Re: Scotts Stuff
I'm using one of the M-Audio extenal units now, but I would probably DIY one but use our stuff because it's free. It's all fairly speculative at the moment. I get a full Labview Pro licence as part of my job and I was hoping to get it to talk to USB2 or Firewire at enough speed to do the job. Friends have demoed me some compiled apps that certainly use more than enough MIPs.
I'm sort of low on speakers at the moment, using a pair of Sequerra MET7's (my lab speakers). I'm partial to big Magnepans, though, if I had all the space in the world. The best I have heard was probably a product of all the equipment together, a classic 1980's Absolute Sound setup with Koetsu,Goldmund, Conrad Johnson, Infinity, etc. The guy had NOTHING but old RCA and Mercury LP's.
PHEONIX said:
I'm using one of the M-Audio extenal units now, but I would probably DIY one but use our stuff because it's free. It's all fairly speculative at the moment. I get a full Labview Pro licence as part of my job and I was hoping to get it to talk to USB2 or Firewire at enough speed to do the job. Friends have demoed me some compiled apps that certainly use more than enough MIPs.
I'm sort of low on speakers at the moment, using a pair of Sequerra MET7's (my lab speakers). I'm partial to big Magnepans, though, if I had all the space in the world. The best I have heard was probably a product of all the equipment together, a classic 1980's Absolute Sound setup with Koetsu,Goldmund, Conrad Johnson, Infinity, etc. The guy had NOTHING but old RCA and Mercury LP's.
john curl said:
No problem you can rewrite SPICE to use I, V, AND T as independent variables. We've done it for 15 yrs.
(guess who helped)
I just want to make something very clear: I have never been behind the wheel of anything even remotely like a Porshe and never care too. My first car was a Gremlin (yes, I actually bought one new) at 110,000 miles it self destructed as expected.
John, I'm having trouble understanding that because of the small swings, high frequencies, and relatively large thermal time constants. Is there any IR or similar data showing detection of any sort of thermal modulation of resistor temperature by audio frequency signals? Not to dispute that there may be distortion differences between resistors (albeit vanishingly small ones), but I have an issue with the proposed mechanism.
Re: Sequerra MET7's
It is a very small two way, not much bass, personally designed by Dick Sequerra in the 70's. It is sort of legendary and I don't know if current versions have the same "magic". I called Dick and he said the drivers are irreplacable and there are no upgrades to the old ones that he recommends. Dick also designed the "Blowtorch" of FM tuners. I might just pair them with a good sub, one could do much worse.
PHEONIX said:
It is a very small two way, not much bass, personally designed by Dick Sequerra in the 70's. It is sort of legendary and I don't know if current versions have the same "magic". I called Dick and he said the drivers are irreplacable and there are no upgrades to the old ones that he recommends. Dick also designed the "Blowtorch" of FM tuners. I might just pair them with a good sub, one could do much worse.
Joshua_G said:
scott wurcer said:
That's the key. A voltage divider network of two caps with a high enough load so that it doesn't significantly perturb them will have a flat frequency response. With real loads of very high impedance (tens of giga-ohms is routinely doable, higher is achievable at a cost), it's easy to calculate how big the capacitances need to be in order to have the response flat to any arbitrary frequency response tolerance above any arbitrary bass rolloff frequency.
Not exactly that what you are describing, but I did try compensated dividers, as I worked with them on professional basis on a large scale.
______________
I am being surprised why, when we speak about volume control, 160Vp-p stress over small (inadequate) resistor is mentioned. "Big" resistors are "better" - maybe yes, maybe no. I am surprised that no one mentiones parasitic impedances of different types of resistors, rather than speaking about size only.
Under "standard" line level conditions, nothing like thermal errors in resistors exists, if yes, the effect is negligible.
I am also very surprised of a mix of bright ideas and total irrationality.
______________
I am being surprised why, when we speak about volume control, 160Vp-p stress over small (inadequate) resistor is mentioned. "Big" resistors are "better" - maybe yes, maybe no. I am surprised that no one mentiones parasitic impedances of different types of resistors, rather than speaking about size only.
Under "standard" line level conditions, nothing like thermal errors in resistors exists, if yes, the effect is negligible.
I am also very surprised of a mix of bright ideas and total irrationality.
I`ll agree with that
Maybe thats why nobodies tried those Qtc things.
regards
Max
ps What I think i`m trying to say is,Jargon is designed to keep you out of the club.tunneling electicity sounds like regular electricity.
pps Maybe all of it already is,I`d certainly take the easiest way home.
john curl said:Irrationality is in the mind of the beholder.
Maybe thats why nobodies tried those Qtc things.
regards
Max
ps What I think i`m trying to say is,Jargon is designed to keep you out of the club.tunneling electicity sounds like regular electricity.
pps Maybe all of it already is,I`d certainly take the easiest way home.
It is not for lack of trying. I never heard of them before, and I don't see, at this time, how they would make a BETTER attenuator than what we already know how to do.
When people reach out for new ideas, like capacitive attenuation, they are subtly giving acceptance that we really DO hear differences in resistors. It is the same with the QTC devices, except they are VERY undeveloped compared to what we already have.
What we hear in attenuator differences is based on our personal hearing and experience with different attenuators. Most of us would not have predicted differences, IF we didn't hear them ourselves. This means that one must have access to a pretty darn good stereo reproduction system. The Met7's (I own 3 pairs, myself) are marginal in making these difference comparisons. However, they are a wonderful general purpose speaker for the office, (where I use one pair), for home theatre surrounds, and even for the main speakers for home theatre when used with a sub-woofer.
They will do, in a pinch, for 2 channel reproduction, but I find them too 'forgiving' for serious work. This may be why many here can't hear these subtle differences we discuss here, and then accuse us of 'hearing things'.
Technical explanations are another thing, entirely. It does NOT take a technical 'proof' to explain good food, prepared properly, or a good bottle of wine. It is our EXPERIENCE that gives us enough credibility, not our imaginations.
We, as engineers and physicists, TRY to find a plausible mechanism for the differences, but we are only giving the best guess that we can come up with. The differences are still there, even if we can't prove them to everyone's satisfaction.
When people reach out for new ideas, like capacitive attenuation, they are subtly giving acceptance that we really DO hear differences in resistors. It is the same with the QTC devices, except they are VERY undeveloped compared to what we already have.
What we hear in attenuator differences is based on our personal hearing and experience with different attenuators. Most of us would not have predicted differences, IF we didn't hear them ourselves. This means that one must have access to a pretty darn good stereo reproduction system. The Met7's (I own 3 pairs, myself) are marginal in making these difference comparisons. However, they are a wonderful general purpose speaker for the office, (where I use one pair), for home theatre surrounds, and even for the main speakers for home theatre when used with a sub-woofer.
They will do, in a pinch, for 2 channel reproduction, but I find them too 'forgiving' for serious work. This may be why many here can't hear these subtle differences we discuss here, and then accuse us of 'hearing things'.
Technical explanations are another thing, entirely. It does NOT take a technical 'proof' to explain good food, prepared properly, or a good bottle of wine. It is our EXPERIENCE that gives us enough credibility, not our imaginations.
We, as engineers and physicists, TRY to find a plausible mechanism for the differences, but we are only giving the best guess that we can come up with. The differences are still there, even if we can't prove them to everyone's satisfaction.
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