il y a cet article à connaître:
http://www.passdiy.com/pdf/diyopamp.pdf
et
http://www.stereophile.com/interviews/1 ... index.html
Nelson Pass: Simple Sounds Better:
Pass: ... Back then National Semiconductor was marketing op-amps and they had some rather large catalogs. For each op-amp they gave you the internal schematic (or something that resembled the internal schematic), and then they would give you pages of applications: how to make an AC to DC convertor with it, how to make phono stages, anything you wanted. I began becoming a topologist in electronics from studying all the internal schematics of the op-amps they were using. There was some incredible design talent going into those products; just about every trick in the book that you might ever want to learn could be found somewhere in the internal workings of some op-amp chip.
There is a reason why we go to the trouble of selecting devices as extensively as we do: When a manufacturer makes them in batches, he can't offer a selection process in any sort of economical sense. So there hasn't been enough emphasis on the quality of the semiconductors. For the most part they have an even greater influence in parts quality. People feel that they understand capacitors and wire better. It's true that a semiconductor is a fairly unfathomable black box with three pins, but I think that's where most of the action is. We use as high a quality parts as we consider to be reasonable, and always in the context of what we think people are willing to spend money on.
But I have a number of thoughts about tubes. The most fundamental is that they enforce, in design, one of the basic tenets that I hold dear: that, all other things being equal, simple circuits sound better. You can't put 57 tubes under the hood of a preamp. But of course you can do so in an IC, which typically has a large number of devices, or even with discrete solid-state. I work very hard to enforce simplicity as part of the design process, and tubes can even take an inept designer and at least see to it that he doesn't make his design too complex.
CDs have been a tremendous boon to the industry. We saw our sales quadruple over the period of time that CDs became popular, and I attribute much of that growth and the growth of our competitors to the heightened interest in audio that CDs have brought. So, whatever else you might think of them, they've been very good for the industry.
And I suppose if I really had my druthers I would take a nice, high-speed, non-Dolby analog tape. Some of the best things I've ever heard came from that source.
et c'est pas moi qui le dit, c'est le méchant nelson pass...
hervé.
