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Old 5th November 2012, 06:28 PM   #201
Hierfi is offline Hierfi  Canada
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Originally Posted by DF96 View Post
An in-out function which is just linear and cubic will produce from a single input sine an output spectrum consisting of just fundamental and third harmonic. The level of the third harmonic will vary like input^3. The level of the fundamental will vary like input plus/minus an input^3 component, because the third-order distortion produces both 3rd and fundamental.

Yes, the third cannot exist alone. It can exist with just the fundamental, though. This is precisely what you get at the output of an ideal P-P stage.
Thanks DF96. This was what I was trying to get at.

There could be a popular misconception that the distortion component is only 3rd harmonic and that the psycho acoustic artifacts only relate to the 3rd harmonics under dynamically more complex conditions. Ultimately the 3rd harmonic is reflecting a weighted cubic in the transfer function.It is understood that that it isn't necessary to determine the level of the hidden fundamental frequency component because it's amplitude is predictable from the 3rd, however this doesn't mean that the fundamental component should be necessarily excluded from being considered responsible for the audible artifacts.

This is like the 2nd harmonic having a DC component. It may be that the 2nd harmonic isn't mostly responsible for the "improved" audible effects, rather that the modulation frequencies from the DC can create the impression of more lower frequencies, as also below the fundamental. The "improvement" in the effects may also be a function of the beginning frequency of an AC coupling mechanism.

Perhaps this is like a single ended tube design feeding into a transformer that thereupon has a higher frequency of low end extension without feedback. This is to suggest that the modulation frequencies are above AC coupling frequency. In other words it may be worse to pass lower frequency modulation components by applying more feedback to the network.

In some experimentation larger coupling capacitors resulted in a deterioration in dynamics and weight. Bear in mind that such impressions could be more of delusion or other forms of a mental disorder.
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Old 5th November 2012, 06:33 PM   #202
DF96 is offline DF96  England
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Originally Posted by Hierfi
This was what I was trying to get at.
You appeared to be saying the very opposite.
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Old 5th November 2012, 06:37 PM   #203
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Originally Posted by Hierfi View Post
In some experimentation larger coupling capacitors resulted in a deterioration in dynamics and weight. Bear in mind that such impressions could be more of delusion or other forms of a mental disorder.

This "delusion or other form of mental disorder" is called changed time constant. Load of the coupling cap, especially in the output stage, is non-linear, so time constants for charging and discharging the caps differ, and they also differ with changing of their values, so characters of dynamic distortions differ. Guitar players are well aware of such "mental disorder" up to the point that they call "Farting distortions".
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Old 5th November 2012, 07:38 PM   #204
Hierfi is offline Hierfi  Canada
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Originally Posted by DF96 View Post
You appeared to be saying the very opposite.
Sorry, my communication skills can best be described as non-existent, mostly because of spending my life in not having to do so.
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Originally Posted by Wavebourn View Post
This "delusion or other form of mental disorder" is called changed time constant. Load of the coupling cap, especially in the output stage, is non-linear, so time constants for charging and discharging the caps differ, and they also differ with changing of their values, so characters of dynamic distortions differ. Guitar players are well aware of such "mental disorder" up to the point that they call "Farting distortions".
Sure. However I am not sure if the distortions as you have chosen to reflect them, when they are set up to faster charging or discharging rates and are reduced in amplitude from being perhaps so aptly named would not be considered part of the "improvement" in sound quality. This is when a more modest 2nd harmonic exists to suggest that to be the case.

It may be that frequency limitations as presented by a transformer may be better psycho acoustically than capacitors charging and discharging. Capacitors can have dielectric issues.
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Old 5th November 2012, 07:47 PM   #205
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Improvements in sound quality happens when distortions become less audible. You seems to me think about statically measured distortions speaking of cases when distortions are changed according to signal envelope, with time. I.e. dynamic distortions. No need to search for dielectric issues and other gremlins when plain resistance, capacitance, vacuum diode, and ever changing input signals are at work.
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Old 5th November 2012, 10:13 PM   #206
Hierfi is offline Hierfi  Canada
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Improvements in sound quality happens when distortions become less audible. You seems to me think about statically measured distortions speaking of cases when distortions are changed according to signal envelope, with time. I.e. dynamic distortions. No need to search for dielectric issues and other gremlins when plain resistance, capacitance, vacuum diode, and ever changing input signals are at work.
Perceived improvements in sound quality can happen when "perceived" distortions become less audible or when the presentation of what exists is perceived more real. Both can support the belief in some reality that doesn't necessarily exist.

If the effects of dielectrics are considered unimportant then it seems to follow that no significance can be attributed to any sonic differences between interconnect cabling. Given that audible differences do exist, where are the distortion mechanisms? What makes specialty cabling necessary. If the cables were inside an amplifier or permanently fixed to the amplifier, is it reasonable to conclude that no significance needs to be attributed to those cables? In the high end community interconnect and all forms of cabling has become universally considered as important. There must be some distortion mechanisms being addressed if indeed the sonic differences can be resolved.
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Old 5th November 2012, 10:17 PM   #207
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When amplifiers are properly designed to ignore cables nobody can hear the differences between cables, given they are reasonably healthy.

Pre-production prototypes of my Pyramids will be available soon, you are welcome to test your cables, and how immune is the amp against them. Also you are welcome to compare end results with setups that include other amps that benefit from certain cables.
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Old 5th November 2012, 10:35 PM   #208
DF96 is offline DF96  England
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Originally Posted by Hierfi
In the high end community interconnect and all forms of cabling has become universally considered as important. There must be some distortion mechanisms being addressed if indeed the sonic differences can be resolved.
The first sentence could be considered tautology: the 'high end community' may define itself as those people who have adopted a belief that cables are important, or perhaps those people who use such equipment that needs certain cable characteristics in order to function properly, when better designed equipment may be less fussy.

The second sentence assumes that there are sonic differences. There is very little evidence for this. If solid evidence arises then obviously it will need to be explained.
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Old 5th November 2012, 10:46 PM   #209
Hierfi is offline Hierfi  Canada
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When amplifiers are properly designed to ignore cables nobody can hear the differences between cables, given they are reasonably healthy.
What I have been using for years is either twisted magnet wire or copper in teflon tubing for the interconnects. The reason for the twisted magnet wire is that the dielectric was viewed good enough to be used at great length inside output transformers and fairly easy to make. These are both rather brutal in the presentation and don't necessarily fair well against other forms of cabling, however they just seem more trustworthy when engaging in design work on other components.
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Old 4th December 2012, 02:14 AM   #210
Gost22 is offline Gost22  Bolivia
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Lightbulb Changes to the schematics!?

Hi guys!
Let's be specific, ie, back to the topic.
Interest schematids which gave Formula 22.
I'd like to see the schematic reduced DC-voltage from 220V to 160V. Now the value of changing the resistor 3k3/2W to 1k/2W, then anode resistors connected in series 2k2 and 2k7 would not trade a single resistor of 10k/1W. I replaced the cathode resistor of 120R on 390R/1W. I threw a capacitor of 680uF. Resistors of 4k7 and 220R I threw out the diode would connect directly to the grid. From the anode of the first triode (1/2ECC88) would connect the serial resistor of 1K5 on the second triode grid. Triode cathode resistor other than 10k5 would not trade with 7k5/2W.
I think it would be that what the right solution for Line-Stage or good preamp that well!
Now please give a solution to this comment.
thank you
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File Type: pdf High-End preamp with ECC88 (Schematic-1).pdf (128.6 KB, 151 views)

Last edited by Gost22; 4th December 2012 at 02:28 AM.
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