Re: 22kOhm
Hi Snoopy,
Maybe it's an attempt to kick the LTP out of balance. I know of one high-end audio guru (cough) who did something like that, because the added 2nd harmonic distortion sounds 'better'.
Another reason why this 22k collector resistor is so stupid is that it adds one more HF pole (Miller!).
Cheers,
Edmond.
snoopy said:.............
Yes it looks a bit funny but that is probably one of those secrets that only the audio gurus knowI wonder if that was in the original design ??
Hi Snoopy,
Maybe it's an attempt to kick the LTP out of balance. I know of one high-end audio guru (cough) who did something like that, because the added 2nd harmonic distortion sounds 'better'.
Another reason why this 22k collector resistor is so stupid is that it adds one more HF pole (Miller!).
Cheers,
Edmond.
No wonder it is a flakey design !!!
Re: quacks
Wow, homeopathic! I bet you've waited for an opportunity to use that word.
I'll try it again leaving out the sarcasm and in between the lines humor.
There is more to designing an audio circuit than selecting the "best" parts, dialing in the operating points, laying out the circuit using the best techniques, adding in the various improvements to drive the measured specs to sub 100db levels and guaranteeing a bandwidth that insures even bats can enjoy.
Some designers chase these subtleties, allot of times at the expense of other attributes that would make the armchair designers of the world hold them in high esteem, with the single goal of making real music in our listening rooms. Many of the things that are important are counterintuitive and have no value to the engineer and his quest, yet they never-the-less do make reproduced music more enjoyable, hence their reputation grows as more people take notice. It's not salesmanship that drives the reputation of classic designs but the actual sound relative to a person’s reference point. People want that elusion of music being made in the privacy of their own home and anything they hear (and I’m not talking about the less serious consumers of the world here) that improves on their memory of a favorite performance is immediately recognized. If one is passionate enough over the years a pretty refined sense of hearing evolves.
What's unfortunate is how specs came to replace listening as the final gauge as to what is allowed on the market and what is not. If you want to know how well your creations actually perform (or that lowly poorly designed Naim) sit down with a female music lover and watch her body language.
Edmond Stuart said:
Wow, homeopathic! I bet you've waited for an opportunity to use that word.
I'll try it again leaving out the sarcasm and in between the lines humor.
There is more to designing an audio circuit than selecting the "best" parts, dialing in the operating points, laying out the circuit using the best techniques, adding in the various improvements to drive the measured specs to sub 100db levels and guaranteeing a bandwidth that insures even bats can enjoy.
Some designers chase these subtleties, allot of times at the expense of other attributes that would make the armchair designers of the world hold them in high esteem, with the single goal of making real music in our listening rooms. Many of the things that are important are counterintuitive and have no value to the engineer and his quest, yet they never-the-less do make reproduced music more enjoyable, hence their reputation grows as more people take notice. It's not salesmanship that drives the reputation of classic designs but the actual sound relative to a person’s reference point. People want that elusion of music being made in the privacy of their own home and anything they hear (and I’m not talking about the less serious consumers of the world here) that improves on their memory of a favorite performance is immediately recognized. If one is passionate enough over the years a pretty refined sense of hearing evolves.
What's unfortunate is how specs came to replace listening as the final gauge as to what is allowed on the market and what is not. If you want to know how well your creations actually perform (or that lowly poorly designed Naim) sit down with a female music lover and watch her body language.
john curl said:
You mean his girlfriend's boobs were flat, cylindrical, and had inverted nipples?
An externally hosted image should be here but it was not working when we last tested it.
se
All this NAIM-Bashing is totally ridiculous and unnecessary. Some of you probably have never listened in an unbiased way and/or have no ideas why the used technique was chosen.
NAIM amps are a very clever example how systems synergies (grounding scheme for example) work and how basically simple and humble "textbook" applications can be turned into something special. NAIM amps were - in contrary to what is claimed here by somebody - never unreliable nor unstable; they always - in their heydays at least - proofed to be more powerful and musical than some many competitors. The fact the NAIM still exists and prospers not only shows clever marketing but also clever engineering, if you like it or not. NAIM never claimed that theirs amps can be used without the equivalent preamps, cause they obviously knowed about the possibilities of simple tweaked circuits. The idea to use very fast selected transistors (custom made by Semelab, quasi complimentary with diode) in common with phase corrected drive was admittedly not invented by Mr. Vereker himself but used with a very good result.
