mains query...

with the talk of mains filters etc, I've got a query...

I know that depending on where you live the electricity will be good or bad and you can then upgrade your PSU's, buy mains filters etc...

how much benefit would be to totallt re-wire your house..?
just I was watching some home improvement show last week and the guys on there suggested that the home owner should totally rewire their gaff as the existing wires were about 50 years old (and dangerous- at a cost of 1400 quid) - would this be the first option to look at..? - I know it's not the cheapest...

I'm just curious thats all, just that the house Ilived in with my ex was built in 1855, and I only live down the road so I'm assuming that this would have been built around the same time...god knows how long the wires have been in there...

cheers

 

First of all a good mains supply is crucial. Similies have been used in the past to describe what connecting your equipment directly to an ac outlet is like; in short, it has been compared to connecting your drinking water supply to your sewage!

First thing to do is check your main consumer unit as this should be stamped with the last inspection date, usually on one of those green and white 'inspected by' stickers. There may even be a sticker or info. on who actually performed the test and inspection. This would give you your first port of call to ascertain how old the wiring is.

If you can not find any information to do the above I would suggest calling your local utility company(s) to see if they will perform an inspection on your household wiring. This used to be a free service, but not sure of costs these days.

Even if everything checks out OK, it would be desirable to think about having a dedicated ring installed just for your audio system but I am fully aware of the problems involved in running these in older buildings.

I was watching 'How Not To Decorate' on Friday and they had a similar situation where the home had to be totally re-wired, the electrician even stated he was surprised that the home had not burned down because the wiring was in such bad shape. They quoted around the £1500 mark, and I think it was a three-bedroom semi. But get your wiring checked out before starting any plans to do any kind of re-wiring.

 

These sort of analogous comparisons are usually put about by those with a vested interest in selling boutique power cables. Check the annual report from your local electricity supplier for a truer picture of the quality of supply.

Voltage/frequency deviations are typically minimal - other anomalies such as clipping can only be corrected by signal regeneration that in turn has disadvantages of its own. If the RFI bogeyman is scary then fit a ferrite to a mains lead!

IMO the best approach is to think locally and consider fitting a separate spur. This will largely negate the influence of locally produced mains harmonics (spurious frequencies at multiples of the original 50Hz) caused by other domestic appliances.

In the case of a complete re-wire it would certainly be a missed opportunity not to do so!

 

I would do as listeningear suggested, have a safety check (i think you have to pay now), and then decide. What ever way a dedicated spur is certainly worthwhile. Maybe after that some decent mains leads aswell, it all helps.
ferrite is not always good, it can kill dynamics, but for the cost it may be worth trying.

 

Does someone on here think that I am always trying provide subliminal buying ideas to exotic products?!!!

For the record I am not part of the industry just a music enthusiast who offer's my opinion and qualified conclusions of former trade contacts within the electronics and audio industry on various issues where I feel forum members can benefit. :MILD:

To agree with 'mosfet', I have to say that mains regeneration and even filters need to be considered carefully as most add another link in the chain in terms of the total systems sonic attributes, some adding very unpleasant characteristics.

I have conducted various mains tests over the years with both those in the sound engineering field and audio community and am of the opinion that as I previously stated, connecting straight to an ac mains supply would be like connecting your drinking water to your sewage!

By way of example: I lived in Reno, Nevada for four-years and it was common knowledge and readily publicised that that mains supply direct from the wall was extremely 'dirty'. In my capacity as Quality Systems Manager for the Americas for one of the largest semi-conductor distributors in the World we had tremendous problems in setting up our state of the art warehousing facility and programming centre with clean mains power.

Also, you only have to consider the electrical installation process for clean rooms, hospitals (especially operating rooms), chemical plants as but a few examples of where using ac mains supply direct from the wall/grid is a big issue.

As for annual reports published by utility companies, I would as a former statistician look very carefully at the published data to see how true a representation this has on my own actual supply.

In short, as I stated previously, get the experts in, get the utility company to come and check your wiring, afterall, we are talking about your total safety not just about how good a supply your audio system has!! Penance agrees too so votes look pretty good my friend

 

Hi.

