DVV, my great grandfather came from your general area, long ago, and apparently he migrated to the USA, partially because the area would be taken over by a different group every couple of years, and they would burn all the textbooks!
Still, I am amazed that you knew about Daugherty and Greiner, 1966. I puzzled over it, for some years. Matti's 1970 paper was published. Still, I stayed an 'op amp' kind of guy, but after 1971, it seemed worthwhile to try Matti's ideas, and I have never looked back.
Still, I am amazed that you knew about Daugherty and Greiner, 1966. I puzzled over it, for some years. Matti's 1970 paper was published. Still, I stayed an 'op amp' kind of guy, but after 1971, it seemed worthwhile to try Matti's ideas, and I have never looked back.
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Of course, there was the small paper in back of the RDH, in later years. Qualitative, but not quantitative. We all knew that amplifiers would 'run out of steam' either with rise-time or higher distortion with higher frequency drive.
However, it was the OP-AMP model that gave slew rate a definitive presence.
However, it was the OP-AMP model that gave slew rate a definitive presence.
Why are we talking about 'belief' in relation to how feedback amplifiers work? I am baffled by this sort of talk. Can we each independently decide which facts of mathematics and circuit theory we choose to believe? The impact on perceived sound quality may be a matter of belief, but the effect on the amplifier in-out function is a matter of fact.
Williamson
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I remember hearing my first Williamson amp and being taken aback by it's transistor like sound . Dry , fast and crystal clear . I have heard very poor ones also where someone used surplus store transformers etc . We built one with Sowter transformers which worked well ( 10 sections not 14 ) . .
The remarks here stand out in my head . I found also but not in this text him saying not to adapt the circuit because a type of distortion not yet named was heard .
I think the lad was 19 when he designed this . I know all the arguments about Williamson , however it is the landmark our industry was built upon . He went on to build robotic machines for car factories and died young I beleive ( 66 ? ) . It is rumored he designed the Quad 11 and ESL 57 .
I remember hearing my first Williamson amp and being taken aback by it's transistor like sound . Dry , fast and crystal clear . I have heard very poor ones also where someone used surplus store transformers etc . We built one with Sowter transformers which worked well ( 10 sections not 14 ) . .
The remarks here stand out in my head . I found also but not in this text him saying not to adapt the circuit because a type of distortion not yet named was heard .
I think the lad was 19 when he designed this . I know all the arguments about Williamson , however it is the landmark our industry was built upon . He went on to build robotic machines for car factories and died young I beleive ( 66 ? ) . It is rumored he designed the Quad 11 and ESL 57 .
You thereby turn something able to be settled by science into a religious matter. Do you by any chance know why you're religious about this? If not, then where is your curiosity?
No it isn't about perception - assuming we're doing science. Its about demonstration of what's so.
Indeed - so where's the evidence you're working to resolve this particular disagreement? So far I've seen you restating your beliefs but not seeking to work harder to understand.
There you go, John, just proves the old adage that we are all connected.
As for knwoing, I wish I could take at least some credit for it but I can't, it seems I was born with a very good memory. Also, with a certain hunger for knowledge. My parents got so tired of reading things to me that they sent me to primary school a year ahead of my time, and a year later, I was a member of the two public libraries in my neighborhood. I love to read, a passion which is till with me today.
So I read a lot. By now, I sift through it - I will forget WHERE exactly I got it from, but not what I got, if I think its worth remembering. It's not a conscious act on my part, it's kind of automatic.
You, for example. I first read about you in 1974, give or take a year, when you did the first Levinson products. Obviously, it was a magazine, and I was subscribed the US's "Audio" and UK's "HiFi News And Record Review", while I bought Italy's "Suono" locally. And so one thing leads to another.
While corresponding with James Bongiorno, I discovered that he and one Bascom King, a favorite author of mine, were good friends, which resulted in an nice exchange of thoughts and messages with Mr King.
I come back here after several years of absence, and who do I find? You. It all revolves in circles, there is no such thing as useless knowledge, though sometimes, you have to wait for decades for it to pay off, but in the end, it always does.
Thank God for Internet's communications capabilities, it allowed me to talk to people I never though I would at the time.
Well 1 yr in the British education system, during that era is equivalent to 10 yrs in the "US" educational system..Subtract points for Pakistan ...
It was better than that, Wayne. I came to ye olde England in September 1967, and started my grammar school (high school) education there. At the time, the system required you to pass O (ordinary) level exams after two years, and then A (Advanced) levels after the other two years.
Your choice of subjects at both O and especially A levels determined your chances of enrolling at a university of your choice, as per the list of requirements each one of them had.
