Does a separate mains spur for hifi make a difference?
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Pterodactyl
pfm Member
Thanks - you have tried a lot of the main ways of doing this.
I suppose the only reason why you might not have got an audible result might be that in both cases the houses were rewired and so had much better than average wiring already??
My house was built in the mid-80s from materials and construction that were not of the highest quality, so I suspect the cables they used were cheap and that they were not as carefully installed as one would hope.
Mike Reed
pfm Member
Then you know the drill...........
9 pp ain't bad for a cable or mains thread.I'd be surprised if the wiring is as substandard as the house except inasmuch as you may still have fuse boards but that's easily sorted. Your question about 'how many lines' was, I believe, misconstrued. I think you meant circuits but Tiggers thought you meant sockets. His radial (10mm2) was, it seems, the first, before the rewire. The second, the ring of 2.5 mm2 would have been inadequate and I would have doubted a difference; after all, nothing was dedicated. Also, I've no idea of the kit involved, which can have a bearing on results.
topa
Sans CDPs
Some feedback on my earthing side topic:
I had a dedicated earth rod installed now, 8m deep into theoretically ideal solid and damp clay earth.
I don't know what size unit we are talking about here, but the electrician measured the result an came up with 50-60. (milli-Ohm?)
He shook his head and said anything above 10 is not ideal, although the worst house he has seen which had to rely on an earthing like this had over 300.
So I stopped it all and will use the normal earth, which measures "0".
Regards,
Tobi.
I had a dedicated earth rod installed now, 8m deep into theoretically ideal solid and damp clay earth.
I don't know what size unit we are talking about here, but the electrician measured the result an came up with 50-60. (milli-Ohm?)
He shook his head and said anything above 10 is not ideal, although the worst house he has seen which had to rely on an earthing like this had over 300.
So I stopped it all and will use the normal earth, which measures "0".
Regards,
Tobi.
Mike Reed
pfm Member
8 metres deep ??!!!? That's one heck of a hole; the height of a house, in fact. Must also have had a VERY long cable connection too. I guess that your normal house earth is TT (i.e. that it is already sunk into the ground and not bonded back to the grid (PME earth)) or your sparks wouldn't have installed it.
Surprise to me that an earthing spike can increase the existing impedance, though.
Surprise to me that an earthing spike can increase the existing impedance, though.
Pterodactyl
pfm Member
sorry to trouble you - there is, of course, always the option of staring at something that interests you instead
I assumed sockets as if he'd meant circuits I thought he'd have said circuits.
Just for clarity as you seem to have mixed things up
Install 1 - house rewired in 1980s, install done in 1990s. Ring circuit (6 double MK unswitched sockets) using 10mm cable off separate MCB in consumer unit.
Install 2 - house rewired in 2000s, install done at same time. Radial circuit with 8 radial 2.5mm cables (1 MK double socket on end of each) routed from separate 8 way consumer unit.
BTW in what way is 2.5 inadequate - it's used on nearly all ring mains in the UK for multiple sockets up to 32A draw. This was used with one socket off one MCB for equipment with a minimal current draw! Upsizing the cable just cannot make any difference IMO!
Anyway at the end of the day after my experiences I'm of the opinion it makes little or no difference, but if you can hear a difference then that's all that matters really.
@JimDog
- How many lines did you install? House 1 and 2: 1 dedicated HiFi circuit.
- Did you do rings or radials? House 1: radial, house 2: ring.
- How old was the wiring in your main house ring? House 1: perhaps 20 years, house 2: perhaps 5 years.