Getting your mains checked out from a safety point of view is something that I'd certainly be doing if my house was over 25 years old.

Given that your current component costs are in the £300-£600 category (am I right? Im a little out of touch with recent models) it would seem clear to me that if you have £1,400 to spend on your hifi an 'uber component' or two would make the largest and most clearly audible difference to your setup.

Improved ampification would be my starting point.

If your post was more about the safety of an ageing wiring loom and less about the best upgrade plan - my apologies

 

mr cat, i'd say it is very worthwhile getting your electrics checked out, especially for peace of mind, just be prepared for what they might find!
in buying our 'new' place (1885 vintage 3 bed semi), i knew the electrics simply looked dodgy, an NICEIC approved check, at around £100, with full written report confirmed this, we got a couple of rewire quotes, all around the £3k mark.
We found out just how dodgy the electrics were when we gutted the place for renovation, how it had not burnt down / hurt someone i'll never know.
Of course i have availed myself of the opportunity and had a dedicated ring main installed to the av outlets in the lounge - wont know how it 'sounds' till we move in in 3 weeks time......

However, i can say this - the system was finally all connected up yesterday and one thing i noticed is that the lights are brighter - sounds an odd statement i know but all rooms just have pendant fittings in them, some with the bulbs taken from the original fittings, where we previoulsy experienced an orange glow from the bulbs we now get bright 'white' light - i can only ascribe that to the new installation.

Regards

Chris

 

I have one of those trichord/duncan big jobbies.

It must weigh 30kg.

I found with a transistor amplifier, it made a good difference to the tactileness/definition of the bass, instead of just a bloated bloom I got more shape.

I also found it gave a smoother more rolled off top end, probably due to hash/harmonics being taken away. tbh it could be too dull at times, and being so used to being without, I did prefer the top without as an a/b.

Only lately I have noticed when the electric blankett was switched on at nite, how bad the thing started buzzing, quite audible, so goodness knows what is inside the blankett controller to cause that, at least its not going into the hifi now, but clearly mains is far from perfect, don't know how these household devices affect the sound for the worse tho'. I am not about to switch fridges and other things on and off whilst putting in and out the mains filter

 

I appreciate your opinion is merely your own and was made as such LE. Rather the 'dirty mains' scenario is the one most often purported by vendors of hi-fi mains products (who clearly do have a vested interest to say such things).

If, as you say, the quality of the mains supply in Bucks is positively effluent like how did you arrive at this conclusion? I'm asking out of interest rather than challenge – I'll take your word for it and cross off Bucks as a possibility for future relocation!

Can you expand on what you mean by “dirty� Are we talking voltage or frequency deviation outside of EU regulations or the presence of RFI or other mains distortions? Are you able to quantify “dirty†with information from your local energy supplier or maybe your own measurements (as you allude to)?

For my part the measurements I've taken have shown nothing of any significance in terms of deviation from 230VAC 50Hz – even when living in a heavily populated area of South London a few years ago. I've not been able to properly investigate RFI because of the lack of appropriate tools – but neither do I believe it's the insidious bogeyman it's made out to be.

 

mosfet, I use valves a lot, and am conversant with design of valve amps.

deviation by 10%( nI think there is a law by how much the mains can vary ,can't recall what it is, 5%? 10% seems a tad high, but I think it can actually go from 210-240 volts, so 10% must be about right) can affect the operating conditions of the circuit, whilst its true that the whole circuit changes by that much, you have to live with it, but it is significant to change your amp significantly.

Also, you get dc on the mains believe it or not, and it can saturate mains transformer cores, making them get hotter, noisy, and buzz.(pehaps the better bass I heard with the filter is due to the mains tx in the amp being happier and not full of magnetism caused by dc?)

As an aside it may be worth it for people to put their ear to their amplifiers with no music but switched on and listen for buzz. may be surprising, doesn't mean to say your mains is bad tho as trannys can buzz due to design.

try it!!

