Yep, we all know the theory. No need for D90 in the first place, D10 already performs below the threshold of audibility. Right?
How about Peter Craven?
I like Hawksford's AES article about time-domain dithering of single-bit sigma-delta's. The conclusion was that he couldn't get it to work, but the idea behind it was very original.
For some people, population at large probably most. I had a burn in issue last night. One of the design parameters of my cheap turntable is that the belt is very loosely coupled to the platter, so much so that if you play 45's for a few days you can not return to 33's without putting the belt in the freezer to shrink it again. It takes a few minutes of run in but you can hear the rumble, wow, and flutter go down, yup real burn-in.
Listened to George Crumb's Voices of Ancient Children one of
Bob Ludwig's great efforts. He had such respect for a diversity of music.
I met Peter Craven along with Michael Gerzon back in 1975 at an AES dinner in London. I was invited to Oxford to talk and hear what Peter and Michael had to listen to for about 1 day. Peter is very accomplished, then teaching at Oxford University, but I am sure that he would agree with me that Michael was extra special, just like Richard Heyser was. I still think these two were the smartest, most insightful people that I have ever talked too. I would have liked to have met Richard Feynman, but I never got to do so.
No, it is getting run back up to room temperature. Frankly if you don't record RH, temperature, barometric pressure, HVAC settings, etc. for a listening session you are wasting everyone's time all of them contribute to pico-second variances in propagation of sound.
I had to look that up. YouTube who needs effects units when you can stick your head into a piano and sing 🙂
I like it!
Last edited:
John,
it’s amazing when you get to meet someone like that. I was fortunate to have met Siegfried Linkwitz and have his undivided attention.
It would be fun to have that kind of time with you 😀
Cheers,
Greg
Thanks for that link! We were some of the original contributors to Mass MOCA, my wife is from Adams MA and her mother worked for years making capacitors at Sprague (the former Sprague site is now Mass MOCA).
Hey John, for the ultimate quality direct to disc, check this out.
YouTube
At least Jack White has a sense of humor.
TCD
Tone control = EQ change altering FR
SET's, 0 x OS DAC's etc etc can be very flat within the audio band FR wise but
the 'tone' change is distortion, filters (or lack of) etc.
Yeah.... I know.... it's nit picking.... 😀 😀
TCD
To your point there seems more SQ damage done in the conversion from the data to the frequency than such is given concern by harmonic analysis alone. In other words, known and unknown mechanisms of "noise" (being defined as anything that isn't signal) seems incorrectly weighted or not yet known to exist. Original criticisms of insufficient sampling rates and bit depths have not proven as significant as considered suggested. This in comparison to alternative advancements in interface mechanisms, power supplies, etc., having seemingly taken much greater strides. This is not to suggest that the original sampling frequencies ought not to have been 88.2 or 96KHz. The substantial reduction in components to perform ultrasonic filtering at 2XOS is in comparison to the potential of considerably more complex networks required at NOS, hence improved SQ is unclear.
The TDA1541 is a non-ideal current source device, that seems to your point a positive attribute, as not necessarily a negative one. This follows if in connection to a wide bandwidth low impedance load such as a common base network. My primary concern isn't "transient overload" (if at all under the circumstances described) rather that full-scale input currents of +/- 2mA from the TDA1541 can yield high levels of logarithmic transfer function distortions. This is of concern being in the presence of wide bandwidth step function currents above the audio band, those being highest of content in a NOS mode. Using common base networks of complementary bipolar design appears of advantage in generating a symmetrical logarithmic transfer function keeping harmonics in the ultrasonics as above the audio band. The disadvantage is that such complementary networks usually raise the input impedance, considered a critical negative to improved SQ.
Hierfi,
your interpretation suffers from inconsistencies. "Transient overload" and "input current" are unorthodox expressions. A transient does not denote a signal property, but an abrupt energetic change in the signal propagation medium, in the digital field, sharp voltage and current spikes (pulses) generated by oscillators, reference clock multipliers and switching elements. It`s like persistently bombarding the Thames River, not a nice place to be if you are a signal.
You seem quite a bit puzzled about the notion of electric current. There is no transanimative conveyance of electric charge from one physical entity to another. Any amplifying device in any position and in any configuration understands just one thing: force. The TDA1541 is not a current source. I had a single-ended, common-base, low distortion "nonlogarithmic" voltage amplifier in mind.
I meant to say that the bombardment itself is more harmful than its timing irregularity (jitter). So rather than taking the usual superclock route, in the case of the TDA1541, it is feasible to go in the opposite direction, aiming at a low energy 44/16 conversion.
Not exactly. You are worrying about the wrong things. You should distinguish between operating frequency and bandwidth, these are inversely related. To alleviate the discombobulation, do yourself a favor and dismiss the THD metric entirely.
Just for the record, bandwidth is not representable. The mathematical step function cannot include bandwidth as it would lead to an unbearable paradox. A "signal" can either be limited in frequency or in time, but physical properties are not independent of each other. A higher frequency entails higher amplitude and higher current.
Great definition. Several types of noise are described at a molecular level without any mathematical formula. Fairly impressive knowledge if you ask me.
That`s what I am trying to say. The considered increment in spectral resolution is questionable. Yes, power supply quality is of central importance, yet largely neglected.
