Thank you for the tips.
As I am no OEM I can do diferently
I take my time, measure the parts against some very high acuracy ones I use as references (0.1% resistors and 0.3% caps).
After that I listen carefully against other builds and other sources untill I get it right
Sorry to spoil you accuracy quest, there's is simply much larger differences in component types than in tolerances....
This thread was primarily about different emphasis curves...not on what people could hear or not...
The purpose was simply to shed some light on the what was good practice....My hope was to get some more exact knowledge on this subject..
Optimum would have been some kind of starting point in making different curves, I know they can be found in this thread by following some of the external links which is focusing on the transfer of vinyls to digital, but no one here has published values...
This thread was primarily about different emphasis curves...not on what people could hear or not...
The purpose was simply to shed some light on the what was good practice....My hope was to get some more exact knowledge on this subject..
Optimum would have been some kind of starting point in making different curves, I know they can be found in this thread by following some of the external links which is focusing on the transfer of vinyls to digital, but no one here has published values...
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What values are you refering to ?
I collected this info:
f = 1 / 2pT
RIAA--------f----------T us
Pole------50,05-------3180
Zero-----500,5--------318
Pole------2122--------75
ffrr LP-------f----------T us
Pole------100---------1592
Zero-----450----------354
Pole-----3000--------53
EMI LP------f----------T us
Pole-------70--------2273,6
Zero------500-------318,3
Pole------2500------63,66
COLUMBIA--f----------T us
Pole------100-------1591,5
Zero------500-------318,3
Pole------1500------106,1
CCIR--------f----------T us
Pole------50---------3183,1
Zero------500-------318,3
Pole------3180------50,0
But I am not sure if these are correct (apart from the Riaa curve).
Hi,
It is worth reading the EQ section in Peter Copeland's book. All of it.
Then compare the other information available.
Ciao T
It is worth reading the EQ section in Peter Copeland's book. All of it.
Then compare the other information available.
Ciao T
Info is readily available:
Equalization of Older Records
78 rpm and RIAA Phono Equaliser
I also extracted the attachment from an old Grommes preamp manual.
The Laplace equations is my tool...with that I can quite easily make passive as well as transimpedance circuits...(though i think one of the curves is off....The Columbia stands out)
Think it's possible to build LT-spice equations..where you subtract the RIAA curve from the one you would like to examine....(new area for me though)
I plan to fiddle the curves with fixed capacitors and then vary the resistors...
Think it's possible to build LT-spice equations..where you subtract the RIAA curve from the one you would like to examine....(new area for me though)
I plan to fiddle the curves with fixed capacitors and then vary the resistors...
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Yes there are really significant differences and they are VERY audible, otherwise Thorsten would not have had the trouble to investigate so much.
The real trouble seems to be that there is no way we can be sure what curve was used by the several brands to master and cut their records.
I read Lipshitz papers and my phonos follow the Riaa curve quite acurately. Any deviations (even small) produce significant differences.
IMO, after many experiments, the most important figure is precisely the 500.5Hz Zero. This value seems to determine the correct timbre of the instruments and is easy to determine and set very acurately.
In a passive filter, between two amp stages, the other two inflexion points are quite difficult to determine because they are dependent on the first stage output impedance and the second stage input Miller.
I guess, using a split filter might be much easier to determine the correct values.
Using active filters might be even simpler as in Joachim Gerhard design Quote" A stage i would build for me would be typical parallel symmetric, cascoded, fast and precise current mirrors. 75usec transimpedance and 318usec and 3180usec active. DC coupled, well buffered."
The real trouble seems to be that there is no way we can be sure what curve was used by the several brands to master and cut their records.
I read Lipshitz papers and my phonos follow the Riaa curve quite acurately. Any deviations (even small) produce significant differences.
IMO, after many experiments, the most important figure is precisely the 500.5Hz Zero. This value seems to determine the correct timbre of the instruments and is easy to determine and set very acurately.
In a passive filter, between two amp stages, the other two inflexion points are quite difficult to determine because they are dependent on the first stage output impedance and the second stage input Miller.
I guess, using a split filter might be much easier to determine the correct values.
Using active filters might be even simpler as in Joachim Gerhard design Quote" A stage i would build for me would be typical parallel symmetric, cascoded, fast and precise current mirrors. 75usec transimpedance and 318usec and 3180usec active. DC coupled, well buffered."
Torsion fields is a practical audio relanost. It is strange that on this forum I have to prove and defend understandable to many Russian designers of audio stuff. Real practical second pole is located on the RIAA curve frequent 501.12 Hz. Which is a 64 harmonic frequencies of 7.83 Hz frequency *** Schumann. German designers knew about it (but then apparently forgot)?
