(Soulution by Spemot AG in Switzerland is 100 percent high end, and about specification)
Well I am finishing up at the commercial AV trade show. 1000 booths and 40,000 or so folks attending.
Audio is about 1/4 of it. Apparently my hearing is deficient as I have heard a number of loudspeaker demonstrations of truly wonderful loudspeaker systems that sound dreadful to me. A few did sound decent.
Staying in a Las Vegas hotel that is nice, by local standards moderately priced, but for some strange reason has the hotel's brand name showing on stuff in the room 41 times by my count. Of course I could have missed a few.
Now being as much of a sceptic as I am there are lots of things that are new to the manufacturer but haven't seen anything really new.
Audio is about 1/4 of it. Apparently my hearing is deficient as I have heard a number of loudspeaker demonstrations of truly wonderful loudspeaker systems that sound dreadful to me. A few did sound decent.
Staying in a Las Vegas hotel that is nice, by local standards moderately priced, but for some strange reason has the hotel's brand name showing on stuff in the room 41 times by my count. Of course I could have missed a few.
Now being as much of a sceptic as I am there are lots of things that are new to the manufacturer but haven't seen anything really new.
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Which sums up all of high end audio now. I have seen virtually nothing new or significantly better that what was available 25 years ago with the exception of digital audio storage and retrieval. I'm hard pressed to visit the high end part of CES since its such a wasteland. Usually this is an indication that "the problem is solved".
yes. all things to be worked on and I do address each over time. Still, can we address the question.... digital recording and digital playback.... all else the same (your source, room, speakers etc). What can cause audible differences in the digital record/playback hardware (only)... especially when compared to different brands/makes/models. I found one: Jitter. What else?
THx-RNMarsh
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I have to agree that there was nothing 'NEW' at the Newport Show either, but then I have been around awhile, like the rest of you, and I know about pretty much 'everything' already, but that does not mean that audio differences are completely understood, or that just about anybody can make an outstanding audio product. There is still room of improvement.
For example, the use of high speed diodes in power supplies. How many of you 'hooted at' that in the last month on this thread? Yet there is an excellent article in Linear Audio on the same subject that makes serious recommendations. I'm afraid there is a way to go! '-)
For example, the use of high speed diodes in power supplies. How many of you 'hooted at' that in the last month on this thread? Yet there is an excellent article in Linear Audio on the same subject that makes serious recommendations. I'm afraid there is a way to go! '-)
Well as one who works on the speaker drivers themselves I have to say there is much room for improvement. I was looking at some software the other day, Finecone and Finemotor and I have to say I wasn't to impressed with where we are. If all you want to do is use commodity components with known properties you can design a driver that will be just the same as everyone else is doing. It is as if that is all there is, why bother with a new material or change the motor beyond the standard configurations which will give you a nice smooth graph and known result. Where is the innovation, I'm not thinking just swapping one commodity part for another or making a different combination of what is already existing but true innovation. I see so little to be enthusiastic about, it is just more of the same with a different packaging at best it seems.
I am very familiar with that article, being the author and all. It was just plain engineering, complete with just plain engineering mathematics. Build a test jig, connect it to some diodes, measure their behavior on conventional test equipment operated in conventional ways. No mysticism, no hyperbolic "review" phrases stolen from the pages of Wine Spectator, no Woo-Woo high end bullsh1t. A simple experiment neither fancy enough nor ambitious enough to be accepted for even a Bachelor's Thesis in Electrical Engineering.
The author and the article
Mark, I want to congratulate you for writing the article. It tells it as it is, but it took a long time to get to this:
I know it might seem obvious, but there are usually three phases to a new idea, and they are: 1. It doesn't work. (Me in 1985 or so) ; 2. It works but it is not important. (diodes ringing relative to audio was first shown in early 90's in 'TAA' by Rick Miller, with the encouragement of Walt Jung and me. (I tried it with success, others still balked at the idea); 3. We invented it (or it was obvious) which is where we are today. In other words, what is obvious today, was not that 25 years ago. But it is important to note that diodes do not always behave as well as we presume that they should. Please remember Mark that there are many 'effects' that are now described as 'Woo-Woo high end bulsh1t' that might have a firm engineering basis in future.
