Cable wars 2020 - a FB experience

[jabbr]

12 minutes ago, Archimago said:

Absolutely, we could play with LTSpice and plug in values for inductance and capacitance that result in nasty cables with significant roll-off at audible frequencies, or nasty phase anomalies, oscillation potential... But those are not typical whatsoever, and audiophiles for the most part do not have to fear! I suspect only some of the most "exotic" audiophile speaker cables might encroach into these "danger zones".

 

I think its natural to focus on the obvious properties of cables and the information they are transmitting.

 

I strongly suspect that many of the "SQ" differences in cables are due to the different shields and the shield effect as a wave guide channeling EMI/common mode nose from one device to another. These effects when large enough to present themselves as "ground loops" are easily understood, but I wonder when they are below the level of an obvious hum.

 

That is speculation on my part, but goes outside the obvious RLC properties of various cables (and are not modeled by LTSpice)

[barrows]

3 minutes ago, Archimago said:

But those are not typical whatsoever, and audiophiles for the most part do not have to fear! I suspect only some of the most "exotic" audiophile speaker cables might encroach into these "danger zones".

I recently had an experience with a high end amplifier (5 figure amp) and very popular and respected high end speaker cable where the cable's capacitance caused the amplifier to go into protection mode.  Swapped out to a speaker cable with lass C, and no problems at all.  I talked to the amplifier manufacturer and they sent out a Zobel network to hang off of the speaker binding posts to stabilize the amp with the higher capacitance cables.

I did some research, and indeed the capacitance of these speaker cables was a bit higher than what I would normally expect. The amp manufacturer knew about the incompatibility and reported that they had only seen this happen with that particular make and model of speaker cable (such that they now include the Zobel with the amp in the case of this happening again). 

 

And then there are Spectral amps, where they specify what cables are permitted to use in order to keep the (very high bandwidth) amplifiers happy.

 

So, not every combination is "safe", and I suspect that CG is referring to less significant "problems" which might not cause al out failures or oscillations, but FR variations and such depending on amplifier loading.  This happens because in home audio there are really no standards, but the circuit the amplifier output "sees" is of course the cable (which varies in properties) plus the speaker (which is highly variable).

[CG]

Holy cow...

 

First, if you take the time to actually do a simulation, or actually measure, you can see the peaking I mentioned.  It doesn't take really extreme cables or speaker loads to get there.  Not by a long shot.  As Barrows alluded to, you don't need to excite the amplifier into full rail-to-rail oscillations at 400 KHz to see how the response changes.  The thing is, the point the response changes too much is the point when you eventually get the system to oscillate.  Before that point isn't perfect - it just isn't to the point of sustained oscillation.

 

If you want to start small with this, just simulate the response of a very, very simple buffer stage consisting of a JFET with a JFET current source.  Vary the source impedance, just like happens with a volume control pot.

 

Again, my point is not the extreme case of smoke inducing oscillations, but instability prior to that that can and will affect sound reproduction properties.  Cordell has something to say about all this, too.

 

BTW, the situation is even more complicated when you add overall loop feedback to an amplifier.

 

But, don't believe me!  Try it yourself!  Or, just don't believe me without even trying!  I'm ok whichever way.

[CG]

45 minutes ago, jabbr said:

 

I think its natural to focus on the obvious properties of cables and the information they are transmitting.

 

I strongly suspect that many of the "SQ" differences in cables are due to the different shields and the shield effect as a wave guide channeling EMI/common mode nose from one device to another. These effects when large enough to present themselves as "ground loops" are easily understood, but I wonder when they are below the level of an obvious hum.

 

That is speculation on my part, but goes outside the obvious RLC properties of various cables (and are not modeled by LTSpice)

 

I often refer to an article by the late Pete Goudreau in regard to this:  http://www.soundstagenetwork.com/articles/pete01.htm

 

Maybe hum is the least of the problems.  Multiple high frequency signals will multiply in a non-linear amplifier - how linear are audio amplifiers at, say, 300 KHz where switching regulators might operate? - and create junk in the audio band.

