"The Natural Philosopher" <tnp@invalid.invalid> wrote in message
news:h2edu4$md7$1@news.albasani.net...
> Fredxx wrote:
>> "Dave Higton" <davehigton@dsl.pipex.com> wrote in message
>> news:2ee3287350.davehigton@dsl.pipex.com...
>>> In message <VA.00000751.00af3130@escapetime.removethisbit.myz en.co.uk>
>>> Roderick Stewart <rjfs@escapetime.removethisbit.myzen.co.uk>
>>> wrote:
>>>
>>>
>>
>> The point is that analogue systems are generally very linear by design,
>> even if individual components aren't.
>
> Not really. We are lucky that we have one relatively linear component -
> the resistor, and by using feedback with THOSE we can achieve pretty low
> distortion set-ups from VERY badly distorting components..transistors and
> FETS.
>

I was thinking of demodualtors, which don't rely upon resisitors to give a
linear response. It's normally inherent in their transfer characteristic.

>
>
>>The major distortion as such is that the bandwidth may not be perfectly
>>flat,
>
> That is not a distortion.

Anything where the output does not follow an input IS a distortion. That
includes frequency response. See http://en.wikipedia.org/wiki/Distortion

>
> And its pretty possible to build an amplifier flat from DC to well over
> 100Khz.
>
> In the video game, flat to 50Mhz is on the cards, but the power is not as
> high. A few watts, not a few hundred.

Video does not demand the same dynamic range as audio.

>
> but our ears are fairly tolerant to
>> such errors.
>>
> Indeed. What our ears really do NOT like is high order harmonics and
> intermodulation products. The harmonics we hear as 'edginess' and the
> intermodulation we hear as lack of clarity or muddiness.
>
>> Don't forget that our ears aren't entirely linear!
>>
>> DAB on the other hand has an alarmingly low bit rate. The consequence is
>> where the decoded signal doesn't follow the original.
>>
>>
> Precisely. There is nothing intrinsically wrong with the digits: the
> implementation is just crap, thats all.
>

Agreed. And the idea of having 2 different DAB systems!