Audio trends and snake oil

What annoys me today in marketing and media that too often today then talking on hi-fi, science is replaced by bizarre belief structures and marketing fluff, leading to a decades-long stagnation of the audiophile domainScience makes progress, pseudo-science doesn’t. Hi-fi world is filled by pseudoscience, dogma and fruitloopery to the extent that it resembles a fundamentalist religion. Loudspeaker performance hasn’t tangibly improved in forty years and vast sums are spent addressing the wrong problems.

Business for Engineers: Marketers Lie article points tout that marketing tells lies — falsehoods — things that serve to convey a false impression. Marketing’s purpose is to determining how the product will be branded, positioned, and sold. It seems that there too many snake oil rubbish products marketed in the name of hifi. It is irritating to watch the stupid people in the world be fooled.

In EEVblog #29 – Audiophile Audiophoolery video David L. Jones (from EEVBlog) cuts loose on the Golden Ear Audiophiles and all their Audiophoolery snake oil rubbish. The information presented in Dave’s unique non-scripted overly enthusiastic style! He’s an enthusiastic chap, but couldn’t agree more with many of the opinions he expressed: Directional cables, thousand dollar IEC power cables, and all that rubbish. Monster Cable gets mostered. Note what he says right at the end: “If you pay ridiculous money for these cable you will hear a difference, but don’t expect your friends to”. If you want to believe, you will.

My points on hifi-nonsense:

One of the tenets of audiophile systems is that they are assembled from components, allegedly so that the user can “choose” the best combination. This is pretty largely a myth. The main advantage of component systems is that the dealer can sell ridiculously expensive cables, hand-knitted by Peruvian virgins and soaked in snake oil, to connect it all up. Say goodbye to the noughties: Yesterday’s hi-fi biz is BUSTED, bro article asks are the days of floorstanders and separates numbered? If traditional two-channel audio does have a future, then it could be as the preserve of high resolution audio. Sony has taken the industry lead in High-Res Audio.
HIFI Cable Humbug and Snake oil etc. blog posting rightly points out that there is too much emphasis placed on spending huge sums of money on HIFI cables. Most of what is written about this subject is complete tripe. HIFI magazines promote myths about the benefits of all sorts of equipment. I am as amazed as the writer that that so called audiophiles and HIFI journalists can be fooled into thinking that very expensive speaker cables etc. improve performance. I generally agree – most of this expensive interconnect cable stuff is just plain overpriced.

I can agree that in analogue interconnect cables there are few cases where better cables can really result in cleaner sound, but usually getting any noticeable difference needs that the one you compare with was very bad yo start with (clearly too thin speaker wires with resistance, interconnect that picks interference etc..) or the equipment in the systems are so that they are overly-sensitive to cable characteristics (generally bad equipment designs can make for example cable capacitance affect 100 times or more than it should).  Definitely too much snake oil. Good solid engineering is all that is required (like keep LCR low, Teflon or other good insulation, shielding if required, proper gauge for application and the distance traveled). Geometry is a factor but not in the same sense these yahoos preach and deceive.

In digital interconnect cables story is different than on those analogue interconnect cables. Generally in digital interconnect cables the communication either works, does not work or sometimes work unreliably. The digital cable either gets the bits to the other end or not, it does not magically alter the sound that goes through the cable. You need to have active electronics like digital signal processor to change the tone of the audio signal traveling on the digital cable, cable will just not do that.

But this digital interconnect cables characteristics has not stopped hifi marketers to make very expensive cable products that are marketed with unbelievable claims. Ethernet has come to audio world, so there are hifi Ethernet cables. How about 500 dollar Ethernet cable? That’s ridiculous. And it’s only 1.5 meters. Then how about $10,000 audiophile ethernet cable? Bias your dielectrics with the Dielectric-Bias ethernet cable from AudioQuest: “When insulation is unbiased, it slows down parts of the signal differently, a big problem for very time-sensitive multi-octave audio.” I see this as complete marketing crap speak. It seems that they’re made for gullible idiots. No professional would EVER waste money on those cables. Audioquest even produces iPhone sync cables in similar price ranges.

HIFI Cable insulators/supports (expensive blocks that keep cables few centimeters off the floor) are a product category I don’t get. They typically claim to offer incredible performance as well as appealing appearance. Conventional cable isolation theory holds that optimal cable performance can be achieved by elevating cables from the floor in an attempt to control vibrations and manage static fields. Typical cable elevators are made from electrically insulating materials such as wood, glass, plastic or ceramics. Most of these products claim superior performance based upon the materials or methods of elevation. I don’t get those claims.

Along with green magic markers on CDs and audio bricks is another item called the wire conditioner. The claim is that unused wires do not sound the same as wires that have been used for a period of time. I don’t get this product category. And I don’t believe claims in the line like “Natural Quartz crystals along with proprietary materials cause a molecular restructuring of the media, which reduces stress, and significantly improves its mechanical, acoustic, electric, and optical characteristics.” All sounds like just pure marketing with no real benefits.

