I'm not responsible for the translation....online pdf translation service.
View attachment Bybee_Quantum_Purifier_Teil2 (1).de.en.pdf
Dan.
View attachment Bybee_Quantum_Purifier_Teil2 (1).de.en.pdf
Dan.
Text says " A technical measurement proved quite difficult, since no significant differences to an equally long piece of wire made in the audio field. Only when the measurements were extended into higher frequency ranges to metrological differences loomed."
But then the THD+N measurement which seem to be in the "audio field" shows a 1 dB difference.
Very "un-german" to make such an obvious mistake/contradiction.
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But then the THD+N measurement which seem to be in the "audio field" shows a 1 dB difference.
Very "un-german" to make such an obvious mistake/contradiction.
//
I certainly appreciate the sentiment. I figure you're exaggerating for good storytelling (totally cool with me), but it's less the Porsche than it is that we are paid a lower salary with crumbs of a retirement package versus what we would make as starting pay right out of college. I'd love to see a company park a brand new junior engineer at my job and see how they do. There's got to be a happy medium in there somewhere where I can afford a very basic house/etc while holding a research job. As it is it's an indentured servitude. But I wanted to give it a 2 year shake before looking for industry jobs (which was the initial intent) and that window is coming to its close.
Hi guys! I got really worked up yesterday. No, not just this thread, but my tech blew up this big Parasound power amp JC1+ yesterday, and my boss wants me to FIX IT now. Oh well, I can still charge him for the technician time. Normally, I blow up the amp, so I gave the job to my tech to measure the DC rail voltage. He found it all right!
Guys:
For the dual voice coil setup, is anybody thinking of trying it?
Would it be useful to start a new thread in the subwoofer forum?
Should I approach one of the prof's at a local university with the concept, let some grad students run with it with some mentoring? Hopefully, some combination of mechanical and electrical engineering students..
Oh, TNT, Richard.....I was thinking, there should be a high value resistor between the output line of the amp to the feedback. That way, if the sense coil for any reason opens, the main coil is protected.
I believe it would be a simple matter to break a normal amp feedback, that way the dc servo is also there.
Also, for A/B testing, a switch to go from normal feedback to dvc.
jn
For the dual voice coil setup, is anybody thinking of trying it?
Would it be useful to start a new thread in the subwoofer forum?
Should I approach one of the prof's at a local university with the concept, let some grad students run with it with some mentoring? Hopefully, some combination of mechanical and electrical engineering students..
Oh, TNT, Richard.....I was thinking, there should be a high value resistor between the output line of the amp to the feedback. That way, if the sense coil for any reason opens, the main coil is protected.
I believe it would be a simple matter to break a normal amp feedback, that way the dc servo is also there.
Also, for A/B testing, a switch to go from normal feedback to dvc.
jn
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Wow, what a PITA.
John, here we have been putting lots of protected test points wherever we need to do LOTO and zero energy checks. Perhaps it would pay to have some test points built in to prevent this kind of thing happening again.
jn
I do not know how they measured, because the plots are not very clear and are hidden in the typical "mist" of the audiophile magazine "science". So I replied in the similar manner. Reduced (measuring) BW and linear frequency scale makes one of the tracks to sit lower than the other. Log scale would show. And I really do not get the fact that no audio band serious measurements are shown in the article. Let's take the Bybees on SYS2722 and let's see. I do not have it, though I have an acces to SYS27X2 in necessary cases, which Bybee's are not to me.
Bybee's- I put one on a CLT-1 and could get no measurable distortion above the -160 dB floor. And no measurable inductance or significant resistance on my ESI videobridge. Essentially a wire. I can set it.up on the VNA but it seems almost silly. I guess it would be looking for a variation on insertion loss vs. level?
Ouch!
A remake of what happened exactly 40 years ago: the tech messed up your amp (a S*****y I think), I accidentally found the cure, and you fixed it while I was on my way back to Switzerland.
Pavel,
A second feedback path so during normal use the impedance of the sense coil would reduce the resistor path's contribution close to zero. But if the sense coil failed or was disconnected the amplifier would still have feedback.
With 100% feedback you could have a high impedance inverting input.
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