"What HiFi" - can it be trusted?
 

David wrote:


Btw - what thousand pound amplifiers have a several percent distortion?

Single-ended triode amps do - and they can cost a *lot* more than
that!

But what are we measuring? Valve "distotion" is viewed as a rosie glow.
Transistor x/over or switching distortion in a poorly designed (or
over-driven) solid state amp of only a few 10ths % is unbearable!

Not all distotions are created eaqual - but they are all deviations from
the "straight wire with gain" model of the "ideal" amp.

David

Exactly. The thing most people forget is that *all* push pull systems are
very good a canceling even harmonic distortion (the type we don't mind/like
even) which just leaves odd harmonic distortions in the output which the
ear abhors. This may explain why some people prefer the sound of single
ended class A amplifiers which produce predominantly second harmonic
distortion. This does not mean they are accurate. Aural exciters use this
very technique.

Ian

"What HiFi" - can it be trusted?
 

On Sun, 04 Jan 2004 10:23:32 +0000 (GMT), Jim Lesurf
wrote:

I fear it is 'dumbing down'. The impression is that they have decided their
readers are too dim to understand, and they can't be bothered to even try
and explain. Easier to say, "I am an expert and X is better than Y, so
there."

Dumbing down implies that there were providing intelligent reviews not
so long ago. I cannot recollect this happening during my adult life.

Has the Scottish Yew Year festivities been more than usually good this
year, Jim? :-) tongue firmly in cheek


--
Chris Isbell
Southampton
UK

"What HiFi" - can it be trusted?
 

On Sun, 04 Jan 2004 10:23:32 +0000 (GMT), Jim Lesurf
wrote:

I fear it is 'dumbing down'. The impression is that they have decided their
readers are too dim to understand, and they can't be bothered to even try
and explain. Easier to say, "I am an expert and X is better than Y, so
there."

Dumbing down implies that there were providing intelligent reviews not
so long ago. I cannot recollect this happening during my adult life.

Has the Scottish Yew Year festivities been more than usually good this
year, Jim? :-) tongue firmly in cheek


--
Chris Isbell
Southampton
UK

"What HiFi" - can it be trusted?
 

In message , Ian Bell
writes
David wrote:


Btw - what thousand pound amplifiers have a several percent distortion?

Single-ended triode amps do - and they can cost a *lot* more than
that!

But what are we measuring? Valve "distotion" is viewed as a rosie glow.
Transistor x/over or switching distortion in a poorly designed (or
over-driven) solid state amp of only a few 10ths % is unbearable!

Not all distotions are created eaqual - but they are all deviations from
the "straight wire with gain" model of the "ideal" amp.

David

Exactly. The thing most people forget is that *all* push pull systems are
very good a canceling even harmonic distortion (the type we don't mind/like
even) which just leaves odd harmonic distortions in the output which the
ear abhors. This may explain why some people prefer the sound of single
ended class A amplifiers which produce predominantly second harmonic
distortion. This does not mean they are accurate. Aural exciters use this
very technique.

Ian


In all this, we mustn't forget that the even-harmonic cancellation
really only happens in class-A operation. When the amp goes into
class-B, and one of the active elements is cut off, then there is no
mechanism to cancel the even harmonics.
--
Chris Morriss

"What HiFi" - can it be trusted?
 

In message , Ian Bell
writes
David wrote:


Btw - what thousand pound amplifiers have a several percent distortion?

Single-ended triode amps do - and they can cost a *lot* more than
that!

But what are we measuring? Valve "distotion" is viewed as a rosie glow.
Transistor x/over or switching distortion in a poorly designed (or
over-driven) solid state amp of only a few 10ths % is unbearable!

Not all distotions are created eaqual - but they are all deviations from
the "straight wire with gain" model of the "ideal" amp.

David

Exactly. The thing most people forget is that *all* push pull systems are
very good a canceling even harmonic distortion (the type we don't mind/like
even) which just leaves odd harmonic distortions in the output which the
ear abhors. This may explain why some people prefer the sound of single
ended class A amplifiers which produce predominantly second harmonic
distortion. This does not mean they are accurate. Aural exciters use this
very technique.

Ian


In all this, we mustn't forget that the even-harmonic cancellation
really only happens in class-A operation. When the amp goes into
class-B, and one of the active elements is cut off, then there is no
mechanism to cancel the even harmonics.
--
Chris Morriss

"What HiFi" - can it be trusted?
 

In article , Chris Isbell
wrote:
On Sun, 04 Jan 2004 10:23:32 +0000 (GMT), Jim Lesurf
wrote:

I fear it is 'dumbing down'. The impression is that they have decided their
readers are too dim to understand, and they can't be bothered to even try
and explain. Easier to say, "I am an expert and X is better than Y, so
there."

Dumbing down implies that there were providing intelligent reviews not
so long ago. I cannot recollect this happening during my adult life.

