Post dedicated cicuit sound problems

Hello. I’m new to the forum but have found it invaluable reading in the past. I’ve had a good search for the issues I’m experiencing, but none that relate specifically to my kit and situation. I hope you’ll bear with me if this has been answered before.
I’ve CDX2, 202/200, Hicap, napsc, hi-line, feeding 20.23s, on two identical cheap extension blocks from a double socket on the wall on a pretty busy house circut, two boxes plugged into each. Sounds pretty good, detailed and alive. Recently I added an XPS. This gave it a fantastic lift in all areas, but especially bringing out weight, timing and imaging, real foot tapping stuff. Flushed with success, I decided to have a dedcated circuit put in, as this is pretty easy in my house, consisting of 6mm cable to two double unswitched sockets on a 32A circuit breaker on the consumer unit. After leaving it for a couple of days to warm up, first impressions were that it sounded lightweight and lacking and just out of sorts. Left it for a week and tried again with the same results - no weight, depth, louder than previously, and very bright, glaring almost. Bass and drums have receded so much that there are not there on some music, and busy pieces are unlistenably loud and ear-splitting. Timing has gone completely, such that I just sit there and stare at the speakers. Oddly though, high frequencies are cleaner, just louder and an octave higher!
My question is: can anything be at fault at all with the wiring? It’s such a change. Or is this actually what it is meant to sound like?! I have read others’ experiences of changing plug order, and have tried this, but to no avail. I would be very grateful for any insights or advice. Otherwise, this may be the end of the road for me.

Sometimes when you have a compromised hifi, your brain adjusts and everything sounds ok. No particularly great soundstage, no amazing bass, etc…, but one can find it satisfying. At some point when one adds a significant upgrade, the sound can open up, big increase in lower hz, sweeter highs, etc… and then your brain hears many things going on and starts to hear benefits and problems. It can be a complex subject.

Two systems; one significantly better at reproducing than the other. Play even a simple Beatles track on both and the better one will sound so much slower and sometimes like you’ve never heard the track.

But, Count.d, your description doesn’t fit the changes Aurinia describes!

To me it sounds as if something is fundamentally wrong, and not meaning the mains wiring - more like something not properly connected. However there is an easy quick check: just take an extension lead, from an ordinary socket nearby, power off, smap connection, and power (in correct order -power amp off first and on last), anfd try it. Not waiting more than maybe half an hour to stabilise. Then back again. And repeat. If the problem remains with the direct wiring but not the ordinary connection, have it checked for fundamentals: live and neutral not swapped, earth correctly connected, before worrying further.

Thank you IB. Indeed I have tried this. Immediately after a very unsatisfactory listening session I put it all back on the old sockets with the extension blocks - immediate improvement. Listening to Cream’s Badge for example, the deep prominent bass opener is there, the rhythm is back and Ginger Baker’s drums roll. Back onto the new circuit and they drop into the background - there is no depth to the bass, just an insipid twang, the drums are barely audible and there is no rhythm., but the rest of it is very upfront.

My main reason for a dedicated circuit was just to get it off the ring with everything else on so it wasn’t exposed. I wasn’t expecting any great changes to sound, certainly not to this extent.

You see IB, bass apparently disappears just by changing the mains supply. It doesn’t disappear, but usually goes very spacious and deep. Sometimes the equipment set-up thereafter, doesn’t capitalise on this bass. Various upgrade bring it all back in spades and more.

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Hmmm - as an advocate of dedicated mains i’m a bit bemused by your findings. I presume from your post that you orignally had the CDX2, 200, HiCap and NAPSC plugged into two, two way extension blocks into the double socket. Yes ?

How do you have them connected at the moment and the incoming 6mm feed - how does that split to the two sockets - you have two, double unswitched sockets ?

Yes, I had two four-way £2.99 extension blocks plugged into a single double socket about 25cm up the wall, and the CDX2/XPS and HiCap were plugged into the left hand block (into sockets 1 and 4 of that block) and the 200 and NAPSC into the right hand block (into 1 and 4). Each block sat on the ground on the respective side of the Fraim.

Now, the incoming 6mm feeds two double unswitched sockets that are side by side (connected by about 30cm of cable in an arc) on the wall, and I had them put in at about 85cm high to aid cable “dangle” (and they all hang rather nicely!). This is level with the top shelf of the Fraim. The cable comes into the left socket first and I have the 200 and HiCap in this and then the CDX2/XPS and NAPSC in the other (I tried the CDX2/XPS and HiCap together in the left socket first).

