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Originally Posted by Johnny Blue /img/forum/go_quote.gif
Oh, great! Just when I'd decided that my (admittedly very limited) understanding of wall wart power supplies (= that regulated is better than unregulated) was wrong, because of that which Andre wrote earlier, then along comes Downrange and re-asserts my initial belief!
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Oh dear. I looks like I started something here.
There are no absolutes in hi-fi electronics, Johnny. It is all a matter of taste, then of execution. When I say I like unregulated supplies better, that is my taste, and the presumption is that the rest of the power supply and amp will be built in the best possible manner without reference to cost. You see, regulation is just a cheap fix of problems cost-engineeering cuts have brought about in the amp and its power supply. If you build the amp silent in the first instance (which means giving up half or more of the possible power it can produce), and don't specify the transformer and caps down to the minimum required so as to save a few bucks in the power supply, and use expensive chokes (I use several, and of a $$$pecial double design -- see
http://members.lycos.co.uk/fiultra/K...dre%20Jute.htm ), and don't skimp on the pricey components for noise reducing circuitry (balanced circuits, current sources -- you won't believe how quickly this drives the cost of an amp into multiples of what is possible to charge on the High Street) -- if you do everything else right, you then don't need to put up with regulation moulinexing your sound. Of course, if you don't agree with me that regulation leeches the colour from your sound, then you should have regulation, and regulation then permits you to cut corners elsewhere. It is, as I say, swings and roundabouts, a continuum (thanks for the very word I was looking for, Downrange) of possibilities, and where you pitch your tent along this long, long line is a matter of experience and taste.
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Originally Posted by Downrange /img/forum/go_quote.gif
Consider this: many people spend hundreds extra to have Justin at Headamp install Black Gate capacitors in the power supply for the KGSS amplifier (1500 dollar amp with no mods). They do this in pursuit of deeper filtration of the 12 V source voltage; the capacitors are not in the signal path.
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Everything is in the signal path. Your return line runs all the way from the plug on the wall through the power supply and the signal amp back to the plug on the wall.
But I hate monster caps too, and escpecially on tube amps, where they can have the same effect as regulators. Oversize caps too are a bodge for not doing the job right elsewhere.
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Originally Posted by Downrange /img/forum/go_quote.gif
Oh, and by the way, there was a statement in one of the posts (I'm not too sure where) to the effect that a good, stiff, regulated supply might make the sound somehow "boring" or less dynamic (believe this was in reference to a tube design). With solid state amps, that's definitely not the case.
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If you build the rest of your amp cheaply and need to gimmick it right with a regulated power supply, it will sound like rubbish without the regulation. If you build the amp right, the presence of regulation is irrelevant in any positive sense, and to my ears has a flattening, negative influence on the sound. A good amp and its good power supply is in a sense self-regulating. See about some of the possible mechanisms above. This soundleeching effect I talk of is most easily heard in tube amps, and especially when you can switch in and out regulated filament supplies (Herb Reichert memorably said that he "despises" the sound of regulated filaments), but it is there in SS amps too; SS amps have been built down because of near-universal presumption of regulation for so long that cheap and nasty has become the norm. The chap who wrote today in nostalgia for battery-powered Stax from a generation ago, and topclass Stax power supplies, has a strong point.
Here is a simple solidstate amp that sounds superb without regulation especially when it is used in Class A:
http://members.lycos.co.uk/fiultra/K...dre%20Jute.htm
The key is a hefty transformer and minimal simplicity.
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Originally Posted by Downrange /img/forum/go_quote.gif
If the design relies on a soft or unregulated power supply for its characteristic sound, you don't want to listen to it.
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Added euphonics, eh? Not on my amps; they're dead silent. But even third and higher harmonics well below the level of conscious perception can bring with them a level of vague unease well above the subliminal. So I shape the residual noise to eliminate all the third and higher harmonics to a vanishing fraction of the tiny residual of THD.
I do this, among other ways, by using either very little or no global negative feedback because NFB manufactures higher order harmonic residuals every time it cycles to reduce the lower harmonics. An NFB amp almost requires the homogenizing effect of regulation so as not to sound edgy with all those high-order residuals. In short, one of the reasons my amps don't need regulation is because virtually the only residual harmonic is second, well below perception, and that is subliminally harmless because second harmonic, unlike third and higher, is actually pleasing.
So, I see regulation as a bodge required by "engineers" without the brains to enquire whether there isn't a better way of doing the job, and without the taste to grasp that their result, while perhaps passable when measured against all the other inadequate results of their peers, isn't fundamentally perverse.
It is worth making a final point. An electrostat like the Stax earspeaker is such a clear, undistorted reproducer, it deserves the simplest, cleanest chain behind it, and regulation is a lot of extra gubbins for the signal-carrier to travel through.
Andre Jute
Visit Jute on Amps at
http://members.lycos.co.uk/fiultra/
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