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About Ajax

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  1. Hi All, I have been reading more and contributing less lately as I get the impression that irrespective of the validity of one's argument it largely falls on deaf ears. We are all set in our ways, on both sides of the fence, and trying to convince someone who has held strong beliefs for a long time IMO is folly, especially if that person is over 40. I call this conditioning and we all suffer from it. Whether it be due to our home environment and our parents beliefs or what is ingrained into us during our teen years by our peers or schools when we are most impressionable. I've been a long time member of this forum and a huge fan of Chris's valiant efforts to walk the tightrope between freedom of speech and civility, however, I'm in total disagreement with the creation of the Objectives sub forum. Segregation is never healthy - in South Africa it was called Apartheid .... although obviously too strong an analogy for an audio forum. I think both @Archimago and @tmtomh have articulated the position of the objective member extremely well. I am an engineer (civil) and would just like to add for the benefit of the subjectives here that we are trained to ask "why" and to substantiate the facts. My introduction to engineering at university was via applied maths where it was instilled in me to prove everything from first principles, to ensure that I really understood what was going on and how the forces of nature work. (Compare that to a school kid today given a computer (and calculator) at an early age and then asking him at school leaving age to write something freehand or do a complicated division). The point I am trying to make is that it is inherent in our education and training to assume nothing and to always ask for "proof". If I designed a bridge or an office building and it subsequently fell down, and people were killed, I would not be able to rely on my "intuition" or my experience. I would need to show my calculations and be able to "prove" that I acted in accordance with the particular design code. Engineers are charged with the responsibility of taking the science and implementing it, and it is therefore extremely hard for us to sit back and ignore comments that fly in the face of facts and commonsense. No doubt they could have been more accomodating but I get why Bill (@wgscott) and @mans resorted to ridicule and sarcasm. They simply couldn't get their message through. They are a great loss to this forum and I will miss them both.
  2. Hi Joe, Thanks for the review and confirming my own thoughts on that album - it is excellent IMO. If you are interested in watching Billy live, then please get a DVD copy of the All Star Tribute to Brian Wilson held at the Radio City Music Hall in 2001. The cast and sound is excellent and Billy is in fine voice and his performance is outstanding. This is one of the best sounding concert DVDs I have ever heard and is thoroughly recommended for lovers of the Beach Boys. https://en.wikipedia.org/wiki/An_All-Star_Tribute_to_Brian_Wilson All the best, Ajax
  3. Hi Richard, I helped my nephew set up his system for his smallish townhouse and after a lot of research we selected the passive LS50s driven by a NuPrime IDA-8, that has its own internal DAC. Sounds great and the LS50 are certainly one of the best book shelf speakers I have heard. Combine that with a well implemented DAC, digital amplification and adding a pair of SUBs and it is easy to see why the wireless version it is such a revered product. I don't know what would compare with it $ vs sound quality for a small listening area except maybe a secondhand Benchmark DAC 2 into a pair of active speakers such as the ADAM A7xs.
  4. Great thread, always interested in opinions of others on gear, and I encourage other members to participate. Value Digital = Auralic Mini at a cost of about US$350. I'm not sure why Auralic discontinued the Mini because it delivers great sound with excellent flexibility at a ridiculously low price. If you can find a unit second hand I highly recommend purchasing one. I have three and use them in several different configurations including: 1. individual streamer utilising the DAC inside a Devialet 220 in my Living Room 2. individual streamer feeding a Benchmark DAC 2 into Nord Hypex NC500 Digital power amp in my Home Office 3. Standalone streamer/DAC with a booster SB linear power supply into a Marantz PM 5005 Integrated AMP at my Beach house I have installed a 500G SSD hard drive in each machine and have content provided