 

(Comment not at all specific to or directed at you:)  It's funny how so many people just assume that audio is "easy".  I've had Fellows - Fellows as in really, really high up the food chain type with the title "Fellow" - at analog ic manufacturers say this.  The answer is always, "oh yeah - this is an effect, but nobody can hear that".  That may be true, and not for this forum.  But, doesn't it make sense to at least investigate before drawing a conclusion?

 

Here's an example:  RF guys worry about intermodulation distortion effects in connectors.  It's a real thing.  (Search terms: passive intermodulation distortion). Is that a concern in audio systems?

[Archimago]

1 hour ago, CG said:

Holy cow...

 

First, if you take the time to actually do a simulation, or actually measure, you can see the peaking I mentioned.  It doesn't take really extreme cables or speaker loads to get there.  Not by a long shot.  As Barrows alluded to, you don't need to excite the amplifier into full rail-to-rail oscillations at 400 KHz to see how the response changes.  The thing is, the point the response changes too much is the point when you eventually get the system to oscillate.  Before that point isn't perfect - it just isn't to the point of sustained oscillation.

 

If you want to start small with this, just simulate the response of a very, very simple buffer stage consisting of a JFET with a JFET current source.  Vary the source impedance, just like happens with a volume control pot.

 

Again, my point is not the extreme case of smoke inducing oscillations, but instability prior to that that can and will affect sound reproduction properties.  Cordell has something to say about all this, too.

 

BTW, the situation is even more complicated when you add overall loop feedback to an amplifier.

 

But, don't believe me!  Try it yourself!  Or, just don't believe me without even trying!  I'm ok whichever way.

 

Sounds good @CG, will give this a try at some point. I'm sure it'll be very educational. In regards to device testing however, it still might be good to have a standard test of actual products for "compatibility" with high-C cables nonetheless...

 

2 hours ago, barrows said:

I recently had an experience with a high end amplifier (5 figure amp) and very popular and respected high end speaker cable where the cable's capacitance caused the amplifier to go into protection mode.  Swapped out to a speaker cable with lass C, and no problems at all.  I talked to the amplifier manufacturer and they sent out a Zobel network to hang off of the speaker binding posts to stabilize the amp with the higher capacitance cables.

I did some research, and indeed the capacitance of these speaker cables was a bit higher than what I would normally expect. The amp manufacturer knew about the incompatibility and reported that they had only seen this happen with that particular make and model of speaker cable (such that they now include the Zobel with the amp in the case of this happening again). 

 

And then there are Spectral amps, where they specify what cables are permitted to use in order to keep the (very high bandwidth) amplifiers happy.

 

So, not every combination is "safe", and I suspect that CG is referring to less significant "problems" which might not cause al out failures or oscillations, but FR variations and such depending on amplifier loading.  This happens because in home audio there are really no standards, but the circuit the amplifier output "sees" is of course the cable (which varies in properties) plus the speaker (which is highly variable).

 

Yikes. A $$$$$ amp with popular cable resulting in such incompatibilities?

 

As a consumer, imagine if we buy an expensive laptop (amp), grab a popular USB cable (speaker cable), and what is considered a good SSD drive (speaker). We plug the components together and the devices fail to operate or potentially even cause damage!

 

I sure hope the amplifier company warns the consumer about incompatibilities right up front. Perhaps the cable company likewise should create a list of amps the user should be wary of?

 

As for the consumer/audiophile, we better have a good reason why we need such a cable to begin with!

 

[CG]

2 minutes ago, Archimago said:

As a consumer, imagine if we buy an expensive laptop (amp), grab a popular USB cable (speaker cable), and what is considered a good SSD drive (speaker). We plug the components together and the devices fail to operate or potentially even cause damage!

 

Know what?  That exact thing happens all the time!  Some of the IT guys sit near me at my day job.  Every single day they deal with just that.  Precisely that.

 

Think of the drivers that don't work right.  As one example.  

 

I believe you're a medical professional, so think of the medications that end up having a bad effect on one particular patient.  Yeah, there's a long list of possible side effects provided by the pharmaceutical company, but clearly they can't test every medication on everybody under every condition.  That list hardly is encouraging to the patient, either.

[Speedskater]

13 hours ago, barrows said:

I recently had an experience with a high end amplifier (5 figure amp) and very popular and respected high end speaker cable where the cable's capacitance caused the amplifier to go into protection mode.