Not necessarily, smaller amplitudes are easier to attenuate. High frequency pulses are tricky, can travel across galvanic isolations.
your interpretation suffers from inconsistencies. "Transient overload" and "input current" are unorthodox expressions. A transient does not denote a signal property, but an abrupt energetic change in the signal propagation medium, in the digital field, sharp voltage and current spikes (pulses) generated by oscillators, reference clock multipliers and switching elements. It`s like persistently bombarding the Thames River, not a nice place to be if you are a signal.
You seem quite a bit puzzled about the notion of electric current. There is no transanimative conveyance of electric charge from one physical entity to another. Any amplifying device in any position and in any configuration understands just one thing: force. The TDA1541 is not a current source. I had a single-ended, common-base, low distortion "nonlogarithmic" voltage amplifier in mind.
I meant to say that the bombardment itself is more harmful than its timing irregularity (jitter). So rather than taking the usual superclock route, in the case of the TDA1541, it is feasible to go in the opposite direction, aiming at a low energy 44/16 conversion.
Not exactly. You are worrying about the wrong things. You should distinguish between operating frequency and bandwidth, these are inversely related. To alleviate the discombobulation, do yourself a favor and dismiss the THD metric entirely.
Just for the record, bandwidth is not representable. The mathematical step function cannot include bandwidth as it would lead to an unbearable paradox. A "signal" can either be limited in frequency or in time, but physical properties are not independent of each other. A higher frequency entails higher amplitude and higher current.
Great definition. Several types of noise are described at a molecular level without any mathematical formula. Fairly impressive knowledge if you ask me.
That`s what I am trying to say. The considered increment in spectral resolution is questionable. Yes, power supply quality is of central importance, yet largely neglected.
Not necessarily, smaller amplitudes are easier to attenuate. High frequency pulses are tricky, can travel across galvanic isolations.
I can't keep up with the orthodoxy (in most things). Testing was done using a digital function generator with about +/- 25nSec rise/fall times into a 2kOhm resistor. The opposing end was connected to the input of variant I/V’s. This "bombardment" of a 4mA (+/-2mA ) "input current" caused visible "transient overload” at the summing junction of I/V feedback networks. This was in isolation of the TDA1541A or other current input devices. My concern isn't limited to transient noise absorption or remnant noise transmission passed on from an input source, rather also to internal noise generation, open loop input impedance vs. frequency, and to open to closed loop gain ratios vs. frequency (as such relates to high frequency phase margins) of the I/V's. Such testing is intended to support design consideration in order to minimize, tradeoff, or preclude the need for oversampling, complex power supply networks and jitter concerns. To your point, there doesn’t appear any justification yet for oversampling that can’t be negated of necessity by the advancement of I/V networks.
Harmonic distortion has become of concern when in conjunction with the analytical unmasking of perceived natural occurring harmonics as signal, particularly in terms of the weight perceived of those variant signals. This suggests that some form of noise masking might ultimately be necessary.
Always. It seems that force can only exist in the presence of an opposition to that force, as some reactance to it. These forces require a common connection for those forces to be applied, as for example a common ground. In partial agreement to your point, differential conveyance of electric charge (the sum of the forward and return path conveyance of charge) can only exist in the presence of capacitance and/or inductance to cause differential charge to be held differentially in the physical entities. This is only until stabilization takes place, hence non-stabilized DC current conditions.
You may be confusing the Ro of the TDA1541 with the Ri of the common base network. Nothing is a true current source, as theoretically modelled as an infinite voltage source with infinite series resistance. Real world current and voltage sources can be modelled as a voltage source with a series resistance Ro. In recent testing to evaluate your point, the TDA1541A tested (as being a fake or otherwise) can be approximately modelled as a +/- 800 voltage source with a 400k Ohm series resistance, hence if the end of this resistor is connected to a ground this would result in +/- 2mA full scale. For this to be realized requires that the TDA1541A operates within a boundary window less than about +/- 300mV to ground, otherwise saturation takes place as drastically reducing Ro.
Let's face facts folks! Audio design is ongoing, mostly because some people are concerned about the differences between products that they consistently hear in actual use, and so if they are able, are trying to improve them.
Now I realize that many here are happy enough with their audio setup, but some of us aren't. We actually find that ferreting out small, but useful audio improvements is a fun hobby! Personally, I admire some of you and your vast listening selections, but I kind of stop outside of hi fi sources with 'Dr. Demento' (interesting songs, but low fi). So I actually have a limited range of music sources that I bother with. Still, I wish to say, from the feedback I get from the general public, real hi fi, even hi end, is still going strong and we still need people like Markw4 to give us further direction as to how to make audio reproduction as close to perfect as possible. Keep on listening!
Now I realize that many here are happy enough with their audio setup, but some of us aren't. We actually find that ferreting out small, but useful audio improvements is a fun hobby! Personally, I admire some of you and your vast listening selections, but I kind of stop outside of hi fi sources with 'Dr. Demento' (interesting songs, but low fi). So I actually have a limited range of music sources that I bother with. Still, I wish to say, from the feedback I get from the general public, real hi fi, even hi end, is still going strong and we still need people like Markw4 to give us further direction as to how to make audio reproduction as close to perfect as possible. Keep on listening!
It was a long time ago some of the most intelligent people on earth were doing electronics and audio science. Too many graduates from MIT and Ivies go to Wall Street these days and it's pretty sad...🙁
