But then the issue of listening to vinyl, which I like more than listening to CD, does not have a clear good solution. If I want there to be no phase change, I have to stay with subsonic frequencies that in turn interfere with the audible frequencies and which, in turn, occupy amplifier power, decreasing the dynamic range. The solution is to return to the CD ?.
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Where is the subsonic coming from - is there some improvements you can do to reduce the generation of subsonic in the first place - is it bearing rumble, warp record or a problem with the table ?
The subsonic comes among many causes, from the deformation although it is slight of the vinyl. Also from the table. You can read the article by Rod Elliott on the subsonic filter P99
Phase shifts are only audible under certain circumstances. Section 4 in particular: Phase, Time and Distortion in Loudspeakers
If the amplitude response is exact RIAA then the phase response will be exact RIAA too - whether you do this passively or via feedback is irrelevant. You get both together, you need both together. The only exception is if the circuit is not minimum phase, but this is unlikely.gabdx said:
The correct phase curve is automatically obtained if you have the correct amplitude curve.ALPUY said:
The algebra of circuit theory. The frequency response of most circuits is a simple complex rational function of frequency and this ensures that if one of phase or amplitude is correct then the other one will be correct too.
You can, to a certain extent, decouple phase and amplitude using a digital filter. Many vinyl junkies would find this unacceptable.
Using analogue techniques you are stuck, as the best you can do is to accept the phase given by a simple amplitude filter; you can do worse than this (e.g. by adding an all-pass filter) but you cannot do better than this.
Using analogue techniques you are stuck, as the best you can do is to accept the phase given by a simple amplitude filter; you can do worse than this (e.g. by adding an all-pass filter) but you cannot do better than this.
Strangely enough me too. And i have owned some pretty respectable and much less affordable pivoted arms.
The last one i had was also on a 124.
As for the topic...i feel lost. Not because all phono stages are equally endowed in subjective dynamics, but because of the startling reference. If it were an old ARC SP-10 i would start nodding in agreement. But this ridiculous tiny box with a power supply more suited to power an mp3 player than a phono preamp...very mystifying.
From a poorly chosen and poorly damped arm-cartridge resonance. It gets excited by warps and to a lesser degree by off-centredness. I prefer dealing with the resonance mechanically, rather than having a silly filter.
If you read the article of P99 subsonic filter of Rod Elliot you will notice that a subsonic filter is no nonsense. I think you have to be open-minded and accept suggestions from others or at least take them into account.
What is the possible detriment or “silliness” of a subsonic filter incorporated directly into the RIAA?
Given that subsonic presumably would mean beneath the range of human hearing, for a properly chosen arm/cart it would make no difference and for a poorly chosen one it would mitigate issues?
Given that subsonic presumably would mean beneath the range of human hearing, for a properly chosen arm/cart it would make no difference and for a poorly chosen one it would mitigate issues?
Actually the little boxes mentioned, maybe not this one, plays better or on the same level as the ARC reference phono.
DF mentioned equalizing vinyl with digital (for no phase shifts), which absolutely removes the whole vinyl idea from the equation.
I have a modification circuit which is a compromise, I did it by adding all the filters I could think of, inductors, it is not very better than a typical hifi phono but maybe worth trying.
Here's an introduction to the general subject. In most circuits of interest
(technically called a minimum phase system), the amplitude response and
the phase response are closely interrelated and cannot be altered independently.
That is, if the poles and zeros of a circuit are specified, then both the amplitude response
and the phase response of the circuit are completely determined.
https://classes.engineering.wustl.edu/jee2330/Exp03.pdf
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Yes, though the best solution was found by Shure, a damping brush designed into the cartridge.
This directly controls the LF resonance, rather than just trying to filter it out.
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I have just read the entire thread - My interest in phono stages has been invigorated since my Original Musical Fidelity 'The Preamp' recently started producing 100VAC throught the chassis!
The Aiwa AP2400 turntable is probably the limitation in the OP's system. But any turntable must be properly supported regardless of its pedigree. The same can be said of many phono pre-amps - The MF 'The Preamp' is well respected but I found it to be very microphonic, and needed proper support before it worked 'Dynamically'.
The nature of vinyl reproduction is very organic. Failure to get the fundamentals right will probably result in disappointment regardless of the budget.
As a sanity check I would suggest recording the Vinyl system with no output from the speakers and with the speakers at normal listening level and comparing the 2 - Any differences in dynamics in the recordings would indicate microphony.
The Aiwa AP2400 turntable is probably the limitation in the OP's system. But any turntable must be properly supported regardless of its pedigree. The same can be said of many phono pre-amps - The MF 'The Preamp' is well respected but I found it to be very microphonic, and needed proper support before it worked 'Dynamically'.
The nature of vinyl reproduction is very organic. Failure to get the fundamentals right will probably result in disappointment regardless of the budget.
As a sanity check I would suggest recording the Vinyl system with no output from the speakers and with the speakers at normal listening level and comparing the 2 - Any differences in dynamics in the recordings would indicate microphony.
The other thing that needs to be pointed out is the RIAA equalization during playback is complementary to the RIAA pre-emphasis and cutter response used when cutting the master.
As others have pointed out the amplitude and phase response are all determined by the poles and zeroes that describe the required (complementary) responses - in an ideal world the phase and amplitude responses are complementary and you get both flat amplitude and phase response on playback.
Transducers generally not being ideal devices you end up with something less than perfect, but sufficiently close to provide some listening pleasure.
As others have pointed out the amplitude and phase response are all determined by the poles and zeroes that describe the required (complementary) responses - in an ideal world the phase and amplitude responses are complementary and you get both flat amplitude and phase response on playback.
Transducers generally not being ideal devices you end up with something less than perfect, but sufficiently close to provide some listening pleasure.
Onvinyl pointed out something I have been using for my preamp and that is the flat amp before RIAA is amplifying a reverse RIAA signal. This allows me to use a cheap low noise transistor for input gains around 10 delivering < 0.01 % THD.
I used this for a tape head amp that is excellent at 63 db s/n way back in 86.
the phono ( RIAA ) version has max levels of 350 mv p-p on signals > 5 khz. 100k ohm 150pf cart loading
operating at 1ma and 20v keeps distortion very low.
I used this for a tape head amp that is excellent at 63 db s/n way back in 86.
the phono ( RIAA ) version has max levels of 350 mv p-p on signals > 5 khz. 100k ohm 150pf cart loading
operating at 1ma and 20v keeps distortion very low.
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