advertisement


Dedicated Mains / Memera / Roy K Riches

Experimentation not just in my own system but also in two systems that were hard-wired straight into the consumer unit has revealed that lowering impedance and the number of interfaces (plugs, fuses etc) between consumer unit and equipment is not necessarily the holy grail.

My own system was not hard wired from the outset unlike the other two systems I mention upon the installation of dedicated mains, uprated incoming fuse and Memera consumer unit. Instead a bank of four sockets was installed on the board mounting the CU and connected to it by 6 mm T&E cables no more than about 8 inches long. I wanted to use 10 mm T&E but in such short lengths it was impossible to work with.

On switch-on the dynamics had improved remarkably and the soundstage was noticeably bigger but there was an unpleasant bloom in the bass. The suspected cause for this was airborn vibrations from the speakers that were being picked up in the wall on which the CU and bank of sockets was mounted and this vibration was feeding back into the equipment via the mains cables. As I said, suspected cause....

This bloom did not sound like a speaker/room interaction issue because it seemed to affect a much broader range of the lower frequency than the overhang or boom associated with obvious room modes. Instead of specific notes seeming to overhang as they would if they set off given room modes, the whole of the bass and lower mid was affected and the overhang was more subtle, but irritating and detracting from the music nevertheless.

Identifying a possible cause, whether this could be proven or not at least, enabled us to look for a solution. Placing a quality star-earthed mains block in line between the sockets by the CU and the equipment remedied the problem. The gains in dynamics and soundstaging were not compromised and in addition the bass tightened up with more detail and texture in the lower registers and midrange overall.

The same experiment was repeated on the two systems hard-wired into their Memera CUs with the same result. These systems are no longer hard wired and use a quality mains block in line.

My mains block is by Music Works and would cost £600. The other two use one from Mark Grant at £180.

Rather than grapple with the theory at this stage, try it first.
 
What 13 amp sockets? Actually it's the plugs which have the fuses. However, above discussions have mentioned 'hard-wired' more than once. This entirely obviates the need for plugs and sockets, f.y.i. (except for the kit, of course).

Yes plugs have fuses, but the sockets are still rated at 13amp's,

Hardwired circuits are where an electrical item (hifi) is physically wired into the circuit and cannot be unplugged, EG fused spur, switched spur. and not a socket whether that be 13amp or 32amp single or 3phase.

So what you write is wrong...sorry.

CU>CABLE>SPUR>FLEX>HIFI= HARDWIRED

CU>CABLE>SOCKET>FLEX WITH PLUG>HIFI=SOCKET CIRCUIT
 
CU>SINGLE SPUR>SOCKET>STAR EARTHED MAINS BLOCK>FUSED PLUGS/LEADS>HI-FI should also be tried as outlined above.
 
Yes plugs have fuses, but the sockets are still rated at 13amp's,

Hardwired circuits are where an electrical item (hifi) is physically wired into the circuit and cannot be unplugged, EG fused spur, switched spur. and not a socket whether that be 13amp or 32amp single or 3phase.

So what you write is wrong...sorry.

CU>CABLE>SPUR>FLEX>HIFI= HARDWIRED

CU>CABLE>SOCKET>FLEX WITH PLUG>HIFI=SOCKET CIRCUIT


I can't follow what you've written; partly because you mention spurs. If you have a cable (or cables) coming out of a c.u. it is a (they are) RADIAL CIRCUIT(S)

A SPUR is taken off an existing circuit, (usually ring main), and by definition cannot be dedicated. Besides, a spur from a cable? (sic) How odd !

My (and Davech's) mains leads ARE hard-wired into connector boxes, which are hard-wired to the t & e, which are hard-wired to the c.u. How physical must it be to qualify as hard-wired?????

ONLY the IEC is detatchable, as aforesaid.

Furthermore, the sockets may be marked '13 amp', but will take a hell of a lot more; it's only the fuse which determines the amperage capacity.
 
Experimentation not just in my own system but also in two systems that were hard-wired straight into the consumer unit has revealed that lowering impedance and the number of interfaces (plugs, fuses etc) between consumer unit and equipment is not necessarily the holy grail.

