Audio myths & dogmas

There are many opinions on audio in forums and other outings on the web: Class A amps sound better, Straigt tone arms have better tracking, XLR cables sound better than RCA cables and so on. But are they true? Well, sometimes they are. I dreamed up this video at the end of my vacation overlooking the Mediterranean Sea near Diamante in the south west of Italy. Tracking some sites and one or two forums made me want to shout out loud that there is no universal single truth. Certainly in audio that’s the case. In the about 50 years I am involved in audio I have heard so much arguments on why a given - usually newly introduced - product should outperform any other product in that price range. Or even at any price.

01:03 - Seasoned marketeers come up with unique names for techniques only they offer. Often the technology isn’t patented but the unique name is trademarked. Sometimes because of the elaborate and thus expensive patent registration but often simply because the idea was not unique enough to be patented. Why do they do that? For the same reason composers of pop songs learn they have to have a ‘hook’ in a song. Unique properties make you remember that product better.

01:37 - And a well chosen trade name is better remembered and easily used as argument in favour of alleged qualities. But generally applied techniques can be used this way too. The automotive industry has used turbo, GT, 16 or 24 valves and so on. The audio industry uses Class A, Class A/B, Class D, local feedback, no feedback, 24 bit, femto clock and so on. In the old days, when I was in my infancy, my parents bought their stereo radio at the local shop. They knew the people that ran the shop and trusted their advise. In my late teens I worked at a large hifi shop in a bigger town and sold equipment costing far more than my parents would ever spend on music reproduction. I was not very talented as a sales person since I wanted to sell the stuff I liked. For that was the best. Colleagues of mine preferred to sell the stuff they got a good commission over. And although the stuff I would like to sell would not always be the best choice for the buyer, it often was a better choice than what some of my colleagues would ‘advise’.

02:56 - On the other side of the spectrum consumer organisations started reviewing audio gear for their members and they made their mistakes too since it was a rather new industry. They advised on individual components in stead of combinations of gear. At one time they had reviewed an IMF loudspeaker as best. That speaker needed a beefy amp but amps were reviewed separately. The outcome of that was a 2 x 12 watts Pioneer receiver that was not suited to drive the IMF’s.

03:29 - Knowing that sales persons in shops not always have the customers interest in mind, customers came with the guide of the consumer organisation in hand to buy those IMF’s and Pioneer receiver, further combined with a Pioneer turntable. The result was a dull sounding stereo. Magazines varied in reliability too - and they still do today. We now have Google as our friend. It brings you to forums, written reviews and video reviews. Although this great new technology connects you to the world, the quality of the information varies even more since anyone can post his opinion regardless of his background. Don’t get me wrong, freedom of press and freedom of speech is a great gift.

04:20 - But it also comes with the responsibility for the reader to weigh the opinions. As they say, the medium is the message. Even with reliable information you have to take in account the preferences of the source. There is no such thing as objective journalism. There is independent journalism at best. Opinions are based on listening training, experience, cultural background and so on. As we have seen, seeking for certainty people go for anchor points. There are often based on dogmas.

04:59 - Let’s look at some: “A tube amp sounds warm.” A good tube amp gets warm but shouldn’t sound warm since that would mean that it’s not a linear design. The argument about even harmonics distortion is also questionable. Good tube amps have qualities you can find with good solid state amps and vice versa. There are, of course, tube amps that are designed to fulfil the myth. These can have a tailored frequency response or increased even harmonic distortion. Good tube amps can have a very clean mid range and a royal stereo image. But so can good solid state designs. The main difference is that tube amps need to be less powerful than solid state amps. Some even say that there is a factor of 10 between them. I must say that my single ended 2 x 15 watt Audio Note can’t drive the speakers to the same sound pressure level as a 2 x 150 watt quality solid state amp without compressing transients.

06:05 - I think a factor of 5 would be more appropriate. Class D amplifiers are considered to offer shiploads of power for little money. And they do. But if serious sound quality is your goal, you do need to spend serious money. As always a single component, like a class D amplifier module DIY’ers use, won’t deliver the sound quality on it’s own. Take for instance the popular Hypex NC400 class D module that delivers 400 watt in 4Ω and costs € 275.

06:44 - You then need a power supply and a housing with connectors and loudspeaker binding posts. Hypex offers a complete kit for € 575. No money for a single channel power amplifier that probably does about 200 watt into 8Ω. If that would offer the highest of high-end sound quality, then why would Mola Mola - which is a Hypex related company - bring out their Kaluga mono power amp for just under € 6,000? Simple: using peripheral components of higher quality and tweaking gives a far higher sound quality. I know, being a ready to use product, labour and distribution costs adds up too. Of course there are ways in between, like the CI Audio C-100S which is a stereo power amp costing € 1,595 and sounds better than the Hypex NC400 kit.

