DVV . You know DIN 45500 was a good attempt at defining hi fi . My recent KT 88 SE has struggled to meet it . I was very happy to get there . 8 W and 1% which is nearly all second harmonic ( - 70 dB third ) .
60 to 10000 will be very acceptable ( good 78's ) . 20 to 15000 - 1 dB starts to be hi fi .
Interesting point . When my SE amp was under development it had the usual nice harmonics valve people favour . I could clearly hear the upper harmonics buzzing in the output transformer as power increased . More so than the music showing distrotion . Now I have mostly second harmonic the transformer sounds as pure as when little or no distortion ( I had it once ) . That has to be significant . I can hear 10 kHz clearly via the transformer metal .
60 to 10000 will be very acceptable ( good 78's ) . 20 to 15000 - 1 dB starts to be hi fi .
Interesting point . When my SE amp was under development it had the usual nice harmonics valve people favour . I could clearly hear the upper harmonics buzzing in the output transformer as power increased . More so than the music showing distrotion . Now I have mostly second harmonic the transformer sounds as pure as when little or no distortion ( I had it once ) . That has to be significant . I can hear 10 kHz clearly via the transformer metal .
Yes, it was a good attempt, and if memory serves, it was the FIRST attempt of its kind, the IHF coming a year or two later.
Too bad the Germans so madly insisted on their system of input/output signals and connectors, never mind how good they were, they were NOT what the market wanted. Anyway, their DIN 3, 5 and more pins was actually a downsized derivative of professional XLR connectors, with them, there was no way under the sun that you could get L and R channels mixed up throughout the system.
But they favored extremely high impedance loads and low level voltage of their signals, and moreover, they failed to update it. So it got too old and too tired and simply had to go.
+2 means you paid twice as much .....
I paid nothing yet. My friend sent me e-mail asking what do they mean.
Audio Codec Comparison Table | Hardware Secrets
Two underneath?
Wave, I'm not pulling your leg, I'm dead serious.
20+ years ago, an acquaintance of mine, a sound engineer, boss of the biggest hall (2,400 people) in the country, had me translate his concept of multichannel sound at home. He then sent it to AES and Dolby Labs. AES never answered (as far as I know), and Dolby Labs got in touch with him. After some weak negotiations, they nominally gave up, but a year or so later, his entire concept was presented by Dolby Labs, with very minor changes, WAY below the required 33% needed to bypass copyrights.
His concept called for what is 7.1 today, and further added 4 floor speakers. I asked him why that, and he told me that this was needed much more than commonly percieved. For example, rain falling - with the added floor speakers, he says you would almost instictively grab your umbrella. And since the frequency range of floor effects was rather limited, you didn't need some space age fancy speaker, all you needed are some decent units and you had to make very sure you got them well aligned in terms of volume and cohabitation with the rest of the system.
Of course, he never sued for intellectual rights because he was naive enough not to take any precuations before mailing anyone anythig, so he couldn't prove that it was his concept. Entirely his fault, I did offer him the services of my lawyer (also my best friend) who specializes in patent and copyrights, but like many people with a head full of ideas, he does poorly on listening to others.
I told him, but he obviously didn't hear me - to get into business, you need a good lawyer and a creative accountant. I heeded the advice and here I am, 11 years later, still at it and my company debt is equal to absolute zero. He hasn't budged an inch since those days.
I know what it means . Sounds nothing like real life . Can be fun . Mostly annoying . Problem is there was no real understanding of producing a vortex of sound . In a storm we would hear and feel it . With this system the sound jumps from here to there . Forgive me if the technical side has accounted for it . Michale Gerzon was so insistent about this defect that someone might have listened . My ears say it isn't solved . This type of sound is like the two colour , colour films ( circa 1920 ) . Very impressive how it fools the eye . Nothing like the 3 colour version .
Funny maths . Did anyone notice Pi is nearly the cube root of 31 ( about 0.02% out ) . 355/113 was a Clive Sinclair version given with his calculators . I found remembering 3.1415927 easier . The kids do not learn logarithms now . I would be lost without them . I think the maths required for our work is usually a gifted 13 year old level .
facts I didn't know.
cube root 31, error <0.0068%
355/113, error <0.000009%
3.1415927, error <0.000002%
error result from Win7 calculator.