My own system was not hard wired from the outset unlike the other two systems I mention upon the installation of dedicated mains, uprated incoming fuse and Memera consumer unit. Instead a bank of four sockets was installed on the board mounting the CU and connected to it by 6 mm T&E cables no more than about 8 inches long. I wanted to use 10 mm T&E but in such short lengths it was impossible to work with.

On switch-on the dynamics had improved remarkably and the soundstage was noticeably bigger but there was an unpleasant bloom in the bass. The suspected cause for this was airborn vibrations from the speakers that were being picked up in the wall on which the CU and bank of sockets was mounted and this vibration was feeding back into the equipment via the mains cables. As I said, suspected cause....

This bloom did not sound like a speaker/room interaction issue because it seemed to affect a much broader range of the lower frequency than the overhang or boom associated with obvious room modes. Instead of specific notes seeming to overhang as they would if they set off given room modes, the whole of the bass and lower mid was affected and the overhang was more subtle, but irritating and detracting from the music nevertheless.

Identifying a possible cause, whether this could be proven or not at least, enabled us to look for a solution. Placing a quality star-earthed mains block in line between the sockets by the CU and the equipment remedied the problem. The gains in dynamics and soundstaging were not compromised and in addition the bass tightened up with more detail and texture in the lower registers and midrange overall.

The same experiment was repeated on the two systems hard-wired into their Memera CUs with the same result. These systems are no longer hard wired and use a quality mains block in line.

My mains block is by Music Works and would cost £600. The other two use one from Mark Grant at £180.

Rather than grapple with the theory at this stage, try it first.

STEVEN,

I don't doubt your findings, but I have a feeling the dedicated circuits of which you speak are singles (I stand corrected if wrong, of course).

If you have a single (or even two), you'll need to 'split' the feed to different pieces of kit, so either it's going to be sockets in line or a block of some sort. Where each cable only feeds one piece of kit, it's a different ball game, surely !
 
I can't follow what you've written; partly because you mention spurs. If you have a cable (or cables) coming out of a c.u. it is a (they are) RADIAL CIRCUIT(S)

A SPUR is taken off an existing circuit, (usually ring main), and by definition cannot be dedicated. Besides, a spur from a cable? (sic) How odd !

My (and Davech's) mains leads ARE hard-wired into connector boxes, which are hard-wired to the t & e, which are hard-wired to the c.u. How physical must it be to qualify as hard-wired?????

ONLY the IEC is detatchable, as aforesaid.

Furthermore, the sockets may be marked '13 amp', but will take a hell of a lot more; it's only the fuse which determines the amperage capacity.

Mike, have you told your home insurance company about these changes and has a part-P qualified electrician been to sign off the mods???
 
Mike, the bank of four sockets are 4 separate radial circuits connected to the CU. Connecting a star-earthed mains block to just one of these, the one showing a slightly lower impedance than the other 3, yielded the results as outlined above.

Why not try it out and report your findings here?

Mark Grant has a 30 day returns policy but the results derived from the Music Works block will likely be more dramatic.

For best results place the mains block on a shelf or some other isolation device.
 
I can't follow what you've written; partly because you mention spurs. If you have a cable (or cables) coming out of a c.u. it is a (they are) RADIAL CIRCUIT(S)

A SPUR is taken off an existing circuit, (usually ring main), and by definition cannot be dedicated. Besides, a spur from a cable? (sic) How odd !

My (and Davech's) mains leads ARE hard-wired into connector boxes, which are hard-wired to the t & e, which are hard-wired to the c.u. How physical must it be to qualify as hard-wired?????

ONLY the IEC is detatchable, as aforesaid.

Furthermore, the sockets may be marked '13 amp', but will take a hell of a lot more; it's only the fuse which determines the amperage capacity.

fullView.asp
 
CU>CABLE(T&E 10MM)>SPUR>FLEX(KETTLE LEAD NO PLUG TOP)>HIFI.

The flex is the danger point when fed with a 32amp rcbo wired this way.
 
Would love to try the 10mm sq cable but huge work lifting carpet/floorboards/skirting's/fishing cable down walls.etc.etc................one day!

My 2.5mm t&e ring circuit made a nice difference so i assume 10mm would be a huge difference.
 
