SY said:
Actually, I realized after the fact that I could have. At the time it was just dealing with the commercial imperative of getting a new preamp tested (beta testing before it was a common term). We were just making sure that it worked in the field. I would definitely do a more rigorous test if I were doing it today. However most companies have few resources to do anything but sell more product today and less money and time to do it with.
Re: Re: Fuses you say?
Not quite.
When the amp is under heavy transient load..and the PS is conducting, ie, loading..the amp is directly connected to the transformer on the pole outside..and like a slow moving rope that is suddenly..at one spot..being pulled FAST..every little transient limiting device or complex reflective point in the chain becomes dominant.
As a component of the full signal it becomes or is negligible.
But..and a BIG BUT..the model of human hearing function has a lot more to say about that.
What it says is that the idea of linear and linear weighted measurement systems in audio is a near total farce. Granted, Linear type measurements and weighting practice within such-has taken us somewhere. Somewhere useful. However - only so far.
The human ear listens primarily, ie..about 85% of what it hears and deals with..is
-Transient edges.
-the length of time of the transient
-The level of it compared to other transients
-the timing between them.
So the ear isn't really even interested in the bulk of the signal.
Only the transients.
When you look at the timing issues between arrival times of point source sounds to the given ear (and then the other ear)..and the audiophiles and testing of human hearing function showing that we can easily exceed differences in arrival times of less than 100,000th of a second (to each ear, to accurately discern the location of a point source). Day in-day out.
This shows only one simple point about the human hearing system, and that one point shows that linear weighted measurement systems have nearly no place at all in the world of audio.
After all, we're not measuring to put neat little numbers on paper we are trying like hell to correlate it to what the ear is hearing.
Therefore, measure like the ear hears, or at the least, understand what the ear is looking for -when looking at the measurements.
It's a case of the proper measurement for the proper situation..but the world of audio and measurement has been looking in the wrong place-at the wrong issues..with the wrong emphasis. Yes..many good things have come from measurement. Now it must be taken to the next level--and most specifically----in the proper context.
I'm listening to FOUR fuses at 2.5A instead of a single 10A fuse in a cheap (but modded-for this test) power amp, right now..and let me tell you it blows the single fuse out of the water..and the only thing that is sonically superior..is the copper bar.
When wiring it up...the fuse holder ( for four fuses, a 'block' type item)..what you do is come in through the small center holes on the one end..and run the SINGLE wire through all four 'lugs'..and then on the output side of the fuse block..do the same..but from the opposite side. This evens out any minor impedance mis matches that may occur.
What it tends to sound like is far more open and delicate on top, with tremendous spacial information, including height and depth that was not there before, soundstage layering..but it ultimately falls apart like a single fuse does (sonic effects that is). More punch and stronger basslines, better 'plosives, and what they like to call PRaT.... When it falls apart, it falls apart at high levels of draw. A single fuse will be muddy in all ways.. and will fall apart sonically as 'mud' but will do it with a lower frequency emphasis. As the four fuses and fuseholder and wiring break in, the slight glare is receding.
syn08 said:
Not quite.
When the amp is under heavy transient load..and the PS is conducting, ie, loading..the amp is directly connected to the transformer on the pole outside..and like a slow moving rope that is suddenly..at one spot..being pulled FAST..every little transient limiting device or complex reflective point in the chain becomes dominant.
As a component of the full signal it becomes or is negligible.
But..and a BIG BUT..the model of human hearing function has a lot more to say about that.
What it says is that the idea of linear and linear weighted measurement systems in audio is a near total farce. Granted, Linear type measurements and weighting practice within such-has taken us somewhere. Somewhere useful. However - only so far.
The human ear listens primarily, ie..about 85% of what it hears and deals with..is
-Transient edges.
-the length of time of the transient
-The level of it compared to other transients
-the timing between them.
So the ear isn't really even interested in the bulk of the signal.
Only the transients.
When you look at the timing issues between arrival times of point source sounds to the given ear (and then the other ear)..and the audiophiles and testing of human hearing function showing that we can easily exceed differences in arrival times of less than 100,000th of a second (to each ear, to accurately discern the location of a point source). Day in-day out.
This shows only one simple point about the human hearing system, and that one point shows that linear weighted measurement systems have nearly no place at all in the world of audio.
After all, we're not measuring to put neat little numbers on paper we are trying like hell to correlate it to what the ear is hearing.
Therefore, measure like the ear hears, or at the least, understand what the ear is looking for -when looking at the measurements.
It's a case of the proper measurement for the proper situation..but the world of audio and measurement has been looking in the wrong place-at the wrong issues..with the wrong emphasis. Yes..many good things have come from measurement. Now it must be taken to the next level--and most specifically----in the proper context.
I'm listening to FOUR fuses at 2.5A instead of a single 10A fuse in a cheap (but modded-for this test) power amp, right now..and let me tell you it blows the single fuse out of the water..and the only thing that is sonically superior..is the copper bar.
When wiring it up...the fuse holder ( for four fuses, a 'block' type item)..what you do is come in through the small center holes on the one end..and run the SINGLE wire through all four 'lugs'..and then on the output side of the fuse block..do the same..but from the opposite side. This evens out any minor impedance mis matches that may occur.
What it tends to sound like is far more open and delicate on top, with tremendous spacial information, including height and depth that was not there before, soundstage layering..but it ultimately falls apart like a single fuse does (sonic effects that is). More punch and stronger basslines, better 'plosives, and what they like to call PRaT.... When it falls apart, it falls apart at high levels of draw. A single fuse will be muddy in all ways.. and will fall apart sonically as 'mud' but will do it with a lower frequency emphasis. As the four fuses and fuseholder and wiring break in, the slight glare is receding.