by own "best off" albums as local files as well as Spotify Connect and Tidal while using the excellent free Lighting DS software. The unit is very small and light (size of the gen 3 Apple TV) and therefore easy to travel with .... just add powered monitors or simply plug it into the RCA inputs of an integrated amp or area amp. Brilliant! see Chris's review here Value Analogue - Rega Planar 3 turntable with Elys cartridge High End Value = Devialet 220, as described above by SJK this is a wonderful piece of electronics that provides incredible sound and flexibility in a very WAG friendly package. I bought it as an Ensemble with OTHM G1 speakers and added 2 x SVS SB 2000 subs, which I configure with the internal DSP crossover. By chance I have a French friend coming over next week (currently dating my wife's bestie) who is a lighting guru and travelled with Pink Floyd for 4 years and also did several Rolling Stones concerts. He is now responsible for the lightning of the Sydney Harbour Bridge on NYE. During his time lighting concerts he also learnt a lot about acoustics and is going to help me EQ my room as I have just completed a renovation. Should be great fun. High End Analogue = Linn LP12 turntable If I was allowed another product I would add the Benchmark DAC / ABH2 power amp combination but as we are only allowed one product per category I won't. All the best, Ajax
  5. I just bought a new house at Bangalow, Australia, which is 15 minutes from the Byron Bay Blues Festival, which is held over 5 days each Easter. There are a series of 5 marques, with around 7 acts in each every day. i.e. over 150 live one hour concerts over a 5 day period. It attracts over 100,000 music lovers and the artists that have appeared over the last 25 years include: Dylan, Canned Heat, John Mayall, Oasis, Taj Mahal, Elvin Bishop, Tony Joe White, Ben Harper, Ket Mo, Steve Earle, Robert Cray, Doctor John, Tony Joe White, Robben Ford, Emmylou Harris, Jack Johnson, John Fogerty, Buddy Guy, BB King, Elvis Costello, Crosby Still & Nash, Santana, Dave Mathews Band, Patti Smith, Robert Plant, Iggy Pop ....... I love my hifi system(s) but there ain't nothing like the real thing ..... standing in a heaving crowd of sweaty bodies grooving to the beat ... play that funky music white boy
  6. Hi Jud, A song from one of the all time great albums. I played it non stop as a teenager .... and still play it regularly. All the best, Ajax Enjoy your holiday listening!
  7. The upside of people making incorrect statements is that often one of our more knowledgeable members replies with a “considered” response from which we can all learn. e.g the numerous replies to “Class D amps suck” taught me a lot about the reasons why they in fact don’t and confirmed my own listening experience. Similarly the MQA threads taught me a lot about the importance of filters and how they work. To those who really understand how digital audio really works, and have been generous with their time in providing factual explanations, pls accept my sincere thanks.
  8. Hi Everyone, Firstly, thanks to all the contributors to date. Many differing views but in the main expressed in a cordial and informative manner, so thanks for that. I received an email from Mark Waldrep wherein he advised he had trouble exceeding his dropbox limit, which is why many of you could not download the files. He is now using google drive. Trouble viewing this email? Read it online The HD-Audio Challenge II has launched. Over 250 audio enthusiasts have already signed up and more are signing up everyday. Please feel free to encourage others to participate in this new research project by linking to this page. Anyone interested should submit their information using the form on the following page: CLICK HERE FOR THE FORM TO SIGN UP Last week, Dropbox informed me that they have banned my account because I exceeded my daily download allotment. So I moved all of the files to a Google Drive and have been sending the link to everyone that has signed up. If you haven't received the link, please be patient. I'm adding about 25-30 people every day to avoid swamping the Google account. Once you have the files, please let me know.
  9. Sorry for the off topic but could you pls expand on your statement "Then I installed proper electrical isolation between the computer and the USB input circuitry and the DAC." Should that have been "of the DAC? Irrespective of the semantics what exactly did you do to electrically isolate the DAC from the computer and enjoy such a large increase in sound quality. I assume the overall purpose / result was to mitigate noise?
