Upupa Epops said:
Upupa,
As a coaxial unbalanced small signal cable between amplifier and source, etc. I have no doubt that 1/4" heliax RF coax (I'd try to find the 75 ohm stuff for audio) would be very good, but not all of the manufacturing virtues of this fine cable are utilized in the audio application. I also have no doubt that 50 ohm coaxial line like RG-214 which has a silvered inner and two silvered braided shields, or the Andrew Heliax in 1/2" you mentioned ought to be very good used as speaker cable, again not all the virtues manufactured into this fine cable being used in the audio application. Since this very fine coaxial cable may as you pointed out, be purchased for quite reasonable cost per meter, perhaps audiophiles wishing to upgrade their cables ought to use this type of product instead of gullibly accepting all the bull feathers and fantasy science promulgated by unscrupulous snake oil specialty audio cable salespersons.
As I pointed out, connectors needed to interface such cable to audio applications are not offered by the manufacturers of these RF transmission line products.
Note that as audio cables the common 50 or 75 ohm rating of coaxial transmission lines has no meaning since they do not function as transmission lines at audio frequency wavelengths. For speaker cable I suspect that the 50 ohm type line would be preferred over the 75 ohm line because the center conductor has a larger cross section and as such, ohmic cable losses would be reduced.
The shunt capacitance of standard 50 ohm coaxial cables with polyethylene dielectric is usually around 30 picofarads per foot. The series inductance could be considered negligible.
As a matter of fact, I have discovered a source of new 6 foot single RG-59 coaxial video cables with molded and gold plated RCA end connectors for 99 cents each. I have been replacing all my cheap audio interconnects in my systems with these as they become available to me in limited surplus quantities. You don't have to spend hundreds of dollars each for quality performance in an audio interconnect.
To rcavictim : Yes, I know that it is not about transmission line 😉 , but about precision shielding ( in both cases ) and about low dielectric loses 😉 . By manufacturer aren't these cable claimed as "audio " ( our dealer was very surpraised by this application ), but results are the best 😎 . But often this cables show, how is " chain " s..t, what is in this time rather contraproductive - people don't like thruth 😀 , mostly like snake's oil. 😀
Hi,
Low DA, O.K. but better shielding is only useful where it's absolutely required.
More of than not cables sound better without shielding.
Coaxial construction are not necessarily a good thing either, I mostly use different geometries with excellent results that far outclass most coaxial wire contraptions.
Among the cables you mentioned the RG214-U was used as an audio product by some Dutch manufacturer as their entry in the cable market.
While it was better than most audio cable at that time, 20 years ago, it has hardly any place in an audio system any more.
In those days most so called audio cable was sourced from the industry catalogues and simply rebranded.
Nowadays that just doesn't pay off anymore as anyone with an interconnection can find where the cable originated from.
Some audio cable manufacturers are simply spin-offs from wire manufacturers, other are a little more innovative and have their wires developped from scratch.
As said many times before, for those wanting to outclass the cable that came with their gear or simply want to brew their own, all you need is readily available from the shops.
With a little time and effort spent you can easily make your own and there's a good chance that they'll give cables costing a number of times the outlay for the raw materials a run for their money.
I couldn't agree more....
Funny thing is that when those cables cost an arm and a leg they'll often be forgiven for being ruthlessly revealing, when they're too cheap they'll get blamed for being too revealing and replaced with something more forgiving.
So, that's one good reason why good wire simply have to cost as much as they do. They wouldn't be taken seriously otherwise....
Cheers,😉
Low DA, O.K. but better shielding is only useful where it's absolutely required.
More of than not cables sound better without shielding.
Coaxial construction are not necessarily a good thing either, I mostly use different geometries with excellent results that far outclass most coaxial wire contraptions.
Among the cables you mentioned the RG214-U was used as an audio product by some Dutch manufacturer as their entry in the cable market.
While it was better than most audio cable at that time, 20 years ago, it has hardly any place in an audio system any more.
In those days most so called audio cable was sourced from the industry catalogues and simply rebranded.
Nowadays that just doesn't pay off anymore as anyone with an interconnection can find where the cable originated from.
Some audio cable manufacturers are simply spin-offs from wire manufacturers, other are a little more innovative and have their wires developped from scratch.
As said many times before, for those wanting to outclass the cable that came with their gear or simply want to brew their own, all you need is readily available from the shops.