CD no evil, hear no evil. But the key thing about the CD was that it represented an obvious leap from earlier recording media that simply weren’t good enough for delivery of post-produced material to the consumer to one that was. Once you have made that leap, there is no requirement to go further. The 16 bits of CD were effectively extended to 18 bits by the development of noise shaping, which allows over 100dB signal to noise ratio. That falls a bit short of the 140dB maximum range of human hearing, but that has never been a real goal. If you improve the digital media, the sound quality limiting problem became the transducers; the headphones and the speakers.

We need to talk about SPEAKERS: Soz, ‘audiophiles’, only IT will break the sound barrier article says that today’s loudspeakers are nowhere near as good as they could be, due in no small measure to the presence of “traditional” audiophile products. that today’s loudspeakers are nowhere near as good as they could be, due in no small measure to the presence of “traditional” audiophile products. I can agree with this. Loudspeaker performance hasn’t tangibly improved in forty years and vast sums are spent addressing the wrong problems.

We need to talk about SPEAKERS: Soz, ‘audiophiles’, only IT will break the sound barrier article makes good points on design, DSPs and the debunking of traditional hi-fi. Science makes progress, pseudo-science doesn’t. Legacy loudspeakers are omni-directional at low frequencies, but as frequency rises, the radiation becomes more directional until at the highest frequencies the sound only emerges directly forwards. Thus to enjoy the full frequency range, the listener has to sit in the so-called sweet spot. As a result legacy loudspeakers with sweet spots need extensive room treatment to soak up the deficient off-axis sound. New tools that can change speaker system designs in the future are omni-directional speakers and DSP-based room correction. It’s a scenario ripe for “disruption”.

Computers have become an integrated part of many audio setups. Back in the day integrated audio solutions in PCs had trouble earning respect. Ode To Sound Blaster: Are Discrete Audio Cards Still Worth the Investment? posting tells that it’s been 25 years since the first Sound Blaster card was introduced (a pretty remarkable feat considering the diminished reliance on discrete audio in PCs) and many enthusiasts still consider a sound card an essential piece to the PC building puzzle. It seems that in general onboard sound is finally “Good Enough”, and has been “Good Enough” for a long time now. For most users it is hard to justify the high price of special sound card on PC anymore. There are still some PCs with bad sound hardware on motherboard and buttload of cheap USB adapters with very poor performance. However, what if you want the best sound possible, the lowest noise possible, and don’t really game or use the various audio enhancements? You just want a plain-vanilla sound card, but with the highest quality audio (products typically made for music makers). You can find some really good USB solutions that will blow on-board audio out of the water for about $100 or so.

Although solid-state technology overwhelmingly dominates today’s world of electronics, vacuum tubes are holding out in two small but vibrant areas.  Some people like the sound of tubes. The Cool Sound of Tubes article says that a commercially viable number of people find that they prefer the sound produced by tubed equipment in three areas: musical-instrument (MI) amplifiers (mainly guitar amps), some processing devices used in recording studios, and a small but growing percentage of high-fidelity equipment at the high end of the audiophile market. Keep those filaments lit, Design your own Vacuum Tube Audio Equipment article claims that vacuum tubes do sound better than transistors (before you hate in the comments check out this scholarly article on the topic). The difficulty is cost; tube gear is very expensive because it uses lots of copper, iron, often point-to-point wired by hand, and requires a heavy metal chassis to support all of these parts. With this high cost and relative simplicity of circuitry (compared to modern electronics) comes good justification for building your own gear. Maybe this is one of the last frontiers of do-it-yourself that is actually worth doing.

 

 

1,575 Comments

  1. Tomi Engdahl says:

    Electronics Tutorial – Common Audio Amplifier Classes (A, B, AB, G, H and D)
    https://www.youtube.com/watch?v=rR69btcolFc

    In this electronics tutorial video I take a look at the most common audio amplifier topologies used – the class A, class B, class AB, class G, class H and class D. What makes each of these amplifier classes different in regards to linearity and efficiency? And to show how such electronic circuits can look in a real circuit, I also simulate them using LTspice.

    https://drive.google.com/drive/folders/19sV0b4Iip4t7th8UGLWJH547rTo3NAhv

    Reply
  2. Tomi Engdahl says:

    https://www.facebook.com/groups/DIYAudio/permalink/5195683050497499/

    Is there a disadvantage using opamp as buffers and preamp stage of a power amplifier? Thanks.

    It has a few:

    1) It cannot be powered with the same voltage as the amplifier, so you don’t have enough voltage swing to drive the next stages, so you need voltage amplification stages. In practice, op amps only replace the input stage.

    2) Again for point 1, the amount of feedback that must return from the output stage is less, because it cannot manage the feedback of the op throughout the swing. This makes it impossible to use the entire open loop of the op, so you cannot achieve a very low level of distortion like that of the op itself.