  10. Hi Audiobomber, Here is the reference I believe that you are referring to, which is from Mark Wadrep's Dr AIX site. He is obviously a fan of Benchmark Media's DACs and AMPs's, as am I. Mark starts of by saying: I'm really fortunate to have friends that are smarter than me. In many aspects of life, it's great to be able to discuss and learn from people with different areas of expertise and life experiences. So when I authored a recent blog on "highly resolving" systems and whether they are necessary (you can read that article by clicking here ), it was a welcome surprise to hear from one of the smartest people I know, John Siau, the principal designer of both analog and digital systems at Benchmark Media. I consider their DACs to be among the finest on the planet — equally at home in my mastering room all these years AND in my home system. Benchmark supplied their DACs and power amplifiers for all of the 5.1 HD-Audio demos that AIX Records assembled at AXPONA shows. Benchmarks' hardware and my recordings delivered a music experience unlike any demo at any trade show in the history of trade shows. Why do I feel confident in making that boast? Because the entire signal path from source recording to speaker output was truly capable of maintaining high-resolution specifications — a truly "highly resolving" system. Read on and see how John's email clarifies the discussion with specifications and insights from a world class designer. Below is John's contribution to this important topic (reprinted here with his permission): Mark, It is not a matter of fancy cables, and esoteric tweaks. It is all about the math (MW bolded). If anyone hears the difference, it probably will not be on the basis of the frequency response. There are exactly three potential advantages provided by high-resolution audio: 1: An increased high frequency limit 2: An increased immunity to the clipping of intersample peaks 3: An increased SNR Items 2 and 3 are audible under the right circumstances. Item 1 may never or almost never be audible. Here is my reasoning: 1: High Frequency Limit Very few listeners will have transducers that extend beyond the 22 kHz limit of the CD format. The exception will be listeners with good headphones or very good speakers. But, most listeners can't hear beyond 20 kHz. You will need the rare combination of someone will excellent hearing beyond 22 kHz who is listening through good transducers. You will also need significant musical content above 22 kHz (at sufficient levels). This is going to be too small a group to be statistically significant. The size of this group is likely to be 0. You need to put some young but trained ears into some good headphones and play the right source material. 2: Clipping of intersample peaks The worst-case clipping is caused by a tone at 1/4 of the sample rate that is shifted 45 degrees relative to the sampling clock. This tone can reach 3.01 dB over 0 dBFS before the maximum digital codes are reached. This 0 dBFS + condition can happen 1000s of times on a single CD track. When upsampled in a sigma-delta D/A converter, these intersample peaks can cause clipping in the D/A converter. This often causes a DSP overload that creates a burst of IMD. This artifact is audible, but completely avoidable. The Benchmark DAC2 and DAC3 converters do not have this artifact at any sample rate. Most other D/A converters have this artifact. This will tend to make high sample rates sound better unless you are using Benchmark DAC2 or DAC3 converters. Here is a case where a better system makes all sample rates sound good. Most systems will make 44.1 sound worse than it should. 3: SNR: A few quick calculations will show that the listeners will need playback systems with at least an 87 dB SNR and they will need to play the audio at peak levels exceeding 93 dB SPL. Otherwise, it is mathematically impossible to hear the noise advantage of anything beyond 16 bits. If the listener's system has a playback SNR of 87 dB and it is playing at a peak SPL exceeding 93 dB, they would be listening for a very small 1 dB difference in the noise floor. If the listener's system has a much better SNR, then the task will be much easier (assuming they turn the volume up high enough the hear the 16-bit TPDF noise). If their system is absolute state of the art, it will have a 130 dB SNR. If they set 0 dBFS to 130 dB SPL, the 16-bit dither noise will be reproduced 37 dB above the threshold of hearing and would be very audible. On such a system, you could easily hear the differences in word lengths until you reach 23 bits. But, you would go deaf listening to the music unless the music had an unusually high crest factor or was recorded at a very low level. You would need to turn the system down to listen to the music. The more you turn it down, the less difference you will hear. Here is the math (nothing here that you do not already know): SNR in dB for a digital channel is (6.02*N)+1.76 measured over the entire Nyquist bandwidth of the channel. If the signal is TPDF dithered, subtract 4.77 dB Therefore, for TPDF channels we have: (6.02*N)+1.76-4.77=(6.02*N)-3.01 dB At 16 bits this gives 93.31 dB. We will round to 93 for the sake of discussion. In order for a listener to detect a difference on the basis of SNR, all three of the following conditions must be met: 1. The recorded noise must be lower than the channel noise of the 16-bit system (-93 dBFS). 