This has been a known problem for over three decades.  Any well designed amplifier should take high total load capacitance into account during the design stage.

[barrows]

3 hours ago, Speedskater said:

This has been a known problem for over three decades.  Any well designed amplifier should take high total load capacitance into account during the design stage.

Or, we could take the other perspective:  Any well designed speaker should not have such high capacitance.  The speaker cable in question has about 6x the capacitance (pF per foot) of the Iconoclast speaker cables I own.

[jabbr]

1 hour ago, barrows said:

Or, we could take the other perspective:  Any well designed speaker should not have such high capacitance.  The speaker cable in question has about 6x the capacitance (pF per foot) of the Iconoclast speaker cables I own.

Or the amp can be designed with positive current feedback -ala the FirstWatt F7– so that it can handle reactive loads better. 
 

 

[PeterG]

On 2/18/2020 at 7:12 AM, DuckToller said:

Sorry, GUTB, that I did not respond earlier ...

Thank you for your participation and your reflective response.
Imho, you made a partially valid point which may help to approach to the core of the debate.

 

I have no personal problems with quality terminals and properly constructed cables for the mechanical aspect of a wired connection, though investing 5k in a pair of interconnects instead of proper room treatment for the same budget occurs to me as a flawed concept that can create the situation, where the need to defend that precise decision with unfounded claims and the rejection of reason may occur more lightly.
At the other hand, we need to ask, if the urge for exagerrated margins on products like cables is a factor and if it does instantly feed the need to have a marketing machine that sustains the debate in all its glory?

I admit,  that I may have been a bit rushed too much into the critic of the subjectivist's role in that dialogue by the force of their agitation when I actually only wanted to be descriptive,

Cheers, Tom

 

Hi DT--

 

My experience with cables has matched GUTB's--some have had a significant improvement in sound quality, some have not--and I have spent several thousand dollars on them, despite agreeing with you that the margins are steep.  But I disagree that I could have done better with room treatments.

 

My system is in my (our) living room, in large part because I like sitting with my wife.  But this introduces different definitions of the word budget.  I have spent about $35K in total, out of a budget that I might call $100K if money became the constraint.  But total dollars are not the constraint.  My budget for speakers (per my wife) is stand mounts.  My budget for room treatments is zero.  On electronics though, I can get away with pretty much anything short of mono blocks--we're sort of on a don't ask-don't tell basis (haha).

 

So when one has constraints other than cash, it is completely rational to spend an irrational amount of money on cables.

[DuckToller]

24 minutes ago, PeterG said:

So when one has constraints other than cash, it is completely rational to spend an irrational amount of money on cables.

Hi Peter,

While I understand your POV, I am not 100 % convinced about the rationale 😁

However,you are correct,  there is an important influence we often forget to count in when we discuss upgrades and sq, not everyone can act inside a dedicated space for personal listening.

When you are talking about no room treatment but standmounts, my mind did connect in an instant to the super integrated I am listening to in that very moment.

The unit will leave me on Monday, as it is already more than a week overdue for return to its manufacturer in Denmark, Steinway Lyngdorf. The TDAI 3400 has transformed my less than stellar office/audioroom into a listening space I had never dreamed of to experience. As a consequence I notice a behaviour which I'd call an inner Gollum, that tells me every morning:enjoy it just another day. So much fur the rationale 😁

The amplifier is aimed for untreated rooms with bad condition and suboptimal speaker placement, which it optimizes with a now already mature DSP software called RoomPerfect. For me,  the unit allowed to blend a  pair of  midpriced Hi-Fi subwoofers (XTZ, Icepower 700) with my B&W 805s in a way that I am a bit afraid to let it go and exoerience the lack of  bass, micro details , soundstage and  advanced sonics again.

The unit consist of a streaming unit with multiple digital inputs,  a DSD capable DAC,  a pre-amp with multiple analogue inputs, and a 2*400w class D output. RP works in the digital domain, that's why everything is up/downsampled into 24/96 for the processing.

The lack of interconnects doesn't sound like a disadvantage to my ears, and eventually impossible treatments can be efficently compensated

Look at it as an option, it has surely some weaknesses in the sense how aufdiophiles are practising their hobby, but I'd guess at conditions like the one you described it could find a good fit .