    3) To do slew rate, you need current. The more current the op has, the lower its maximum supply voltage. If an op has 100V / uS of slew these do not necessarily apply to the following stages, because the stages do not have infinite speed. Therefore the maximum slew will always be less than that of the op. The lower the supply voltage, the lower the maximum output swing, the lower the slew even if this is very high in the parameters of the op.

    Reply
  3. Tomi Engdahl says:

    Audiophile-sounding DAC for almost no money
    https://hackaday.io/project/27001-audiophile-sounding-dac-for-almost-no-money

    0DAC – delivers engaging, immersive sound with a pricetag at least two orders of magnitude from commercial audiophile DACs

    Several years ago, a blogger ‘NwAvGuy’ introduced a DAC design named ‘ODAC’. ‘O’ meant ‘objective’ because it was designed to achieve the best objective criteria (measurements, in particular THD+N). My design is the complement of that, designed entirely for listening enjoyment with little regard for measurements. The broader aim is to make audiophile sound quality a commodity so everyone gets to get off on the music. Wave a cheery ‘goodbye’ to fatiguing digital sound! The BOM cost is low (sub $10) and the circuit board area modest (75cm^2) – to keep both down it has only I2S input. The output stage is a single-ended classA buffer which can drive low-impedance headphones direct if desired.

    The name of this design is 0DAC, pronounced ‘lingDAC’ (zero = ling in Mandarin).

    Reply
  4. Tomi Engdahl says:

    Speaker cables are two wires that needs to be relatively thick especially in high power systems.
    Microphone cables have a pair of thin shielded wires twisted together and covered with shield. Trying to use microphone cable as speaker cable could work at short distance at low power (few watts), but at longer disrance and/or high power leads to many problems. Thin wire has lots of resistance, which can affect speaker response (frequency response, control) and cause power loss that heats the cable (up to the point of insulation melting and putting out smoke with hundreds of watts or more available power played at high volume, very this wire can fail at much lower power).

    Reply
  5. Tomi Engdahl says:

    Audio cords never carry enough voltage (or current? whatever) to shock you if you grab this?

    Consumer audio interconnection cords do not generally carry enough voltage to shock you. You can get shocked with cable if the equipment they are connected to leak mains voltage to their case and audio signao ground.
    Speaker cables can carry dangerous voltages and current on high power audio systems. The 48V phantom power can be felt like mild shock in some cases.

    Reply
  6. Tomi Engdahl says:

    Some cable claims:

    1: Gold makes a better surface connection than all other metals (plugs e.g.)
    2: Silver conducts best of all metals (but not much better than copper), pr. cross section
    3: Characteristic impedance can be an issue. For speakers not.
    4: The “skin effect” – high frequency signals tend to wander more on the outside of a conductur than evenly in the cross section. This *may* be an issue at 10-20kHz and above.

    Reply
  7. Tomi Engdahl says:

    Cable talk from
    https://www.facebook.com/groups/517919938413134/permalink/1795166490688466/

    What are peoples thoughts on expensive cables for studio routing? i.e. Mogami, Van Damme etc. I get it for live work where they are being plugged in and out and moved every day, build quality would be a consideration but aside from that is there an audible difference between the aforementioned and say a Hosa snake for £30.00?

    1: Gold makes a better surface connection than all other metals (plugs e.g.)
    2: Silver conducts best of all metals (but not much better than copper), pr. cross section
    3: Characteristic impedance can be an issue. For speakers not.
    4: The “skin effect” – high frequency signals tend to wander more on the outside of a conductor than evenly in the cross section. This *may* be an issue at 10-20kHz and above. In this case a “Litze-wire” or a wire with several individual wires will do the surface area job.

    For studio routing, you should be in the digital realm and using Cat5 or 6 cable. If you need to be in analog, Belden 9451 will give excellent results.

    Good cables help prevent outside noise from influencing the sound. I’ve experienced a different sound with different line level cables but only slightly different based on the gauge. Thicker gauge generally transmits bass better, but it’s also more noisy. The quadstar style cables are technically an inductor, so they could work as a low pass filter and a cable!

    I like mogami 2549 for like level and i use 2534 on long runs for tracking.

    Cheap cables are also assembled cheaper… cheaper solder and cheaper labor, so you could waste time rewiring transformers to fix polarity issues only to find out it was the HOSA snake going to the pre which was built wrong from the factory!

    2 hours of my life gone before I figured out what the real issue was.

    Yeah copper is copper 100% but you better pay attention to those connectors. You will have to replace Hosa quality cables after a few years of heavy use if not sooner. Soundquality is not going to matter that much at first but you’ll notice it deteriorates over time. Much higher quality cable uses better materials but have a proprietary process for shielding or braiding, and the connector is going to be light years better.

