A good read, thanks for that, dvv. What's the saying, "Quality is remembered long after the price is forgotten ..."
Shame about the fusing, I guess using the slowest of the slow blow variety helps to some degree ...
As regards actives, the joke is that I have not knowingly heard a truly excellent unit, even though I believe in the concept.
The "other pieces" I was referring to were the articles you wrote for the TNT website, the first being the Noise Basics, Filters ahoy!, part of a set of 3.
Talking of 'excellence',
, I'm having an interesting time modelling an amp suitable for the likes of our master a.wayne , aiming for short term 2000W into 1R, better than 120dB down on all distortion harmonics at 20kHz while running at this level. The front end is not a problem, the output stage is the fun bit, . Of course, this assumes a perfect power supply, so the next trick will be to lift a realistic version of the latter to a level such that the whole box can still perform this well ...
......
The power sounds impressive, but of course it only translates to 250W into 8R, nothing special in itself - the key is to give the unit clean current drive, founded on decent voltage swings.
With the pre-amp 'issue' I would put on my troubleshooter's hat and investigate a step at a time:
* Make sure I'm really hearing "something" - at normal listening levels the sound from one amp really changes when another amp is plugged into the pre-amp.
* Listen on headphones when one channel is driving the former alone, and compare, on the headphones, when the other pre-amp channel then also drives a power amp. What does that tell you?
* Work out what the impedance is that the power amp presents to the pre-amp, assemble a tiny test rig with just the parts to match that, and a connector - test what effect that has, plugged in or not, on the other pre-amp out
* Depending on results so far, compare sound differences heard when 2nd power amp plugged into pre-amp, but the former is in an electrical vaccuum, not plugged into mains, not connected to anything else, a dead lump.
* Again, with 2nd amp plugged into mains, but not switched on - any earth loop type misbehaviour going on?
* Again, with 2nd amp now switched on but doing zip, nothing hooked up to the outputs
* Again, ...
Get the idea ... ?
With the pre-amp 'issue' I would put on my troubleshooter's hat and investigate a step at a time:
* Make sure I'm really hearing "something" - at normal listening levels the sound from one amp really changes when another amp is plugged into the pre-amp.
* Listen on headphones when one channel is driving the former alone, and compare, on the headphones, when the other pre-amp channel then also drives a power amp. What does that tell you?
* Work out what the impedance is that the power amp presents to the pre-amp, assemble a tiny test rig with just the parts to match that, and a connector - test what effect that has, plugged in or not, on the other pre-amp out
* Depending on results so far, compare sound differences heard when 2nd power amp plugged into pre-amp, but the former is in an electrical vaccuum, not plugged into mains, not connected to anything else, a dead lump.
* Again, with 2nd amp plugged into mains, but not switched on - any earth loop type misbehaviour going on?
* Again, with 2nd amp now switched on but doing zip, nothing hooked up to the outputs
* Again, ...
Get the idea ...
?
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Yes, an interesting one, dealing with potentially major voltage sag and modulation! Probably will do a combo of greatly stiffening the rails, via a number of techniques that are whizzing around my head, and getting pretty decent PSRR. One thing I've discovered is that output trannies need very good voltage headroom, otherwise they start going into a distortion inducing death spiral - so sag control will be essential.
Won't be silly about it, I'm not aiming to create a unit that can roast every speaker out there - rather just be able to 100% cleanly handle transient current demands, for a specified short time frame.
Even in Ultra High End audio? ...Where prices can go for $650,000/pair of Magico Ultimate speakers, or $600,000 for a Naim Statement preamp and amp. ...And even much higher. ...And that $650,000 turntable (forgot her name). ... The VPM 2010-1 by Haus Dereneville ? ...See below.
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Yes, that's the sort of thing that can be very effective - give the PS some "intelligence" to dynamically compensate for stress loading, rather than grossly over-engineer all the components to deal with that which occurs 1% of the time.In my view, the future of power supplies for amps lies in digitally correcting for the sag before it occurs. Think 'active suspension' but applied to audio - it does require the DAC to be closely integrated with the amp, none of that old-style 'component' thinking
Do they measure analog turntables and euphony?
What truly is sound quality, Bob?
And do measurements (when properly well done and set with the right measurement tools) correlate with what comes up at the end (sound quality)?
Last, sound quality; to who's set of ears? ...And where? ...Which room?
The sledgehammer approach may work, the idea is to build an efficient, resource conservative solution ...Easy , full regulation on Vas voltage and 280,000uf/ch on the outputs, knock Psrr to the curb ...
Star Man, stop and think in purely practical terms.
1) I come from a country which has been villified for 30 years now. That alone will cost you twice the work time.
2) 99.9% people from the West have been weaned on the idea that technology comes only from the West and have trouble even imagining that something good can come from the East. The East is where all the cheap junk comes from. Try competing with that.
3) Like everybody else, I started with my savings as my initial basis. Most High End companies from the West can outspend me to death on their monthly advertising budgets alone.
4) We speak of a free market, but in reality, most markets get closed very quickly, by one or two, generally local, manufacturers simply close the market in very simple and completely legal ways. For example, What Hi-Fi? tested one of the fiters. They could not find anything wrong and admitted it improves the sound. But, they formulated the text to be still luke warm, because a British manufacturer has regular monthly ads in their mag, and I have nothing. If they say that mine is better, and I know first hand it is better, that manufacturer might take his trade elsewhere.
