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Post by MartinT on Jun 25, 2015 6:22:33 GMT
As for mains fuses, I was given one of those solid bars that are gold plated and supposedly replace a fuse in the chain. I went to try it a while back and can't find the bloody thing anywhere. I haven't tried posh mains fuses and probably won't spend significant sums on them, but I would like to experiment with reducing the number of fuses at some future stage (I use a multi block) What about hard-wiring vs IEC vs Bulgin vs whatever? You don't see it discussed as much, but should it be? Again I have no entrenched view and would welcome both technical,and subjective opinion. As for mans conditioners, balanced mains etc, I probably won't go there. Ugly boxes and wires would spoil my enjoyment simply by defiling my living space Good to hear other people's experiences though. Hah, thanks for making me giggle about my 'ugly boxes and wires'! I don't have ugly boxes because I buy silver components (sorry Mike) and the wires are behind everything where they belong!
I could write so much but I'm at work so I'll limit it to a couple of points: 1. Everything is important about the power reaching my system components. I can certainly hear changes made by cables and fuses and, if I turn my regenerator off (it goes into pass-thru mode) I can hear the quite obvious change, too. I can hear the effect of changing the waveform in my regenerator and I can hear when Cleanwave has been applied. 2. Fuses are subtractive devices, so when I say "an SR Red sounds better" I mean it subtracts less. It's pretty much the same thing for power cables. 3. Noise reduction is important. The more passive noise removers I have placed around the house, the 'quieter' my power has become and the better the sound. I will not have mains-borne ethernet plug devices in the house for the same reason and I minimise how many switched-mode chargers I use. The PC is on a big filter to reduce the crap it puts back into the mains.
Happy to expand on these things later.
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Post by MikeMusic on Jun 25, 2015 7:05:36 GMT
In the world at large there are so many things being discovered. They come as new knowledge, a surprise, counter intuitive and not possible - if you use the previous knowledge. Hifi is not life threatening, (usually !) so the sheer force of massive multinationals is not brought to bear on R&D. When I see some of the stunning work in medicine, where massive multinationals are working R&D big time I surmise that hifi is going to stay very back water and the things being discovered will only gradually make it into public acceptance. Add in the vast amount of the "good enough for me" people the chances reduce further. Looks play a part in hifi which is a bit baffling for me as it's the ear brain connection doing it. Black or better still invisible has to be the way. I don't want or need to see the kit. I'm experimenting with black paper over parts of my Mana racking to make it less obvious. Yes I did say "Mana" and "less obvious" in the same sentence Take the abstract Would you do something minor to improve the sound of the music you listen to ? (some would say "good enough") Would you spend some dough to hear an improvement ? (some would say "good enough") If either of the above ring true then have a listen to mains tweaks Does listening to music give you immense pleasure ? Would you like to improve that pleasure even further ? Mains tweaks will help
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Post by MartinT on Jun 25, 2015 7:30:35 GMT
Yes, agreed with all of that, Mike. The 'good enough' view is pervasive which is why so many people think iPods sound good. However, I DO have to look at my kit and I'm glad it's not black
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Post by dvh on Jun 25, 2015 13:18:18 GMT
Looks play a part in hifi which is a bit baffling for me as it's the ear brain connection doing it. Black or better still invisible has to be the way. I don't want or need to see the kit. Of course, really good speakers disappear, so best to focus on those.
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Post by MartinT on Jun 25, 2015 17:41:43 GMT
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Post by Deleted on Jun 25, 2015 18:30:59 GMT
I'll probably join in this properly later on.... if I'm still welcome here. I'll likely be posting rather more often here in future in fact. I'll warrant that my troubles of the last couple of days have spread through the grapevine and reached TAS by now, and every other forum I guess, hence the "if I'm still welcome here". For any that haven't heard, I had a VERY public complaint from a customer, not over quality etc, which no one has had anything but praise for, but for missing delivery deadlines. I do not deny the allegation. A few other customers who had never complained in the past (I'd assumed they were happy customers, most of them anyway. A couple had mentioned to me in PM's that it took too long for delivery) then decided that, as someone else had broached the matter of broken delivery estimates, they would add their tuppence worth. Disgracefully, several people who were not even customers decided to really put the boot in, gloat etc. It was like a pack of hyenas tearing up their pray for a while, and quite the worst behaviour from people on a hi fi forum I have ever witnessed. Moderators have since deleted the worst examples. The long and the short of it is that the reputation it took so long to get was completely destroyed in minutes... to the point where it may not be tenable for me to remain trading.... certainly not through pfm which was my main source of work.