I have sold many of these amps in the eighties, only very few customers had problems, failures of amps were very rare. Mostly because people used the small underpowered NAIT for parties etc.
Why NAIM amps sometimed did not work so well with some "special" loudspeaker cables? Simply because the design of these cables was essentially flawed (high capacitance etc). They could tailor the sound of the odd exotic amp brand, but that does not prove anything.
NAIM amps set standards in musicality - until today.
The schematic showed some postings before was NOT the original schematic, neither of the NAP140 (which used Sanken output transistors) not of the famous NAP250 - parts of it resemble to the very first NAIM amps from the mid-seventies, when they were developed as prototypes. This schematic was without mentioning the original source copied from the HP of Avondaleaudio, a tiny british company who survives supplying a tiny group of tweakers.
The NAIM preamps use technologies which are well known and well respected (single ended ClassA with CCS) - any criticism should criticize also other manufacturers (Like PASS/Threshhold). This technology also showed that the quality of the power supply cannot be rated high enough. Instead of searching a possible unreliable technique which was too expensive maybe they decided to select humble LM317s - and it worked, so who cares.
I - and I am repeating myself here on DIYaudio - have listened to many NAIM clones, no one was bettered the original ones.
NAIMs recipy very often was to modify and develop basic techniques until getting something special: Isn't it what we all are doing to get better sound (if possible)? That probably also make their CD Players so special. Have you ever been listenind to the CD555? If you have, you will never say anything stupid about this company anymore. Well, it definitely IS very expensive, maybe too expensive, but nevertheless...
Most NAIM amps used (and still use?) tantal capacitors, something which is an absolute NoNo in audiophile communities. But their sound prove that if correctly biased even these items can sound perfectly well. This is just one example.
I could go on - but this should be a enthusiast and devellopers forum. Please use the search button for more discussions and statements.
I really get angry when people make clever statements out of no knowledge at all, judge sound qualities by looking at the (wrong) schematic or by laughing over possible design faults. Do inform yourself a bit better before making bland statements.
You said you have no scientific evidence that these amps are anything better than ordinary ones? Then you are either deaf or you talk about something you have never seen nor listened to.
I always wondered why NAIM amps sound so good, although they textbookwise shouldn't. I always wanted to start a discussion why this is so, and what could we learn from that. But mostly just ill-informed bashing occurred.
Why this company rises so much hatred? Is it because most tweakers must learn that their results were simply inferiour to the original?
Is it why we do not like to admit that engineering alone does not necessary proof good sound?
To compare NAIM from inside with cheap Japanese technology is not only uninformed but shows how stupid and blind textbooks and prejudices can make.
Are or were these amps expensive? Yes, but you do not have to buy them if you do not want. Prices never really showed anything about the inherent quality, the so-called highend market is full of quality wise overpriced items. For the calculation of the shop-price of a piece of equipment the technical side is only partly important.
Julian Vereker was a man with verve and vision: He wanted to get somewhere - and he got it. He was using all his abilities for that, in that way or another. Why are we not doing the same instead of grumble about others ideas or results?
NAIM amps are a very clever example how systems synergies (grounding scheme for example) work and how basically simple and humble "textbook" applications can be turned into something special. NAIM amps were - in contrary to what is claimed here by somebody - never unreliable nor unstable; they always - in their heydays at least - proofed to be more powerful and musical than some many competitors. The fact the NAIM still exists and prospers not only shows clever marketing but also clever engineering, if you like it or not. NAIM never claimed that theirs amps can be used without the equivalent preamps, cause they obviously knowed about the possibilities of simple tweaked circuits. The idea to use very fast selected transistors (custom made by Semelab, quasi complimentary with diode) in common with phase corrected drive was admittedly not invented by Mr. Vereker himself but used with a very good result.
I have sold many of these amps in the eighties, only very few customers had problems, failures of amps were very rare. Mostly because people used the small underpowered NAIT for parties etc.
Why NAIM amps sometimed did not work so well with some "special" loudspeaker cables? Simply because the design of these cables was essentially flawed (high capacitance etc). They could tailor the sound of the odd exotic amp brand, but that does not prove anything.
NAIM amps set standards in musicality - until today.
The schematic showed some postings before was NOT the original schematic, neither of the NAP140 (which used Sanken output transistors) not of the famous NAP250 - parts of it resemble to the very first NAIM amps from the mid-seventies, when they were developed as prototypes. This schematic was without mentioning the original source copied from the HP of Avondaleaudio, a tiny british company who survives supplying a tiny group of tweakers.