Looks like remembering 3.1415927 is good enough for most calculations using Pi.
BTW, What is the asci code for Pi? alt+0xxx?
Another BTW, Napier was brilliant. It's the addition and/or subtraction of logs that make it so powerful and yet so easy to manipulate.
I attended a few courses at Napier University (Edinburgh) when it was still a college.
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Hi Andrew . Think it is circa .0.02025 % of 31 . Know what you mean and you are probably right . 31.0063 ish . 22/7 is not bad . A lady in the pub tried to convince me that 22/7 is correct and 3.1415927 an approximation . She is sort of right . We were told at college 22/7 would be more correct as we might have an opportunity to cancel 22 or 7 in the calculations . I built my first calculator £14.95 and it save £5 on ready built .
The other nice number is the so call Fibonacci no of
1.6180339887
Squared is
2.6180339887
Reciprocal is
0.6180339887
Nice thing with that one is it can be calculated if you forget the number very simply by doing the sequence . 1 , 1 , 2 , 3 , 5 ,8, 13, ............. 4181 , 6765 ( i.e . 6765/41812 = 1.618034 ) .
I love irrational numbers .
The other nice number is the so call Fibonacci no of
1.6180339887
Squared is
2.6180339887
Reciprocal is
0.6180339887
Nice thing with that one is it can be calculated if you forget the number very simply by doing the sequence . 1 , 1 , 2 , 3 , 5 ,8, 13, ............. 4181 , 6765 ( i.e . 6765/41812 = 1.618034 ) .
I love irrational numbers .
Also, golden ratio (and isn't this the "best" Measurement for a rectangular speaker box of the "best" Sound Quality?) = (1 + sqrt (5)) / 2
or in keystrokes for the Windows calculator:
5y2r=+1=/2=
(copy-and-paste into the calculator!)
Pi = alt-227 (thanks to Google) = π, but to me it's not "real" ASCII, as ASCII was originally only a 7-bit code. Lots of terminal and microcomputer displays used the highest eighth bit to double the number of displayable characters, but each manufacturer used different codes until the IBM PC sold a few million and its extended character set became a de facto standard, and then part of the real Unicode standard (or maybe there really was an 8-bit extended ASCII standard somewhere in there). It always bugs me when those high-bit characters are called ASCII. It's the danger of knowing too much history, er, obsolete info.
or in keystrokes for the Windows calculator:
5y2r=+1=/2=
(copy-and-paste into the calculator!)
Pi = alt-227 (thanks to Google) = π, but to me it's not "real" ASCII, as ASCII was originally only a 7-bit code. Lots of terminal and microcomputer displays used the highest eighth bit to double the number of displayable characters, but each manufacturer used different codes until the IBM PC sold a few million and its extended character set became a de facto standard, and then part of the real Unicode standard (or maybe there really was an 8-bit extended ASCII standard somewhere in there). It always bugs me when those high-bit characters are called ASCII. It's the danger of knowing too much history, er, obsolete info.
Michael Gerzon had the ideal as 9 speakers . That would be 8 , one at each corner of a cube and a central speaker . I suspect the centre one would be difficult as if I understand it correctly that would not be just a subwoofer . The system worked by using the speakers as a decoder . Difference signals fed to each speaker . This would allow the sound to be rotated and create real stereo images in every position . That being true any image in any position is possible . I thought the 8 speakers could be electrostatic as in the middle section of Quad ESL 57's or Magnaplanar . I would imagine polar response to be important and might need something special .
My friend Paul Stewart who was at JVC said CD4 was very convincing ( tape source ) . During a demonstration a lady offered him a drink . She wasn't there ! He said the big deal was he felt her approach . That should be possible and would be very realistic .
This is how it started .
http://www.audiosignal.co.uk/Resources/What_is_wrong_with_quadraphonics_A4.pdf
I found Hafler decoding preferable . If a vinyl record was played through Hafler it generally sounded more relaxed . The surface noise seemed outside of the listening area ! Using a Dolby decoder to do the same made the noise more noticeable . Friends and I got use to using Hafler and liking it . That would be for films also . Sources then were VHS / FM / LP / CD . BBC Radio 3 was always good . The speakers need to be matched and of good quality .