I think that's absolutely right.

I admit that until recently I thought the hi-fi magazines had deteriorated
since I was first interested (about 1975). However in a New Year
clear-out I found a small cache of HFN&RR issues and annuals ranging
from 1977 to 1985.

Contrary to my expectations, I was struck by how similar they were then
to the stuff we now get fed by the hi-fi press. Even the same sorts of
controversy over cables and the like.

I conclude that the hi-fi press's output remains much the same as it ever
was and I must have become more cynical over the years (or should that be
"better educated" instead, or maybe even "less gullible"?).

--
John Phillips

"What HiFi" - can it be trusted?
 

In article , Chris Isbell
wrote:
On Sun, 04 Jan 2004 10:23:32 +0000 (GMT), Jim Lesurf
wrote:

I fear it is 'dumbing down'. The impression is that they have decided their
readers are too dim to understand, and they can't be bothered to even try
and explain. Easier to say, "I am an expert and X is better than Y, so
there."

Dumbing down implies that there were providing intelligent reviews not
so long ago. I cannot recollect this happening during my adult life.

I think that's absolutely right.

I admit that until recently I thought the hi-fi magazines had deteriorated
since I was first interested (about 1975). However in a New Year
clear-out I found a small cache of HFN&RR issues and annuals ranging
from 1977 to 1985.

Contrary to my expectations, I was struck by how similar they were then
to the stuff we now get fed by the hi-fi press. Even the same sorts of
controversy over cables and the like.

I conclude that the hi-fi press's output remains much the same as it ever
was and I must have become more cynical over the years (or should that be
"better educated" instead, or maybe even "less gullible"?).

--
John Phillips

"What HiFi" - can it be trusted?
 

Chris Morriss wrote:

In message , Ian Bell
writes
David wrote:


Btw - what thousand pound amplifiers have a several percent
distortion?

Single-ended triode amps do - and they can cost a *lot* more than
that!

But what are we measuring? Valve "distotion" is viewed as a rosie glow.
Transistor x/over or switching distortion in a poorly designed (or
over-driven) solid state amp of only a few 10ths % is unbearable!

Not all distotions are created eaqual - but they are all deviations from
the "straight wire with gain" model of the "ideal" amp.

David

Exactly. The thing most people forget is that *all* push pull systems are
very good a canceling even harmonic distortion (the type we don't
mind/like even) which just leaves odd harmonic distortions in the output
which the
ear abhors. This may explain why some people prefer the sound of single
ended class A amplifiers which produce predominantly second harmonic
distortion. This does not mean they are accurate. Aural exciters use this
very technique.

Ian


In all this, we mustn't forget that the even-harmonic cancellation
really only happens in class-A operation. When the amp goes into
class-B, and one of the active elements is cut off, then there is no
mechanism to cancel the even harmonics.

I beg to differ. In *all* push-pull systems successive half cycles are
similar so even harmonics are negligible.

Ian

"What HiFi" - can it be trusted?
 

Chris Morriss wrote:

In message , Ian Bell
writes
David wrote:


Btw - what thousand pound amplifiers have a several percent
distortion?

Single-ended triode amps do - and they can cost a *lot* more than
that!

But what are we measuring? Valve "distotion" is viewed as a rosie glow.
Transistor x/over or switching distortion in a poorly designed (or
over-driven) solid state amp of only a few 10ths % is unbearable!

Not all distotions are created eaqual - but they are all deviations from
the "straight wire with gain" model of the "ideal" amp.

David

Exactly. The thing most people forget is that *all* push pull systems are
very good a canceling even harmonic distortion (the type we don't
mind/like even) which just leaves odd harmonic distortions in the output
which the
ear abhors. This may explain why some people prefer the sound of single
ended class A amplifiers which produce predominantly second harmonic
distortion. This does not mean they are accurate. Aural exciters use this
very technique.

Ian


In all this, we mustn't forget that the even-harmonic cancellation
really only happens in class-A operation. When the amp goes into
class-B, and one of the active elements is cut off, then there is no
mechanism to cancel the even harmonics.

I beg to differ. In *all* push-pull systems successive half cycles are
similar so even harmonics are negligible.

Ian

"What HiFi" - can it be trusted?
 

On Sat, 3 Jan 2004 23:44:41 -0000, "Oliver Keating"
wrote:

One simple but effective way I have found to test hi-fi is to have it
playing a recording, and then have a microphone positioned in an ideal
location recording the output.

With really high end stuff, the recording will be indistinguishable from the
original, but of course there is degredation directly related to the
speakers/amps, so perhaps a could test would be to record the recording, and
repeat until a blind test reveals the difference between the original and
the recorded, and simply note the number of recordings it took.

Btw - what thousand pound amplifiers have a several percent distortion?


You have actually, personally, found this a good way to test hifi
gear? Sorry, I don't believe you :-)