As I say, I wasn’t expecting any great changes - it was mainly done so it was all under my control and not the fridge and kettle’s! If there was a change I though it would be subtle and debatable. This is quite a big change.

To isolate the dedicated circuit from the rest of your mains, you really want to run it from a separate consumer unit of its own. I can’t explain why your new supply sounds worse that your ring main did, but my experience, in line with comments here from others, was that there is a much greater gain to be had if the dedicated circuit is on an MCB in a separate consumer unit run by splitting the tails from your meter.


I’d agree with Chris. Although you’ve got away from multiple sockets connections on a ring (and in a typical house a load of SMPS supplies dumping leakage current onto the earth), the main benefit comes from getting as close to the incoming mains supply from the street hence the separate CU and its connection to the meter tails and earth block. Is the new radial connection from the 32A MCB next to the consumer unit RCD (or two pole isolator) ?
Any chance of a pic of your consumer unit with the new radial MCB shown. Interested to see where it is in relation to the other existing circuits.

Two pictures are shown of the consumer unit. Do these help? The hi-fi connection is the 2nd from left on the protected side. The ring it was on is 4th from left, next to trip switch. I had asked the electrician to put the hi-fi connection on the unprotected side so it didn’t trip when something fused on the socket rings, but he forgot. A new empty dry lining box appeared by the CU during the process (seen in pic 1).

The picture you show of your consumer unit is similar to mine before I had new ones put in this year. If I understand the situation your new radial circuit is still sharing an earth with the rest of your circuits.

When I split my consumer unit to provide a dedicated CU for my hifi my electrician also put in a dedicated earth for it. My electrical system now looks this with two consumer units; the left one is for the hifi (thanks to another member for the schematic).

I should say the change in the Sound was dramatic; I likened it to becoming un muddied. It was not bad before but everything became clearer with the new wiring.

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I suspect your electrician decided that the RCD protected side of your consumer unit was the correct side for the circuit, and so just put it there. (In fact, on a new installation, all circuits would normally be RCD protected under current UK regs) although the general advice is to just use an MCB rather than an RCD for best sound quality. It would be that this is contributing to your reduced SQ, but that’s just speculation.

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Yes, I was aware of these options beforehand, but was happy with SQ. The gear on the new circuit may be sharing an earth with the other circuits, but in that case it is using the same earth as before. It was on an RCD before too, so no change in either of those aspects, yet reduced SQ.

Hi aurinia,

It looks to me like the current hifi MCB may not be seated correctly on the bus-bar, I believe that sometimes it is possible to clamp the MCB against the plastic body, rather than between the metal contacts.

Whether that would have any bearing on your issue, I don’t know.


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Well spotted, Neil, it does look a bit wonky!

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Hi Neil, yes I noticed that it is somewhat proud compared with the others. I’ll have a closer look.

Therein lies a story that I didn’t think significant. When I first came to turm on with the new circuit, the HiCap tripped everything (so before I got to the XPS and 200). I tried 2 or 3 times before I realised that the electrician had used a 6A breaker. He came back and fitted the 32A that you can see - a rather old, used one! I hoped that this had had no effect on the HiCap.

I’ve a handful of friends who had dedicated radials put in and describe what is being described here. Your system will have improved in a number of respects but your current speaker positron may no longer be optimum. Really nothing more complex than that.

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That’s an interesting thought. When I added the XPS I brought them out from the wall and moved them apart a bit. I hadn’t thought that I might need to reverse this.

If a change in speaker positioning doesn’t fix your issue, I would be asking the electrician to return and check the seating (as mentioned) and replace the breaker with a new one - the cost of the latter is v.small in relative terms. As you flag, I’d also ask them to reposition the breaker order to ensure the hi-fi radial pulls from the bus bar in the CU closest to the feed (cables allowing) - it sounds like they didn’t fully grasp the job spec?

Being the curious type, I’d also check the connections in the sockets as 6mm can be challenging to seat/secure, noting the amount of cabling in the 1st backbox/pattress - I assume the 2nd set of sockets is simply a spur from the 1st? – appears to be by your words. I also assume the 2nd sockets aren’t fed by thinner cable (?).

Don’t worry about the switch-on and the Hi-Cap - this is nothing new and no damage is done.

I’d also plug the NAPSC in to house ring as an experiment, as these PS’s can be quite ‘noisy’.

A 32 Amp MCB should be about right, but if you do get it replaced, ask your electrician to fit a Type C breaker rather than type B and you should find it much less prone to tripping when you switch on your Naim boxes.