Respected ThorstenL of course ...
But the third op-amp in his system - once! As an extra capacitor in the signal chain. In addition there are krichtichnosti on the part of the foil material of capacitors. Material capacitors - this is important! Although this is my know-how - practical innovation ....
But the third op-amp in his system - once! As an extra capacitor in the signal chain. In addition there are krichtichnosti on the part of the foil material of capacitors. Material capacitors - this is important! Although this is my know-how - practical innovation ....
I still wonder what the answer to AndrewT question
(post #217) might be. There was a lot of talk which
degree of precision is sufficient, but nevertheless
if you design a eq network you should start with the
correct numbers in the first place, no ?
I think somwhere a paper by the RIAA (or the IEC which
adopted the RIAA and added a time constant (frequency ?))
must exist which defines that.
(post #217) might be. There was a lot of talk which
degree of precision is sufficient, but nevertheless
if you design a eq network you should start with the
correct numbers in the first place, no ?
I think somwhere a paper by the RIAA (or the IEC which
adopted the RIAA and added a time constant (frequency ?))
must exist which defines that.
Hi,
The answer was in my post #218 as:
"A variety of standards have defined this with the time constants and listed next to them the TRUNCATED (read round) numbers of Frequency.
So you can actually see on the paper something like "3180uS (50Hz)"."
In other words the standards (I have seen this for both DIN and IEC) carry both sets of data in writing and clearly with full knowledge and understanding that (for example) 50Hz does not equal the turnover frequency of a 3180uS RC filter or that the time constant of an RC filter with a 50Hz turnover is not 3180uS.
Therefore the question "but which is it" is meaningless, in the context.
One might note given that the timeconstants are given more coverage they may take precedence, however there is no explicit clarifications in the standards.
Ciao T
The answer was in my post #218 as:
"A variety of standards have defined this with the time constants and listed next to them the TRUNCATED (read round) numbers of Frequency.
So you can actually see on the paper something like "3180uS (50Hz)"."
In other words the standards (I have seen this for both DIN and IEC) carry both sets of data in writing and clearly with full knowledge and understanding that (for example) 50Hz does not equal the turnover frequency of a 3180uS RC filter or that the time constant of an RC filter with a 50Hz turnover is not 3180uS.
Therefore the question "but which is it" is meaningless, in the context.
One might note given that the timeconstants are given more coverage they may take precedence, however there is no explicit clarifications in the standards.
Ciao T
Hi,
Sorry, I do not follow: "the third op-amp in his system"?
My personal system has no op-amp's.
Ciao T
Sorry, I do not follow: "the third op-amp in his system"?
My personal system has no op-amp's.
Ciao T
Thorsten,
""but which is it" is meaningless" - Scott mentioned a software implemented
RIAA-EQ which claims ".00006dB accuracy", one would think that for this
kind of accuracy, Andrews question is not meaningless. (Or the ".00006dB accuracy"
is meaningless then.
I agree with you that in the literature timeconstants are given more coverage thus they _may_ take precedence; I would be curious to know what record companies use.
(I always assumed the time constants are the "standard".)
""but which is it" is meaningless" - Scott mentioned a software implemented
RIAA-EQ which claims ".00006dB accuracy", one would think that for this
kind of accuracy, Andrews question is not meaningless. (Or the ".00006dB accuracy"
is meaningless then.
I agree with you that in the literature timeconstants are given more coverage thus they _may_ take precedence; I would be curious to know what record companies use.
(I always assumed the time constants are the "standard".)
Hi,
It remains meaningless. Those who set these standards neither considered such accuracy possible or necessary.
Record companies used what they used. It tends to vary.
I doubt that EQ in the Neumann Lathe cutting amplifiers was much better than +/-0.5dB 20Hz-20Khz, at least in the 60's and 70's, I would be quite incredulous if the 1980's versions where any better +/-0.25dB.
Ciao T
It remains meaningless. Those who set these standards neither considered such accuracy possible or necessary.
Record companies used what they used. It tends to vary.
I doubt that EQ in the Neumann Lathe cutting amplifiers was much better than +/-0.5dB 20Hz-20Khz, at least in the 60's and 70's, I would be quite incredulous if the 1980's versions where any better +/-0.25dB.
Ciao T
Thorsten,
you completely miss the point. Anyone here who has a basic
understanding of the tolerances involved in making a record
know that such an accuracy is wether possible nor required.
The question is, would the IEC define (!) a standard in such
a sloppy way ("318us which is approximatly 500Hz take whatever
suits you more") ?
You obviously don´t have an answer to this question (nor do I).