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Post by Deleted on Jun 25, 2015 19:01:54 GMT
You're VERY welcome as far as I'm concerned, Jez. This forum is painfully short of us Northerners lol.
Without breaking the ethos here of commenting on other forums, may I just say I had my eyes opened recently as to just how cruel and mal-adjusted some "human beings" can be in their treatment of another forum contributor.
I really hope you can carry on trading too. Isn't it ironic that someone who would schmooze and bullshit a customer wouldn't have had the same flak? I am a novice when it comes to such things, but would a crowdfunding venture be a possibility? Quite a few people would undoubtedly chip in. My only other thought would be to use the dreaded EBay as the buyer gets the certainty of buyer protection and you reach a bigger audience.
Good luck and best wishes from me and I look forward to you proving a few individuals completely wrong.
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Post by John on Jun 25, 2015 19:40:49 GMT
It sounds like you run into some bad cash flow issues, this can happen a lot to small business. Get yourself a good plan to get yourself back on track, set realistic goals and do everything you can to achieve them. Small business often go through these kind of issues
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Post by pinkie on Jun 26, 2015 8:46:52 GMT
Jez. Everyone makes mistakes. It's how you set about putting them right that counts. I haven't seen what you are referring to on the other forums but focus on your business and doing it right and ignore those rubber-necking a road crash.
In my experience, if your product is good enough, and you try to treat people fairly going forward, poor customer service is soon forgotten. You are selling to a constantly renewing customer base with little interest in history.
Marketing without a dealer network can be tough. Unless after being banned from enough forums you start your own as disguised marketing tool, and recruit some sycophants.
We all have to sell-and every business needs a sales function. If free marketing from forums is not possible, then time, money, or both need to be invested elsewhere. Social media maybe. Or more sophisticated Web marketing techniques like list building.
Nil carborundum illigitimis
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Post by pinkie on Jun 26, 2015 18:07:00 GMT
Weekend guest just phoned to see if he could bring anything. I think Sue thought he meant flowers, wine, something for the barbecue... His list was Pip2, Benchmark, Isolation transformer and variac... Sadly the Integral is not fit for combat this time around. Apparantly my buzzing transformer is because they used the wrong one (?!?!) - DC offset shouldnt be a problem with the right value of transformer -explanation and demonstration due tomorrow Better get back to marinading the tandoori chicken
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Post by pinkie on Jun 27, 2015 22:23:14 GMT
The benchmark has landed. My hum problems have disappeared (balanced inputs) The right transformer rating eliminates saturation buzz from dc offset In response to "if you redesigned pip today would you include balanced inputs" I got 4 redesigns of the pip input stage in 5 minutes on the back of some 7 column analysis and a conclusion of "no" (too much noise added). Tomorrow we measure the dc offset on the mains, and my esl's get a blow dry to retension their covers. And far too many bottles of wine got drunk.
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Post by MartinT on Jun 27, 2015 22:27:54 GMT
In response to "if you redesigned pip today would you include balanced inputs" That's probably the wrong question to ask. Balanced only works well when the entire circuit is balanced, rather than just the inputs.
IMO.
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Post by pinkie on Jun 28, 2015 7:56:49 GMT
In response to "if you redesigned pip today would you include balanced inputs" That's probably the wrong question to ask. Balanced only works well when the entire circuit is balanced, rather than just the inputs.
IMO.