So, in 1969, I passed my own seven O levels, and much to the surprise of my English teacher, actually got a grade 3 in English language. Official O level diplomas carried no grade then, but the initial notice did have the marks. It turned out he was uncertain I'd even pass, and I not only passed, but got a very high grade (grade 6 was a pass, grade 1 was as rare as wisdom teeth), and my British friends scraped by with grade 5 being the best.
Next, I enrolled for the A level courses, did the first year, but went back home to Yugoslavia in July 1970, as my dad's tour with UNESCO was over. This turned out to be most fortunate for many reasons, but that's a long and very convoluted story up Alfred Hitchkok's alley.
Then dad went on to complete his work for the UN in Cairo, Egypt, leaving me to study at home and visit every three months or so. So, just for a change, I was allowed to actually complete my university studies in one, straigh run, with no funnies in between. Sometimes, it's just great doing things the plain vanilla way.
Americans. You Americans are actually resposnible for teaching me just how relative things can be, and often are. When dad first started working for the UN, his first post was Ankara, Turkey, where he taught meachine elements, probably the hardest part of being a mechanical engineer. Mom and I joined him in February 1964. At the time, my "knowledge" of English boiled down to reciting "Twinkle, twinkle, little star" - literally. At home, we had just started learning foreign languages at school.
Then I found out that we lived in a part of Ankara which was almost all inhabited by US Air Force personnel and their families. Remember, in 1964, the Cold War was on full force. Ankara alone had an Air Force and Army population of over 30,000. So, who did I have to play with, at a tender age of 11? Americans, that's who.
Thank God I was blessed with an ear for languages, because I went from zero to hero in 3 months flat. From nothing to fluent (at that age). Half of that was sheer inborn talent, the other half hard work. I won't bore you with details, but trust me on this, February-July 1964 was the hardest part of my life, get up at 6 AM, work, work, work all day, go to bet at 10 PM, free time Saturday afternoon. I did it all, and rather well at that. But I wouldn't wish that on any child.
Believe me, you cannot even imagine the cultural gap between those kids and me. Enormous! But still doable. Without actually realizing it, or being able to vocalize it, I learnt that there is a world of difference between a country's policy and actual people behavior. Like Air Force mothers serving us kids afternoon sandwiches without bothering to even ask who's who. I was just another kid on the block, who just happened not to be US made. I even got stitches, courtesy of Uncle Sam and the Air Force, at their hospital, after my head happened to be in trajectory of a rock; Dave, the guy who threw the rock, had a very unpleanst close encounter with his dad's service belt right there, on the street. I reckon he got off worse than I did, but we still stayed friends.
As for your comment on education capabilities, don't write the US off so quickly. In 1991, I helped a professor from Babson College near Boston organize a seminar for young enterpreneurs. This resulted in a month's worth of a seminar, mostly in Boston, but also in NYC. Walk down their alumini lane and you will see some far from insignificant faces hanging on the walls, for example, people like Ken Olson (who invented Vax and established Digital as a company), Charles Wang, and so forth. True, that is very much a rich man's school, but quality is NOT an issue. Some of their concepts were, though, but hey, what's the academia to do but argue concepts?
Agreeing with something is a religion? If so, what are you religious about?
I never claimed my ears were a scientific matter. And I don't do science, I will not go so far as to claim that what I hear and how I hear it is science.
On the other hand, if "science" would have me do something I know for a fact to be detremental to what I hear, all I can say is thank you, but no thank you.
Well, I did post a working model proposal right her - but I never saw anything specific in that nature that you posted?
Or perhaps you do science only, no practical proof required?
Tell you what - you do the science bit, and I'll try to do the practical bit, let's see who gets further.
No kiding? You don't do the science part first, but get right down to it and rock 'n' roll?
I though it was only me, and now my guilt has been appeased.
Speaking strictly for myself, I usually get the sim model to work within 2-3 days. However, making it sound right to me often takes months of additional work, and I have never been so lucky as to strike the jackpot on the first go.
High Fidelity .
I was at a gathering of the great and the good of Vinyl at a hi fi show in Frankfurt . My friend Terry had just been told off by a German guy ( not in our group ) for using the F word too much . It was pure Monty Python . There were the usual polite arguments . Terry suddenly gets up and says why don't you lot all shut up . Nige says there are more brains around this table than at Oxford University . If there was half the brains where he makes body scanners his job would be easy . Terry proposed we should do an engineering project to make money . Everyone looks stunned . Nothing happened and life went on . Yes guys it is a religion . However that talk was good . It was shaping pole pieces along Fibonacci curves for linearity in magnetic circuits . I said nothing ( they were right ) .
I was at another show talking with the very beautiful wife of one of the most eccentric designers . We talked the effect of various German writers on the German mindset ( compound words which say that has already been thought ) . Suddenly the group turns to us and said what have you two been talking about for three hours . Shakespeare we said . Impossible , Nige cant talk about anything but hi fi for 3 hours .
