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Leonard Smalls

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Everything posted by Leonard Smalls

  1. [quote name='flyfisher' timestamp='1356003116' post='1905475'] But what is the upper frequency response of a fully-analogue recording chain ending in a vinyl recording and replayed on a decent hi-fi system? 20kHz? 22kHz? If that theory holds true then surely analogue/vinyl systems would also need a much higher frequency response? As previously pointed out, most adults struggle to hear 10kHz, so a music reproduction system capable of twice this sounds like a reasonable compromise. I wonder what the response would be to an 'improved' television system that worked into the ultra-violet spectrum? Would we expect this to give us higher quality pictures? [/quote] The theoretical limit for vinyl frequency response is 45kHz. However, you need a good piece of vinyl and excellent playback/equalisation devices to get anywhere near that! As for adult hearing limits, these may or may not be relevant if beating or intermodulation effects occur below these frequencies... So while cd at 44.1kHz/16 bit is technically superior to vinyl in some ways, it isn't necessarily in all. It depends on what, and more importantly, where, you measure. After all, the output of a loudspeaker as measured through a microphone may not be the same as you would hear it; I mean why does your own voice sound so different when you speak, and when you hear it played back off tape? TV picture-wise, I don't think it would be a good idea to have full spectrum TVs. First of all, you'd have the heating effects of I.R, plus the skin cancer problems of UV A and B. And it would add an enormous amount to the cost of production (both programmes and tellies), and electricity bills! And talking of high definition TV, many years ago I was on a BBC panel researching hi-def formats relative to film. Needless to say the standard we recommended (1250 lines) was not used...
  2. I didn't read the article to say: a) that beating frequencies are "magically" lost vinyl has no noise What I understood it to say is that some beating frequencies are as a result of resonance within our skulls, i.e. bones etc, so while it may not be an actual recorded sound, our perception shows it to be there, or not there. So if frequencies above the Nyquist limit cause this, they won't appear on a digital recording unless the sampling frequency is increased to accommodate it. As for thermal or any other noise in vinyl, he doesn't mention it as such; he puts forward a hypothetical analogue source with 100dB SNR - Studer 24 track at 30ips perhaps - and contrasts it with the theoretical cd red book SNR of 96dB via high resolution amplification. My amps, frinstance, have an SNR of 113dB... So he's not arguing for or against vinyl, just for higher sample rates! At the end of the day it's all academic, as most folks are happy with MP3, and see Bose as high end hifi...
  3. Just discovered this long but quite interesting article, which may shed a small amount of light on why vinyl can sound better than cd, especially with amplifiers with high signal:noise: [font=georgia,serif]High Resolution: Is It Really Necessary? A white paper by Marco Manunta – M2Tech Srl, Italy * We’re facing a seemingly unstoppable run towards very high resolution in digital audio: from CD to 96/24, to 192/24 up to 352.8/24 and even 352.8/32, not to mention DSD (2.8MHz/1bit or 5.6MHz/1bit). Considering how good some 44.1/16 systems (CD players or DAC) sound, the question is: do we really need very high resolution, and how high should “high resolution” be? * Bit depth This parameter is maybe the easiest one to evaluate and justify. First, it’s useful remind readers that bit depth defines the signal-to-noise ratio of a digital playback or recording system, through a simple formula: * SNR(dB) = 1.76+6.02*N, * Where N is the number of bits per sample or bit depth. In a CD-standard system (N=16), SNR is 98.08dB, a 24bit device will allow for 146.24dB. Literature often forgets the 1.76dB constant, so you may find 144.5dB instead of 146.24 and so on. We can also define a “virtual” bit depth for analog devices and systems, through *the ENOB parameter (Equivalent Number of Bits): * ENOB (bits) = (SNRmeasured-1.76)/6.02 * The ENOB of an amplifier with 105dB measured SNR is 17.15 bits (note that .15 bit has no real meaning). It’s easy to realize that a digital source delivering true 24 bits resolution connected to a system in which the overall ENOB is, say, 18 bits, is not guaranteed to fully exploit its performance. On the other hand, one may apply the law of balance and say that a digital source with 18 bits resolution (110dB) is sufficient to obtain the best overall performance from that system. Things are not that easy. First of all, let’s consider the nature of noise in digital systems. Noise is the sum of two contributes: quantization noise and thermal noise. The first one is related to bit depth and is very disturbing for humans ear-brain due to its correlation to the signal (in fact, it is sometimes called “quantization distortion”, rather than quantization noise). The second one is related to the analog circuitry used in the analog-digital and digital-analog boundaries and is generally much more tolerated by human ear-brain due to its total non-correlation with the signal. Devices, and even systems, in which thermal noise buries quantization noise are generally well-sounding setups. This explains why we cannot define a specific bit depth as a limit value to judge digital devices and systems: a 14-bit source will probably behave very well in a system in which the amplifier has only 70dB SNR, while it will sound awful in another system in which the amplifier has 100dB SNR. Also, this may explain why CD players with tube output have generally a pleasant sound: tubes are noisier than opamps and even than solid-state, discrete components buffers, thus their thermal noise buries the quantization noise from the conversion IC (I won’t enter the mined field of harmonic composition of tubes’ distortion or biasing issues as it’s beyond our scope). Conversely, an analog source with an outstanding 125dB SNR driving a 16bit ADC is a waste of money, as the quantization noise of the ADC will be easily heard over the source’s thermal noise, giving a typical “digital” sound. On the contrary, an analog source with 100dB SNR driving a 24bit ADC will give very good results to listening, as the thermal noise of the source will act a dithering with regards to the quantization process, transforming the signal-correlated quantization distortion in a “quasi-thermal” noise which is much more tolerated by our brain. Things are even more complicated when we have a more complex digital signal chain than a single-step unit. Let’s consider, for example, a CD player with digital volume control. We all know that dithering and noise shaping are necessary to avoid distortion increase when we approach low levels (high attenuation factors). This is due to the fact that the processing engine which does the attenuation (multiply for a number less than one) has generally the same resolution as the incoming signal: to the usual errors due to the finite-resolution mathematic (errors = noise), the final truncation adds a lot of damage, leading to the raise of distortion products. If we measure the effective resolution of a signal passed through a digital volume control, it is generally lower than that of the incoming signal. It’s easy that the quantization noise after the attenuation raises over the system thermal noise. What was a good sounding digital signal before attenuation has become a “digital” sounding one. Things improve as resolution increases: computational and truncation noise can remain below thermal noise, so that no dithering nor noise shaping are necessary. This is already true with 24-bit systems, and even better with 32-bit systems: even if we use 4, 8 or even 16 bit only to sample noise, that noise helps us to keep the sound good while it travels through our system to the loudspeakers. Summarizing, I dare to say that bit depth is very important for sound quality, even more than sampling frequency. To test the above “on the field”, take a good 96/24 recording and get a 96/16 version and a 48/24 version using some editing software. Chances are that you will hear little differences between the 96/24 and the 48/24 versions, while you’ll hear a bigger difference between the 96/24 and the 96/16 versions. * Sampling frequency It’s widely known that the ear of a young boy from the countryside (grown far from discos) can easily hear 20kHz, while a mature music lover hardly catches 16kHz. Thus, a digital audio system with an upper frequency limit of 20kHz should be enough to enjoy the real high fidelity. As usual, things are more complicated. Complex signals contain multiple frequencies which interact to produce intermodulation in all systems in which they travel. Our ear, together with our skull bones, is one of these systems. High frequencies intermodulate to the lower frequency range (for example, a 21kHz and a 22kHz tones can modulate down to 1kHz, well into our audible range). If we record and/or play a recording through a system with 20kHz limit, we miss those tones which should intermodulate into our ear and head, losing some of the original information content (that 1kHz tone which is part of the original signal, even if is produced into our body). Recording professionals may say that no microphone can capture frequencies higher than 40kHz, so this may state the real useful high frequency limit in the recording-playback chain. Even so, this means a minimum sampling frequency of 80kHz (according to Nyquist, the minimum sampling rate to accommodate a certain bandwidth is twice the bandwidth). Standards indicate 88.2 or 96kHz, with a usable bandwidth of 44.1 or 48kHz, respectively. But there is something more. It’s known by signal processing experts, and absolutely not popularized amongst music lovers, that converting an analog signal into a discrete-time one (as it happens when converting from analog to digital) destroys the phase information in the two top octaves of the resulting spectrum. In a CD-standard digital recording, all phase information are lost from 5.5kHz up to 22kHz, which is the highest frequency present in that recording. This affects mainly harmonics (very few fundamentals are available over 5kHz), disrupting the notes’s envelope. This may explain why different instrument of the same kind recorded on CD’s often sound very similar. To raise the lower limit of the affected range to 20kHz, we need to record with a bandwidth at least 80kHz, so we need a sampling frequency at least 160kHz. Standards indicate 176.4 or 192kHz, for a usable band of 88.2kHz and 96kHz, respectively. Then aliasing comes in. Aliasing is a phenomena due to sampling process which must be avoided in order to keep the original sound quality. The only way to do it is low-pass filtering the original analog signal before converting it into digital. This can be problematic when the signal’s upper frequency limit is very close to half the sampling frequency. In this case, a very steep filter (commonly called “brickwall”) is necessary, which is affected by a sever phase rotation down to audible frequencies. This is the case of the CD, in which the upper frequency limit (20kHz) is very close to half the sampling frequency (22.050kHz). In CD-like systems, at least 90dB attenuation must be obtained with a transition band of just 2kHz! Using higher sampling frequencies means having a larger transition band, thus less steep filters and more gentle phase behaviour, affecting higher frequencies. A 24-bit, 192kHz system handling an audio signal with 20kHz bandwidth can use a transition band of *76kHz to attenuate at least 120dB. This means that a simple 10-pole filter is sufficient. Much better and easier to implement than a 200-poles filter used in CD-like systems! Even better, a 32-bit, 384kHz system may use a 7-pole filter, something which is very similar to the natural band limiting in analog systems. * Conclusions High resolution is not marketing hype. It can help to make a digital system of device sound more similar to an analog one, provided users and experts keep in mind the real meaning and usefulness of having large bit depths and high sampling frequencies.[/font]
  4. [quote name='ScreencastTutor' timestamp='1355766886' post='1902477'] Right now... probably Good Times by Chic. If I could play them 100% it would be: Parliament - Give Up The Funk The Allman Brothers - Jessica [b]Brothers Johnson - Get The Funk Outta My Face[/b] [/quote] We used to do a thrash funk version of that!