With a little time and effort spent you can easily make your own and there's a good chance that they'll give cables costing a number of times the outlay for the raw materials a run for their money.
I couldn't agree more....
Funny thing is that when those cables cost an arm and a leg they'll often be forgiven for being ruthlessly revealing, when they're too cheap they'll get blamed for being too revealing and replaced with something more forgiving.
So, that's one good reason why good wire simply have to cost as much as they do. They wouldn't be taken seriously otherwise....
Cheers,😉
Frank, some amps haven't output filter and so they can to be sensitive to hf disturbing. From this look is coaxial cabel better solution. But best solution is " insect f.....g ", monoblock beside box and no cable 😎 or active box.
Hi,
Quite often you don't need a coaxial cable for that really.
All you need is some form of shielding, I usually opt for a (shielded) twinaxial construction and connect the shield at the preamp (or going in that direction) only, making sure no audio signal passes through it.
Another way to have some RFI shielding is by the use of twisted pairs, braiding as it's commonly called when going beyond the simple twisted pair configuration.
This is often effective enough and usually sounds better compared to a shielded coaxial cable.
This applies basically to single ended configurations, balanced runs allow for a totally different approach.
Cheers, 😉
Quite often you don't need a coaxial cable for that really.
All you need is some form of shielding, I usually opt for a (shielded) twinaxial construction and connect the shield at the preamp (or going in that direction) only, making sure no audio signal passes through it.
Another way to have some RFI shielding is by the use of twisted pairs, braiding as it's commonly called when going beyond the simple twisted pair configuration.
This is often effective enough and usually sounds better compared to a shielded coaxial cable.
This applies basically to single ended configurations, balanced runs allow for a totally different approach.
Cheers, 😉
carlosfm said:
Hi Carlos,
That title was ironically meant, and this was made clear in the thread. I just used it to draw attention😉. I do not believe all cables sound the same.
The thread documents a clear case where personal biases of professional listeners are so strong, that they falsify the outcome of a blind test because it didn't fit their bias! Very enlightening.
But, I guess after a few pages nobody reads THAT part anymore.
Jan Didden
Hi,
But Jan, surely you're not trying to tell us now they actually LISTENED to Coca Cola and Pepsi, do you?
And falsified the results to boot...Madre madonna...Tsik.🙄
Just pulling your leg, Jan. 🙂
O.K. I didn't quite get the part about monoblocks and boxes the first time around.....
Yeah...Using coax cable for LS cables, why not.
You could still make a twisted pair and connect the shields together at one of (stereo amp with ground common to both channels) minus speaker terminals if RFI is a concern.
By doing so you actually extend the shielding of the amplifier chassis, in case of a metal one) up to the loudspeaker.
After that it's an open door to RFI again...........
Cheers,😉
But Jan, surely you're not trying to tell us now they actually LISTENED to Coca Cola and Pepsi, do you?
And falsified the results to boot...Madre madonna...Tsik.🙄
Just pulling your leg, Jan. 🙂
O.K. I didn't quite get the part about monoblocks and boxes the first time around.....
Yeah...Using coax cable for LS cables, why not.
You could still make a twisted pair and connect the shields together at one of (stereo amp with ground common to both channels) minus speaker terminals if RFI is a concern.
By doing so you actually extend the shielding of the amplifier chassis, in case of a metal one) up to the loudspeaker.
After that it's an open door to RFI again...........
Cheers,😉
I thought I mention a little gem that I found in the Letters section of Februari's Electronics World, I mean this thread IS about perception, more or less.
This is a letter from Stan Curtis. Now, his name may not ring a bell, so let me introduce him. Mr Curtis was founding director of Mission Electronics and Cambridge Audio. He also was Chairman of Wharfdale and Quad. He was the designer of the VERY succesfull Rotel amps of the 80's. He was so succesfull because he realised that the task of an audio hifi designer is NOT to design the perfect amp, rather his task is to design amps that sell. Mr Curtis has obviously discovered the link between measured performance and audible preference, but don't expect him to tell ME.
He talks about a stringent double-blind test he performed for Decca between a digital and an analog recorder in the early 80's. He was very proud to be able to identify the two sets of equipment statistically reliably. So far, so good. Unfortunately, the recordings he identified as digital were made on the analog machine, and vice versa. Isn't that intriguing? Man, this perception business doesn't cease to amaze me!