Too old to Rock'n Roll , too young to die, says Jethro Tull, and I feel transfered back in time to that extraordinary concert when I saw them at the age of 14.

Cheers, Tom

[PeterG]

20 hours ago, DuckToller said:

Hi Peter,

While I understand your POV, I am not 100 % convinced about the rationale 😁

However,you are correct,  there is an important influence we often forget to count in when we discuss upgrades and sq, not everyone can act inside a dedicated space for personal listening.

When you are talking about no room treatment but standmounts, my mind did connect in an instant to the super integrated I am listening to in that very moment.

The unit will leave me on Monday, as it is already more than a week overdue for return to its manufacturer in Denmark, Steinway Lyngdorf. The TDAI 3400 has transformed my less than stellar office/audioroom into a listening space I had never dreamed of to experience. As a consequence I notice a behaviour which I'd call an inner Gollum, that tells me every morning:enjoy it just another day. So much fur the rationale 😁

The amplifier is aimed for untreated rooms with bad condition and suboptimal speaker placement, which it optimizes with a now already mature DSP software called RoomPerfect. For me,  the unit allowed to blend a  pair of  midpriced Hi-Fi subwoofers (XTZ, Icepower 700) with my B&W 805s in a way that I am a bit afraid to let it go and exoerience the lack of  bass, micro details , soundstage and  advanced sonics again.

The unit consist of a streaming unit with multiple digital inputs,  a DSD capable DAC,  a pre-amp with multiple analogue inputs, and a 2*400w class D output. RP works in the digital domain, that's why everything is up/downsampled into 24/96 for the processing.

The lack of interconnects doesn't sound like a disadvantage to my ears, and eventually impossible treatments can be efficently compensated

Look at it as an option, it has surely some weaknesses in the sense how aufdiophiles are practising their hobby, but I'd guess at conditions like the one you described it could find a good fit .

Too old to Rock'n Roll , too young to die, says Jethro Tull, and I feel transfered back in time to that extraordinary concert when I saw them at the age of 14.

Cheers, Tom

 

We have similar taste/thinking--I also have B&W 805s, mine paired with a B&W DB3D subwoofer.  I do not have to economize on space with the electronics, so I have a McIntosh C22/MC275 combo.  I tried a McIntosh MEN220, which I believe is driven by Room Perfect (DSP software from Linn?).  My bass was improved, but I sacrificed detail on the high end; so I did not purchase.  My thinking at the time was that my room was not quite compromised enough for the MEN220 to be a net positive.  I had much better luck with upgrading cables and adding a Nordost QKore and QBase grounding system.  The power upgrades did what I had hoped the DSP would do-- improved lows, detail, and imaging, with no sacrifice I could discern--it was dramatic.

[DuckToller]

Peter,
thank you for replying. It sounds like you have solved your problem.
The hardware match between the MC275 & the B&W 805s is already excellent, I've read not only once ...
The DSP you once tested is actually the one from Lyngdorf, called RoomPerfect !  Though having a slightly different configuration/software and lacking the digital amplification option for the processed signal, therefore it may be regarded as less advanced than the 2018 TDAI3400, afaik.
From my personal experience, I would allow myself to have doubts that we could substantiate the effect of cables and interconnects against the impact of signal processing/room interaction from crossovers, sound processors and DSP in general, which in turn means, that as long as it works out for you & your specific situation, you just have a perfect solution - combined with a lot of headroom until you run out of budget 😉
That could be a call for the Audio Society of Minnesota to get some excellent cables tested against the impact of the TDAI3400 or Trinnov’s Amethyst, using the same power amp/speaker configuration ....
Have a nice weekend
Tom

[vmartell22]

The conversation has moved pretty far from the Original Post -  some things I wanna say, though

 

1.- I think the idea of connecting a printer using audiophile data cable is extremely funny - made me chuckle as soon as I saw the picture

 

2.- Of course the next step in the joke had to be making claims about the quality of the printer! Very funny too

 

3.- But there is some food for thought - frankly, the claims re: the quality of the printing  with the fancy cables sound silly and it is easy to explain why those cables in fact would not make a difference. YET, why is there a full segment of another industry (audio) making those claims regarding what is essentially just the same kind of data? Then you had to talk about the audiophile industry before digital and how it adapted to it - and how it tries to double down on principles from the analogue era by applying them to digital even if they were shaky enough for analogue.