07:42 - I have mentioned this already several times but it needs to be mentioned again. Using a given DAC chip - the component that does the actual conversion from digital to analog - does not guarantee a given sound quality. Take for instance the ESS Sabre ES9038Q2M. That can be found in € 300 costing DACs but also in far more expensive ones. Here the story is the same as with the class D amps. The DAC chip on itself can’t deliver the quality. It needs a quality power supply, quality input circuits, a quality clock oscillator, quality analog audio after the DAC chip and a very clever circuit board. And of course it is most likely that the ESS Sabe ES9038Pro version will sound better than the ES9038Q2M. But if the latter is applied in a quality design it will sound absolutely better than the pro version in a poor design. There are those that use sophisticated measurement equipment to carefully measure the signal to noise ratio and all kinds of distortion to judge the quality of equipment.

09:07 - The outcome of these measurements are then compared with other products with equal function. The best measurement figures define the winner. The problem is that depending on the technology used, measurements need to be different. This requires deep insight into the design of a product, insight that can normally only be found with people that design equipment professionally on a day to day basis. I know I don’t have those skills. One of the reasons I don’t publish my measurements lies there.

09:41 - Comparing measurements does not bring you the best sounding product. It merely gives you peace of mind, thinking you have made the right choice. If that’s fine with you, that’s great. Chances that you really did pick the best sounding product are slim. Another myth: XLR interconnects are always better than RCA’s. Balanced audio connections use three pin connectors, the so called XLR connector. It’s sometimes also called the Cannon plug after its inventor James H. Cannon. The pins are numbered; 1 is connected to ground or shield, 2 caries the positive polarity and 3 the negative polarity. With RCA connectors the negative polarity is combined with ground. This means that interfering signals on the ground plane will automatically be added to the audio signal. This is not the case with balanced connections on XLR.

10:44 - Unfortunately not every input and output on XLR is truly balanced. Most consumer equipment use asymmetrical circuits, circuits that use the system ground for the negative polarity of the audio signal as well. It’s more economical since it uses half the components. For a balanced circuit you need the same components twice: once for the positive and once for the negative polarity. Because of market demand manufacturers started mounting XLR inputs and outputs on asymmetrical equipment.

11:18 - On the output you simply connect pin 1 and 3 and on the input you use a so called op-amp to convert from balanced to asymmetrical. In both cases the advantage of a separate ground is lost while at the input an extra amplifier stage is needed that can only degrade the sound somewhat. So for an XLR cable - a balanced cable - to be advantageous both the sending and receiving device needs to be fully balanced. Today more and more DAC’s offer balanced outputs since DAC chips have balanced outputs. The audio circuit needed between the DAC chip and the output connectors is rather short so the component count - and thus the cost - is low. For amplifiers it’s different.

12:05 - Most amps have single ended circuits so there will not be an advantage using XLR cables. Today many class D amps, like the earlier mentioned Hypex modules, do have balanced inputs which is great if you also have a DAC with volume control. Then using XLR interconnects is the best choice. Since you often don’t know if your amp is balanced, it’s good to know that there is no harm in using XLR interconnects. They will function like single ended cable, only the price of the cable might be higher.

12:44 - The group of AES3 digital interfaces all use the same audio data. So TOSlink, SPDIF and AES/EBU are effectively data compatible.TOSlink and SPDIF even use 100% identical data; TOSlink is the electrical SPDIF signal converted to light and back. Officially AES/EBU uses some different status bits that for instance have to do with copy protection. Status bits tell the receiving device what signal is sent. But on consumer audio - including high-end equipment - the SPDIF data is used. But in stead of using 0.5 to 0.6 volts over a single ended 75Ω cable according to the SPDIF specs, 2 to 7 volts is used over a 110Ω balanced cable using XLR’s. In good designs a small transformer or high speed isolator is used on the receiving end for galvanic separation and then AES/EBU is the better choice if you use a 110Ω XLR cable. I recently got a question whether it is true that playing a cd in a cd-player sounds better than playing a downloaded FLAC file. Friends of his claimed that. It’s a simple question that needs a complex answer.

