Nelson Pass said:
Is this significant when the speaker cables are unterminated?
I mean, is it audible if the cables are unterminated?
myhrrhleine said:
For amplifiers whose gain-bandwidth product is unity anywhere
near the region of resonance, you can experience oscillation,
noise, or simply high distortion. In the worst cases, the amplifier
chooses to excite your olfactory instead of auditory sense.
If you are just talking about zip cord at reasonable lengths and
amplifiers with ordinary bandwidth and/or low feedback, it is not
normally a problem.
I have in the past tested myself as to the audibility of termination
versus none in ordinary circumstances, and the results were
not conclusive, but I figure it can't hurt.
😎
ingrast said:
This is where an actual research professional on hearing would
be useful. Where is Biosonar when you need him?
😎
john curl said:
John,
I presume you intended this to indicate that mentioned skilled listeners did hear a difference although you did not specifically say so - just in case we have another analysis of semantics. Regarding this I would suffice with the contents of my post #710 above. Subjective experiences are not normative when as many "skilled listeners" do not hear differences.
No John, some of us DID listen. But you also did not seem to, when I explained many moons ago why one does use a coil in the interest of added safety when one cannot predict what folks would throw at an amplifier's output, and when there are more important demands than to design for no coil. You really do seem to ride the horse of "Look Ma, no coils" as if it is a major indication of superior amplifier design. Really, if that was the only claim-to-fame of your designs .... fortunately I know it is not, from having investigated what there was to be found on your designs and achievements.
Then, since you opened the door here regarding justification of your attitude:
With respect, you were not disregarded because of your achievements, you generated irritation by what came over as, with apology, an arrogant stance. You have repeatedly been asked to give certain details - perhaps given before and not grasped by some as they should have; we are not all equally bright - only to reply in a manner that can only be construed as putting down. You desire to convey experience to this forum, and that can only be applauded coming from someone like yourself, but success in tutoring implies that you be sensitive to those in need of the same, however "irritating" such demands (from someone who lectured himself). As said by others, audio would be the poorer every time that John Curl is unsuccessful there, so please.
And since you also opened another door (which is really irrelevant, but then): Yes, time in practice normally translates into experience worthy of respect, but not automatically so! I have worked professionally (also) in the field of amplifier design for 57 years. I may not have started a business and sold a hundred dozen models, but I modestly believe a research environment does not have substantially less scope for innovative enterprise than industry. The demands there might even, occasionally, be more stringent than required for mere production of the same thing.
So you are not the only one. Please, your use of terms like "whipper-snappers" etc. are below par in the realm of veterans - if I might be so bold as to include myself in that bracket with some justification then, I believe.
This may seem personal, John, and I post with reluctance - but as said, you did open the door here. Please accept this in the spirit intended, for the good of all.
On a lighter note: As to the age of children and grandchildren compared to yourself and Bob..... 😉 🙂 - well, perhaps back to those tiny but apparently irritating inductors!
Best regards.
mikelm said:
Some people are convinced that the earth is flat, and even claim that they can prove it.
and you just accused John of the A word !
how can you be so sure ?
did you did any kind of testing for this ?
what happened to your spirit of inquiry ?
how can you be so sure ?
did you did any kind of testing for this ?
what happened to your spirit of inquiry ?
ingrast said:
I respect this, but this effect would have been included in tests designed to "model" hearing characteristics.
I also respect post #718 by Myhrrhleine. I am not suggesting a blinkered stance in that uninvestigated things should be ignored, however "obvious". Rather I suggest that where tests did shed light on the likelihood or not that previously uninvestigated matters could occur, that evidence should be taken into account - in fact then, the matter is no longer uninvestigated!
mikelm said:
I am humbled, Mikelm. I must have missed something last time I was on a Sputnik. 😱
Johan Potgieter said:
Remember, those who danced were thought to be quite insane
by those who didn't hear the music
Thanks Myhrrhleine!
I can sign off in a VERY cold Pretoria with a smile on my face and go to bed now.
I can sign off in a VERY cold Pretoria with a smile on my face and go to bed now.
There seems to be a trend of thinking with some academically trained types that the laws of nature act according to their understanding which of course is complete & infallible.
I find this utterly astonishing and sad
🙂
I find this utterly astonishing and sad
🙂
Mikelm, I tried to say something, but I erased it. I am truly amazed that so many people hardly know how the real world works. It is hardly worth my time and energy.
Johan Potgieter said:
Hello,
What I'm suggesting is that the matter may still need investigating, not because investigation was lacking, but the wrong thing was investigated.
Temporal alignment was investigated (as an example) as far back as early theater sound (pre-altec) but the investigation methodologies determined temporal effects such as driver alignment were not audible.
There may be something there [wrt coils] besides amplitude, phase, THD, RF pickup of cellphones and bluetooth, damping factor, etc.,
I'm not saying we cannot measure it, i'm saying we may not have figured out what to measure *yet*
mikelm said:
When the results of a controlled experiment conflict with what we treat as law (say, Maxwell's equations or whatever), then that's cause for serious investigation.
But if the experiments are uncontrolled, there's no cause to investigate anything at all. That doesn't mean uncontrolled experiments are bad. I do them all the time with my system to try to make it sound better. But I don't attempt to make more of these experiments than what they really are.
Well John- I don't know how the real world works so I just proceed with trying new ideas to see if they make my system sound more like the natural acoustic world.
Thanks for the idea on coils I was planning to use them on by next amplifiers but now I will check very carefully to see if I can hear the difference with and without.
Perhaps I will also try making up a set of leads using insulated copper wire with spacers to keep them separate and another identical set but with no insulation - ( hope I don't blow up the amp ! )
I suspect that the uninsulated will sound better but if they do I will not understand why ....and you know what - I don't care.
cheers
mike
Thanks for the idea on coils I was planning to use them on by next amplifiers but now I will check very carefully to see if I can hear the difference with and without.
Perhaps I will also try making up a set of leads using insulated copper wire with spacers to keep them separate and another identical set but with no insulation - ( hope I don't blow up the amp ! )
I suspect that the uninsulated will sound better but if they do I will not understand why ....and you know what - I don't care.
cheers
mike
Johan Potgieter said:
Hi Johan. The most scientific means to that end is to bring the evidence forward.
Conrad,
yes - I know what you mean, it can be fascinating.
I guess we all build up a kind of understanding that makes sense to ourselves based on our own experience...
...but trying to formulate a theory with maths and all that is not my forte at all.
yes - I know what you mean, it can be fascinating.
I guess we all build up a kind of understanding that makes sense to ourselves based on our own experience...
...but trying to formulate a theory with maths and all that is not my forte at all.
estuart said:
Hi Bob,
I have bootstrapped my I/P stage based on the output signal, which (the latter) is flat to about 250kHz. It out performs a cascode topology. So, under which conditions it is of dubious value?
Cheers, Edmond.
PS: In case you need more info to answer my question, I'll send you the schematic of the I/P stage.
Bootstrapping the EC is of dubious value, since feedforward "bootstrapping" of the EC circuit is just as good, if not better.
I also have run the bases of my input cascode off of a scaled-down version of the output signal, if that is what you mean. It works well.
Cheers,
Bob
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