 

we have some fairly hefty dedicated mains circuits at work, even our own sub station within the grounds. We still get a lot of noise on the mains, and deviation from voltage.

 

Actually the mains supply where I live is fine, in fact if you read my thread correctly I don't think you will find I alluded to any problems with power supply in Buckinghamshire

All I personally use at home are some dedicated filtered double outlets as used in a clean-room/hospitals in place of the standard MK switched outlets and one Eichmann power cord connected up to a home-made 10-way power strip with IEC connection.

I am only using mid-range solid state electronics and the nosie floor is at an absolute minimum, plus I have no issues with RFI, DC or other 'dirty' interferances to cause me to think about improving.

Does Lt CDR Data answer your queries on dirty/variable mains issues etc. mosfet, or do you still require supply of further test data?

 

Its actaully 230V +/-10% so 207 to 257v. they dropped the voltage from 240v to 230 just so they could make that percentage variant.
We did a an indepth 6 month study of the mains in 8 sites throughout Gloucestershire taking samples 8 times a day, not just voltages either
Has anyone actually measure the mains lately, and if so spotted anything odd about it? Wm

 

Tone
are you meaning fluctuation in an odd way?
Or the slight frequency changes?

 

Just searching through some reference material on the stability of mains electricity and found the following which may be useful on an introductory level:

Electricity consists of a single phase or three phase waveform
(normally a sinewave with little if any distortion) characterised by:
• Voltage
• Current
• Frequency
• Symmetry (only for three phase supplies)
From the source to the connected loads, the sinewave can be polluted
with various types of electrical disturbance:
• Spikes and Electrical Noise (Common and normal mode)
• Sags and Brownouts
• Frequency fluctuations
• Voltage harmonics
• Momentary interruptions and mains failures
• Transient Voltage Surges
These disturbances are caused by a variety of sources including failures
and switching problems within the electrical transmission and
distribution system, extreme weather conditions and the operation of
heavy industrial and/or faulty hardware. Mains interruptions are the
only immediately evident disturbances. Spikes, transients, sags and
brownouts are far more common and can stress sensitive electrical equipment connected to the point where hardware damage (data processing errors in IT systems), and costly downtime result
Harmonics can cause unexpected heating damage to electronic switching.

As you can probably ascertain from this brief summary, there are a few variables involved here in terms of what can cause interferance and mains pollution.

This is actually quite a topical subject for me as a friend of mine who lives in a small village on the border of Bucks/Northants does have a polluted mains issue, which has been caused by several factors inclusive of poor supply and obsolete wiring, distribution panel, low-voltage lighting transformers etc. etc.

If anyone is interested I also have some info from a Chinese company on consumer units, fuses and other mains electrical items that offer a substantial improvement over standard items (improvement in relation to build quality and raw materials used). However, how 'much' of an improvement these make sonically I have yet to test.

 

More something that shouldn't be there Andy surprised no-one has mentioned it before
Mind you, thats not the only 'extra' thats kicking about in there these days Wm

 

Hmm, cant say anyone has mentioned it, but then weve not been using the measuring kit for a few weeks (its monitored when critical measuring is done).
Some data transfer is done on experimental levels i believe, that was mentioned a while back as a possible cause of some spurious noise we were seeing.

 

there is a lot of extra stuff using the mains nowadays from home networks to meter monitoring hardware. all injecting high frequency crap into the supply to use existing copper for networking and communications instead of having to run new cables. this is great if all you use is a toaster, microwave and panasonic ufo music center. for hi-fi it's a pita.

http://www.mutek.co.uk/acatalog/copy_of_Ethernet_Mains_network_adaptor.html

cheers


julian

 

The thing is its easy to remove and cost virtuialy zip to do so. I would have though Richard would have spotted it? though seems even he may have missed it

 

Oh how I love your cryptic clues Tony!

Now I know that you say you know something but this something is something that you consistently decline to share. How can I possibly comment further until you do? Giz a clue!!

LE, Have you considered that raising the mains impedance seen by your kit through the use of inductive / capacitive filtering is not necessarily a good idea – this at least is my thinking and the reason I avoid mains filters.