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Post by MikeMusic on Apr 26, 2017 9:06:01 GMT
The more I find out about mains and the effect on system sound quality the more I am amazed it is not considered, by most, to not be remotely important.
Reinforces my view that the *start* of the hifi chain is - the mains
Moving house can give you a different sounding system even if the room is almost identical.
Tis a struggle to assimilate. The more we know...
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Post by Deleted on Apr 26, 2017 10:16:01 GMT
Moving house can give you a different sounding system even if the room is almost identical. Yes agree, I certainly found this when I moved from my flat in Horsham to this house in Newbury. The difference my then Merlin power cable and TCI 6-way block made in the flat was astonishing, whereas when I did the same test in my current house, there was a difference but it was a lot less obvious. |
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Post by orbscure on Apr 26, 2017 10:24:17 GMT
Some observations for you guys, the UK suffers greatly from DC offset, here in Buckinghamshire south we regularly see between 1.5~2.1Vdc sitting on the incoming mains (It should be ZERO, its AC!) DC offset will cause many transformers to destabilise, and not being able to form the field (The humming / buzzing of a TX can without question be caused by dc) which can result in a down turn in SQ. Mike's mains for example were reading between 0.9 and 1.2Vdc yesterday (Surrey)some area's in the UK are affected more than others. When dealing with mains be VERY careful, if an ANY doubt seek professional advice at all times. With Martin's systems its interesting as his amplifier has a DC blockers built in so the rest of the system must be gaining benefit from having one in there. theaudiostandard.net/post/89598/threadVery interesting... I'm in Surrey too and having moved back into the old family home in 2014, I've had constant issues with transformer buzz on nearly all of my amplifiers. I have a friend who is a qualified electrician and will see if he is able to measure the DC offset on my circuit. I'd already spoken to him about a dedicated CU and its own circuit for hi-fi use, but he didn't think that would make much difference. In the meantime, I've used a sub-£100 DC blocker bought on eBay without much change and I'm currently using one of MCRU Excelium DC Blocking Mains Leads between the wall socket and my AN Oto SE amp, but with little/minimal improvement. I've even considered BMU's or regenerators, but the prohibitive cost (irrespective of 30 day money back offers) has stopped me from experimenting further... |
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Post by MikeMusic on Apr 26, 2017 15:41:23 GMT
Moving house can give you a different sounding system even if the room is almost identical. Yes agree, I certainly found this when I moved from my flat in Horsham to this house in Newbury. The difference my then Merlin power cable and TCI 6-way block made in the flat was astonishing, whereas when I did the same test in my current house, there was a difference but it was a lot less obvious. That makes me think of my various house moves. My first house was ok. I had no other comparisons except bedrooms. Second house definitely good. I remember playing Quadrophenia when we moved in, sounded fantastic. Third house was a step back. Improved by a dedicated circuit for the system and started with Mana. This, fourth house was horrific and a lot of that was stupidly using two cheap 4 way adaptors and not knowing the earth was faulty. Fixed and sounding way better. Temporary move into the extended garage while the house was refurbed. The system always sounded good in there. Back into the main house where we are now and it was 'OK'. Never as good as in the extended garage I thought until maybe now. Many changes to mains and the system has dramatically improved the now totally different, much upgraded system. Some of this will be room and building based. Some mains. Possibly other. Food for thought |
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Post by MikeMusic on Apr 26, 2017 15:48:12 GMT
Some observations for you guys, the UK suffers greatly from DC offset, here in Buckinghamshire south we regularly see between 1.5~2.1Vdc sitting on the incoming mains (It should be ZERO, its AC!) DC offset will cause many transformers to destabilise, and not being able to form the field (The humming / buzzing of a TX can without question be caused by dc) which can result in a down turn in SQ. Mike's mains for example were reading between 0.9 and 1.2Vdc yesterday (Surrey)some area's in the UK are affected more than others. When dealing with mains be VERY careful, if an ANY doubt seek professional advice at all times. With Martin's systems its interesting as his amplifier has a DC blockers built in so the rest of the system must be gaining benefit from having one in there. Very interesting... I'm in Surrey too and having moved back into the old family home in 2014, I've had constant issues with transformer buzz on nearly all of my amplifiers. I have a friend who is a qualified electrician and will see if he is able to measure the DC offset on my circuit. I'd already spoken to him about a dedicated CU and its own circuit for hi-fi use, but he didn't think that would make much difference. In the meantime, I've used a sub-£100 DC blocker bought on eBay without much change and I'm currently using one of MCRU Excelium DC Blocking Mains Leads between the wall socket and my AN Oto SE amp, but with little/minimal improvement. I've even considered BMU's or regenerators, but the prohibitive cost (irrespective of 30 day money back offers) has stopped me from experimenting further... When we had the house refurbed our good electrician Paul made changes while we were living here. I asked him a few times what he had done that before, winding him up for a little while. Turned out he had made changes to breakers, earth and boards. He had no idea I would hear the system differently and had no understanding of why. He was slightly interested. Ate there some tweaks you could get your tame sparky to do and see if they change the sound ? |
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Post by julesd68 on Apr 26, 2017 18:11:59 GMT
Hi Pete - did you consider the Power Inspired regenerators? If you can get away with the 500W version they are £275 so would be worth considering ...