    Copper is copper, for the most part.

    the hosa molded on ends suck

    Reply
  8. Tomi Engdahl says:

    https://gearspace.com/board/high-end/36853-gold-plated-connectors-not.html

    Avoid mating disimilar metals. Mating gold with other non gold alloys will eventually cause “metal migration” where the alloys chemically react and begin to separate. This causes a diode effect where low levels of electrons will stick until enough current arrives to push them through. This causes low level grit on the signal. See papers on the subject written by D.W. Electrochemicals, the makers of Stabilant 22, a chemical when applied will prevent this problem.

    Reply
  9. Tomi Engdahl says:

    Einar Nyaas gold to gold connection is good because gold connectors won’t oxidize like non-gold connectors. However, when you use gold connectors in conjunction with non gold connectors you can run into a dielectric situation. So if you go for gold connectors, you should ideally use gold throughout.

    XLR connector contacts are typically made of bronze or brass material that has has had traditionally silver contact surface, but there are nowadays also some XLR connectors with gold contact surface.

    Reply
  10. Tomi Engdahl says:

    It all depends.
    How big is your studio (i.e. how long are your cables)?
    What gear are you connecting to it? (Very cheap and the cables won’t be your weakest link, very expensive and it won’t be – or shouldn’t be – so fussy! It’s in the middle that the biggest advantages often come of spending more.)
    Balanced or unbalanced? (Same sort of thing, a fully balanced installation is less fussy about cable type – or, more strictly, differently fussy.)
    So there’s probably no one “just right” price / quality point for cables. But, as several have said, do get decent connectors on the end of them!!

    Reply
  11. Tomi Engdahl says:

    Make an $80 Amp Beat $1,000 Amps?! Find out How!
    https://m.youtube.com/watch?v=iMOSrFYola8

    Reply
  12. Tomi Engdahl says:

    There are generally two types of distortion:

    Frequency distortion—caused by insufficient bandwidth and non-flat frequency response between the bandwidth limits
    Nonlinearity distortion—caused by nonlinearities in the hardware.

    https://www.allaboutcircuits.com/technical-articles/what-is-it-about-audio-distortion/

    Reply
  13. Tomi Engdahl says:

    Tested: Where Does The Tone Come From In A Speaker Cab?
    https://www.youtube.com/watch?v=Dwgkjm8PWvk

    Reply
  14. Tomi Engdahl says:

    https://www.facebook.com/groups/DIYAudio/permalink/5279982002067603/

    The Holy Grail of Audio . . .

    It’s fitting that “audiophiles” are often called “audiophools” – we’re always searching for the ultimate sound, and as a rule, few are ever 100% satisfied, which drives equipment sales and eBay trades.

    Folks ask why I have built so many amps and [now] preamps . . . it’s that quest for perfection driven by some degree of dissatisfaction.

    Reply
  15. Tomi Engdahl says:

    While the holy audio grail may not exist at all, you are guaranteed not to find it in the Realm of Passive Crossovers and 2 Channel Amplifiers

    Reply
  16. Tomi Engdahl says:

    https://www.facebook.com/105030045390581/posts/pfbid02JiWfLP7Wa4DFT9xZCtTo2YXa4eNpUKDSbTorqEYHfcqHvG5awog1mfUzWmeaRGqHl/

    A couple of people have asked whether it’s worth substituting the PSUs currently supplied with the Spartan 10 as they certainly feel rather ordinary. While they look like normal modern switching wall-warts, they are in fact linear transfomers with much quieter operation and far better capacitive isolation from the mains than switchers. A low leakage capacitance is important as it stops the mains coupling into the ground path which will be connected in some form to the low voltage output to derive relative power supply rails.

    The first photo shows the linear type used by Classic Audio with only 30pF measured between the mains and low voltage side (in reality it’s more like 20pF due to leakage between the test leads). Very little AC current from the mains can be coupled from the high voltage to the low voltage side.

    The isolation is excellent and there are no components connected between the high and low voltage sides. The low voltage low frequency AC output is then rectified and regulated to very quiet DC rails inside the Spartan 10, although it’s not really necessary as the amplifiers inside the S10 have superb rail rejection. The regulation is there mainly to protect from power surges and ensure the headroom doesn’t vary with mains voltage.

    The second photo shows a switching supply commonly found with a lot of similar audio gear. Here the isolation is not great due to the need to connect a ‘suppression’ capacitor between the high and low voltage sides of the switching supply to prevent the high frequency switching transients from coupling across to the low voltage side and causing radio frequency emission from the output lead. It measures at 660pF of leakage capacitance, some 30 times higher than the linear transformer. In reality it is more than double this as it sits behind the high-voltage rectifier which skews the reading on the meter. This isn’t good news as 30+ times more HF noise from the mains can get into our ground path and our equipment will now ‘float’ on the end of this leakage capacitance if not grounded. Switching transients from the high voltage rectifier will also make their way into the ground path at a considerably greater level.

