Are you sure though?
Even if it was just dropped off the table, not thrown down the stairs, it’s still a variability much greater than what we are discussing with amplifiers.
I think we can all (many?) perhaps agree we’ve done some abuse earlier in our lives. Rock concerts, military / rifles, and so on.
I’d be interested to compare your results with others here.
From what serious audio listeners can actually hear, most of what has been put up here is misleading. Of course, most of us hear high frequencies easier when we were younger, but the ability to differentiate between amps, preamps, etc, does not really diminish as we get older, although I must agree, we might not get the same amount of listening 'headaches' that we once might have gotten when we were 30-50 years younger. It just might take a little longer to note differences as we get older. Why? Probably because our brains still do most of the processing, and we really don't listen to test tones to make our evaluation. We gain in learned experience over the decades, and until our hearing really fails, and we are forced use a hearing aid, so for those who really care about audio differences, we keep hearing differences.
IF you are young and don't hear serious differences between amps, you just do not have a developed discrimination for such things. I have noted the same with good food, wine, etc. I have seen young folks chug cheap wine, where I could not, mostly because, while the same age, I had spent a summer in Europe, and had been exposed to better wine. If these same people were tested 'objectively' who is to say that their taste buds were in essence so different at the time? Same with audio testing, objective testing tells you if you need a hearing aid, not whether you can hear audio quality differences.
IF you are young and don't hear serious differences between amps, you just do not have a developed discrimination for such things. I have noted the same with good food, wine, etc. I have seen young folks chug cheap wine, where I could not, mostly because, while the same age, I had spent a summer in Europe, and had been exposed to better wine. If these same people were tested 'objectively' who is to say that their taste buds were in essence so different at the time? Same with audio testing, objective testing tells you if you need a hearing aid, not whether you can hear audio quality differences.
It doesn't change the fact that you, on more than one occasion, misrepresented what Earl Geddes was saying in your thread about hearing responses of autistic people. http://www.diyaudio.com/forums/the-...responses-auditory-stimuli-8.html#post5425545 My observation is that it appears to be a habit of yours
JC,
I’m having trouble understanding how you view quality as both having strictly defined metrics, while also having a “timeless” or ethereal quality of which isn’t subject to the same burden of proof or data. How do you isolate one from the other?
For example, what attributes could enable one to hear the quality of a Teflon capacitor yet at the same time the individual has a massively diminished ability to hear crickets?
I understand and agree with you as to the wild card of training and that there’s a level of artistry involved just the same as a visual artist learns about color.
However, research into vision changes and artistic color periods sheds a lot of light on how biological changes do indeed influence perception and use of color in their work.
Eye diseases changed great painters' vision of their work later in their lives
I think the same can be true for sound and that it would be a mistake to not at the very least take it into consideration.
I could see it as quite plausible that, for example, your designs may have taken on different motifs or goals subconsciously driven by biological changes in your ears or mind over the years.
Im not saying this is true for you, or true for anyone in particular- I don’t know. But I think it’s a valid assumption and certainly worth exploring.
Given the minute areas of concern electrically speaking, I find it strange this isn’t a bigger topic of conversation.
From what I have seen this is quite uncharted, with the exception perhaps of the loss of hearing in musical composers such as Beethoven or sound perception peculiarities within the Autistic population.
And to be clear I’m not just describing hearing LOSS but hearing CHANGE in perception of loudness (both increased and decreased) of various frequencies due to aging, damage and recruitment.
I’m having trouble understanding how you view quality as both having strictly defined metrics, while also having a “timeless” or ethereal quality of which isn’t subject to the same burden of proof or data. How do you isolate one from the other?
For example, what attributes could enable one to hear the quality of a Teflon capacitor yet at the same time the individual has a massively diminished ability to hear crickets?
I understand and agree with you as to the wild card of training and that there’s a level of artistry involved just the same as a visual artist learns about color.
However, research into vision changes and artistic color periods sheds a lot of light on how biological changes do indeed influence perception and use of color in their work.
Eye diseases changed great painters' vision of their work later in their lives
I think the same can be true for sound and that it would be a mistake to not at the very least take it into consideration.
I could see it as quite plausible that, for example, your designs may have taken on different motifs or goals subconsciously driven by biological changes in your ears or mind over the years.
Im not saying this is true for you, or true for anyone in particular- I don’t know. But I think it’s a valid assumption and certainly worth exploring.
Given the minute areas of concern electrically speaking, I find it strange this isn’t a bigger topic of conversation.
From what I have seen this is quite uncharted, with the exception perhaps of the loss of hearing in musical composers such as Beethoven or sound perception peculiarities within the Autistic population.
And to be clear I’m not just describing hearing LOSS but hearing CHANGE in perception of loudness (both increased and decreased) of various frequencies due to aging, damage and recruitment.