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Post by Deleted on Apr 26, 2017 18:34:09 GMT
I have DC on my mains.
I use an AG1500 and have no issues with humming transformers anymore.
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Post by orbscure on Apr 26, 2017 19:33:50 GMT
Hi Jules - since I've had the AN Oto, I've simply tried a cheap eBay and more expensive MCRU DC mains filter, both without any improvement. I've considered all manner of possible fixes (BMU, regenration, dedicated spur/circuits/CU) hence my interest in this thread. Since I've been at my current address, my buzzing amp history is as follows:
Quad 306 or Quad 406 - no buzzing, but Croft Micro 25 Basic pre buzzed
Monarchy SM70pro - buzzing
NVA A40 MKII monoblocks - no buzzing, but high frequency treble ringing, confirmed as local to me as RD tested same amps at NVA towers, in my presence, without the issues
Audio Note P-Zero monoblocks - buzzing
Restek MAMP monoblocks - buzzing
AN Oto SE - buzzing
@ Kevin - as has been highlighted by this thread alone, what might work for one doesn't always appear to work for another and that is why constructive discussion and debate (without the constant need to question technical/scientific points) is very much appreciated and valued. I've followed your experiences here and elsewhere with interest, in the hope that they'd offer hope to me.
@ Richard - as outlined above, I have a history of buzzing amps. I also have a friend who is a electrician by trade and when I next see him, I'll be asking him to come around and check my DC offset. With regards voltage, when I had my ISOL-8 Sequence, I seem to remember that it would swing between early 230's to late 240's.
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Post by Deleted on Apr 26, 2017 20:13:02 GMT
Have you measured the voltage?
I bought one of those Bluetooth smart meter plugs so I could track the voltage. Hey are not 100% accurate, but will,give you an idea about how bad your supply is.
When I saw the voltage swings on my supply, that was the point I thought I would try the AG1500 knowing that if I did not like it, or it did not work then I could send it back.
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Post by orbscure on Apr 26, 2017 20:39:05 GMT
Have you measured the voltage? I bought one of those Bluetooth smart meter plugs so I could track the voltage. Hey are not 100% accurate, but will,give you an idea about how bad your supply is. When I saw the voltage swings on my supply, that was the point I thought I would try the AG1500 knowing that if I did not like it, or it did not work then I could send it back. I've not measured it Kevin, but as I mentioned in my reply to Richard, when I had it, my ISOL-8 Sequence display used to drift between 230 to 250v. With regards an AG1500, £550+ is a lot for me to shell out, unless I can find a seller happy for me to test and return if no changes take place. I don't think the cheaper AG500 would be man enough for all of the components in my rack... |
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Post by Deleted on Apr 27, 2017 0:46:37 GMT
Speak direct to Power Inspired. They seemed happy enough for me to try it at home, and if I was not happy, I could return it.
They are required to by law, but it is much easier if they are happy to take the return if you don't want it.