- Did you put in 10mm/2 cable in the dedicated lines? House 1: 10mm sq T&E, house 2: 4mm sq T&E
- Did you use a separate CU? House 1 I don't recall, I don't think so, house 2: no, dedicated circuit in the main consumer unit
- Did you plug your kit into the wall sockets afterwards, or use a power distribution block? House 1 & 2: wall sockets
- Was it done by a qualified electrician? House 1 yes, house 2 no, I did it myself, but then I was C&G qualified at the time just not a practising spark so not fully qualified
- I'm not being snarcy, but is your hearing ok? (A lot of hifi lovers are of an age where they suffer from hearing problems...) House 1 my hearing was defo reasonable, I was young (20s) and I recall e.g. a Bristol HiFi show where HN&RR did a listening test with something like a transistor Quad setup and a valve Quad setup into horn speakers and blind ABX testing, I comfortably spotted the difference but assumed it was a trick so put down the valvey smooth sound as the transistor system and the sharper sound as the valve system, I was completely wrong of course, but I was the only one in the room at the time to reliably spot the difference on all tracks, I just put them in the wrong order! So my hearing was better than the couple of dozen others in the room at the time I would suggest. I was young, impressionable, and if there was a difference I wanted to hear it. House 2 I am now mid 40s, my hearing is not what it was, I am a little less easy to convince I hear differences than I was in house 1 too! Houses 1.1 and 1.2 did not get a separate HiFi circuit I don't think, though house 1.1 was compeltely rewired so I might have? Now I just made myself look senile ... I can't remember.
Darth Vader
From the Dark Side
No its not inadeqate and wouldn't be installed if it was. This cable is rated at 18.5A which is more than enough for HiFi. As you say its also the major wire for a 32A ring main as you are then effectively using two parallel cable runs so the rating is then 37A with a 32 breaker.
And as you say it'll make zero difference to HiFi kit.
Cheers,
DV
My point being that the nays are unlikely to be swayed by the ayes
martin clark
pinko bodger
Spikes in the ground are very poor compared with an incoming wired earth by the supplier (that is essentially a dedicated cable back to the substation’s Neutral)
One project I was involved in had a new 1.5 MVA substation and its own genset, and the design earth solution for bonding was a large copper mat laid in/below the enclosure; but site measurements showed it wouldn’t be good enough and so the local earth ‘spike’ required turned out to be 120 metre depth bored with a continuous 120mm dia casing driven into it - quite expensive...!
Mike Reed
pfm Member
I assumed sockets as if he'd meant circuits I thought he'd have said circuits.
Just for clarity as you seem to have mixed things up
Install 1 - house rewired in 1980s, install done in 1990s. Ring circuit (6 double MK unswitched sockets) using 10mm cable off separate MCB in consumer unit.
Install 2 - house rewired in 2000s, install done at same time. Radial circuit with 8 radial 2.5mm cables (1 MK double socket on end of each) routed from separate 8 way consumer unit.
Yes, got that completely arse about face; also makes more sense ! 8 x 2.5mm2 radials to separate c.u.; presumably one for each piece of kit. Good stuff. I also have 8 (6x 10 and 2 x 6mm2) and one to each piece but it's almost certainly overkill, although impedance might be marginally lower. However, I don't use extra connections like sockets/plugs. Do you have separate RCBOs or MCBs covered by RCD ?
BTW in what way is 2.5 inadequate - it's used on nearly all ring mains in the UK for multiple sockets up to 32A draw
See above; I thought you meant the ring with all those sockets connected. Sorry, should have copied your text individually.
Mike Reed
pfm Member
My point being that the nays are unlikely to be swayed by the ayes
'Twas always thus. Just another piece of hifi controversy. On dedicated mains, it's usually the technical (scientific?) among us who are the 'nayes'. The 'ayes' comprise those who've installed it, appreciated the difference and considered it very good v.f.m. in the upgrade stakes, as it affects all connected items rather than the usual kit upgrade.
Then there are those who are on a learning curve and interested and those who only tune in to nay-say from a technical high point.
There has, however not been one forum poster that I've read over the 14 odd years who has said it makes the hifi sound worse. No practical downside then.
Andrew C!
Been around a while....
Agreed.
topa
Sans CDPs
No, the rod is 8m, no digging involved. Imagine this like drilling for oil, although its not drilled but rammed. Anyway, you take a 1m rod, drill/ram in into the earth, connect the next 1m part, drill/ram further and so on.
