lead, then another etc and then the final one into the dirtiest mains supply available.
 
I'll repeat what I just said in a similar thread... EVERYTHNIG said about mains quality effecting sound quality is total bunkum and entirely a product of expectation bias.
What, including my fridge and CH pump and the audible clicks and farts? No it's not. That's measurable and repeatable. Get a 'scope on the mains and you can see it. Same goes for my mate and his massive inductive load every time he fires up his welder and the neighbours curse the TV going funny.
 
What, including my fridge and CH pump and the audible clicks and farts? No it's not. That's measurable and repeatable. Get a 'scope on the mains and you can see it. Same goes for my mate and his massive inductive load every time he fires up his welder and the neighbours curse the TV going funny.

Yes it's measurable and repeatable and makes no difference. I would happily power up my system from the dirtiest mains around. I don't regard the odd click from a fridge etc as an issue personally. So long as it is AC and about the right voltage it will switch the rectifiers on at its peaks and troughs and dump volts into the smoothing caps. The worst that you will generally get is audible buzzing from the transformer but it doesn't effect what comes out of the speakers.
 
Yes it's measurable and repeatable and makes no difference. I would happily power up my system from the dirtiest mains around. I don't regard the odd click from a fridge etc as an issue personally.
Really? I certainly do! I noticed it when I started buying "proper" hifi, I bought a Quad 33/303 and that was very sensitive to the crud on the mains. Probably because it is a simple circuit with no filtering and a straightforward (unregulated AFAIK) PSU. I had to fit a suppressor to the fridge, which helped, and I got a fault fixed on the CH because it would have 3 or 4 goes at switching off the pump when the 'stat clicked off, and each one was accompanied by a fart through the speakers. After I'd had it fixed there was only the one fart per thermostat operation, but fart it did and it was a pain that I had to live with until I got a 44-405 that was more tolerant.
 
Unplugging your kit and plugging it back in again (cleaning the contacts like when doing rca swaps) will make as much difference as getting a new ring fitted, in my opinion(!)
 
Really? I certainly do! I noticed it when I started buying "proper" hifi, I bought a Quad 33/303 and that was very sensitive to the crud on the mains. Probably because it is a simple circuit with no filtering and a straightforward (unregulated AFAIK) PSU. I had to fit a suppressor to the fridge, which helped, and I got a fault fixed on the CH because it would have 3 or 4 goes at switching off the pump when the 'stat clicked off, and each one was accompanied by a fart through the speakers. After I'd had it fixed there was only the one fart per thermostat operation, but fart it did and it was a pain that I had to live with until I got a 44-405 that was more tolerant.
I think you are confusing RFI with dirty mains. Its not the same thing.

Cheers,

DV
 
And what about seperate earthing? In my new house, I could install a seperate earth rod straight into clay soil without much hassle, anyone ever tried that?
 
Really? I certainly do! I noticed it when I started buying "proper" hifi, I bought a Quad 33/303 and that was very sensitive to the crud on the mains. Probably because it is a simple circuit with no filtering and a straightforward (unregulated AFAIK) PSU. I had to fit a suppressor to the fridge, which helped, and I got a fault fixed on the CH because it would have 3 or 4 goes at switching off the pump when the 'stat clicked off, and each one was accompanied by a fart through the speakers. After I'd had it fixed there was only the one fart per thermostat operation, but fart it did and it was a pain that I had to live with until I got a 44-405 that was more tolerant.

33/303 are regulated. One of few power amps with a regulated supply (and, bizarrely, the negative rail is regulated). Much noise from contacts arcing etc is RFI.
No amount of spurs or anything else will have any effect on the mains entering your house. Only filtering or regeneration can have any effect. The type or make of cable is completely irrelevant. Bad mains waveform etc can effect synchronous motors in TT's etc, hence TT power supply's (actually very small mains regenerators) can have a beneficial effect.
Virtually everything not powered directly from AC (pretty much everything but TT's) is powered from its smoothing capacitors, which are topped up on the peaks and troughs of the mains waveform, and not from the mains directly.
The stepped down AC supply is only actually connected for around 5-20% of the time, when the voltage from the transformer secondary is greater than that on the smoothing caps. The caps are topped up by what could be described as "violent bangs" of power 100 times a second... there is nothing "smooth", "quiet" or linear about the way a typical PSU takes it's power from the mains.
 