That's intriguing, ROBERT. It says 'spur', but looks like a fused connector for a spur (or radial, I suppose, but couldn't imagine why). Where would one use this in a hifi installation?

When you hardwire your hifi to a socket (ring/radial) circuit it's made for a 2.5mm cable circuit but would fit a 10mm cable.
 
CU>CABLE(T&E 10MM)>SPUR>FLEX(KETTLE LEAD NO PLUG TOP)>HIFI.

The flex is the danger point when fed with a 32amp rcbo wired this way.


Must be senility settling in.:) Still can't understand why you mention 'spur'. If you had a spur from a radial (via a junction box/connector) you'd have more than one, surely? A hydra or in-line sockets are more usual, I'd imagine.

Yes, the mains lead would be the most susceptible, but to have a surge of that duration is highly unlikely in an urban, underground cabling supply; lightning storms excepted. 32 amp. RCBOs are, I believe, the norm in this type of installation, but that may well hark back to RKR
 
When you hardwire your hifi to a socket (ring/radial) circuit it's made for a 2.5mm cable circuit but would fit a 10mm cable.

Yes, my friend used to have MK unswitched sockets with separate 10mm2 cables. Tight fit, but possible.

Not sure why you'd want to hard-wire mains leads to a socket, though, or maybe I misunderstood the above.
 
Hello Davech,
Just finished reading your magnificent tome, which I found extremely interesting.
I’d also be interested to read your account of how the musical presentation, dynamics, soundstage, flow, imaging of players and instruments, changed/altered with regard to the number of modifications/upgrades you made. What music/artists/ albums did you play and what impact did the new changes make to those specific albums and tracks? Does the music communicate better and is it more involving? Do you end up going to bed in the early hours because the “last” track you were going to listen too became the whole album ?
Davech, I believe it may be prudent/useful for you to start a new thread of your own using the original posting you made here, which I believe is now somewhat “lost” on page 17. I suggest this course of action because it appears from the recent replies that the contributors here are more interested in electrical minutiae, than the quality of the music.

Praise to your Electrician.
I would comment that your electrician is to be congratulated for installing the 80Amp rated 16mm2 T&E, a hand-numbing task! To my knowledge you are the first in the world to have gone this 16mm2 route. Anyway I may be able to put more of these Hi-Fi installations his way, if he is interested, as people often ask me for a qualified electrician to do this work.. Bizarrely, I’ve had recent reports of electricians who scorned & denigrated their customer and refused to install anything larger than the 32Amp rated 4mm2 T&E indicating that the whole installation is a complete waste of time and money. They are of course correct in believing the THEORY that compels them to form this view. If we were to use their THEORY and perceived logic then a single run of 1mm2 T&E lighting cable rated at 14Amps will be more than is necessary to power all the Hi-Fi? After all if one just adds up all the current rating of the Hi-Fi equipment’s internal case-fuses then this total will usually be below 14Amps and the circuits in question usually draw no more than about half that current approx - 7Amps?
From my experience & perspective a system so powered by this 1mm2 T&E would be unlistenable and normally I’d score below 3/10. Assuming a Hi-Fi system costing £10K that would equate to £7K of wasted potential.

Best regards
Roy
 
Hello Davech,
Just finished reading your magnificent tome, which I found extremely interesting.
I’d also be interested to read your account of how the musical presentation, dynamics, soundstage, flow, imaging of players and instruments, changed/altered with regard to the number of modifications/upgrades you made.

I am looking to upgrade my musical presentation and "flow". "Flow" is especially important to me, as my friends say that my system has not enough flow just now. I would even sacrifice a little "musical presentation" (say 10-15%) for extra "flow", if that were possible. Even 3-8% extra flow would be great. Please advise!!! Is this possible? TIA
 
I am looking to upgrade my musical presentation and "flow". "Flow" is especially important to me, as my friends say that my system has not enough flow just now. I would even sacrifice a little "musical presentation" (say 10-15%) for extra "flow", if that were possible. Even 3-8% extra flow would be great. Please advise!!! Is this possible? TIA

For those seeking maximum flow there is only one option

http://www.drugs.com/flomax.html
 


advertisement


Back
Top