  5. The only ones that get played voluntarily at our house are the mighty Tap's "Christmas with the Devil", and of course Bootsy's "Christmas is 4 ever", which has the funkiest "Silent Night" - it's the way it should be played!
  6. I enjoy playing both covers we do - one's "P-Funk (wants to get funked up)". The other's this: [media]http://www.youtube.com/watch?v=w2G_MwJSmWg[/media]
  7. Aye, obviously RIAA implementation is in the eye of the product designer! I tried a number by the likes of Tom Evans, Whest, Sutherland, Lehmann, Brinkmann and EAR. The EAR valve one won for me...
  8. [quote name='bigjohn' timestamp='1355493516' post='1899180'] Comparing vinyl to cd on the same HiFi isn't really playing fair. The signal chains are different. The vinyl chain has a phono-preamp. It's like plugging a passive bass into a nice pre-amp and saying "wow, listen to this, it's alive with these sounds and dynamics", then comparing it with an active bass plugged straight into a poweramp and saying it sounds dull and crap. Have a listen to a decent HiFi with a decent DAC and compare that with vinyl. The digital stuff sounds fine then. [/quote] The output from a phono stage is line level (give or take, depending on the phono stage). All the phonostage does is take a low level signal from a cartridge, boost it to line level and apply (hopefully) accurate RIAA equalisation. Some phono stages have variable input impedance to better match cart types, but otherwise it gives out an analogue signal at about the same level as the analogue output of a DAC. It's not like a graphic equaliser with variable frequency adjustments - though you can buy phono stages with variable (fixed) RIAA equalisation to match older standards. An active bass has boost and cut available, whereas a passive one only has cut... And talking of decent DACs, mine's an Advantage; they don't exist any more, but check out Bladelius hifi to find out what it's like - same designer. It sounds better than a Wadia 861 if that means owt! Even though it sounds excellent there's still a tiny bit (subjectively!) missing compared to vinyl - at least to my jaded and no doubt deafened ears.
  9. Funnily enough my phono stage has no rumble filters, or attentuation at any higher frequency, and it still sounds subjectively more pleasing! CD sounds pretty good as well, but after all, I'd prefer to hear badly recorded, poorly reproduced good music than extreme hifi music (like you'd hear on the Linn and Naim labels) on the world's most expensive stereo... It's the music I'm listening to, not the hifi!
  10. They should've got that nice Michael Buble in...
  11. I managed to give myself a nasty black eye yesterday by underestimating the torque reaction of a drill bit jamming and due to being jammed in a cupboard, being too close to a chunky 18V battery as it swung round... And I've split my thumb from excessive plucking.
  12. First time I noticed bass was when a lad at 6th form started playing in a band called the Action Transfers - he let me play his violin bass Then I heard Norman Watt-Roy and that was it, I gave up piano and got a mohawk together...
  13. I've been enjoying Bruichladdich PC7 as well...
  14. [quote name='51m0n' timestamp='1355230856' post='1895613'] Having said all of which the best reproduction I've ever experienced was 192KHz 24bit in a great control room. So IMO CD can be bettered, although I struggle to see how many of us would benefit from the difference between CD and even 96KHz in the front room, with the kids.... [/quote] Funnily enough, I haven't heard much better in a studio than at home - though this of course relies on auditory memory which is quite unreliable! However, as an exBBC sound recordist I was trained to listen, and have worked in some pretty serious places so maybe it's not so unreliable as it could be, and I do use the same amps as those at BBC Maida Vale (Bryston 14bsst) Room treatment-wise, I discovered that anything that was domestically acceptable made very little difference - as a result I don't use DSP either, though I have fiddled rather a lot with speaker placement. So it's as good as I can be bothered to make it; and if it sounds rubbish I turn it up (record is 123dB peaks at the listening position) and pretend I'm at Brixton Academy!