You could go a lot deeper than 8m, but I was told with the sort of damp clay we have here 5m would be enough. So I told them to do just a bit more than 5m.
westsea
Retirement present
There has, however not been one forum poster that I've read over the 14 odd years who has said it makes the hifi sound worse. No practical downside then.[/QUOTE]
True, but not a very good argument for installing radials, maybe something like 70 to 80% of users found a significant improvement in ...dynamic range, presence, midrange clarity....etc would carry more weight
I have to confess the engineer in me just finds it difficult to believe or justify. Kind of inadvertantly I have some hi fi connected radially in my attic rooms, in the next week or so this will be converted to a ring main, should I expect a reduction in sound quality? It is all 2.5mm sq. At the risk of giving offence I can't understand the suggestion of 10mm sq cables to feed hi fi, Ok for a 9kw shower, but not for 300/700 watts of hi fi.
Apologies, just remembered Arkless has been through this previously
True, but not a very good argument for installing radials, maybe something like 70 to 80% of users found a significant improvement in ...dynamic range, presence, midrange clarity....etc would carry more weight
I have to confess the engineer in me just finds it difficult to believe or justify. Kind of inadvertantly I have some hi fi connected radially in my attic rooms, in the next week or so this will be converted to a ring main, should I expect a reduction in sound quality? It is all 2.5mm sq. At the risk of giving offence I can't understand the suggestion of 10mm sq cables to feed hi fi, Ok for a 9kw shower, but not for 300/700 watts of hi fi.
Apologies, just remembered Arkless has been through this previously
Mike Reed
pfm Member
Indeed, it never was a prima facie consideration, but comforting nonetheless, surely.
How do you convert radials to a ring, and why would you want to ? I'd imagine that your attic room is rather a long way from the incoming, so maybe you mean change to the existing ring ?
Yes, probably overkill, but what the hell ! As I said above, there may be a very slight reduction in impedance. However, if you only have one radial circuit to feed a number of hifi pieces, I'd say that 10mm2 t & e is de rigeur, and why not for the marginal difference in cost relative to the kit in situ?
The ubiquitous Jez has been through most things which deviate from established engineering/technical rules, as is his wont.
westsea
Retirement present
Mike Reed
It was not my intention to enter into a debate but to answer your points in order.
but comforting nonetheless, surely
Comforting, and technically within regulation, but not common practice in this country except for high power requirements. Could be hazardous for DIY enthusiasts without proper understanding/technical competence. As previously said by others design and installation requires a competent person to implement.
How do you convert radials to a ring
The loft is a large space without doors (fire regulations are onerous) presently served by one radial with several outlets, plan is to extend round the whole space back to the consumer unit in 2.5mm2, I think that makes a ring main.
Yes, probably overkill
Sometimes in overkill leads to complacency, with unintended consequences.
The ubiquitous Jez has been through most things which deviate from established engineering/technical rules, as is his wont.
Jez is a very competent engineer, his approach is sometimes a little terse, but I can understand his exasperation. He rightly challenges deviation from established engineering / technical rules or practices, and I quite understand the desire to develop new techniques and solutions, but the technical appraisal along with the rules and regulations are serve a very real purpose.
My main concern is that encouraging the stretching of the 'rules' in the case of mains electricity can be hazardous, particularly when many do not understand the full implications of what they do
Like you I have stretched the rules sometimes, but only in particular circumstances, and with the clear knowledge of the risks and benefit.
It was not my intention to enter into a debate but to answer your points in order.
but comforting nonetheless, surely
Comforting, and technically within regulation, but not common practice in this country except for high power requirements. Could be hazardous for DIY enthusiasts without proper understanding/technical competence. As previously said by others design and installation requires a competent person to implement.
How do you convert radials to a ring
The loft is a large space without doors (fire regulations are onerous) presently served by one radial with several outlets, plan is to extend round the whole space back to the consumer unit in 2.5mm2, I think that makes a ring main.
Yes, probably overkill
Sometimes in overkill leads to complacency, with unintended consequences.
The ubiquitous Jez has been through most things which deviate from established engineering/technical rules, as is his wont.
Jez is a very competent engineer, his approach is sometimes a little terse, but I can understand his exasperation. He rightly challenges deviation from established engineering / technical rules or practices, and I quite understand the desire to develop new techniques and solutions, but the technical appraisal along with the rules and regulations are serve a very real purpose.
My main concern is that encouraging the stretching of the 'rules' in the case of mains electricity can be hazardous, particularly when many do not understand the full implications of what they do
Like you I have stretched the rules sometimes, but only in particular circumstances, and with the clear knowledge of the risks and benefit.