 

v

[barrows]

14 minutes ago, vmartell22 said:

The conversation has moved pretty far from the Original Post -  some things I wanna say, though

 

1.- I think the idea of connecting a printer using audiophile data cable is extremely funny - made me chuckle as soon as I saw the picture

 

2.- Of course the next step in the joke had to be making claims about the quality of the printer! Very funny too

 

3.- But there is some food for thought - frankly, the claims re: the quality of the printing  with the fancy cables sound silly and it is easy to explain why those cables in fact would not make a difference. YET, why is there a full segment of another industry (audio) making those claims regarding what is essentially just the same kind of data? Then you had to talk about the audiophile industry before digital and how it adapted to it - and how it tries to double down on principles from the analogue era by applying them to digital even if they were shaky enough for analogue.

 

v

It is not the same kind of data!  USB audio is a continuous stream with no error correction.  If you send a document to a printer it is error corrected and the data is check summed before printing.  USB audio does none of this.

 

Although I do not think that data errors are responsible for differences in sound quality with USB audio.  If you would actually like to learn what might be responsible, search this site for John Swenson's thoughts on this, he has done a lot of research and thinking on the topic, and he is a very, very good high speed circuit engineer.

[vmartell22]

24 minutes ago, barrows said:

It is not the same kind of data!  USB audio is a continuous stream with no error correction.  If you send a document to a printer it is error corrected and the data is check summed before printing.  USB audio does none of this.

 

Although I do not think that data errors are responsible for differences in sound quality with USB audio.  If you would actually like to learn what might be responsible, search this site for John Swenson's thoughts on this, he has done a lot of research and thinking on the topic, and he is a very, very good high speed circuit engineer.

 

Oh sure - Isochronus vs. bulk - etc - right - sure - there is a chance errors affect FIDELITY - sure... maybe.

 

However the joke - and the subjective folklore around fancy digital cables is about ENHANCEMENT. That's what is and why is funny.

 

v

[Paddlefoot]

On 2/19/2020 at 9:21 PM, barrows said:

No arguments here...  I have one thing to contribute:

 

Iconoclast Cables, designed using solid science and measurements, and manufactured by world respected industrial cable giant Belden!

 

(shhh, ps: they sound good to, oops!)

I am in full agreement here borrows, i have them, they sound fantastic 

[kirkmc]

On 2/20/2020 at 5:09 PM, CG said:

 

There is another aspect to this that rarely gets mentioned.

 

It's too long to go into detail on a forum like this, but amplifiers are inherently unstable devices.  That's because the devices used have parasitic elements associated with them and the basic processes used to fabricate the parts cause a rolloff in gain as you go higher in frequency.

 

As one example, an emitter follower stage, such as used in almost every bipolar transistor power amplifier output stage, reaches a frequency where the current gain starts falling.  This translates into a change in input impedance at that frequency.  This can and usually does cause a peaking in voltage gain.  Stability can therefore be a problem.  

 

The details of the instability and the amount depend on the devices themselves, the circuit they are used in, whatever other parasitic elements are in that circuit, and the load itself.  

 

This is why you see "Zobel" networks used at amplifier outputs in an attempt to mitigate the effects of the load.  (Bob Cordell's book on audio amplifier design discusses this at length.). There's other possible solutions, too.

 

With regard to cables, they are part of the load impedance.  That is true whether you're talking about power amplifiers with loudspeakers or preamps with the power amplifier input as the designated load.

 

So, there's an effect caused by the cables with regard to instability.  This in turn can change the characteristics of the amplifier performance.  This is mathematically demonstrable and testable - as objective as you can get.

 

Neither of these links were written by quacks.

 

https://www.eevblog.com/forum/beginners/noise-on-emitter-follower/?action=dlattach;attach=348962

 

http://audioworkshop.org/downloads/AMPLIFIERS_OSCILLATION_BJT_CIRCUITS.pdf

 

Yeah, no consumer product should have these problems.  No "pro" product should either.  How many are tested in this regard?  Have you ever seen published measurements?