Said that, the general consensus in the literature I´ve looked
at so far (Stanley Lipshitz, Paul Skritek) seem to be that
the time constants define the standard.
you completely miss the point. Anyone here who has a basic
understanding of the tolerances involved in making a record
know that such an accuracy is wether possible nor required.
The question is, would the IEC define (!) a standard in such
a sloppy way ("318us which is approximatly 500Hz take whatever
suits you more") ?
You obviously don´t have an answer to this question (nor do I).
Said that, the general consensus in the literature I´ve looked
at so far (Stanley Lipshitz, Paul Skritek) seem to be that
the time constants define the standard.
Hi,
Then why bring up .000000000XXdB digtal EQ?
Based on the printed matter before me, they did it that sloppy way.
Remember this was in the 1960's. People where a bit more aware of real world accuracies, less anal retentive and generally by far more intelligent...
My point is in the literature of the time (not just standard documents) used 500Hz/318uS completely interchangeable, even though strictly speaking they are not.
Ciao T
Then why bring up .000000000XXdB digtal EQ?
Based on the printed matter before me, they did it that sloppy way.
Remember this was in the 1960's. People where a bit more aware of real world accuracies, less anal retentive and generally by far more intelligent...
My point is in the literature of the time (not just standard documents) used 500Hz/318uS completely interchangeable, even though strictly speaking they are not.
Ciao T
I wonder if anyone would be able to hear the difference (no peeking)?
There may be a good reason why they considered 500Hz and 318uS interchangable.
jan didden
Hi,
I think it would hard to establish audibility for this, I posted earlier the amount in dB, might have fallen victim to chainsaw though.
I have to say I used these completely interchangeable (aware of the slight error but ignoring it) in the 80's (and still do actually) when both LP's and tape where common and we used these all the time (EQ seems to be an esotheric subject these days).
BUT, we have some people who wish to have a precise answer to a question that involves something defines quite fuzzily.
Ciao T
I think it would hard to establish audibility for this, I posted earlier the amount in dB, might have fallen victim to chainsaw though.
I have to say I used these completely interchangeable (aware of the slight error but ignoring it) in the 80's (and still do actually) when both LP's and tape where common and we used these all the time (EQ seems to be an esotheric subject these days).
BUT, we have some people who wish to have a precise answer to a question that involves something defines quite fuzzily.
Ciao T
Hi,
You said sloppy, I said realistic.
Back in the 80's anyone understood that if a service manual said 22V for a particular test point this was not the exact but subject to a fair bit of tolerance.
Nowadays I get e-mails regarding DIY Build manuals that list explicitly the allowable voltage range asking which exact voltage to expect and what to do if they do not get this exact voltage...
Ciao T
You said sloppy, I said realistic.
Back in the 80's anyone understood that if a service manual said 22V for a particular test point this was not the exact but subject to a fair bit of tolerance.
Nowadays I get e-mails regarding DIY Build manuals that list explicitly the allowable voltage range asking which exact voltage to expect and what to do if they do not get this exact voltage...
Ciao T
I was referring to your design, "bugle" (at least as it is translated into Russian) on the OPA 134 c powered by two batteries.
It turns out a faulty phone because of the multiple translations.
A link to your website unfortunately lost when the virus ate my hard drive..
Speaking about the frequency of Schumann, I had the same support that it vvilu chatota torsion fields. That is the exact combination maskimalnuyu required linearity and phono audio channel to be using the algorithm allows reading of data from these fields. The paradox is that the acoustic hologram for broadcast through a microphone keeps track of the magnetic and electrical component. It is only necessary to have a correct point otchscheta decoder composes magnetic torsion field. In classical systems the threshold at 20 Hz is very small for the required accuracy of music perception.
Typical best effort back then was 1% resistors and 1% silver mica capacitors
This would have initially lead to about +/- 0.2dB errors in the reverse equalisation. Only wire-wound resistors were stable back then, so age could easily take this up to +/- 0.5dB and beyond.
As meters were analogue, measuring anything to better than a few percent was unrealistic
Why the reference to the percent accuracy of resistors and capacitors ?
I always measure all my components using a well calibrated DMM and so I do not care about the written acuracy of parts.
If a 3300r resistor measures 3280r instead of 3300r I use 3280r for my calculations.
Do you mean in the past people tended not to measure parts real values and base themselves on the acuracy imprinted in the parts bodies ? It seems quite vague to me
I always measure all my components using a well calibrated DMM and so I do not care about the written acuracy of parts.
If a 3300r resistor measures 3280r instead of 3300r I use 3280r for my calculations.