My friend Paul Stewart who was at JVC said CD4 was very convincing ( tape source ) . During a demonstration a lady offered him a drink . She wasn't there ! He said the big deal was he felt her approach . That should be possible and would be very realistic .
This is how it started .
http://www.audiosignal.co.uk/Resources/What_is_wrong_with_quadraphonics_A4.pdf
I found Hafler decoding preferable . If a vinyl record was played through Hafler it generally sounded more relaxed . The surface noise seemed outside of the listening area ! Using a Dolby decoder to do the same made the noise more noticeable . Friends and I got use to using Hafler and liking it . That would be for films also . Sources then were VHS / FM / LP / CD . BBC Radio 3 was always good . The speakers need to be matched and of good quality .
Funny thing is mono comparability was and is still a very serious requirement of the more professional radio stations . The cheapest CD players had problems in the early days , they sounded dull in mono due to time delay . That was just a case of spending money . Denon DCD 300 was one that dealt with it . Philips also although taking different routes at that point . I still remember the DCD300 as an exceptional low cost CD player . I seem to remember Michael Gerzon was obsessed with mono compatibility . Perhaps he felt that the BBC would need convincing .
Advice please .
A friend is trying to upgrade a Rotel CD965 . Rotel UK not only helped with a technical manual they also supplier an extensive upgrading guide !
They mention changing the clock . I have always fancied making a clock from a CD4060/ 74HC4060 and RC astable . I have a digital frequency meter so can get it right by tweaking resistors . Even if the Rotel can be configured that way I fancied the clean output of a 4060 an advantage . I will use COG caps and perhaps the full 14 divisions . I suspect caps are more stable in the nS ?
74HC4060 will drive LED's well . If over 20 mA they do the MOSFET self limiting very well . A White LED runs directly without harm to itself nor chip if 5V is used .
4060B counter/divider and oscillator
A friend is trying to upgrade a Rotel CD965 . Rotel UK not only helped with a technical manual they also supplier an extensive upgrading guide !
They mention changing the clock . I have always fancied making a clock from a CD4060/ 74HC4060 and RC astable . I have a digital frequency meter so can get it right by tweaking resistors . Even if the Rotel can be configured that way I fancied the clean output of a 4060 an advantage . I will use COG caps and perhaps the full 14 divisions . I suspect caps are more stable in the nS ?
74HC4060 will drive LED's well . If over 20 mA they do the MOSFET self limiting very well . A White LED runs directly without harm to itself nor chip if 5V is used .
4060B counter/divider and oscillator
I agree.
Caps should not be used for any precision function, unless absolutely unavoidable. They are too fickle overall, from delivering precise capacitance, via thermal behavior, to loss of precision over time. They are THE weak link of any circuit, and while they are irreplacable for power supplies and PSU decoupling, they should be avoided elsewhere.
I'd also go for crystal.
Perish the thought that I'm trying to dissuade you in any way, Nige, but my experience has taught me that the best way to tune a CD player is to buy a Real Time DAC.
Esentially, it has 8 DACs working in parallel, and thus eliminates the need for oversampling and brick wall digital filters, with their associated phase shifts, good as they may be.
When I bought mine from the Land of Oz, for something like US$250 including shipping (that's about 150 quid), and when I connected it with my Yamaha CDX 993 CD player, it's original very musical character moved up a notch or two. It's a whole new ball game, and it's rather obvious from second No.1.
A clarity I think must be very hard to achieve by classic methods (though certainly not impossible), or at least, I have heard it done only once or twice, and in devices which did cost an arm and a leg.
Mine uses an AD 847 op amp for its output stage, but you could exchange it for tubes or discrete op amps if you like. In your case, even with MOSFETs.
Overall, my feeling is that this will bring about greater changes than using classic methods of tuning, but I hasten to add this is based on my sample only, not a comprehensive research project.
The additinal benefit is that such an outboard DAC can also be used to do its work on signals from your PC.
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