Attachments
fredex said:
AND. It's ALWAYS in your head. This is basic understanding of perception.
Jan Didden
Re: Re: Re: Fuses you say?
Only about 2mS in every 10mS, 20% of the time, of course. The other 80%, the transformer and everythig before it is isolated from the amp by reversed non-conducting diodes.
Jan Didden
KBK said:
Only about 2mS in every 10mS, 20% of the time, of course. The other 80%, the transformer and everythig before it is isolated from the amp by reversed non-conducting diodes.
Jan Didden
Hi Syn08,
would you please care to elaborate the point for which you cited this paper some pages ago?
"A macroscopic time dependent electrical conduction model for thin phosphosilicate glass films", J. Appl. Phys. 73, 824 (1993)
In what way glass films are of interest as insulating material for conductors? I thought PTFE (for "audio"-grade wiring) or other long-chained stuff is used for that?
Have fun, Hannes
would you please care to elaborate the point for which you cited this paper some pages ago?
"A macroscopic time dependent electrical conduction model for thin phosphosilicate glass films", J. Appl. Phys. 73, 824 (1993)
In what way glass films are of interest as insulating material for conductors? I thought PTFE (for "audio"-grade wiring) or other long-chained stuff is used for that?
Have fun, Hannes
1audio said:
You know, if you pull a chain in the horizontal direction all links must be of equal strength. If, however, you hang something (a Blowtorch preamp for example) in a chain (vertical) the upper link carry the BT AND the rest of the links in the chain, while the lower link carry only the BT. 🙂
Well, do not focus only on details, try to see the whole as well. It has been said God is in the details, however, other says the Devil is in the details.
For now...
RK
Re: Re: Re: Re: Fuses you say?
Reversed non-conducting diodes have, of course, a very important effect on the sound. In fact, I can hear the reversed non-conducting diodes as I write this.
And why limiting the analysis to the pole transformer only? In fact, I think I can identify the sound of the U235 atoms that are slowly burning in the Pickering reactors, feeding my house with electricity.
janneman said:
Reversed non-conducting diodes have, of course, a very important effect on the sound. In fact, I can hear the reversed non-conducting diodes as I write this.
And why limiting the analysis to the pole transformer only? In fact, I think I can identify the sound of the U235 atoms that are slowly burning in the Pickering reactors, feeding my house with electricity.
h_a said:
That paper shows an analytical model for current conduction in any polar dielectric and the relationship to the material macroscopic properties. The model predicts an exponential decay of the current with the maximum (after the displacement component is gone) and time constant depending mainly on the polar momentum of the dielectric molecules and the material viscosity. In a macroscopic view, after an electric field is applied across a polar dielectric, the polar molecules (having the dipoles randomly oriented) are slowly rotating (depending on the material viscosity) and orienting parallel to the electric field.
The paper was targeted originally to the semiconductor industry, however I was eventually pleasantly surprised to find out that Keithley was using (and cited) this paper for characterising their ultra low (in the fA) leakage instrumentation cables.
Thanks a lot for your write-up, Syn08! 😀
So the title was just a bit misleading.
Have fun, Hannes
So the title was just a bit misleading.
Have fun, Hannes
1audio said:
Earthworks gets a special mod to a standard computer mic capsule (so they say). The frequency response of these $1 capsules is amazing, even stock, for what they are as many concert bootleggers will tell you. The Earthworks mic also draws near the limit for phantom power at ~10mA, would never fly in a cell phone.
Remember every dollar spent in the phone itself is essentially viewed as a throw away by the providers.
I remember the old Audio paper that showed a distressingly high DA for glass. But someone recently posted a link to a datasheet for some current parts, which look pretty impressive. Might be worth a try since other properties of glass are quite good.
I have heard that Earthworks selects the capsules and sells the rejects from someone who knows. The Earthworks mikes are very good. But for measurements today a calibration curve for the specific mike will make any mike essentially perfect across its usable range. And the equivalent Behringer ECM8000 mike is $50.
john curl said:Do you say that glass has DA? What a concept!
Don't know about "regular" glass, but the phosphosilicate glass (PSG) used as a case study in the paper has high DA. PSG is widely used in the semiconductor industry as a (relatively thick) dielectric layer.
syn08 said:
Relatively thick because it absorbs moisture and also flows.
One of the best dielectrics is polyethylene, but it flows and don't like temperatures.
scott wurcer said:
The capsule itself don't need even one milliampere. It is self powered from a charged electret film. The problem with phantom powered mics is, their amplifiers need to be powered from 48V, but drive 200 Ohm through high capacitance of cables. With an impedance matching transformer it is fine, but without it it is a challenge. Cellphones may use such capsules without need to drive cables connected to standard microphone inputs of mixing consoles.
When you run the bare capsule off of 1.8V with a pullup resistor you're probably back to no better off than the mic buried in your computer.
scott wurcer said:
I made one for a stage, 4.5V powering a mic amp (27K resistors from phantom, 2 LEDs in series). Cellphone has 7.2V battery, why 1.8V?
Edit: what we are trying to say, sometimes beliefs in what is good enough create weak points in chains. Like John said, "fast food".
Current phones use one cell and usually like everything to run off of 1.8V (for 90nm CMOS)switching supply. They have 100uA MEMS mics and nothing will turn them back. There's no real point in arguing the guys at Nokia are pretty smart they could probably design a mic at any level of quality. From what I hear the built-in mics in some of the cheap point and shoot recorders are pretty good and probably cost nothing as well.
1audio said:
The point is that we are not discussing audio in general, but the blowtorch specifically.
Given this specific topic, why discuss other possible shortcomings?
let's assume in this thread that all other issues have been addressed.
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