Do you mean in the past people tended not to measure parts real values and base themselves on the acuracy imprinted in the parts bodies ? It seems quite vague to me
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As for the differences between 500,5Hz and 500Hz pole on the Riaa curve, let us consider the following values:
R = 6800ohm
C = 46.76nF
R x C = 6800 x 0.04676 = 318 corresponding to 500.5Hz using f = 1 / 2pT
Now let us use a slight variation:
R = 6800ohm
C = 46.80nF
R x C = 6800 x 0.04680 = 318.2 corresponding to 500Hz
The difference is only 40pF in the cap.
It is clearly audible and the 500Hz option produces a more nasal sound with more attack.
500.5Hz produces perfect instrument timbre.
I already wrote that I can distinctly hear a 10pF difference here and I am not alone in my subjective listening impressions.
But than again, I am not corrupted by years of engineering beliefs that all caps should sound the same (as long as they measure equaly) and I can also hear differences between several types of resistors (depending on their position in the schematic).
I also hear differences between cables (signal and mains cables).
I also believe that cart loading differences produce more audible effects than small Riaa inaccuracies.
Please do not ask for graphs and measurements... I am just posting my subjective impressions based on years of experimentation using a Hands On Approach methodology.
R = 6800ohm
C = 46.76nF
R x C = 6800 x 0.04676 = 318 corresponding to 500.5Hz using f = 1 / 2pT
Now let us use a slight variation:
R = 6800ohm
C = 46.80nF
R x C = 6800 x 0.04680 = 318.2 corresponding to 500Hz
The difference is only 40pF in the cap.
It is clearly audible and the 500Hz option produces a more nasal sound with more attack.
500.5Hz produces perfect instrument timbre.
I already wrote that I can distinctly hear a 10pF difference here and I am not alone in my subjective listening impressions.
But than again, I am not corrupted by years of engineering beliefs that all caps should sound the same (as long as they measure equaly) and I can also hear differences between several types of resistors (depending on their position in the schematic).
I also hear differences between cables (signal and mains cables).
I also believe that cart loading differences produce more audible effects than small Riaa inaccuracies.
Please do not ask for graphs and measurements... I am just posting my subjective impressions based on years of experimentation using a Hands On Approach methodology.
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Hi,
Do you really think your DMM has enough accuracy for that? And your capacitance meter?
And you expect a manufacturer to do it like that for each and every product shipped?
I normally specify 0.1% tolerance resistors (in part also because they usually use better sounding manufacturing approaches) and multiple 1% tolerance Capacitors in parallel. This can normally guarantee better than 0.5% total accuracy with averages better than 0.3%, this gives usually better than 0.05dB accuracy.
A manufacturer of products made in 100's and 1,000's most certainly do not measure each and every part. They design using the normal tolerances. Not just in the past.
Here the Stereophile test of a 6,000 USD Phonostage (names are not being provided to protect the innocent):
Ciao T
Do you really think your DMM has enough accuracy for that? And your capacitance meter?
And you expect a manufacturer to do it like that for each and every product shipped?
I normally specify 0.1% tolerance resistors (in part also because they usually use better sounding manufacturing approaches) and multiple 1% tolerance Capacitors in parallel. This can normally guarantee better than 0.5% total accuracy with averages better than 0.3%, this gives usually better than 0.05dB accuracy.
Do you mean in the past people tended not to measure parts real values and base themselves on the acuracy imprinted in the parts bodies ? It seems quite vague to me
A manufacturer of products made in 100's and 1,000's most certainly do not measure each and every part. They design using the normal tolerances. Not just in the past.
Here the Stereophile test of a 6,000 USD Phonostage (names are not being provided to protect the innocent):
Ciao T
You are quoting your probable accuracy as +-0.3% within your target accuracy of +-0.5%.
That gets close to the differences between frequency and time constant.
I recall you said the equivalent of "It doesn't matter" and "we don't need to care for these levels of component selection accuracy"
That gets close to the differences between frequency and time constant.
I recall you said the equivalent of "It doesn't matter" and "we don't need to care for these levels of component selection accuracy"
Hi,
I do it because I CAN and it matters if someone measures. BTW, in absolute terms I make my RIAA EQ flat within +/-0.5dB with very good sample to sample consistency.
I use the leeway in the spec. to shape the response to one I like, instead of allowing for component tolerances.
And no, it is not my experience that the difference between 500 and 500.5Hz turnover is audible, but the one between 500 and 350Hz definitely is.
Ciao T
I do it because I CAN and it matters if someone measures. BTW, in absolute terms I make my RIAA EQ flat within +/-0.5dB with very good sample to sample consistency.
I use the leeway in the spec. to shape the response to one I like, instead of allowing for component tolerances.
And no, it is not my experience that the difference between 500 and 500.5Hz turnover is audible, but the one between 500 and 350Hz definitely is.
Ciao T
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