The high priest of audio nonsense.
https://www.stereophile.com/reference/70/index.html
http://hifisonix.com/the-case-for-feedback/
https://www.stereophile.com/reference/70/index.html
http://hifisonix.com/the-case-for-feedback/
An ancient article predicts accurately the fact that 24 years later, the vast majority of contenders for the very top of the amplifier pinnacle will lack overall feedback.
Interestingly, at the time, barring some Pass Labs designs there were hardly any nfb free solid state high end amps. Look at today. Nonsense, huh?
Lately I build few 4way speakers, rather than 3way. With crossovers at 150, 900 and 9000 Hz.
If I do design 3way, I select smaller mid which can be crossed higher, say 5kHz. Much easier on the tweeter, and smoother of axis.
Make sense to me what he says about crossover frequencies.
Martin Colloms is best described as a pretty decent speaker designer* and loopy audio reviewer
*YMMV on your views on his speakers of course.
*YMMV on your views on his speakers of course.
Sorry analog_sa, just because some people believe in (insert reference of your choice here) does not make it true. The fact that the ‘pinnacle’ of audio (whatever that means) has zfb amplifiers does not change the fact that his pronouncements on audio amplifiers and feedback are nonsense - and that’s putting it politely. He used his position as a journalist to poison honest technical discussion, replacing it with absolute nonsense.
When someone says feedback goes ‘round and round’ or that an amp operates in open loop during the feedback electrical signal loop time (which is travelling at relativistic speeds), I struggle to believe anything they say. These matters (feedback) have been dissected by some of the finest minds on the planet and we understand it’s behaviour exactly. Clearly, Colloms does not.
His stuff is on the same level as medical quackery. Sorry to be blunt, but that is the truth of it.
When someone says feedback goes ‘round and round’ or that an amp operates in open loop during the feedback electrical signal loop time (which is travelling at relativistic speeds), I struggle to believe anything they say. These matters (feedback) have been dissected by some of the finest minds on the planet and we understand it’s behaviour exactly. Clearly, Colloms does not.
His stuff is on the same level as medical quackery. Sorry to be blunt, but that is the truth of it.
Yet Jiri Dostal says, "Operational-circuit dynamic errors in the time domain are mathematically
predictable only in simple, idealized cases." Maybe Colloms would have been better off to have studied the real problems with opamps and feedback?
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Sorry, corrected spelling is 'Jiri Dostal.' https://www.amazon.com/Operational-Amplifiers-Second-Design-Engineers/dp/0750693177
It's obvious what needs to be inserted. People believe in their ears, especially when shelling big bucks for a system tasked to provide them with listening pleasure. Convoluted engineering theories are certainly applicable in technical fields, but people keep forgetting that listening pleasure is not a technical field.
So, whether scientifically right or wrong, Mr Colloms' prediction turned out to be true 🙂
I have no issue with people having subjective preferences.
The objection is when folks like Colloms try to justify their subjective dogma with bogus technical theories or trash people with different subjective viewpoints with nonsense.
‘A Future Without Feedback’ should be recognised for exactly what it is: a load of claptrap.
The objection is when folks like Colloms try to justify their subjective dogma with bogus technical theories or trash people with different subjective viewpoints with nonsense.
‘A Future Without Feedback’ should be recognised for exactly what it is: a load of claptrap.
Martin Colloms has plenty of experience and he is clearly not an idiot. What he is effectively reporting is that people like to have their listening experience tailored to their preferences. Nothing wrong with that. Returning to the original application of NFB which was to make telephony more intelligible, you have the info for its technical and subjective benefit for audio. I don't see many recording studios (none to date) that use any of the boutique zero NFB gear in the monitoring chain, even though some have the budget.
I know of one case where a studio tried to use highly regarded boutique valve amps. These ended up in a cupboard.
I know of one case where a studio tried to use highly regarded boutique valve amps. These ended up in a cupboard.
There were lots of low NFB and no NFB around the output stage designs back then just as now. as for the vast majority today care to put up some facts or you pulling conjecture out from where the sun don't shine? Back in the 80s the feedback bad mantra was being chanted a lot in magazines.