It's complicated. I'll almost certainly get it wrong, but I'll have a stab at a precis based on what I can remember after Owen and Shirley have gone. When you say "fully balanced" I take it you mean "active balanced" with the balanced signal from the output being derived from an inverting amplifier. The connection between the Pip output and the Benchmark input is "fully balanced" - it just loses 6db of signal gain by not being derived from an amplified output. (The Pip is properly suited for this sort of connection due to its internal grounding - the RCA socket shields are insulated from the chassis and connected by wire to a common star ground point in the circuit) Back to simpler MAINS stuff I understand : The buzz from the transformer is due to DC offset on the mains The buzz is actually due to the transformer design being too close to the limits. Adding an isolating transformer removes the DC element and eliminates the buzz Adding a Variac and dropping the AC voltage by 2 volts eliminates the buzz Yes - sods law applied in full and when we went to test this morning the buzz was almost inaudible - the measured voltages were 244v AC and a mere 2v of offset The fact that the sub is left on constantly and the buzz fluctuates indicates the variation is due to fluctuating DC offsets during the day rather than progressive transformer saturation Bit hit and miss, but using the Variac to get the "worst" level of buzz (by ear) suggests the peak DC offset is about 10V (Ok - our bottle went - we didn't want to damage the subwoofer by artificially taking its voltage beyond 255V) The best DC blocker is a transformer. Any transformer, including a centre tapped one will block DC - so that includes Balanced Power Supplies. If they do nothing else (and arguably the only other things they do make things worse) they block DC on the mains. Time to cook a fried breakfast
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Post by Deleted on Jun 28, 2015 9:08:28 GMT
Well, adding an isolating transformer just relegates the DC offset buzz to that one. Similarly a balanced mains transformer, which I have heard a stratospherically expensive one buzzing very loudly. So-called DC offset is due to even order harmonics on the mains, caused by industrial users. Legal requirements are that 2nd harmonics in the EU are less than 2% of the fundamental, and in practice are less than 1%. It is unlikely that this in and of itself is a problem in a correctly specified transformer. The two manufacturers I use are Canterbury Windings www.canterburywindings.co.uk/ , and Paul Houlden at TEC, who designs for Trichord, used to for Krell and I think Chord. I have never had one of their transformers, from 50VA up to 750VA be anything other than silent under all circumstances, even with an ear pressed to the darned thing. Silent at all time of day, any day. Transformer buzz comes from three sources: 1. An underspecified transformer where the core is running into saturation. Any mains asymmetry ("DC offset") will offset the saturation and give rise to buzz. Unforgivable design error. 2. Windings imperfectly potted, so the windings move in the magnetic field. Unforgivable manufacturing error, often driven by a push to minimum cost. 3. Equipment from the USA. Even audiophile brands have a complete blind spot on this and design the transformers for 60Hz, even if they have dual primaries for use elsewhere. The effect at 50Hz is to increase the magnetising current by 6/5 = 20%. This pushes even a generous design at 60Hz into a marginal one at 50Hz. Which is why US product in the UK is particularly prone to either buzzing all the time, or being sensitive to the small amount of second harmonic, which means they buzz at some times of day, but not others. This is one of the root causes of "my system sounds better late at night" - ie when industry has gone to bed. Mechanism for this is magnetosctriction in the core causing it to twitch at the harmonics of 50Hz. I've had both Audio Research and Krell gear do exactly that. But the rule is: pay the money and buy properly rated transformers from a reputable manufacturer.
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Post by pinkie on Jun 28, 2015 10:04:27 GMT
Yup -that's the point Craig. The buzz in this case is a transformer that is not adequately rated. It is not the DC itself that causes the buzz - but the transformer in saturation.
The "blocking" transformer didn't buzz because it was adequately specified
The buzz in the subwoofer transformer was because the DC shifts the AC on one half of the cycle above the limit the transformer can handle. Using the Variac shifted the AC past that limit and produced the same result. Using an isolating transformer or other DC blocking device (intrigued to see this cable when BK supply it) will fix the problem by bringing the AC voltage on both halves of the cycle back within the transformers ratings.
But the proper solution would have been to fit a decent transformer in the first place which had adequate margins for the voltages encountered.
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Post by pinkie on Jun 28, 2015 12:30:56 GMT
I didn't have to wait long. It was in the post box all the time. Obviously there is a cover over the exposed side - I just took it off to photograph. And it works! (The buzz, and hence offset, was quite loud just now when I tried it). The subwoofer buzzes for about half a second while the capacitors charge, and thereafter is silent. I have to emphasise just how impressed I am with BK electronics, their products, and their customer service. Whilst I appreciate the engineering point Craig (and Owen) were making about the right answer being to design the product with a properly rated transformer in the first place, the sub-woofer is excellent, and BK have provided this solution FREE long after the original purchace, quickly and efficiently - and it works. I would recommend their sub-woofers unreservedly. And I fail to see how anyone can ask hundreds of pounds for a lead which essentially does the same job, with a couple of diodes and a couple of electrolytics. Unless you believe fat wire, and fancy plugs and connectors are essential. Back to put the carnage in the living room back and listen to the Benchmark a bit more (the weather was too lovely yesterday). I'm not sure the sub is going to be used in the 2 channel whilst the benchmark is a house guest - it wasn't missed yesterday. But I haven't really had a chance to listen properly and compare with the Quad. The amp is extraordinary - if only because it is so tiny and runs stone cold even thrashed!