14:01 - If the downloaded file contains the same data, for instance if it is ripped from that cd using a good drive and quality ripping software, the sound should be identical. But it often isn’t and one or the other will sound better. But why and which one? It all has to do with the quality of the playback equipment. Let’s assume that we play both over the same d/a-converter for fair comparison. If you then use a normal computer with the standard music player like Windows Media Player on Windows or iTunes on MacOS and compare that with a cd-player, the cd-player will win hands down.

14:43 - The standard music player will always play the music over the OS’s software audio mixer that will do volume and sample rate conversion. That will absolutely degrade the audio quality. You want every bit in the file to be sent to the DAC: you want bit perfect reproduction. That can be done with many software players. I use Audirvana, JRiver Media Center and Roon but there are many more. On Windows computer you do need to make other adjustments which will be described in the manual of the bit-perfect software. Now the FLAC file might win from using the cd-player if the cd-player is a cheap one. To have the FLAC file be equal or win from the cd-player you need to eliminate the interference signals that live inside a computer. For instance by using a top quality USB cleaner like the Uptone Audio ISO Regen USB reconditioner I reviewed over a year ago. Even better is using a network bridge. See my video “What is a network bridge and how does it work?” Or use a computer that is specially made to reproduce music at a high quality.

15:58 - These are often called music servers or audio servers. See my playlist “Audio servers”. Or use a network player or network bridge. Links are in the comments below this video in Youtube. It is my experience that using normal 44.1 kHz FLAC, WAV or Apple lossless files on quality equipment will offer better quality sound than CD-players costing the same. And you then have the option to go for even higher sound quality by buying high resolution files at for instance 96 or 192 kHz sampling.

16:38 - Another popular item is the sound quality between carriers and services. Does the ripped cd sound better dan Tidal or Qobuz? Does a track from Tidal sound different from that same track from Qobuz? Again many different opinions can be found on the web. And they are all valid for that single event and that single setup. Why? Because of the work of mastering engineers. When musicians finish an album or single, it is sent to a mastering engineer.

17:14 - His job is to make the files the best sounding on any medium. There will be a version for cd-mastering, versions for streaming services, versions for radio stations and a version for vinyl cutting. You might think four versions will suffice but this is not the case. Every streaming service has their own sets of requirements and will apply their set of signal processing. Spotify uses lossy compression so the music files are tailored for that use. Tidal prefer to use MQA, which might need adaption. Qobuz uses FLAC up to 192 kHz so they might want a 44.1 kHz and a 96 or 192 kHz version if the recordings were made in high-res. For radio stations it’s even worse since every station uses multiband compressors like those from Optimod to make their specific sound. The mastering engineer needs to find out how he can tailor the audio files so that after the station processing the music still stands out.

18:22 - And every radio station - sometimes every DJ - has its own processing. If we leave radio stations out of the equation, we still have other problems caused by the playback equipment. We all know that perfect audio equipment doesn’t exist. There only are workable compromises. These can yield great results, don’t get me wrong. But choices made by the mastering engineer might work better on some equipment than on others.

18:51 - So a normal FLAC file from Tidal might sound different than the same track from Qobuz. Let alone high-res files that Tidal sends as MQA files while Qobuz uses regular FLAC files. Tidal might therefore sound better using an MQA compatible DAC while Qobuz high-res might sound better on a non-MQA DAC. Although that even isn’t sure for that depends on the quality of the DAC’s. I just mentioned a few of the audio dogmas, there are many more.

19:28 - They often start by enthusiast spending hours on comparing equipment at hand and draw general conclusions from it. Understandable and in fact great that they show so much interest in music reproduction. But as you might have seen in the comments on YouTube I stay away from commenting on equipment I have not reviewed myself. Audio reproduction is based on many disciplines: physics, electronics, ICT, mechanics, psycho-acoustics and even neurology. Especially people with an electronics or ICT education often don’t realise that.

20:06 - It is clearly safer to just trust your ears. If it sounds good, it sounds good. At least for you and you’re the one that bought the equipment for enjoyment. There sure are traps and you might make mistakes, but so will others you base your decisions on. Be an audio Jedi, feel the force. Trust your own ears. You can do it. Which brings us to the end of this program. But there will be another video next Friday at 5 pm central European time.

20:38 - If you don’t want to miss that, subscribe to this channel or follow me on the social media so you’ll be informed when new videos are out. If you liked this video, give it a thumbs up. Many thanks to those viewers that support this channel financially, it keeps me independent and thus trustworthy. If that makes you feel like supporting my work too, the links are in the comments below this video on Youtube. I am Hans Beekhuyzen, thank you for watching and see you in the next show or on theHBproject.com. And whatever you do, enjoy the music. .