    The switching supply is cheaper and doesn’t require internal regulation inside the piece of equipment it’s connected to (although such regulation is likely to be ineffective if required as the noise on the output will be high frequency and harder for a linear regulator to reject).

    The external PSU for the S10 is a plain simple low frequency transformer. The power supply rails are derived within the unit itself with the rectifiers, smoothing capacitors and regulators. The internal components determine the performance of the power supply which as already mentioned is much better than it already needs to be, the transformer simply supplies the working voltage and ensures excellent isolation from the mains.

    Contrary to marketing lies told by others regarding highly dubious claims of ‘transient headroom’, or ‘high instantaneous current for punch and slam’ (whatever that means!) a bigger transformer will do nothing except reduce the isolation due to the larger area between the high and low voltage sides. Anyone making these claims should be treated with suspicion as they either don’t know what they’re talking about or are just straight up making fraudulent claims.

    Instantaneous current demand is met by the internal reservoir capacitors, not the external transformer which only charges the reservoirs for a few milliseconds 50 times per second. The rectifier essentially disconnects it from the reservoir and DC rails for 80% of the time! As long as the reservoirs hold up the voltage ahead of the regulators then the power supply delivers the voltage and the current. This is not a linear process and the regulator doesn’t care what the exact voltage is in the reservoir so long as it’s above 18 volts or so. In the Spartan 10 it remains around 22V at full load, ensuring an excellent margin of operation. The transformer is rated to supply the average current and then some, so the small size is quite adequate.

    So there we are! Fortunately they really are the best devices for the job! You can try this one at home also if you have a capacitance meter handy. Rant over :) !

    Reply
  17. Tomi Engdahl says:

    Can you define “sounds terrible”? Does the sound lack body, too much top end, too much midrange for example?

    Reply
  18. Tomi Engdahl says:

    If you feel retarded today.. remember – there is someone out there who will pay for this –

    Audiophiles are always very easy to part with money and this is, frankly, pure genius. I wish I did this, lmao! These go for 4 to 5 figures.

    https://www.entreq.com/products/ground-boxes-17667704

    Reply
  19. Tomi Engdahl says:

    $1,000,000 The World’s Greatest Audio Systems and United Home Audio tape decks
    https://www.youtube.com/watch?v=fr8O_jZhpl4

    I was thinking how amazing this sounds coming out of my $15 desktop speakers.

    Reply
  20. Tomi Engdahl says:

    One Man’s Dream – Ken Fritz Documentary about the world’s best stereo system
    https://www.youtube.com/watch?v=4b2IOOhJmxw

    Reply
  21. Tomi Engdahl says:

    John DeVore goes on a rant about the High End Audio lie that inspired him to start his company
    https://www.youtube.com/watch?v=PEcFkSQMc8g

    How specifications can be accurate and still be a lie. Some facts about sensitivity.

    Reply
  22. Tomi Engdahl says:

    How a $300,000 Speaker is Made
    https://www.youtube.com/watch?v=wX65iSZTI7E

    Oswalds Mill Audio makes $300,000 speakers from wood like ash, cherry, and walnut—plus slate and special cast iron. The sound quality is as good as the materials.

    Made is a series of simple, gorgeous short films that demonstrate how everyday luxury objects are made, and honor the process and artisans behind them.

    Reply
  23. Tomi Engdahl says:

    Bowers & Wilkins Factory Video: 803 D3
    https://www.youtube.com/watch?v=V6r5SiiZbV8

    B&W Nautilus Loudspeaker story – Laurence Dickie.
    https://www.youtube.com/watch?v=0FKyfTsyYZI

    Reply
  24. Tomi Engdahl says:

    Class AB Op Amps: The Solution for Low-Iq Audio
    June 22, 2022
    Want a high-performance audio amplifier with great quiescent-current performance numbers? The class AB amplifier improves the efficiency and lowers the distortion versus other amps.
    https://www.electronicdesign.com/technologies/analog/article/21244938/electronic-design-class-ab-op-amps-the-solution-for-lowiq-audio?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS220620018&o_eid=7211D2691390C9R&rdx.ident%5Bpull%5D=omeda%7C7211D2691390C9R&oly_enc_id=7211D2691390C9R

    What you’ll learn:

    Different classes of amplifiers.
    What are the benefits of class AB amplifiers?
    Patents that address the quiescent current of class AB amps.

    Amplifiers have many classifications, and each class has its advantages and disadvantages. The different classes of amplifiers are A, B, AB, C, D, E, F, T, and even more “alphabet soup.” Designers typically work with classes A, B, AB, and C.

    The class A amplifier has high linearity with high gain ability. It has a 360-degree conduction angle that leads to the amplifier remaining in the active state at all times, and it’s able to use the entire input signal. The class A amp has good high frequency and feedback-loop stability.A drawback is that it only has 25% to 30% efficiency.