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Post by pinkie on Jun 28, 2015 13:48:32 GMT
Not sure where a separate thread is appropriate. But for the moment, Martins comment on balanced connections was in the context of noise rejection, and specifically mains noise rejection, and so I guess this thread is still relevant Rather than repeat great lumps of it - the following document is an excellent reference text Understanding, finding and eliminating ground loopsThe only purpose of balanced connections is to reject unwanted noise. They do not "tune up" the signal. (I may need help from a proper engineer on the next bits - I sort of got it last night, but my only notes are scribbled schematics) The point about a "fully balanced" connection is made at paragraph 3 on page 21. "An interface may be unbalanced or balanced, depending only on the impedances (to ground) of the line’s conductors. In balanced interfaces, both conductors have equal (and non-zero) impedances.". There is no requirement for the output of a balanced connection to be provided by an amplifier. The benefit of "driving" the balanced output is a 6db increase in signal strength. The cost is the noise and distortion of another amplifier. Some other points of interest are that the cable Owen made up for me uses a screen grounded at the output end only. Paragraph 5.4 covers Balanced Power Supplies - their use (along with other transformers) in pro audio situations -as devices to tackle mains noise imposed onto the signal, and the reason they are like "a shotgun rather than a silver bullet" as a means of tackling these problems in systems. It also explains how, in practice, they probably have at best a marginal effect on this noise. Note - their theoretical purpose is to prevent mains noise reflecting into the signal cables - not to make less noisy mains voltages for some possible benefit of "better power".
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Post by MartinT on Jun 29, 2015 8:29:32 GMT
The only purpose of balanced connections is to reject unwanted noise. They do not "tune up" the signal. (I may need help from a proper engineer on the next bits - I sort of got it last night, but my only notes are scribbled schematics) The point about a "fully balanced" connection is made at paragraph 3 on page 21. "An interface may be unbalanced or balanced, depending only on the impedances (to ground) of the line’s conductors. In balanced interfaces, both conductors have equal (and non-zero) impedances.". There is no requirement for the output of a balanced connection to be provided by an amplifier. I think we may be in danger of confusing the readership: balanced mains units are transformers that supply a better impedance matched and more noise-free mains power supply to a component or system.
Balanced connections are where interconnects contain a +ve and -ve signal around ground (i.e. three wires) to connect up professional and high end hi-fi equipment where common mode noise is eliminated.
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Post by pinkie on Jun 29, 2015 9:06:05 GMT
The only purpose of balanced connections is to reject unwanted noise. They do not "tune up" the signal. (I may need help from a proper engineer on the next bits - I sort of got it last night, but my only notes are scribbled schematics) The point about a "fully balanced" connection is made at paragraph 3 on page 21. "An interface may be unbalanced or balanced, depending only on the impedances (to ground) of the line’s conductors. In balanced interfaces, both conductors have equal (and non-zero) impedances.". There is no requirement for the output of a balanced connection to be provided by an amplifier. I think we may be in danger of confusing the readership: balanced mains units are transformers that supply a better impedance matched and more noise-free mains power supply to a component or system.
Balanced connections are where interconnects contain a +ve and -ve signal around ground (i.e. three wires) to connect up professional and high end hi-fi equipment where common mode noise is eliminated.
No. There is no confusion. Both are balanced connections, and both reject common mode noise on the connection. The quote from the "understanding finding and eliminating ground loops" article referred to professional balanced audio connections of the signal- and the "fully balanced" arrangement Owen has provided for me between the Pip and the AHB2 is balanced in the same way your connections are. The purpose of both balanced arrangements is the same - to reject noise. But, in terms of noise rejection balanced mains achieves nothing on the "mains noise" since it only rejects noise that might otherwise be imposed on the lead from the BPS to the amplifier (or other device) which is of no real value. By contrast stopping noise being added to a low level signal interconnect is of potentially great value. Balanced Power Supplies , if you read the article (p39 and p40), do not supply a "more noise free" mains power supply. They can (not very effectively) reduce the noise from the mains which might enter the signal path in poor grounding scenarios. That is their use and purpose in pro-audio situations. I quote "In reality, many of the benefits often ascribed to “power treatment” schemes are simply due to plugging all system equipment into the same outlet strip or dedicated branch circuit. For obvious reasons, this is always a good idea!"
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Post by Deleted on Jun 30, 2015 13:07:09 GMT
Many Bryston amps have mains DC blockers built in...
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