None come close. (BD-Design)

by PeterSt. ⌂ @, Netherlands, Friday, January 25, 2008, 15:38 (5908 days ago) @ MikeH

Mike,

Not that this is about GC, but indeed it doesn't work with 96/24, if that is what you said. I'm currently working on that though.

Back to your (difficult) subject, what I actually want to make clear, is that all comes down to rather stupid 1:1 representation of matters. Might it be the source, the DAC, the amp, the preamp, the speakers, as long as things are represented 1:1 you'll be fine.

Well, how stupid is that remark, thinking of how obvious it is.

It may not be all that stupid, when you know that this 1:1 can be achieved in the individual elements. Easy example : grab a scope, put a sine wave in the player, measure at the output of the main amp, and measure at that same cable at the other end of it (speaker input). You can bet that when the wave shown is the cleanest (at e.g. comparing speaker cables) that this is the cable to stay.

And so easy it is.
Thus, all becomes stupid theory, and listening is only needed to confirm applied "tweaks", which has become a wrong word now. :yes: One very important thing : you must allow yourself to reach the end by means of this principle. Example again : at applying the most clean speaker cable, it is certainly not said that you have the best sound. Why ? because that cleanest cable will be filtering the least, so e.g. harsh sound now comes out unfiltered. Oops. You did one thing though : enable the audability of the harsh sound which obviously comes from somewhere.

Sidenote : it is very important to just plain KNOW that today's sound reproduction can be so real live, that anything else should dissatisfy you. Or better : go and look for where the problem is, until death is near.:cool:
This too has become stupid theory, and handy to know. It just exists. Nothing to show off if you have it (just enjoy !!), but something to explicitly hunt for when you don't. Anyway, this is your virtual reference, early 2008.

The Class-D I meant "badly". Now try to believe in this too, coming down to what Bert said earlier : any good performing system shows everything and every little change. But here's a chicken-egg one too : first you must have that good performing system, in order to have it as a reference to compare with. But now a couple of things come together :

If you examine the principe of operation of the D-amp, you know that at least there is some very high frequency going around in there (the triangle or sawtooth carrier wave) with which all D manufacturers have problems to get rid of. Also, 80% of them have switching PSU's.
Both are audible. But, in order to hear it, you should not emphasize on the good things (like often the low frequencies), but on the bad. Do NOT think "all is a compromise", but think about disturbances, like a high frequency flair being the very first. I think Bert pretty well described it at his CrazyA description, which you might read as a commercial, but of which I can tell you it really is not. I was there, and I don't have shares in Bert's company.

Above is one thing, and a next is the crazy influence such an amp can have on the loudspeaker. Maybe you recall the tweak Bert came up with, in order to let the D (I think it was about a Tripath mainly) not rise the high frequencies sky high. This is the opposite of 1:1 representation, and it is just measureable.

Have you heard a couple of D's, then you are lost in the speed they show. Oh yes. So again you tend to look at it as all compromises, but you better search further. Because really *all* D's we listened to add a similar sound/flair to the sound, by now I caNot imagine that D's exist that don't do this. It's just a path to give up upon.

From the sheer enjoyment of speed as an in fact dumn phenomenon (but it's so much audible which you probably know) "we" searched further in complete other directions, and from a by me well respected audio equipment suplier we came to the idea of what Bert explains in his commercial, although by heart I don't think Bert emphasizes on the speed dumn phenomenon : the thing which was right under our nose. Btw, Bert will tell what drives his amps if he likes to, and if not you can find it in this forum somewhere. I know it's there anyway.

Now, how dumn is "speed" for a requirement ?
This, in the end, is simple too : 1:1 representation of sound waves.
You may find amp producers cick on their reproduction of square waves. "This says nothing !" many say. I say it does, and it is just a prerequisite to reproduce sound lively.
This time you feed your system with high frequency square waves. Any amp not fast enough, can't follow. Ok, but what about the 1:1 representation then ? well, not much.

From one comes the other, and that is the importance of the square wave reaching your ears. You probably know about my ideas about this (and that in fact ALL is built around this), and this starts with the non oversampling DAC. I won't tell this story once again, but start off with the wrong DAC (being an oversampling one), and the speed of the amp does nothing.

I think you get it by now;
All parts of the chain muct be able to represent 1:1. The more do, the better the sound will be. The most stupid obvious theory, but now with controllable / measureable phenomena to deal with.

All ends with fast speakers (drivers). There too counts the same. You could say, the slower the driver is, the more distortion you'll have. Here too underlaying theories can help you, like the knowledge of a high sensitive driver will be more speedy. Or indirectly : that a front loaded horn speaker incurs for better sensitivity.
That a horn goes along with more directional sound, hence less prone to standing waves and room modes (all incurred by reflections), is another thing that coincidentally helps. Note though that with a normal speaker my expressions about the standing waves count just the same, and you can get rid of them with normal speakers too (and in fact easy; there appears to be a great deal of headroom, when it comes down to how thick my before mentioned line (wave) is allowed to be before things start to go wrong -> ... which only tells how many things *are* wrong when those waves bother you).

1:1 Peter :cool:

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