Oh sure, when you're talking about mechanical connections you can get non-linearities. But that's a bit different issue than diodes inside the wire itself.
se
Because of boundaries built up in the metal, the center part of the sinewave, near the zero-crossing point, cannot pass. The result is a kind of crossover distortion, where the low-level signal disappears completely.
If what you said were true, antannas which pick up microvolts and transmit them to receivers on ordinary copper wire with ordinary pvc insulation would not work.
I don't think Scott was saying that, he was quoting the fellow who sells hideously expensive wire and quack medicine. It is, of course, utterly wrong.
One of my three weapons, viscious sarcasm. You really need to delve into the history here. And I still would like your critique of Earl Geddes CD wavegide in the context of nothing of any value has been done in 30yr.
Last edited:
When a thread is as long as this one, the essence of it is long lost.
The up coming subjects are maybe interesting, but you guys talking in to a deep well.
Let us invoke Abaddon the angel of the bottomless pit.
Here's my blowtorch:
Hey Steve ,
If you haven't used the Hitachis for anything ....
I'll trade you a bunch of IR robust ones for them ..
(more applicable to class A)
An externally hosted image should be here but it was not working when we last tested it.
Hey Steve ,
If you haven't used the Hitachis for anything ....
I'll trade you a bunch of IR robust ones for them ..
(more applicable to class A)
Nice. Looks more Pass than Curl though.
Yeah, I still have 'em. Haven't got 'round to doing anything high current yet. And been using bipolars for the low current stuff so far.
Gimme a call (457-7946) or shoot me an EMail and we can talk about it.
Thanks, Mike!
se
CD jitter?
Scott,
I missed this comment on the first reading, can you elaborate on which clock Bob Gendron was watching the modulation caused by spokes? Was he monitoring the clock driving the spindle servo? it certainly was not the output DA clock, which is entirely independent of the CD data stream. The CD's EFM data rate is of course established by the scanning velocity of the pickup, and the output DA clock is entirely fixed crystal controlled. Unlike many other digital systems where the downstream equipment is clocked by the source, in the CD player the source clock (the CD itself) is effectively modulated by varying the rotational speed.
I have heard some misrepresentations of this used to sell reclocking circuits which claim to reduce the jitter in the output bitstream due to the CD jitter, which is entirely impossible. There are other good reasons to amplify, square up and retransmit the AES, SDIF or SPDIF bitstreams, but any jitter cleaned up by doing this does NOT come from the CD pit/land EFM jitter in any way. EFM jitter is resolved before the input buffer.
I have seen design flaws in players which make it look this way, such as inadequate power supply isolation between the spindle motor servo and the clock supply. In this case as the spindle servo drew spikes of current to accelerate the CD, the clock supply sagged, introducing noise into the clock. This source of jitter was not the actual CD data jitter, it was the spindle motor. I got into a ******* match with a Studer engineer over that one.
Oh well, these days digital audio from a disc is passe anyway... (said the optical disc replication engineer wistfully).
Howard Hoyt
CE - WXYC FM 89.3
UNC Chapel Hill
www.wxyc.org
1st on the Internet
Scott,
I missed this comment on the first reading, can you elaborate on which clock Bob Gendron was watching the modulation caused by spokes? Was he monitoring the clock driving the spindle servo? it certainly was not the output DA clock, which is entirely independent of the CD data stream. The CD's EFM data rate is of course established by the scanning velocity of the pickup, and the output DA clock is entirely fixed crystal controlled. Unlike many other digital systems where the downstream equipment is clocked by the source, in the CD player the source clock (the CD itself) is effectively modulated by varying the rotational speed.
I have heard some misrepresentations of this used to sell reclocking circuits which claim to reduce the jitter in the output bitstream due to the CD jitter, which is entirely impossible. There are other good reasons to amplify, square up and retransmit the AES, SDIF or SPDIF bitstreams, but any jitter cleaned up by doing this does NOT come from the CD pit/land EFM jitter in any way. EFM jitter is resolved before the input buffer.
I have seen design flaws in players which make it look this way, such as inadequate power supply isolation between the spindle motor servo and the clock supply. In this case as the spindle servo drew spikes of current to accelerate the CD, the clock supply sagged, introducing noise into the clock. This source of jitter was not the actual CD data jitter, it was the spindle motor. I got into a ******* match with a Studer engineer over that one.
Oh well, these days digital audio from a disc is passe anyway... (said the optical disc replication engineer wistfully).
Howard Hoyt
CE - WXYC FM 89.3
UNC Chapel Hill
www.wxyc.org
1st on the Internet
That has always fascinated me. Like, where would reggae music be without echo and ganja?
Oh were you bring funny? Sorry I missed it. My loss. One less chuckle for the day than I could have enjoyed.
I've been mathematically modeling acoustic fields and applying my own principles and discoveries for 37 years. I use my own still proprietary model but I do have a US patent for one application of it. Only enough of the model was revealed to obtain the patent.
My goal is still to reproduce the sound of (acoustic) musical instruments from recordings using electronic sound systems. I've solved my model in two ways. In one way the model's goal is to produce sound fields that would exist if the instruments were in your own room or one only slightly larger. Needless to say this is only usable for soloists and small ensembles (accurate loudness which is almost always overlooked is very important.) In another solution the goal is to produce sound fields that would be heard in very large rooms of as much as a million cubic feet and more. I've also been studying concert hall acoustics and how hearing works including how the brain interprets sound. I have come to some interesting unpublished conclusions there as well.
