It occurs to me that, at this point, it might be a good time to distinguish between and discuss differential and common-mode output impedance.
Exactly. That's why I used in my Pyramods a combination of Concertina and LTP. The same trick was used in some Altec - Lansing amps for cinema theaters.
It is interesting that Chris Hornbeck stated that impedance changes depending on how you test it. Perhaps that might be backwords. Doesn't it make more sense that impedance is a fixed property, and that there is a right and wrong way to test it?
I think we all need to drive toward the general definition of the impedance between arbitrary points A and B in an arbitrary circuit. The first step in coming to an agreement about Cathodyne impedances would be agreeing about the definition of impedance in general.
Does that make sense to you? Are you interested in a discussion to try to reach an agreement on such a definition?
I think we all need to drive toward the general definition of the impedance between arbitrary points A and B in an arbitrary circuit. The first step in coming to an agreement about Cathodyne impedances would be agreeing about the definition of impedance in general.
Does that make sense to you? Are you interested in a discussion to try to reach an agreement on such a definition?
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My background? MS EE, Russia, Tomsk. Design and Technology of Manufacturing of Radio and Electronics Equipment. Lots of theory, plus lots of laboratory works of experimental character. We were taught to design original equipment to work in different special conditions where differences in properties literally are the question of life and death...
Tomsk was a special place: scientific institutes, real high-tech manufacturing, and educational institutes, with multiple interconnections, surrounded by deep Siberian forest. I can name only few professors who were working for education only, the rest worked as well either for science, or for manufacturing.
I believe I know why Western chemists can be better electronics engineers than Western EEs. Because chemists were trained to do experiments, while EEs were trained to copy/paste from datasheets and give links on "proper answers" in literature. In USSR it was not called higher education, it was Professional-Technical-Education, they were trained to solve always the same problems, unlike Engineers who were more like scientists here...
There are destructive and non-destructive methods of testing. Non-destructive methods are especially designed not to change properties that are measured, by measurement tools.
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I answered your direct question. If you are satisfied by my answer, let's stick together with technology. If you are not, let's stick with technology anyway.
So it's not a Concertina anymore.
And you can't apply properties of Non-Concertina to Concertina.
I said (but not to you):Originally Posted by CPaul http://www.diyaudio.com/forums/tube...9153-phase-splitter-issue-13.html#post2801690
It is interesting that you have stated that impedance changes depending on how you test it. Please consider that that might be backwords. Doesn't it make more sense that impedance is a fixed property, and that there is a right and wrong way to test it?
It is interesting that you have stated that impedance changes depending on how you test it. Please consider that that might be backwords. Doesn't it make more sense that impedance is a fixed property, and that there is a right and wrong way to test it?
You replied:
There are destructive and non-destructive methods of testing. Non-destructive methods are especially designed not to change properties that are measured, by measurement tools.
I'm misssing the connection between these two paragraphs.
It is interesting that you have stated that impedance changes depending on how you test it. Please consider that that might be backwords. Doesn't it make more sense that impedance is a fixed property, and that there is a right and wrong way to test it?
It is interesting that you have stated that impedance changes depending on how you test it. Please consider that that might be backwords. Doesn't it make more sense that impedance is a fixed property, and that there is a right and wrong way to test it?
You replied:
There are destructive and non-destructive methods of testing. Non-destructive methods are especially designed not to change properties that are measured, by measurement tools.
I'm misssing the connection between these two paragraphs.
Sure. Because I can smear modern Russian education the same way: it is now commercialized, so it is more like Professional - Technical Education. Invest in skills and practical knowledge, and get your job... As soon as they are obsoleted, invest in one more MS EE diploma... And so on... So, let's better stick to the technology: we discussed this "educational" topic already in the Lounge, we can continue there.
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Probably. Depending on the topology. For example, if it contains some kind of overcurrent protection you can get as the result measurement of very high dynamic resistance of overcurrent protection instead of much lover dynamic resistance of the amp when it does not protect itself from destruction.
By the way, I've found the topic about education, we can continue there if you wish: http://www.diyaudio.com/forums/lounge/188500-university-has-no-clothes.html
So I would suggest 2-point measurement technique: load both outputs by 2 equal resistors each and measure voltage drops on them, then load both outputs by equal resistors of a different value and measure, then calculate output resistances of each output. They will be equal.
I only disappeared for less than 48 hours and this thread has grown enormously! Fortunately most of it is going round in circles, as these threads do. Any analysis or measurement must maintain balance, as otherwise you are not measuring/analysing the right circuit. This includes injecting currents. The issue of feeding transmission lines is interesting, but if they are identical (same length, termination etc. - balance, again) then any reflected signal will maintain balance.
I think the issue is that the doubters keep trying to sneak in unbalance by some means or other. As I said right back at the beginning, if you take the ports one at a time you get different impedances. How can you get two different impedance measurements/calculations at the same port? Easy: by changing the impedance at the other port you have changed the circuit you are measuring/calculating at this port, so it is not the same port at all!
I am very tempted to comment on chemists vs engineers but that sort of debate has got me into trouble so I will have to remain just tempted.
I think the issue is that the doubters keep trying to sneak in unbalance by some means or other. As I said right back at the beginning, if you take the ports one at a time you get different impedances. How can you get two different impedance measurements/calculations at the same port? Easy: by changing the impedance at the other port you have changed the circuit you are measuring/calculating at this port, so it is not the same port at all!
There could be some variation in Miller capacitance for a triode output. This will unbalance the cathodyne.SY said:
I am very tempted to comment on chemists vs engineers but that sort of debate has got me into trouble so I will have to remain just tempted.
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