    Class B amplifiers use two active devices that are biased one-by-one, each in half of the actual full cycle, meaning that every device will only be biased during 180 degrees of the cycle. Two transistors provide the combined current drive to the load. This improves the efficiency as compared to the 25% to 30% efficiency of the class A amp.

    Class C amplifiers operate in two different operating modes, tuned or untuned (class C amps have a huge distortion across their output). The efficiency of this amplifier is much higher than the A, B, or AB: A maximum 80% efficiency can be achieved, especially in radio-frequency-related applications.

    What is a Class AB Amplifier?

    Class AB amplifiers overcome the cross-over distortion that plagues class B amplifiers. The class AB amplifier, which combines class A and class B amps, eliminates the low-efficiency issues of class A amplifiers, and reduces the distortion and improves on the poorer linearity exhibited by class B amps.

    The class AB configuration has a reduced efficiency and dissipates a reasonable amount of power while in the zero-input condition. Class B has the highest efficiency at 78.5%, followed by class AB, which is between 78.5% to 50%, and then class A at 50%. In terms of distortion, class A has the lowest, followed by class AB, with class B bringing up the rear.

    Audiophiles, or “Golden Ears” as we called them in my audio days at Empire Scientific Corporation during the 1970s, typically like class AB amplifiers because of their “warmth” or “coloration,” which was really relished at the digital amplifier outputs.

    Many “Golden Ears” claim that digital amplifiers are less likely to “color” the sound. Analog amplifiers are particularly useful for the mid- and high-ranges due to this “coloration.” That’s why they’re preferred in the amplifier substages, since the signal starts out more like the original recordings.

    A disadvantage of the class AB amplifier is that temperature matching of each current mirror will be necessary, especially when emitter degeneration resistors aren’t used, such as in Figure 2.

    Reply
  25. Tomi Engdahl says:

    How much something is worth varies from person to person and sometimes changes over time. I for example, don’t spend money on expensive cars. When I change a cable, sometimes the better cable (for my system and me) is more expensive, and sometimes it is cheaper.

    and how much cable characteristics affect the sound can vary quite much depending on the technical characteristics of connected equipment. For example the effect of some interconnect cable capacitance change can vary easily 1:100 depending how devices connected to cable ends are built. The generally decent modern pro audio gear tend to be on the least affected end vintage high end gear on the most affected.

    Reply
  26. Tomi Engdahl says:

    https://www.stereonet.com/forums/topic/253908-anyone-else-notice-silver-plated-cables-sound-bright/

    I’ve tried silver plated RCA cables a few times (can’t remember the brand) and found they sounded bright- the treble was emphasized. Why is this the case???

    There is no electrical parameter that should be causing brightness here. The skin effect shouldn’t happen at audio frequencies, and yet plating the cable with silver gives the sense of high frequencies having less resistance, and a more trebbly sound. Weird!

    Anyone else notice this and want to have a guess at why?

    I have no idea!

    FYI guests noticed the same thing in a cable swap experiment. It wasn’t my imagination.

    Feel free to discuss.

    “Anyone else notice this?”

    Some yes.

    Some no.

    “and want to have a guess at why?”

    Metallurgy/material science, different sources of metals contain different levels of impurities, and the combination/amounts of those individual impurities can vary from one source to another. One contributing aspects can be the refining processes, also the drawing process, maybe…………….and how the plating is applied and at what ratios ect’.

    Just my layman understanding.

    I use a pair of coax IC’s in my system where the centre conductor is silver clad copper, they lean on the warm side with no sense of brightness or emphasis in the highs, I have also used pure silver cables from Aurealis Audio that are on the warm side if anything and have no brightness or emphasis in the highs.

    Note that if this effect is real, it could be linked to different inductance or capacitance of the 2 cables.

    In a sighted/uncontrolled test … I can hear lots of different things…. but the tell is that I can hear completely different things if the test is repeated, or if I get “tricked”.

    Yes, that. Home made cables using solid neotech copper vs. no name solid milspec silver plated copper…. both with copper eichman bullet RCA plugs…. Twisted, but unshielded (for ease of construction). Also commercial cables (but not heaps, as I don’t typically do super-high $…. eg.

    too many variables to do a fair comparison
    solid core vs. multi-strand
    neotech vs. milspec

    i like silver plated copper.
    I use the Van damme Lo- cap 55 cable and i can’t hear anything wrong with it….. but then again i think wireless bluetooth mini boom boxes sound pretty good as well.

    I thought this was well known. Silver-plated copper can sound bright in terms of the upper frequencies seeming to get a boost. But it is system dependent – that is, it depends on how your system reacts to silver-plated copper. And this in some cases comes down to how well your tweeters handle the higher frequencies.

    Higher frequencies tend to group and travel on the outside surface of a strand of wire. This results in higher frequencies potentially running into a higher resistance – more stuff trying to get through a thinner space – while at the same time the lower frequencies travel more towards the centre of the wire. To reduce the resistance at the surface of the wire, you can apply silver-plating with the aim of keeping the resistance for the high frequencies and lower frequencies around the same. So you don’t lose the amplitude of the high end compared to the low end. But how to get this perfect? Most likely very difficult to do when it comes to music where the frequency range is largely variable from track to track , and artist to artist.