The NAIM preamps use technologies which are well known and well respected (single ended ClassA with CCS) - any criticism should criticize also other manufacturers (Like PASS/Threshhold). This technology also showed that the quality of the power supply cannot be rated high enough. Instead of searching a possible unreliable technique which was too expensive maybe they decided to select humble LM317s - and it worked, so who cares.
I - and I am repeating myself here on DIYaudio - have listened to many NAIM clones, no one was bettered the original ones.
NAIMs recipy very often was to modify and develop basic techniques until getting something special: Isn't it what we all are doing to get better sound (if possible)? That probably also make their CD Players so special. Have you ever been listenind to the CD555? If you have, you will never say anything stupid about this company anymore. Well, it definitely IS very expensive, maybe too expensive, but nevertheless...
Most NAIM amps used (and still use?) tantal capacitors, something which is an absolute NoNo in audiophile communities. But their sound prove that if correctly biased even these items can sound perfectly well. This is just one example.
I could go on - but this should be a enthusiast and devellopers forum. Please use the search button for more discussions and statements.
I really get angry when people make clever statements out of no knowledge at all, judge sound qualities by looking at the (wrong) schematic or by laughing over possible design faults. Do inform yourself a bit better before making bland statements.
You said you have no scientific evidence that these amps are anything better than ordinary ones? Then you are either deaf or you talk about something you have never seen nor listened to.
I always wondered why NAIM amps sound so good, although they textbookwise shouldn't. I always wanted to start a discussion why this is so, and what could we learn from that. But mostly just ill-informed bashing occurred.
Why this company rises so much hatred? Is it because most tweakers must learn that their results were simply inferiour to the original?
Is it why we do not like to admit that engineering alone does not necessary proof good sound?
To compare NAIM from inside with cheap Japanese technology is not only uninformed but shows how stupid and blind textbooks and prejudices can make.
Are or were these amps expensive? Yes, but you do not have to buy them if you do not want. Prices never really showed anything about the inherent quality, the so-called highend market is full of quality wise overpriced items. For the calculation of the shop-price of a piece of equipment the technical side is only partly important.
Julian Vereker was a man with verve and vision: He wanted to get somewhere - and he got it. He was using all his abilities for that, in that way or another. Why are we not doing the same instead of grumble about others ideas or results?
Thanks, Lohk, for your informed input. Julian and I did NOT share our schematics, but we sometimes shared design philosophies. When I told Julian that I had 30A peak current in my regulated supplies for a 250W power amp that I was designing for Gale, in 1976, he did a rough computation in his head and told me that it was OK. I had not asked him, but I did get informed feedback, anyway. Today, I think that even 30A is too low for a 250W amp, and I have had an amp rejected by the customer to prove it. Julian did NOT tell me about removing the coil and I was using a total of 4uH at the time with my balanced bridge design. Also, I learned much later that the capacitor return path was more important in a power amp than even series regulation. That took me a few years to learn.
In all audio designs there are tradeoffs. The tradeoffs MUST, in the end, be decided by the human ear: If not the designers, then 'golden eared' friends, or impartial reviewers. It is like designing a car on the computer and never putting it on a difficult test track. You will miss SOMETHING!
In all audio designs there are tradeoffs. The tradeoffs MUST, in the end, be decided by the human ear: If not the designers, then 'golden eared' friends, or impartial reviewers. It is like designing a car on the computer and never putting it on a difficult test track. You will miss SOMETHING!
The tradeoffs MUST, in the end, be decided by the human earThat is the crux of the issue here. The Naim amplifiers were designed and built to sound a particular way. Production testing involved a listening test on each and every amplifier after a minimum 24 hour burn-in period.
If you believe that all amplifiers sound the same (to misquote Peter Walker) then such a design goal is heresy. And you can get all hot and bothered about people who do listen to amplifiers (as opposed to music! '
Snoopy, you will be searching in vain for 'scientific evidence'. It is the equivalent of demanding scientific proof that I prefer brunettes. I really can't be bothered to explain my preference. I would rather that spend the energy/time to enjoying the company of my wife.
If you are prepared to accept that an audio amplifier is designed for the purpose of listening to music then, as in my logical realm, the acceptability test procedure requires a human being using said amplifier to listen to music, then... you might find a discussion about the Naim (and other amplifiers with similar design goals) useful.
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