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Post by pinkie on Apr 27, 2017 7:06:16 GMT
This is working in Martin's system it may or not work in other Systems as mains very Perhaps this is something Ps audio need to look into But in the context of Martin's system seems a bargain When I said "it's probably not the mains" , I meant the cause of Orbscures buzzing amps is probably not the mains. But it needs further investigation. As a first test I powered up my Fender Blues Junior, and confirmed it is the only device in my household with an audible hum. It is not fixed by the DC blocker. It hums everywhere. That is acceptable in a guitar amp (its very low level - soon drowned by the guitar playing). |
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Post by orbscure on Apr 27, 2017 7:21:03 GMT
There is a presumption that your problem is related to the mains - which on this forum, and this thread attracts enthusiastic "wet finger in the air" well-meaning suggestions (like Kevins) for fixes. Let me go out on a limb here. It's probably NOT the mains. Breakfast calls. I can suggest some reasons later, if you would like The problem for me Richard is that the .net (and hi-fi fora in particular) are full of self appointed guru's who think that just because they have a qualification or that they've read an online paper, that it makes their opinion final. I value the opinion of everybody, but more so those who've had first hand experience of the issue in question and who've also tried recommended fixes, especially those which have worked. Seeing that the issue being discussed is suffered by several people here, of course we'd like clear concise recommendations for alternatives to the mains causing this issue. However, before we apportion blame to my current amp, please run your eyes over my post outlining the buzzing issue with several previous amps, all at the same property and all attached to the same wall sockets. Of course, it may be that the amps which have buzzed are simply more sensitive to this issue than those that don't. However, I'd like to think that the designers and builders of these amps factor in mains quality. When I had my buzzing Croft Micro 25 Basic pre, I send this back to Glen who kindly checked it over for free, found nothing wrong and sent it back. I connected it back and it still buzzed.
Throwing money at solutions is fine, but like most here, I don't have a bottomless pit of funds available, especially when an expensive fix isn't guaranteed to work. The DC filters I've tried haven't worked, but if my electrician friend measures DC offset, where does that leave me? No DC offset, then of course, other areas need checking. I've even spoken to an Audio Note dealer about having my Oto checked out and serviced, not a bad thing to have done even if I didn't suffer with a buzz, but as you can no doubt imagine, this comes at a cost too. |
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Post by MartinT on Apr 27, 2017 7:41:56 GMT
At this point (and forgive me if I've missed it), I would have a qualified electrician check your earth quality, as well as DC. A good earth is paramount to system performance.
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Post by pinkie on Apr 27, 2017 7:47:32 GMT
Pete (?) - Orbscure
Lots of points. You need a systematic approach.
I presume the Oto is the only amp at your house at the moment and the others on the list are no longer available as controls
If there is DC on the mains (it is not easy to measure properly) then I assume it is blocked by the MCRU gizmo. If your electrician can measure DC offset properly then he can measure whether it is present on the output of the MCRU device, and if it is, the device doesn't work. That seems exceptionally unlikely.
Pretty much the only other option possibly causing a mechanical noise from the transformer related to the mains would be over-voltage. That IS easy to measure, and might be fixed by a device such as Wonky's which provides a regulated supply. However, it is unlikely that it will be outside permitted range (about 216-255v I think, without looking it up) and so equipment SHOULD be designed to tolerate that. I find it astonishing that Rextons P10, a device costing £5000, intended to improve the mains and with it the sound from a HiFi, buzzes loudly enough to interfere with listening enjoyment and be blamed for it. You couldn't make it up.
Have you tried taking the amp somewhere else and finding it doesn't buzz as you did with the NVA? If it buzzes everywhere you go, then there isn't a problem with your mains.
(The NVA episode doesn't point to mains either. Did you use the same equipment connected? They have special needs for cables. If there was a high frequency oscillation are there other possible causes present at your house but not NVA towers (wifi boxes close, mobile phones etc).
Do you have other equipment with transformers working without buzzing at your house at the moment?
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Post by orbscure on Apr 27, 2017 9:01:20 GMT
At this point (and forgive me if I've missed it), I would have a qualified electrician check your earth quality, as well as DC. A good earth is paramount to system performance.
I'll ask him to check this too... appreciate the suggestion Martin 
Pete (?) - Orbscure Lots of points. You need a systematic approach. I presume the Oto is the only amp at your house at the moment and the others on the list are no longer available as controls. If there is DC on the mains (it is not easy to measure properly) then I assume it is blocked by the MCRU gizmo. If your electrician can measure DC offset properly then he can measure whether it is present on the output of the MCRU device, and if it is, the device doesn't work. That seems exceptionally unlikely. Pretty much the only other option possibly causing a mechanical noise from the transformer related to the mains would be over-voltage. That IS easy to measure, and might be fixed by a device such as Wonky's which provides a regulated supply. However, it is unlikely that it will be outside permitted range (about 216-255v I think, without looking it up) and so equipment SHOULD be designed to tolerate that. I find it astonishing that Rextons P10, a device costing £5000, intended to improve the mains and with it the sound from a HiFi, buzzes loudly enough to interfere with listening enjoyment and be blamed for it. You couldn't make it up. Have you tried taking the amp somewhere else and finding it doesn't buzz as you did with the NVA? If it buzzes everywhere you go, then there isn't a problem with your mains. (The NVA episode doesn't point to mains either. Did you use the same equipment connected? They have special needs for cables. If there was a high frequency oscillation are there other possible causes present at your house but not NVA towers (wifi boxes close, mobile phones etc). Do you have other equipment with transformers working without buzzing at your house at the moment? Pete is fine Richard...