Jan Didden
["Is this mere hypocrisy?", Stan Curtis, letters, EW Feb 2005, pp 48]
This is a letter from Stan Curtis. Now, his name may not ring a bell, so let me introduce him. Mr Curtis was founding director of Mission Electronics and Cambridge Audio. He also was Chairman of Wharfdale and Quad. He was the designer of the VERY succesfull Rotel amps of the 80's. He was so succesfull because he realised that the task of an audio hifi designer is NOT to design the perfect amp, rather his task is to design amps that sell. Mr Curtis has obviously discovered the link between measured performance and audible preference, but don't expect him to tell ME.
He talks about a stringent double-blind test he performed for Decca between a digital and an analog recorder in the early 80's. He was very proud to be able to identify the two sets of equipment statistically reliably. So far, so good. Unfortunately, the recordings he identified as digital were made on the analog machine, and vice versa. Isn't that intriguing? Man, this perception business doesn't cease to amaze me!
Jan Didden
["Is this mere hypocrisy?", Stan Curtis, letters, EW Feb 2005, pp 48]
Jan - how do you evaluate gear for your own system?
There is *NO* test, not even a double blind one, that you could apply to two known pieces of gear where your natural skepticism would not influence the results. Do panels of experts evaluate gear for your system? Or do you hire people off the street?
If you evaluate the gear yourself, even in a double blind test, then you aren't any different from anyone else - even those who don't use such a test. If you think something makes a difference then it's in, if not it's out - just like everyone else.
There is *NO* test, not even a double blind one, that you could apply to two known pieces of gear where your natural skepticism would not influence the results. Do panels of experts evaluate gear for your system? Or do you hire people off the street?
If you evaluate the gear yourself, even in a double blind test, then you aren't any different from anyone else - even those who don't use such a test. If you think something makes a difference then it's in, if not it's out - just like everyone else.
jeff mai said:
Hi Jeff,
I know I have my own biases as anyone, but I think if you are aware of it, and you give yourself some trouble to try to concentrate on the thing you want to evaluate like a change in sound, you can do better than just making a change, listening and pulling conclusions from that.
If I make a change, I know I WANT to detect a difference because that is why I made the change in the first place, because I think I could improve it.
To give you an example, I have just bought two older identical amplifiers. One will stay as is, the other one will have it's guts replaced with the new power amp I'm working on. I selected this particular test amps because they have the same output power so the same power supply voltage as my new amp, I leave in the original power supply. I will not be able to see from the outside which is which (I hope). After making the mod, I will invite some people and we will spend an evening swapping the amps around trying to identify a difference.
But, to be honest, I probably get more pleasure from the design and building itself then the final listening result, I am not particular on sound quality, most reasonble systems sound OK to me.
Jan Didden
kelticwizard said:
Yes, indeed. But it appears from the way he told this story, he himself was surprised that he mixed them up. Here is a man who by any yardstick knows what he is talking about and has a very succesfull career of 40 years designing amplifiers that people bought by literally the hundreds of thousands. He heard the difference between digital and analog, and mixes the two up! He STILL gets surprised by his own perception, that for me was the amazing thing.
Also it seems to me that those people that know these things, have experienced them, and know that even with these shortcomings they are very succesfull, are not afraid to relate such things.
[Edit: Maybe it is just BECAUSE they know these things that they can be so succesfull?]
That perhaps should give others the mental courage to confront these hard questions, that touch your very self-image.
Jan Didden
fdegrove said:Hi,
Man, these double blind tests really suck, don't they?
Cheers,😉
Frank,
Why? This particular blind test gave the subject, in this case Stan Curtis, an insight he would NEVER have gotten with anything else. As I said before, blind test are no panacea, but they beat sighted tests for accuracy and confidence hands down, and then some.
Jan Didden
analog_sa said:
I don't know which "we" you are talking about, but *you* certainly didn't. I never posted anything on how important or not sound quality is for me. I posted a LOT that I don't accept sighted, casual tests at face value, and that I feel nobody should. Since you don't even accept the concept of perception versus actual events, you need another way to reconcile your believe with what I post.
And that is of course quite easy: just go into full denial mode, and convince yourself I am stupid, deaf, don't care about sound quality etc.
Man, you follow the pattern so easily and predictably, you're one of my best witnesses!
On a positive note, let me give you a quote for you personally:
"When the mind is ready, a teacher appears" - Zen proverb.
I'm sure you'll recognise it when it happens.
Jan Didden
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