I was at a gathering of the great and the good of Vinyl at a hi fi show in Frankfurt . My friend Terry had just been told off by a German guy ( not in our group ) for using the F word too much . It was pure Monty Python . There were the usual polite arguments . Terry suddenly gets up and says why don't you lot all shut up . Nige says there are more brains around this table than at Oxford University . If there was half the brains where he makes body scanners his job would be easy . Terry proposed we should do an engineering project to make money . Everyone looks stunned . Nothing happened and life went on . Yes guys it is a religion . However that talk was good . It was shaping pole pieces along Fibonacci curves for linearity in magnetic circuits . I said nothing ( they were right ) .
I was at another show talking with the very beautiful wife of one of the most eccentric designers . We talked the effect of various German writers on the German mindset ( compound words which say that has already been thought ) . Suddenly the group turns to us and said what have you two been talking about for three hours . Shakespeare we said . Impossible , Nige cant talk about anything but hi fi for 3 hours .
78 Vinyl RIAA
Just about to start today's work and should have started . Many years ago I went to a cutting of a very famous band . Rock music with classical overtones . The cutting lathe was Scully with a SP 10 used as a motor ( not ideal if the music has pace ) . The cutting was strict analogue and a very wide dynamic range although soft sounding . Tests were done at 33 1/3 45 and 78 ( all RIAA microgrove ) . 78 was so close to the original as to defy belief ( we were doing A/B in real time , it was a test cut ). This cut was strictly to the production master and had calibration settings . The playback was via SME 12 inch and Shure . The engineer then produced a SACD to compare ( from the same tape ) . He was rather horrified when I said it sounded like a tribute band . I was shocked also as I am content with CD . In his place I would have made the CD from the acetate copies ( not DMM ) . Now that's bonkers , yet I have a hunch it will work . How we do shaping is important .
Now here is a thing .Basically analogue tape recording is a digital process . The bias frequency pushes the magnetic circuit into something that looks suspiciously like digital . So we have ways of doing things which "approximate" to the same thing . 100 kHz bias could be said to be 198 kHz sampling if you look at it . One sounds better .
I don't accept that cutting is a black art . Yes it is , however it speaks badly of an engineer who can hear every defect if vinyl yet can not get a CD to sound the same . Not least he was so proud of the CD. Many people now are getting digital removed from the laths . They are fitting old vario-matix . An analogue vario matrix 78 micro grove can be 12 minutes long .
Lets be clear I have no problem with digital . However these inconvenient truths refuse to go away .
Monitoring was Tannoy and bespoke American 1970's tube amps .
SSL now sell special effects which mimic other companies mixing desks . They apparently do well with it . The engineer David Mate is especailly gifted in knowing why things we like work and has proved it by doing this . David tried to sell some Hi Fi once . No one would even talk to him . Best speakers I ever heard were his . They had feed forward error correction and produced square waves .
Just about to start today's work and should have started . Many years ago I went to a cutting of a very famous band . Rock music with classical overtones . The cutting lathe was Scully with a SP 10 used as a motor ( not ideal if the music has pace ) . The cutting was strict analogue and a very wide dynamic range although soft sounding . Tests were done at 33 1/3 45 and 78 ( all RIAA microgrove ) . 78 was so close to the original as to defy belief ( we were doing A/B in real time , it was a test cut ). This cut was strictly to the production master and had calibration settings . The playback was via SME 12 inch and Shure . The engineer then produced a SACD to compare ( from the same tape ) . He was rather horrified when I said it sounded like a tribute band . I was shocked also as I am content with CD . In his place I would have made the CD from the acetate copies ( not DMM ) . Now that's bonkers , yet I have a hunch it will work . How we do shaping is important .
Now here is a thing .Basically analogue tape recording is a digital process . The bias frequency pushes the magnetic circuit into something that looks suspiciously like digital . So we have ways of doing things which "approximate" to the same thing . 100 kHz bias could be said to be 198 kHz sampling if you look at it . One sounds better .
I don't accept that cutting is a black art . Yes it is , however it speaks badly of an engineer who can hear every defect if vinyl yet can not get a CD to sound the same . Not least he was so proud of the CD. Many people now are getting digital removed from the laths . They are fitting old vario-matix . An analogue vario matrix 78 micro grove can be 12 minutes long .
Lets be clear I have no problem with digital . However these inconvenient truths refuse to go away .
Monitoring was Tannoy and bespoke American 1970's tube amps .
SSL now sell special effects which mimic other companies mixing desks . They apparently do well with it . The engineer David Mate is especailly gifted in knowing why things we like work and has proved it by doing this . David tried to sell some Hi Fi once . No one would even talk to him . Best speakers I ever heard were his . They had feed forward error correction and produced square waves .
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