I know it might seem obvious, but there are usually three phases to a new idea, and they are: 1. It doesn't work. (Me in 1985 or so) ; 2. It works but it is not important. (diodes ringing relative to audio was first shown in early 90's in 'TAA' by Rick Miller, with the encouragement of Walt Jung and me. (I tried it with success, others still balked at the idea); 3. We invented it (or it was obvious) which is where we are today. In other words, what is obvious today, was not that 25 years ago. But it is important to note that diodes do not always behave as well as we presume that they should. Please remember Mark that there are many 'effects' that are now described as 'Woo-Woo high end bulsh1t' that might have a firm engineering basis in future.
Zero. What was questioned were some of the sonic claims accompanying it (not by Mark, who did a careful job).
John I know you understand this but some readers may not: "diodes ringing" is incorrect. What rings is the RLC resonant circuit comprising the transformer leakage inductance, transformer secondary self-capacitance, diode capacitance, and any additional capacitors the designer may have connected to the transformer secondary.
It's not "diodes ringing" it's "diode-stimulated transformer ringing" and indeed the title of the article isThe RLC resonant circuit is the bell which rings. The diode reverse recovery current-step is the hammer which strikes the bell. It's the stimulus that induces the bell to ring.
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Mark, you know that the diodes, 'overshoot' when they are slow. Call it what you want, BUT that is the key. Perhaps transformers change it to something else, but the effect is the same. Now, I did not address the subjective aspect of this effect. I have personally heard the difference with my own design, after 10 years of using standard diodes in the same design. However, I can't say that everyone will hear a difference with every design or with every person's attitude toward changes in audio quality. This is the next hurdle, Mark. To get people to believe in what the listening differences can be, and perhaps why, (in engineering terms).
The most important factor was the presence or absence of the three optional passive components. The snubber.
1. All diodes stimulated ringing. Even the Hexfreds, even the Schottkys.
2. A snubber directly across the secondary completely eliminated ringing in every case.
3. The worst diode, plus snubber, stimulated no ringing at all -- better performance than the best diode without snubber.
2. A snubber directly across the secondary completely eliminated ringing in every case.
3. The worst diode, plus snubber, stimulated no ringing at all -- better performance than the best diode without snubber.
Actually, that is not the case.
There are two diode "speed" effects.
The first is TFR, or transient forward recovery. It will produce a transient voltage slightly higher than that of the forward voltage of the device. It appears as a softening of the rate of current rise in any circuit affected.
For the product I tested, this was measured at the below ten nanosecond timeframe, and at voltages less than 2 for diodes with a vf of 1.3.
The second is TRR. It is the way in which the diode shuts off it's reverse conduction. It is this entity which causes the ringing of the circuit the diode is a part of.
As Mark said, the diode does not ring. It will cause it.
The term "overshoot" is inconsistent with actual diode behaviour, but consistent with the circuit's response.
John
ps. Mark, excellent work (if I have not stated it before)
The second most important factor might have been the datasheet specification of "softness factor" (tb/ta). Diodes with a datasheet spec'd value of softness factor (tb/ta) tended to rank quite a bit higher than diodes whose datasheet omits softness factor. And higher numerical values of softness factor, tends to rank higher than lower values of softness factor. The #2 finisher in the preamp (100mA) test, was the highest softness factor diode of them all (tb/ta = 4.2 on the datasheet). However, the #1 finisher was a diode that doesn't spec softness factor on its datasheet.
Somebody else can build a test fixture capable of measuring (tb/ta) for those diodes which don't bother to specify it on their datasheet. It sure won't be me.
Somebody else can build a test fixture capable of measuring (tb/ta) for those diodes which don't bother to specify it on their datasheet. It sure won't be me.
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