  15. I've tried a few room treatment options such as bass traps and absorbtion panels.Because of the room it is - very old with sound absorbing lime plaster walls, no 2 walls parallel, ceiling not parallel to floor and broken up by beams - it made very little difference, in fact a heavy sofa and curtains was all that was needed. In a lot of cases it's worthwhile, and cost effective, to try digital room correction like [url=http://www.bd-audio.co.uk/room-correction.html]THIS[/url].
  16. [quote name='flyfisher' timestamp='1355137722' post='1894423'] Interesting that the general consensus on here seems to be that £20k mains leads are snake oil but £20k turntables are not. [/quote] £20k is an enormous amount for a turntable, though there's a lot of pride of ownwership to be had if you like that sort of thing, and can afford it. A Clearaudio Master Reference is a thing of beauty - even Lara Croft had one And it will make vinyl sound as good as it possible could. However, in terms of bang per buck it would only be a tiny bit better than a £3k turntable (like mine), which is much a higher percentage better than a £300 one... As for mains leads, so long as it can pass the appropriate current, any old one will do. After all, there's miles of non-foo cable getting the electricity to your house, so what difference can a stupidly expensive one that's been hand-rolled on the thighs of Brazilian virgins make? As far as I'm concerned, this also applies to all hifi cables - all they have to be is electrically sufficient and not too high in terms of capacitance, inductance and to a lesser extent, resistance (unless you have a Naim amp, but that's another story...)
  17. [quote name='gelfin' timestamp='1355088146' post='1893934'] For everyone's info the top spec turntable from Linn the LP12 now costs in the region of £20k [/quote] £20k if you buy all the factory upgrades such as the Keel sub-chassis, Trampolin base-board, Lingo/Radikal power supplies etc. But in terms of vinyl reproduction only die-hard Sondek-ers would dispute that you can do much, much better than that for a fraction of the cost. Frinstance, you can buy one of the best TTs in the world (in my opinion!) for £8k, the Platine Verdier: Or if you really want to push the boat out (short of buying a Rockport at £70k), you can spend the same as a full-spec LP12 on the next TT up from mine, complete with parallel-tracking tonearm:
  18. A good record cleaner works wonders - you'd be surprised at the difference it can make to a crackly-sounding record. £40 buys you a Knosti Discostat, which works pretty well though it's a faff, up to £1000 (if you're made of money) will buy you a VPI vacuum record cleaner. Of course, any hifi would be incomplete without one of [url=http://www.machinadynamica.com/machina45.htm]THESE[/url] (and no, it isn't a joke website!).
  19. As has been pointed out, cd (and definitely higher resolution digital formats) is technically superior to vinyl. However, I find that when played side-by-side, folks still prefer the sound of vinyl. For me, the sound of a record is more musical, somehow, than a cd. And for the record (!) I have a Clearaudio Reference TT, and Advantage cdp. Perhaps it's the valve phomostage?
  20. [url="http://www.knightonmusiccentre.com"]www.knightonmusiccentre.com[/url] have got a Parker SB51 5 string at £699. It's not shown on his website, but I saw it there today... I bought the 4 string version off them, here with my Sandberg and Wal:
  21. You wouldn't have heard me squealing like a girl over the vtwin racket!
  22. [quote name='daz' timestamp='1337518766' post='1661198'] Aha, Shropshire middle of nowhere. I know it well Welcome. (I only once road a 1970s Moto Guzzi,850 and the brakes failed, just as I was coming up to a roundabout. I ended up riding straight over the grass in the middle!) [/quote] Never had the brakes fail, though the throttle stuck open once on the A1... Got it up to around 120mph before realising switching the engine off would stop it! Good noise though...
  23. Aye - we were proper fashion victims! Didn't matter what we sounded like so long as we were looking good. Or at least crazed...
  24. Lawks! 6 rehearsals a year? That's pretty much professional as far as my 2 bands are concerned. One is a funk rock band doing 30% covers - we're lucky if we get 1 rehearsal a year (as one guitarist is in the south of France) where we'll usually write/work out 3 new songs. And gig soundcheck is a chance to quickly run through anything we're a bit worried by. And the other band doesn't rehearse at all; we have a list of songs, ranging from Hendrix to John Coltrane that we all decide on by email though no=one decides what key, speed, feel etc until we're actually playing it. Luckily it's meant to be improvisation! Still, it would be nice to get together a few more times with both...
  25. [quote name='LukeFRC' timestamp='1334908346' post='1623182'] wow. that was a sight for sore eyes over breakfast! How does it sound/play too [/quote] It's nowhere near as good as my Wal, sandberg or Parker, despite the EMGs. Which is why it's hanging on the wall. And we were well known for our collective handsomeness back then - probably about 1989!
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