scott wurcer said:
This is my opinion, too. Thanks 😉 Scott for help try to give some facts to this debate 🙂
If you have enough copper area to transport current from
- Amp output
to
- Loudspeaker terminals
... This will cause no problems, as the
- impedance of cable is so very small
vs.
- impedance of an 4/6/8 Ohm speaker system (including crossovers!)
Say you have dist in cable -140 dB
Say you have a dist in speaker -50dB
(like tests of von Schweikert high end speakers show, at nominal 1-2 Watt level
Lets not be unfair and use the average diyMembers Speaker system for this example 😀 )
Z1 = 0.01 Ohm /cable
Z2 = 4 ohm speaker
Total sound system dist (after amplifier)
... Formula:
(Z1 x -140dB) + (Z2 x -50db) = HDistortion
0.01 x 0.0000001 + 4.0 x 0.00316 =
0.000 000 001 + 0.01264=
Total = 0.012640001 = 1.264 % HD
Of which the cable contributes:
.... 0.000 000 001 % HD
For Simple 10 Myths in AUDIO
we have one of my favourite topic in www.diyaudio.com other forum:
diyAudio Forums > Top >Other Stuff >Everything Else
> 'Audio Lies'
Hi Lineup,
Your math is too simple. 😉
If the two sources of distortion are uncorrelated, I would take the RMS value for the total HD ~= 0.000 000 001/2 + 0.01264=0.0126400005
As you see, that makes a huge difference. 😀
Your math is too simple. 😉
If the two sources of distortion are uncorrelated, I would take the RMS value for the total HD ~= 0.000 000 001/2 + 0.01264=0.0126400005
As you see, that makes a huge difference. 😀
It would be best to avoid speaker cable discussion this thread. I don't teach 'high school' and the level shown about this topic is pretty 'basic'. (No disrespect intended)
lineup said:
Lineup, posting links to David Rich and the Audio Critic will only serve to "stir the pot". John is right these discussions are best left elsewhere.
Thanks, Scott. Let's talk about more important things, like RF protection and IC choices.
As you probably know, I have designed your AD797 into a phono stage and your recommended AD825 into an amp design to be released in future. I find these two IC's amongst the best that I have ever used. Of course, I still need servos, but I usually defer to an OPA2134 for servos, these days, for practical reasons. No problem with the AD711-2 series, except availability.
As you probably know, I have designed your AD797 into a phono stage and your recommended AD825 into an amp design to be released in future. I find these two IC's amongst the best that I have ever used. Of course, I still need servos, but I usually defer to an OPA2134 for servos, these days, for practical reasons. No problem with the AD711-2 series, except availability.
john curl said:Now, what? Have I said something wrong, (again)?
No John I have not seen anything wrong, and I support you and Scott.
Surprised? No I guess not.
I don’t know why lineup posts a link like that in this thread and I don’t know why the moderators haven’t deleted it, both you, Edmond and others me included have had posts deleted that was a lot more “On-Topic” than the post by lineup (Carl, gromanswe, halojoy)
OK, let me TRY to get things on a smooth track. As I have said, repeatedly, I am trying to make the best 'frosting' and the best 'cake' possible, not to find hardware store bargains, or Safeway grocery store favorites. There really is a difference, even if you, dear reader, has not yet been exposed to it.
I don't want to 'debate' and potentially 'denigrate' people or even myself with serious misunderstandings between what works best, and what sort of works.
I know that some who contribute here, think that I waste my time making 'serious' audio designs, and others know better. However, I don't find it 'practical' dismiss my critics, as I, invariably, incur their, and ultimately the moderator's rebuttal, and censure. Let's try to avoid that, as I am old, with health problems looming in the future, and I don't have 'time' left for it.
I don't want to 'debate' and potentially 'denigrate' people or even myself with serious misunderstandings between what works best, and what sort of works.
I know that some who contribute here, think that I waste my time making 'serious' audio designs, and others know better. However, I don't find it 'practical' dismiss my critics, as I, invariably, incur their, and ultimately the moderator's rebuttal, and censure. Let's try to avoid that, as I am old, with health problems looming in the future, and I don't have 'time' left for it.
Hey!
Dont be sad John Curl.
Just because I posted simple math about cable imedance vs. speaker+crossover.
If we would think the same of everything .. we would have to be more than twins.
And if I or you hadnt any unique set of thoughts, than we would be un-necessary persons
with nothing to contribute to mankind.
If I would let others RUN and live my life and think for me .. what would be the purpose of the one unique individual?
I might just go and end it all ...