5) In short, magazines are chauvinistic to their core, but at the time, early 2000, they were still influential. I got two very good reviews from a French mag (by editor Jean Hiraga, no less, the author of the truly legendary Hiraga amp) and from a Danish mag, where it was directly compared with Nordost's unit and a third (I forgot which) unit, which was dismissed pretty quickly. The verdict was that mine was a bit better than Nordost's, but was less than half its price. Result - sales improved in both France and Denmark. But I got into those magazines only because I had friends willing to help, and that is hardly a lasting policy.
I am not adverse to sharing company ownership with a backer if need be, I always remember that Ken Olson, who founded Digital, sold his shares keeping only 5%, but those 5% are worth several b illion USD today, and besides, Olsen graduated on Babson College near Boston, where in 1990 I helped organize and took some courses in enterpreneurship and had some heated discussions with some of the lecturers (even then, they were heavily bent towards the service sector, almost completely overlooking manufacturing).
To boot, I have a degree in economics, majoring in foreign trade, so I am hardly uninformed. I served as a consultant to a few rather good companies, such as Philips and HP (albeit regarding PC in HP's case), so I was in very good shape.
Lastly, I have a rather rich background in media - I authored and anchored my own weekly 45 minute show about PCs for three seasons, ditto for an audio related radio show also three seasons, I published a book in 1990 which sold out the first edition, then the second and the third was cut short by the outbreak of local wars, and I published over 240 texts in local magazines 1986-1994.
So, many most useful ingredients were already there, but my geographical origin was a problem, and the lack of distributors, who feared doing business with somebody from a country with such a bad rep. In short, I was short on money to invest into manufacturing, which would drive the prices down by quite a bit, it all stayed on a manual manufacturing level.
And the Chinese revolution was the last nail in the coffin. They kung fud history and turned their greatest weakness (lack of previous manufacturing experience and base) into their greatest strength, when they went into industrial work, they bought only the latest machinery, unburdened by the need for amortization of the old machines. And, as we all know, they were into unbrideled out and out theft of other people's decades of reasearch and development, blatantly copying.
They even made a business of the act of stealing. I had a few messages from Chinese companies offering, for a sum of USD 300, to make sure my products were not copied in that manner. Great stuff, huh?
Just to spite them all, I am still here, but I am not really any further down the sales road than I was 11 years ago. Just surviving. It would not matter if my price tag was 5 times as big as it is, now when my most expensive model costs around USD 1,500 at your doorstep, thanks to UPS or FedEx. If you don't have literally millions at hand for advertising, you can forget it.
And then God put before Him a man and a woman and looked at them crtically.
He looked at the man and said rto himesf: "I know I am God, but I just have to say that this is perfect, exactly the right proportions, length, width, weight, everything is quite perfect, and even I am satisfied."
He then looked at the woman for a long time, shook his head and said: "I am sorry, my dear, but you will have to use make-up."
Well, if it quacks like a duck, floats like a duck and looks like a duck, I'd say chances are it is a duck.
I've had on my table two DVD players way back in 2000. Both were made in China, one was a Panasonic and the other a name I have never heard before. Upon opening them up, it was hard not to notice than both had all the PCB boards from obviously the same source, the only difference between them being that the Panasonic has a universla voltage switchmode PSU, while the other had a dedicated 210/220/230/240 V analog PSU.
Even the menus were the same, and the outward appearance was minimally different in detail only.
If the Panasonic cost 100%, the other cost like 40%.
I'd call that copying, wouldn't you? It fails the fundamental test set by international copyright law, which states that the difference between two products must be 33% or more for one not being a copy of the other. This device clearly failed that test.
Anybody would have a tough time convincing me that the world's largest consumer electronics company, Matsushita, copied an uknown Chinese manufacturer, or had them do the entire design and development work.
The last time I serviced my car, my mechanic produced a Chinese made ECU tester, costing about 15% of the price of a US designed same thing (I forgot the original manufacturer's name). However, while it was an obvious hardware copy, it seems the Chinese unit had better, or better updated, software, because it could analyze some models the original couldn't. While this shows the Chinese are no longer blindly copying things but have started developing them, it remains a fact that the underlying hardware IS a blatant copy.
And Rick, you're dead wrong about stealing experience - all that experience is embodied in concrete products, so if you blatantly copy the product, you are in fact stealing that experience and R&D work required to make that product.
I guess we must be meaning totally different things by this word 'experience'. If you blatantly copy something then its because you're unable to innovate for yourself. Its what beginners do before they start to develop their own ideas and before they're courageous enough in a particular domain to test their own notions out. So no, the copier does not benefit from the experience of the originator merely by parroting a design. But if the copier is smart he or she might be inclined to start asking questions about why the original designer did something one way and not another.
I'm a teacher - if a student does not attempt to blatantly copy my spoken English pronunciation then in my estimation they're not a hot student. The ones that show listening skills though are the ones I wanna have in my classes. They show they listen by adapting their manner of speaking to the teacher's.
I'm a teacher - if a student does not attempt to blatantly copy my spoken English pronunciation then in my estimation they're not a hot student. The ones that show listening skills though are the ones I wanna have in my classes. They show they listen by adapting their manner of speaking to the teacher's.
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