1. Other than a Sony AV amp as part of my home cinema set-up in the living room, the Oto is the only amp I currently have. 2. I haven't tried the amp elsewhere in the property, but I'll try that over the bank holiday weekend and see what happens 3. At the time I had the NVA A40's monos, my system was completely different (NVA p50sa & NVA cables). Neither of the A40's buzzed and the high frequency ringing was speaker borne, either via JBL4311's or Tannoy Cheviots I had at that time. 4. I have a AE sub as part of my home cinema set-up and that buzzes, but it also buzzed at the two property's I lived in
Cheers Pete
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Post by pinkie on Apr 27, 2017 9:12:34 GMT
Pete
The buzzing sub-woofer might well be DC on a toroidal. Try the MCRU blocker on it and see if it fixes it
Trying elsewhere in the home - probably won't be helpful. That related to a problem on the NVA's that apparantly was other than transformer buzz
First things first - are you sure the noise is transformer buzz?
If you are, can you take it anywhere (friends or relatives sufficiently far away to be "different mains") where it doesn't buzz?
(Sony AV amp, TV, BluRay, Skybox etc don't buzz? Again, this suggests looking for the answer in the mains rather than the equipment may be a false trail)_
I have a faulty buzzing transformer on the 2nd hand DaCapo I bought a couple of years ago, and replacing it has been on the "to do" list for that long. But it is not intrusive, (I rarely listen in a silent environment - today there is a lot of wind noise, but birds, dogs, horses...) and so fixing it is just for "Pretty", and not a priority. It is a very faint buzz (and that is EI not toroidal). The toroidal in the PIP is silent. It may be the unit itself.
Richard
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Post by pinkie on Apr 27, 2017 9:17:53 GMT
An electrician should check your earth for certification purposes. If you want to test it yourself, and test individual sockets, this device is excellent and safe Martindale EZ150 |
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Post by orbscure on Apr 27, 2017 9:38:08 GMT
The buzzing sub-woofer might well be DC on a toroidal. Try the MCRU blocker on it and see if it fixes it Trying elsewhere in the home - probably won't be helpful. That related to a problem on the NVA's that apparantly was other than transformer buzz First things first - are you sure the noise is transformer buzz? If you are, can you take it anywhere (friends or relatives sufficiently far away to be "different mains") where it doesn't buzz? Sony AV amp, TV, BluRay, Skybox etc don't buzz? Again, this suggests looking for the answer in the mains rather than the equipment may be a false trail 1. I'll try the MCRU filter with the AE sub in the living room tonight
2. Testing elsewhere in the property, refer to point 2 in my last reply
3. Definitely the transformer, I've taken the lid off the Oto and as a non-expert, I'm 99.99% sure
4. Testing the Oto at another property is not easy for me, I don't drive, so that is a difficult test to perform
5. I've not heard anything from the Sony AV amp, Denon BluRay, Skybox, Kodi box etc, but as an aside, the transformer in the Roksan ROK-DSP CD transport on the same circuit as the Oto hums. As far as I can tell, nothing else hums on either circuit.
Pete
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Post by pinkie on Apr 27, 2017 9:55:11 GMT
Pete
Great - we'll await the results, although as noted, tests elsewhere in the house, different mains circuits are probably a red herring
Just looked on another forum, where at least 3 Oto owners observe mild transformer hum and conclude it is normal and acceptable. Like my Fender Blues Junior perhaps. If it ain't broke...
This comment from that thread may be of interest
"Check that all the screws (case screws and transformer mounting ones) are present and tight. The case is relatively large and the panels are un-braced and can resonantly enhance any acoustic transformer hum. If it used to be quiet but it's suddenly started humming then it's just possible that one or more valves have started drawing excess HT current (age, bias drift etc can cause this). If you have a multimeter and are happy that you can work safely on live equipment then there are ways of checking these things."
Note - careful taking the lid off a valve amplifier - the capacitors can retain lethal charges.
Richard
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