 

These aren't simple and obvious details.

 

So hold one a minute. For years, the cable wars have divided families, led to multi-generational feuds, and broken marriages. And now you say that it's not the cables that are different, but the way amplifiers react to different cables? I find this quite stunning. 

 

Related: how many people have tried a new cable and found that their music sounded worse? Lots of people say that different cables make their setups sound better, or that they don't change anything; if cables do make a difference, then the corollary should also happen: some cables should make music sound worse, especially if it's not the cable changing the sound. 

 

 

[DuckToller]

3 hours ago, kirkmc said:

if cables do make a difference, then the corollary should also happen: some cables should make music sound worse, especially if it's not the cable changing the sound. 

Kirk,

I have the infinitive feeling that we have a case of British sarcasm in the last part of the quote. 
Usually I do enjoy that, however I did not understand the context, shouldn't it be like "some cables should make the amplifier sound worse, especially if it's not the cable changing the sound" just to have it sound less contradictionary?? Could be the language barrier as well ...

To my recall, for most of the people who found cable make a significant difference, it is about the quality of their system and price of the cables, which supports their findings that they substantially enhances the sound (or their perception thereof).
Which in turn implicates that a change to the worse may be perceived especially with lower priced products and cables that meet exactly the specs/standards for data transmission i.e USB cables or Ethernet. Or the cables they just had in place in their revealing sytems, whatever quality they have attached to them when they were brand new.
In my reading of the subjective discourse, If these (old cables, correctly specc'ed cables and low priced cables) would make that kind of significant positive difference in SQ in general or to the amplifier's sq specifically, there would be only a very small market for expensive cables.
cheers, DT
 

[kirkmc]

Sorry, there shouldn't be a "not" in that last bit. 

 

And I'm not British, I'm American; I just happen to live in the UK. 

 

My point being that if a cable can make music sound better, then some cables should make it sound worse, assuming that there is a situation where the cables and amplifiers don't get along. I don't think I've read any of those claims. 

[DuckToller]

Kirk,
Thanks for the disclaimer, I appreciate sarcasm and irony as a vehicle, nonwithstanding the nationality, as an art form.
However:
https://www.bbc.com/news/world-us-canada-46846467

there seems to be some cultural diferences 😉

 

[pkane2001]

1 hour ago, kirkmc said:

My point being that if a cable can make music sound better, then some cables should make it sound worse, assuming that there is a situation where the cables and amplifiers don't get along. I don't think I've read any of those claims. 

 

I find that an unplugged cable sounds much less musical than a cable that's plugged in. But that's just my subjective opinion.

[Speedskater]

1 hour ago, kirkmc said:

 

My point being that if a cable can make music sound better, then some cables should make it sound worse, assuming that there is a situation where the cables and amplifiers don't get along. I don't think I've read any of those claims. 

There have been engineering papers about combinations of reasonable amplifiers, reasonable speaker cables and reasonable loudspeakers ringing or even oscillating at megahertz frequencies.

[Speedskater]

1 hour ago, kirkmc said:

My point being that if a cable can make music sound better, then some cables should make it sound worse, assuming that there is a situation where the cables and amplifiers don't get along. I don't think I've read any of those claims. 

There have been engineering notes about digital interconnect cables causing differences do to poor design of component digital output & input stages.

[kirkmc]

Let me expand on the point I made above. I always assumed that speaker cable were passive; that any cable would work with any pairing of amplifier and speakers. Now I'm learning that is not the case. So, let's say user A has an amplifier with speaker cables - which may be cheap, or may be expensive - that don't work with their amplifier, that cause some loss in sound quality, distortion, etc. When they get another set of cables, maybe more expensive, that don't interfere with their amplifier, they will natural sound better, even if the cables themselves don't make the sound any different. In other words, all they're doing is not deteriorating the sound of an amplifier. From what I'm reading here, this is possible, and it is therefore possible that someone will hear certain cables as sounding better even though they are simply sounding the way a cable should. Is that correct?

 

In which case, how do you know which cables will cause the sound of your system to be worse? I know that with USB-C cables, for example, not every cable provides power, has high data throughput, etc. Is there a similar way of grading speaker cables, beyond all the magical terminology used to sell them?