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I don’t believe that to be the case, and honestly from his responses I wouldn’t be surprised if he was on the spectrum himself...
Even though I don’t think it’s worth rehashing you are welcome to discuss whatever dissatisfactions you have there and ill be happy to respond to them. I’d rather not drift OT here.
“I” would rather look at it from the perspective of a locus of control, as well as the description of ones own thoughts as an experience rather than a statement of fact.
The Locus of Control
But to each their own.
The Locus of Control
But to each their own.
I'll do a new version and start a new thread over the weekend. Probably sunday when I'll find time.
What perfect timing. This appeared yesterday on the Stereophile website
BorderPatrol P21 EXD power amplifier | Stereophile.com
From the review:
<snip>
<snip>
Then look at the measurements
BorderPatrol P21 EXD power amplifier Measurements | Stereophile.com
It's truly horrible. $14,000 will buy you a very nice complete rig (albeit without JBL M2).
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Link me.
Personally I find safety ground and chassis are all about controlling RF. It seems to be detrimental. So I'm not sold on JN's clearly very good way of reducing audio currents. Maybe I'm cooky, but I like the things I do that are audibly better. While matching potentials is nice, so you have an ultimate reference at no volume, what we hear seems more consistent with the changes in volume that don't seem that respective towards ground so long as the appliance is consistent to itself.
Ott, Johnson, Van Doren, that other guy(I'll remember his name 1 minute after editing is closed..
.) Every time I read, or am at one of their presentations, I find I have to correct them on their misunderstandings. That said, what I learn from them vs what they learn from me scales at about 100:1.
You are entirely correct.
John
Sorry that I'm late to the conversation.I think I will keep posting this image for as long as anyone is willing to discuss it.
...................................
Let's start with the Neil Muncy (RIP) 1994-95 AES paper, later referred to as "the pin 1 problem". Basically it's all external cable shields need to be connected to the chassis at their connectors. The exception being for multi-conductor cables when the shield does not carry a signal (like XLR balanced interconnects). Then the shield may remain open or be connected to the chassis thru a small RF capacitor.
With an external RCA unbalanced interconnect cable the shield is also the return signal conductor so it needs to follow the shield connection rule.
While inside the chassis a wire that carries a signal from one part of the circuit to another part may have a shield with only one connection because the return signal is part of the circuit common (aka Ground).
* * * * * * *
Moving on to the schematic.
That long internal wire from the audio interconnect will act as a noise/interference antenna and be "the pin 1 problem".
The input connector has two signal conductors.
The idea of the noise just going away thru the IEC connection is an oversimplification and it seldom works that way.
So what to do?
- connect the Safety Ground/Protective Earth to the chassis near the IEC connector
- connect all the signal interconnect shields to the chassis (at their connectors)
- connect the DC supply common (aka Ground) to the chassis at a single point
- connect the audio circuit common (aka Ground) to the chassis at a single point
- the above two commons connect to the same single point and it should connect to the chassis near the input connectors (this connection may have a series resistor)
You do not have to be sold at all. It's a discussion, no worries.
My focus in that set of drawings was two fold..
1. With all components bonded, the low frequency currents of the signal from the pre to the amp will take the path of lowest impedance, which would not be the IC shields, but rather the bonding grounds. That rears the ugly head of coupling between the amp haversine draw and the input signals. With no signal, all is quiet. But with major power, the input may be compromised due to coupling.
How one measures this coupling without disturbing the system is a big question, the coupling depends on the low resistances.
2. The loops allow field coupling of external sources. Big loops, big coupling. Big enough, near strikes will toast the equipment.. Sadly, been there, replaced that..
I am more than happy to be proven incorrect, that is familiar territory (anyone with kids knows this position).
Jn
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Just a question in general. The attached doohickey is std fare in RF design for getting power in and out of ones hogged from solid boxes. Some neat little SMT ones these days. Not sure I've ever seen them in audio, which is a shame as they would seem ideal for what we are discussing, which is herding the RF into the chassis and not to your amplifier. Anyone had a play?
But to use them you almost have to double box your unit, not unlike LNAs which need 2 or 3 boxes to get 50/60Hz out of the way.
Going balanced really does make some of this easier....
But to use them you almost have to double box your unit, not unlike LNAs which need 2 or 3 boxes to get 50/60Hz out of the way.
Going balanced really does make some of this easier....
Attachments
I use the SMD versions of those. VERY handy for increasing the PSRR of (discrete) voltage regulators for (discrete) line stage / DAC / phonostage applications. If I'm remembering correctly my first choice vendor is TDK/Epcos. Just channel Walt Jung and you'll instantly get three or four ideas about where these little babies might be helpful.
Warning to people whose job is to design to a price point: the good ones cost a dollar. Oh the humanity.
Warning to people whose job is to design to a price point: the good ones cost a dollar. Oh the humanity.
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