About why I refer ro 'Audio Lies'
is because all are maybe not familiar with The Cable Lie.
Which is a common myth be some audio-philers.
Investigation, like done here, with different opiniions posted,
My post and Scottt's Post about ZIP Cord, who triggered mine,
triggered by some paper by Dr.Geriner etc. etc.
.. is something else. Not one Myth.
But in this con-text it deserves to mentiones, what traps one ordinary diy audio guy
can risc to fall in .. like those taking The Cable Lie for the truth.
Fred E. Davis investigation ends with a Conclusion,
and If I get it same as Engineer Scott Wurcer, it is that a proper cable can not be heard.
Under- dimensioned cables can of course effect the transfer of higher currents.
/Regars, 'linie' Lineup, hopes JC health be with him .. some additional years
Dont be sad John Curl.
Just because I posted simple math about cable imedance vs. speaker+crossover.
If we would think the same of everything .. we would have to be more than twins.
And if I or you hadnt any unique set of thoughts, than we would be un-necessary persons
with nothing to contribute to mankind.
If I would let others RUN and live my life and think for me .. what would be the purpose of the one unique individual?
I might just go and end it all ...
About why I refer ro 'Audio Lies'
is because all are maybe not familiar with The Cable Lie.
Which is a common myth be some audio-philers.
Investigation, like done here, with different opiniions posted,
My post and Scottt's Post about ZIP Cord, who triggered mine,
triggered by some paper by Dr.Geriner etc. etc.
.. is something else. Not one Myth.
But in this con-text it deserves to mentiones, what traps one ordinary diy audio guy
can risc to fall in .. like those taking The Cable Lie for the truth.
Fred E. Davis investigation ends with a Conclusion,
and If I get it same as Engineer Scott Wurcer, it is that a proper cable can not be heard.
Under- dimensioned cables can of course effect the transfer of higher currents.
/Regars, 'linie' Lineup, hopes JC health be with him .. some additional years
Why don't you start Fred E Davis' thread, Lineup, to discuss transmitter line properties of speaker cables? I can contribute then, since I used to support transmission lines on audio frequencies.
Everyone, can't we get beyond the recent past and keep to discussions relevant to this topic?
I, personally am pretty open minded, but many of YOU, out there, are not. This is, in my opinion, what creates the trouble. No one is forced to read this thread, it is one of hundreds, even on this website, and there are many other websites, as well.
I 'try' to inject the 'wisdom and experience' of older and successful audio designers, in order to help the craft, and to foster an open-minded attitude about what seems to work in audio design.
I don't know 'everything' and sometimes an input, or a link from a contributor can be very valuable. However, if I am talking about RCA or XLR connectors, don't bring in obscure military connectors, especially Russian, or anything that is incompatible with the discussion. I don't CARE what you personally use, it doesn't matter, and it doesn't contribute to the discussion, except in special cases. There it might be useful, but THINK before you contribute.
I, personally am pretty open minded, but many of YOU, out there, are not. This is, in my opinion, what creates the trouble. No one is forced to read this thread, it is one of hundreds, even on this website, and there are many other websites, as well.
I 'try' to inject the 'wisdom and experience' of older and successful audio designers, in order to help the craft, and to foster an open-minded attitude about what seems to work in audio design.
I don't know 'everything' and sometimes an input, or a link from a contributor can be very valuable. However, if I am talking about RCA or XLR connectors, don't bring in obscure military connectors, especially Russian, or anything that is incompatible with the discussion. I don't CARE what you personally use, it doesn't matter, and it doesn't contribute to the discussion, except in special cases. There it might be useful, but THINK before you contribute.
One topic that is very important is the requirement for a LINEAR TRANSFER FUNCTION. This seems to be the essence of audio quality.
Back in the 'very old days' before I was born, making an open loop linear transfer function was just about everything. Tubes ruled, and they COULD be very linear if used correctly.
In the 'old days' when I was young, negative feedback ruled, usually with tubes, but little more than 20dB, in most cases. Sometimes, it made better amps, sometimes worse.
When I became an adult designer, op amps ruled, and their design. Now, 60,100, or 120dB might be possible, and is used up to today. However, the open loop LINEAR TRANSFER FUNCTION is now often ignored, because feedback HIDES the open loop characteristic. Is this OK? What do your ears tell you? Ever listen for yourself?
Back in the 'very old days' before I was born, making an open loop linear transfer function was just about everything. Tubes ruled, and they COULD be very linear if used correctly.
In the 'old days' when I was young, negative feedback ruled, usually with tubes, but little more than 20dB, in most cases. Sometimes, it made better amps, sometimes worse.
