John Byrns wrote:
In article ,
Patrick Turner wrote:
Many listeners have heard better sound using Zero Impedance transformers
even when the load match was OK in theory; ie, when the load value was
raised higher than "it should be" and the load is "underpowered", the
music sounded better, and so it should have because the THD was lower,
and DF higher. The "underpowered" load match means less maximum PO is
available abd in SE amps it means clipping is asymetrical because the
wave clips onj one side due to grid current before cut off occurs. But
who cares how the amp clips if there is **enough** power before clipping
occurs?
Not to mention that asymetrical clipping is more musical than symetrical
clipping.
Clipping of transient peaks in music signals which have not been
compressed may not change the nature of the music much except to reduce
the sound of the recording to a lowest common denominator everyone has
been forced to get used to; hence we don't notice the change; until we
attend a live concert, and *then* we notice a big change allright.
And its remarkable how much clipping you can have on peaks before anyone
notices, symetrical or assymetrical.
I have often heard audio with clipping to one side of the signal and it
sounds bad if the clipping digs deep enough, and not at all musical
imho. In AM radios its a common fault to find clipping of the detected
audio waves after the detector. Once you trim values or change the
circuit to make the detector linear, voila, music, and despite the
limitations of the IF amp and audio amp and poor speaker in the radio.
Today, many recordings have been compressed a lot, and usually
compressed symetrically, which means you've added large amounts of 3H,5H
,7H,9H to waves whose crests have been flattened. A lot of pop music
recordings show that the bass waves are quite clipped and compressed.
But all the people I know never run the levels anywhere near clipping of
anything any time. Most run less than 40W per channel and speakers with
88dB/W/M sensitivity. They ain't deaf.
Patrick Turner.
--
Regards,
John Byrns
Surf my web pages at, http://fmamradios.com/