My methods are different from others and obtain very different results. Applying my theories does not rely on what audiophiles would regard as state of the art equipment. The mathematical model not only shows what the ideal solutions are depending on the goal, it shows me where the shortcomings of all efforts including my own reside. It also shows why any attempt to reproduce concert hall acousitcs using the capture/store/retrieve/reproduce strategy is doomed to fail no matter how many recording playback channels are used. My methods are also different from quadraphonic, ambiphonic, and ambisonic strategies in all their variations that are also IMO doomed to fail.
The constant directivity strategy for high fidelity reproduction of the sound of musical instruments according to my analysis will not result in sound fields that are similar to those produced by real musical instruments. There will be major differences that are easily audibly detectable in all but the most highly contrived arrangements. This was also the conclusion I reached about the AR3 LvR demos Roy Allison conducted in the 1960s, two of which I attended.
The best use of constant directivity loudspeakers is for sound reinforcement. It's no longer an art, it's an exact science. Software exists to design the precise number and location of constant directivity loudspeakers to maximize gain before feedback in such a system taking into account the radiation as a function of propagation angle of the speakers.
The most recent significant contribution to this art IMO was the invention of the digital compact disc. Its commercial introduction was around 1982. Its improvement over the vinyl phonograph record is nothing short of monumental. These media for storage of electronically or mechanically recorded analogs of music seem to have a lifespan of around 30 years before they are obsoleted. The LP was introduced around 1950. I'm not sure when the 78 RPM RCA and 80 RPM Edison flat shellac phonograph record replaced wax cylinders but it wouldn't surprise me if it was around 1920. I've already heard talk about the end of the compact disc. It seems sales are so poor Sony is closing a plant in NJ that produces 20 million of them a month at the end of March.
Cable Issues
Pavel, you are spot on. The only repeatable conductive issue I have ever seen with cables (not getting into ES or EMF shielding) was due to connector effects, the very popular use of gold RCA or BNC plugs on nickel jacks comes to mind. The gold to nickel interface requires frequent abrasion and/or Cramolin or other contact oxidation inhibitor to stay low resistance. Many audio systems have this configuration. I have heard odd level dependant distortions many times from this problem, as the audio arced across oxide barriers.
You want to see odd connector issues? I began my career in media replication at the US's largest independant cassette replication plant. We distributed 4 channels (stereo side A and B) of high speed 64x audio (20Hz-20KHz turned into 1.28KHz-1.28MHz) and 8MHz bias from the master bins to the slave recorders on unbalanced (but impedance controlled and terminated) RG-59 and BNCs. We scrupulously avoided dissimilar materials, standardized on nickel shells and gold center pins, yet STILL had frequent issues with odd cracklings and distortions and 0.9375Hz poppings (60Hz slowed down by 64:1.). This required us to constantly clean and remate all of the 400+ BNCs on a schedule.
With our development of the high speed digital bin (replacing the tape-loop bin), we had to keep the entire system at better than 90dB S/N from 1KHz to 1.3MHz. And think about why the inter-channel crosstalk had to be lower than -90dB: Side B channel audio was non-correlated with Side A and BACKWARDS! That job was learning about distributed audio by jumping into the fire, I tell you... Instant grey/lack of hair!
Howard Hoyt
CE - WXYC FM 89.3
UNC Chapel Hill
www.wxyc.org
1st on the Internet
Pavel, you are spot on. The only repeatable conductive issue I have ever seen with cables (not getting into ES or EMF shielding) was due to connector effects, the very popular use of gold RCA or BNC plugs on nickel jacks comes to mind. The gold to nickel interface requires frequent abrasion and/or Cramolin or other contact oxidation inhibitor to stay low resistance. Many audio systems have this configuration. I have heard odd level dependant distortions many times from this problem, as the audio arced across oxide barriers.
You want to see odd connector issues? I began my career in media replication at the US's largest independant cassette replication plant. We distributed 4 channels (stereo side A and B) of high speed 64x audio (20Hz-20KHz turned into 1.28KHz-1.28MHz) and 8MHz bias from the master bins to the slave recorders on unbalanced (but impedance controlled and terminated) RG-59 and BNCs. We scrupulously avoided dissimilar materials, standardized on nickel shells and gold center pins, yet STILL had frequent issues with odd cracklings and distortions and 0.9375Hz poppings (60Hz slowed down by 64:1.). This required us to constantly clean and remate all of the 400+ BNCs on a schedule.
With our development of the high speed digital bin (replacing the tape-loop bin), we had to keep the entire system at better than 90dB S/N from 1KHz to 1.3MHz. And think about why the inter-channel crosstalk had to be lower than -90dB: Side B channel audio was non-correlated with Side A and BACKWARDS! That job was learning about distributed audio by jumping into the fire, I tell you... Instant grey/lack of hair!
Howard Hoyt
CE - WXYC FM 89.3
UNC Chapel Hill
www.wxyc.org
1st on the Internet
Last edited:
Soundminded, so if I read your post correctly, you have a better way of reproducing sound and evidence/analysis that other approaches are inferior. But these methods are neither published nor available for demonstration, peer review, or replication, so we are to take this on faith.
Is this correct?
Is this correct?
- Status
- Not open for further replies.