    Too much silver and the high frequencies end up getting less resistance through the silver than the lower frequencies do in the copper. Hence the higher frequencies have a bit more amplitude than they should. This normally doesn’t cause issues if your tweeters are a bit on the dull side, but if they’re not you might feel that you want to turn the amplitude of the high frequencies down a bit.

    Yes, this is what would be called skin effect and it does apply. It always applies to a piece of wire to some extent

    Silver-plated copper mil spec wire in teflon insulation is some of the best quality wire in the world at a very cheap price. It can work extremely well in some systems. But it was developed for general communication purposes and obviously worked well or so much of it wouldn’t still be produced.

    None of this applies to pure silver wire.

    I’ve tried the “very silver” end – pure silver cables in an xlr config as interconnects between pre and power amps, and yes – in my system too bright. Lots of detail but not “good” to my ear. I went back to my (cheaper) copper (with some silver) cables and much preferred them. These were not subtle differences either.

    On the other hand, the same pure silver cables sounded great in a mate’s system, but his gear is much less revealing. Interesting…..

    Most of the skin effect tables you will read describe the absolute skin effect depth where there is no further conductivity, being around 18 awg for 20kHz as you said. However, this is an exponential function, and by that point the conductance is zero (at the core of the wire) so making the cable thicker does not add any further conductance at those frequencies. This is why often skin effect tables recommend more along the lines of 20awg where conductivity has dropped by 63%, or 24 awg where conductivity does not drop at all for anything below 17kHz. To actually get identical conductivity between 20-20,000 Hz you need 25 awg. However, the actual amount of overall resistance increase is so minuscule that it’s debatable whether this is audible or not. My experience says it is.

    Using silver plated copper for where the high frequencies travels sounds good in theory but the fact is that the low frequencies get to travel in the silver part as well, and the silver part adds very little overall conductance – the relationship between skin depth, and the 6% higher conductivity of silver means there is no clear “ideal” way to make this tiny silver plating make up for the difference based on pure conductivity for the high frequencies only – copper’s resistance is already extremely low.

    Reply
  27. Tomi Engdahl says:

    For interconnection cabled that carry line level signal, the output impedance vary normally from below 20 ohms to over 2 kilo-ohms. The input impedance on the other end is typically 20-100 kohms range. Pro equipment tend to be at low output impedance (50-150 ohms usually) while high end hifi (especially tube equipment) at high impedance end.
    Also record players have quite high output impedance.
    Higher output impedance, more cable capacitance affects.

    Reply
  28. Tomi Engdahl says:

    From https://www.facebook.com/groups/2420755034736319/permalink/2858405797637905/

    I dare anyone to conduct a scientific, double-blind A-B study to objectively measure any perceived difference in the vast majority of available cables. Electronically, audio signals travel their merry way and don’t know the difference. Manufacturers are making a lot of money based on nonscientific claims that have never been proven through unbiased, objective measurements and tests.

    I wrote above, the placebo effect,for expensive and beautiful cables.

    At least its all physics. A real double blind test would help to factor out psychology. But an astonishing behavior of how information is transfered was new to me too. And that impulse reproduction is one of the parameters that qualify a cable. A cable transfer information over the electric magnetic field. But impedances have a big impact on cables for different purposes. A cinch cable has different requirements than a passive loudspeaker cable. 2 (german) youtube videos enlighten the physical laws. Thats a good start to set up a measurement configuration. My proposal would be to demystify audio fake infos : Identify the physical laws of a cable in a certain environment (XLR , cinch, loudspeaker), then doe a measurement, and then do a double blind test. Thats an academic approach, thats quite complex to build. The marketing approach has no really interest in this, if they sell expensive gear that could be bought cheaper and better.

    Reply
  29. Tomi Engdahl says:

    Audio Myths: Silver Wire sounds ‘bright’
    This is one of those persistent myths that is frustrating yet ultimately has a basis in truth.
    https://www.decoaudio.com/deco_audio_silver_wire.html

    Reply
  30. Tomi Engdahl says:

    The Holy Grail of Audio . . .

    It’s fitting that “audiophiles” are often called “audiophools” – we’re always searching for the ultimate sound, and as a rule, few are ever 100% satisfied, which drives equipment sales and eBay trades.

    . . . it’s that quest for perfection driven by some degree of dissatisfaction.

    Reply
  31. Tomi Engdahl says:

    There is no real difference on your post shown:
    “Good speaker cables must be able to carry the output current from the amplifier.”
    Proper mains cable needs to be able to carry it’s rated current properly.

    “It must stranded and flexible enough, even as the wire gauge is sufficient.”
    This applies to all flexible mains cables.
    In wall wires do not need to be that flexible so do not need to be stranded.