Was your SQ good before you did your radials? So was it getting rid of a background problem, or adding to something that was already v good?

No idea, Jim. Whereas I've had modern dedicated mains here for nearly 2 decades, I installed them in previous houses going back to the late eighties, though with fuse boxes and (by modern standards) archaic fittings, I wonder if it made much difference with hindsight but it was something which just made sense at the time and since. Never suffered from clicks and pops though, despite old wiring and 23 rooms (but incl. cellars and loos!!!)

And what about separate earthing? In my new house, I could install a separate earth rod straight into clay soil without much hassle, anyone ever tried that?

Suggest you read my posts on previous page where I covered that scenario. If you mean NEW house (as in recently built), you may have a PME earthing arrangement. If so, and you stick an earth spike on it, you can potentially create a dangerous situation, I understand, where a major fault down the road on the same phase could come back to bite you, as it were.

Nobody so far has mentioned one of, and possibly the most important aspect of having a proper dedicated circuit as opposed to domestic rings, and that is in lowering the impedance, which can also be aided by an earth spike, grid or whatever (if safe). On some kit (Naim again, but probably other stuff), lowering impedance increases dynamics (or s.q. by another name). In theory (as I understand it), each connection, especially if dirty, increases impedance.
 
No idea, Jim. Whereas I've had modern dedicated mains here for nearly 2 decades, I installed them in previous houses going back to the late eighties, though with fuse boxes and (by modern standards) archaic fittings, I wonder if it made much difference with hindsight but it was something which just made sense at the time and since. Never suffered from clicks and pops though, despite old wiring and 23 rooms (but incl. cellars and loos!!!)



Suggest you read my posts on previous page where I covered that scenario. If you mean NEW house (as in recently built), you may have a PME earthing arrangement. If so, and you stick an earth spike on it, you can potentially create a dangerous situation, I understand, where a major fault down the road on the same phase could come back to bite you, as it were.

Nobody so far has mentioned one of, and possibly the most important aspect of having a proper dedicated circuit as opposed to domestic rings, and that is in lowering the impedance, which can also be aided by an earth spike, grid or whatever (if safe). On some kit (Naim again, but probably other stuff), lowering impedance increases dynamics (or s.q. by another name). In theory (as I understand it), each connection, especially if dirty, increases impedance.

Whilst a technical ground can be a good idea if done well enough, the impedance stuff is irrelevant as you are talking about things which may add or subtract say 0.01 Ohm and the transformer primary is more like 5 - 100 Ohms or more depending on VA etc. Beyond that the riveted connections inside IEC sockets, fuse holder, fuse, push on connectors, switch etc in a typical unit have considerably higher resistance than the heavy duty stuff in mains installations.
 
Whilst a technical ground can be a good idea if done well enough,

Can you expand on this, Jez ? What is a 'technical ground' and if it's a good idea, then what benefits can it bring ? All I know in domestic grounding is TT and PME earthing bonds or are we at angry porpoises * here ?

* (Sorry, cross purposes).
 
Can you expand on this, Jez ? What is a 'technical ground' and if it's a good idea, then what benefits can it bring ? All I know in domestic grounding is TT and PME earthing bonds or are we at angry porpoises * here ?

* (Sorry, cross purposes).

It's a separate ground for the audio gear, ideally something like an old metal water tank buried in damp soil or less good an earth rod. All grounds go back to this and so it keeps "ground bounce" noise from other appliances etc separate from the audio ground and can also help to avoid ground loops if used properly.
 


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