2. The channel noise of the 16-bit system must be played at a level that exceeds 0 dB SPL. Therefore, the SPL at 0 dBFS must exceed 93 dB. 3. The noise produced by the playback system must not be more than 6 dB higher than that of the 16-bit system. This noise summation will produce just detectable noise difference of 1 dB. Therefore the SNR of the playback system must exceed 93-6 = 87 dB. Item 1: You are controlling item 1 with your choice of source material. Item 2: The listener may or may not choose to exceed a peak SPL of 93 dB during the test. The peak SPL chosen by listeners will be higher on uncompressed material due to the higher crest factor. You are choosing the source material and can experiment with different crest factors. Item 3: This is a big problem! Many "high-end" systems are not capable of delivering an 87 dB SNR. There are almost no speaker systems that can do better than about a 105 dB SNR because of amplifier limitations (the Benchmark AHB2 is a notable exception). A few state-of-the-art systems can deliver a 130 dB SNR to headphones if all of the components are properly gain staged (Benchmark DAC3 driving a Benchmark HPA4 is one example). A Benchmark AHB2 power amplifier driven by a Benchmark DAC3 can deliver a noise-free 130 dB SPL if it is driving speakers that have a sensitivity of at least 104 dB at 2.83 Vrms. We have a few customers with such systems, but there are less than 10 examples worldwide. Here is a chart that I created. It sums the digital channel with the playback system noise to calculate the SNR that will be delivered to the listener. I included bit depths of 8 through 24 bits. Find your playback SNR or peak playback SPL (whichever is lowest) on the X axis and then find the y value for each bit-depth curve. If the lines are separated at your SNR or SPL, then you will be able to hear a change in the noise floor. Example 1: If you have a noise-free playback level of 100 dB SPL (find 100 dB on the X axis), you should be able to hear changes for bit depths up to 19 bits. Beyond 19 bits, there will be no audible (or measurable) improvement. Example 2: If you have a system that can achieve a noise-free playback level 130 dB SPL, and you are playing it that loud, find 130 dB on the X axis. You should be able to hear the noise differences for bit depths up to 23 bits. Beyond 23 bits, there will be no audible (or measurable) improvement. Example 3: You have a system that has a SNR of 87 dB and you are playing it at a peak SPL of 100 dB. Take the lower of the two (87 dB) and find this on the X axis. Any bit depth above 16 bits will produce a 1 dB reduction in the noise relative to the 16-bit system. Longer word lengths may be just noticeable, but 17 bits will give the same performance as 24 bits. Example 4: 100 dB SNR playing at a peak level of only 80 dB. Find 80 dB on the X axis. Changes should be noticeable up to a bit depth of 14 bits. I should also note that a given D/A converter may deliver different performance at different sample rates. They often use entirely different filters and may have entirely different THD performance. The filters may have distinctly different phase response and this can be perceived as a change in frequency response. Early oversampled converters performed poorly at higher sample rates due to poor stop band attenuation. To mitigate this problem, I would suggest separating the word length tests from the sample rate tests. Change one parameter at time. Test 44.1/16 against 44.1/24. Then test 44.1/24 against 192/24. This will tell you if the audible differences are related to word length, sample rate or both. Once this has been established, you could look at 18, 20, and 22 bit depths to determine the threshold of audibility. You could also run a separate test to determine the audibility of sample rate is linked to intersample clipping or to bandwidth. John Siau
  11. Hi Alex, Apologies I just assumed it was you. Not sure why my name was on the quote regarding the files being uploaded? Not a big deal just weird.
  12. Ajax, would it be possible to hand ALL the original Hires to me by PM etc., so I can judge them for being genuine and / or not ruined ? I ask, because the chance anno 2019 is still a virtual zero that they are OK. Your list comprises just of too much to be all OK. Mind you, downconverts from multi channel are flawed by guarantee ... and you know your sources. So just saying ... Hi Peter, Not sure what is going on but that quote was from Alex (@Sandyk) not from me? i.e Alex uploaded files to his Dropbox
  13. Hi Hi Jud, Nice to hear from you. I hope you are enjoying your new home. My own renovations will be complete next month and my life should get back to normal. Tom Hank's "The Money Pit" has taken on a whole new meaning With regard to Hi Res I have a similar approach to yours, I've simply selected different experts being Mark Waldrep and John Siau. I'm not anti Hi Res as suggested by Alex, I'm simply sceptical, especially when it is open to manipulation by the likes of MQA. Mark has spent most of his career promoting the benefits of Hi Res but is now expressing some doubt of it's actual benefits. Hence the study and my promotion of it. in terms of experts Barry Diament has always maintained that 90% of the quality of the sound/music is determined before it leaves the microphones. He has selected 24/192 as his preferred format and believes that there is no need to go higher, whereas Mark Waldrep believes 24/96 to be sufficient, but is now second guessing that. John Siau believes 16/44.1 is sufficient assuming the DAC is property designed... it's just maths. George provided sound reasons (as have you) in his earlier comment why Hi Res is beneficial, however, can't they be overcome by well implemented noise shaping & dithering at the mastering end, and up sampling at the Software/ DAC end? For me personally CD quality just makes more sense as most of the music I listen to is either from the 70's and early 80's recorded to tape, or more recently music that has been heavily compressed. Both I believe are easily accommodated by CD's resolution. In a world where we all need to reduce our foot print shouldn't we strive for smaller data files not larger? For better or worst 16/44.1 was chosen as the benchmark by Sony & Phillips, accordingly the majority of music is in that format, should we not therefore focus our attention on better mastering of that format instead of allowing the marketing men to promote even greater and greater sample rates, whether PCM or DSD.
  14. Hi Alex, I've got a deal for you - I'll listen to Barry's Kay Sa if you agree to join Mark's Study and publish your results after he publishes his. Deal?
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