Frequency noise does not fix the value of a deviation is within a day. It is the magnitude of this deviation does not allow accurate interpritirovat frequency of the second pole. Accordingly, it is impossible to pinpoint a maximum of 64 harmonics, and its specific frequency for a specific unit records (in the classical corrector)
Approximation quality for a vinyl record, gives the deterioration of the other. The error of this fact is not a lack of specific proof-reader! It is present in the original soundtrack. Some types of lamps have a secondary generation of Schumann frequencies on the principle of PLL (due to the design of the cathode), and higher musical characteristics of course!
The accuracy of resistors or capacitors is secondary. These games are a little math relevant to the nature of sound. The accuracy of these elements in the 0.5-1% is equal to the accuracy of the tool by mechanical action and is sufficient.
More music will be the proofreader who has a greater range of frequencies down to Schumann and the ability to determine its exact meaning in a particular record. You need to take the information with a weak magnetic field as recorded indirectly in a phonogram.
Self-excitation "successful lamp" comes to a similar effect to the microphone. At the peak of the low-frequency instruments in the bass section.
At the same time is modulated by analogy with the varicap their vnurennee Loop resistance allowing the capture of harmonics (including the 64 harmonics of the second pole).
The phenomenon of "self-trapping" is unstable and depends on the quality of recording and transforming properties of the head for a whole range of fields - vibratsinnogo (acoustic), electric (working), magnetic (a minor but has a pilot information)
Failure to understand the physical realities of a constructor is a battle for the shifting of the pole and a mathematical tochnost.I'll ask again what was the accuracy in the phonograph? What was the accuracy of the devices 50-60 years? Surely no one thinks logically and gentlemen!
Crystals transistor less susceptible to the phenomenon of deviation of resistance and stable ... This izh trouble! Although germanium transistor showing promise, but it does not really have time to study ....
Frequency noise does not fix the value of a deviation is within a day. It is the magnitude of this deviation does not allow accurate interpritirovat frequency of the second pole. Accordingly, it is impossible to pinpoint a maximum of 64 harmonics, and its specific frequency for a specific unit records (in the classical corrector)
Approximation quality for a vinyl record, gives the deterioration of the other. The error of this fact is not a lack of specific proof-reader! It is present in the original soundtrack. Some types of lamps have a secondary generation of Schumann frequencies on the principle of PLL (due to the design of the cathode), and higher musical characteristics of course!
The accuracy of resistors or capacitors is secondary. These games are a little math relevant to the nature of sound. The accuracy of these elements in the 0.5-1% is equal to the accuracy of the tool by mechanical action and is sufficient.
More music will be the proofreader who has a greater range of frequencies down to Schumann and the ability to determine its exact meaning in a particular record. You need to take the information with a weak magnetic field as recorded indirectly in a phonogram.
Self-excitation "successful lamp" comes to a similar effect to the microphone. At the peak of the low-frequency instruments in the bass section.
At the same time is modulated by analogy with the varicap their vnurennee Loop resistance allowing the capture of harmonics (including the 64 harmonics of the second pole).
The phenomenon of "self-trapping" is unstable and depends on the quality of recording and transforming properties of the head for a whole range of fields - vibratsinnogo (acoustic), electric (working), magnetic (a minor but has a pilot information)
Failure to understand the physical realities of a constructor is a battle for the shifting of the pole and a mathematical tochnost.I'll ask again what was the accuracy in the phonograph? What was the accuracy of the devices 50-60 years? Surely no one thinks logically and gentlemen!
Crystals transistor less susceptible to the phenomenon of deviation of resistance and stable ... This izh trouble! Although germanium transistor showing promise, but it does not really have time to study ....
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I fully agree with ThorstenL. And this anal-retentiveness of trying to achieve more than 0.5dB precision is starting to make me sick.
Anyway, that wasn't the original topic. The original topic was the usage of non-RIAA curves, if i recall correctly.
IMO in a SE non inverting two stage implementation with a passive riaa filter (or other) in between, it is very difficult to implement severall curves, because the first stage output impedance affects the filter.
Maybe an active split filter might be easier to modify using switches and different resistor and caps values.
Maybe an active split filter might be easier to modify using switches and different resistor and caps values.
Hi,
I disagree. Look at my "Tube El Cheapo" it would lend itself very easily to an adjustable RIAA circuit, however, for extreme cases, you can switch the whole EQ section for different EQ's.
Ciao T
I disagree. Look at my "Tube El Cheapo" it would lend itself very easily to an adjustable RIAA circuit, however, for extreme cases, you can switch the whole EQ section for different EQ's.
Ciao T
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