When I became an adult designer, op amps ruled, and their design. Now, 60,100, or 120dB might be possible, and is used up to today. However, the open loop LINEAR TRANSFER FUNCTION is now often ignored, because feedback HIDES the open loop characteristic. Is this OK? What do your ears tell you? Ever listen for yourself?
Here we go again...
No, this thread can talk about these things. Please go to your own thread. You have one, please keep it going.
John
I am sorry if I was slightly offtopic some posts.
fuses
and relays are certainly more than cables
and at least Fuses has a significant resistance/impedance .. has to have!
I avoid fuses and/or relays .. never ever needed them.
Personally Just using a good multistranded LSP Cable 2x 6mm2 area
Why should I resort to using ZIP cords?
When there are dedicated speaker cables, with good quality for normal money ..
I have told befoire what I recommend and would buy next time I need a pair of loudspeaker cables
(still wouldnt need any fusing between amp-lsp, nor relays, is in my likings)
Which in a way tells you what I think: they may in some way corrupt signal, in unlucky cases
and even if not .. if I can do without .. then I will .. just not to have to concern/worrying
http://www.jenving.se/image/ply3_4.jpg
If you need shielded Speaker cable:
go for the brother:
Supra Ply [tm] is manufactured here in Sweden by
http://www.jenving.se/
I am sorry if I was slightly offtopic some posts.
fuses
and relays are certainly more than cables
and at least Fuses has a significant resistance/impedance .. has to have!
I avoid fuses and/or relays .. never ever needed them.
Personally Just using a good multistranded LSP Cable 2x 6mm2 area
Why should I resort to using ZIP cords?
When there are dedicated speaker cables, with good quality for normal money ..
I have told befoire what I recommend and would buy next time I need a pair of loudspeaker cables
(still wouldnt need any fusing between amp-lsp, nor relays, is in my likings)
Which in a way tells you what I think: they may in some way corrupt signal, in unlucky cases
and even if not .. if I can do without .. then I will .. just not to have to concern/worrying
An externally hosted image should be here but it was not working when we last tested it.
http://www.jenving.se/image/ply3_4.jpg
If you need shielded Speaker cable:
go for the brother:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
With this flat Structure
Supra Ply [tm] is manufactured here in Sweden by
http://www.jenving.se/
PMA said:
If the input and output and the chassis are all connected via the chassis connection, then where is the ground reference to be found?
Is this an issue for ground loops or ground noise?
_-_-bear
Linearity vs. load is an interesting issue.
Here is the question- if you have an intrinsically linear device (AD797) and you get very little distortion at the output (the measured distortion was around -108 dBc) BUT it seems that the circuit is working much harder than it should (load impedance is at or below spec.) will the sound suffer?
Context- I was evaluating a highly "rated" DAC chip, one with exceptional performance, but I was not getting sound that reflected what I should be hearing. Clearly something was wrong. The demo board uses AD797's throughout so it should be OK. There is a question about something like a 797 with a limited slew rate handling the very high frequency switching inside the DAC at the I/V stage but I think that could be a red herring. More of a concern was a feedback resistor of 120 Ohms to a summing junction. (And a .1 ceramic across a differential amp's + to - inputs). I don't think the AD797 was the reason for the "boring" sound but I invested a little time moving upstream to see if I could get better sound. It got better, but still was not good.
I think the DAC is the big problem, but it led me to wonder about the "sonic" effect of making amplifier stages deliver more current.
Here is the question- if you have an intrinsically linear device (AD797) and you get very little distortion at the output (the measured distortion was around -108 dBc) BUT it seems that the circuit is working much harder than it should (load impedance is at or below spec.) will the sound suffer?
Context- I was evaluating a highly "rated" DAC chip, one with exceptional performance, but I was not getting sound that reflected what I should be hearing. Clearly something was wrong. The demo board uses AD797's throughout so it should be OK. There is a question about something like a 797 with a limited slew rate handling the very high frequency switching inside the DAC at the I/V stage but I think that could be a red herring. More of a concern was a feedback resistor of 120 Ohms to a summing junction. (And a .1 ceramic across a differential amp's + to - inputs). I don't think the AD797 was the reason for the "boring" sound but I invested a little time moving upstream to see if I could get better sound. It got better, but still was not good.
I think the DAC is the big problem, but it led me to wonder about the "sonic" effect of making amplifier stages deliver more current.
It's obvious: output current is reflected from output of an even triple diamond buffer to VAS, and reflected non-linearly.
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