    “The insulation must also be good.”
    Insulation needs to be also good in mains cable to be safe. Mains cable insulation needs to withstand more voltage than hifi speaker wires.

    “Other factors also count.”
    Are those factors aesthetics what the cable looks and the story told by cable salesman?

    I have used both speaker cables and mains cables for speaker connections. No noticeable difference that could be verified when cable thickness and length have been same.
    I know PA companies that have successfully used rubber insulated mains power cables for amplifiers to speaker connections (4 cores from 5 core cable normally used to carry three phase power 2.5mm2 or 4 mm2).

    Reply
  32. Tomi Engdahl says:

    Without realizing it, you just started a war! Choosing the wire used for speakers is trickier than you might suspect. Audiophiles will spend inordinate amounts of money to purchase special, high-performance speaker wire.

    Aside from the DC resistance of the wire, which matters for high-current subwoofer drive, there is the skin effect of the wire, where higher frequency current moves towards the outer edges of the wire. From my standpoint, the speaker wire you use depends upon how good your speakers are – and how picky you are.

    I’ll let others chime in on this controversial and interesting subject.

    Some audiophiles worry about the skin effect of the wires at the higher audio frequencies. It can get crazy.

    I’ve seen them argue where is it best to have solid or flexible wire.. to mitigate the skin effect.

    by the way don’t mention “oxygen free cable”

    Reply
  33. Tomi Engdahl says:

    some interesting test results are published at
    https://www.soundguys.com/cable-myths-reviving-the-coathanger-test-23553/

    Below is a plot with our coathanger pitted against a high-end OFC (14-gauge) cable. We took the average of each cable’s performance and subtracted them from each other to get the total deviation. Right away, there are a few issues we can see, but they’re mostly under 1dB—and not exactly the way we’d expect.

    We then tested three hypotheses against all the results, and came up with the following:
    Few people could reliably tell the difference between a coathanger and a high-end cable: inconclusive
    Fewer people prefer the coathanger over the high-end cable: rejected
    Fewer people prefer the high-end cable over the coathanger: confirmed

    Reply
  34. Tomi Engdahl says:

    Cable myths: reviving the coathanger test
    Updated 6/13: polling results added
    https://www.soundguys.com/cable-myths-reviving-the-coathanger-test-23553/

    Reply
  35. Tomi Engdahl says:

    Oh please tell me there are some 802 fans here. I just love pointing out the POS 1 ohm plastic basket drivers they use. Literally ghetto blaster quality.
    https://www.simplyspeakers.com/replacement-speaker-bose-style-901-802-full-range-f-901.html

    Reply
  36. Tomi Engdahl says:

    Keep in mind that a 70V line does not carry 70V on-average. Rather, it peaks at 70V (or sometimes just above). With the average signal for music and speech being at least 10 dB lower than peak (often even lower than that, but let’s assume worst-case in terms of highest power), the average will be much, much lower than 100 Watts. Typically around 10 Watts or less. Yes, the load will draw 100W when the voltage hits 70V, but again, that’s the momentary peak. Lots of people presume they’re getting 100W average from the speaker — they’re not.

    Reply
  37. Tomi Engdahl says:

    testing op amps and using Rightmark Audio Analyzer
    https://www.youtube.com/watch?v=M__E5ZOtPOA

    This is a video on how we test op amps after we put them together.
    We use Rightmark Audio Analyzer for testing and a op amp test board from Five Fish Audio

    http://audio.rightmark.org/index_new.shtml

    https://www.fivefishstudios.com/diy/opamptestjig/

    Reply
  38. Tomi Engdahl says:

    About op-amps part 2: audio test
    https://www.youtube.com/watch?v=DlKAXTMKpjI

    A follow up to my first video on op-amp (here https://youtu.be/PhC1ywrBk7I ).
    This time we (try to) listen to the differences in 4 op-amps when put to work inside a Red Crown: TL072, LF353, LM1458 and TLE2022.
    Please visit http://zenzeroelectronics.com for more on our pedals.

    About op-amps part 1: what we look for in an op-amp for a distortion pedal?
    https://www.youtube.com/watch?v=PhC1ywrBk7I

    Reply
  39. Tomi Engdahl says:

    Most audiophile stuff is snake oil… There was a thing years ago with black cd-r’s where you would rip the original with a specific iomega external USB drive and then reburn to a black CD-r and it was supposed to make it sound better than the original press.

    There is a whole paper written on it..
    https://forum.audiogon.com/discussions/why-does-the-copy-sound-better-than-the-original

    Reply
  40. Tomi Engdahl says:

    Never discuss cables in groups that tend to get infected quickly. There are those who say they can hear the difference between cables and those who can not. Let it remain so, you still can not persuade the other side to change your mind. I’ve seen groups where people have become real enemies over cables, so we can not help but discuss such things in this group.

    Reply

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