The term escapes me for when say negative going audio output is absent and
only positive going is present, or vice versa. ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N Cook" wrote in message
...
The term escapes me for when say negative going audio output is absent and
only positive going is present, or vice versa. ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



Asymmetry is the term that springs to mind ...

Arfa

N Cook wrote:
The term escapes me for when say negative going audio output is absent and
only positive going is present, or vice versa. ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



rectification

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no
Like you have the term clipping distortion for being driven into the DC
rails, of course Googling for something like gets nowhere

N Cook wrote:
no
Like you have the term clipping distortion for being driven into the DC
rails, of course Googling for something like gets nowhere





Half wave?

Ron(UK)

N Cook wrote:
The term escapes me for when say negative going audio output is absent and
only positive going is present, or vice versa. ?


If the audio voltage is "low level" -- under 1 volt peak, and the
amplifier output is a push-pull type especially class B, then it is
probably crossover distortion.

If the audio voltage you see is well over 1 volt peak (with no negative
voltage swing), then what the other guys above said is correct, but
there is no standard term for that kind of distortion I can think of
other than "rectification".

tlbs wrote:
N Cook wrote:
The term escapes me for when say negative going audio output is absent and
only positive going is present, or vice versa. ?


If the audio voltage is "low level" -- under 1 volt peak, and the
amplifier output is a push-pull type especially class B, then it is
probably crossover distortion.

If one half cycle was missing, you couldn`t have crossover distortion as
there wouldn`t be any crossover.


If the audio voltage you see is well over 1 volt peak (with no negative
voltage swing), then what the other guys above said is correct, but
there is no standard term for that kind of distortion I can think of
other than "rectification".

Half wave rectification maybe, tho it`s not being 'rectified', it`s just
missing.


Ron(UK)

tlbs wrote in message
ups.com...

N Cook wrote:
The term escapes me for when say negative going audio output is absent
and
only positive going is present, or vice versa. ?


If the audio voltage is "low level" -- under 1 volt peak, and the
amplifier output is a push-pull type especially class B, then it is
probably crossover distortion.

If the audio voltage you see is well over 1 volt peak (with no negative
voltage swing), then what the other guys above said is correct, but
there is no standard term for that kind of distortion I can think of
other than "rectification".


I'll call it complementary output failure half-wave distortion,
but as its a specific and recognisable sort of distortion that it had a
specific name.
Just writing up a Laney R4 repair brief.

I've asked this one before but is anyone aware of a collection of audio file
snippets with simulated or actual named distortions to point non-technical
owners of equipment to to help diagnosis of intermittant faults.

"tlbs" wrote in message
ups.com...

N Cook wrote:
The term escapes me for when say negative going audio output is absent
and
only positive going is present, or vice versa. ?


If the audio voltage is "low level" -- under 1 volt peak, and the
amplifier output is a push-pull type especially class B, then it is
probably crossover distortion.

If the audio voltage you see is well over 1 volt peak (with no negative
voltage swing), then what the other guys above said is correct, but
there is no standard term for that kind of distortion I can think of
other than "rectification".

Crossover distortion is a very specific type of distortion that results from
incorrect bias in a class B output stage. That incorrect bias causes the
'handover' from one output device to the other, to not take place in a
smooth manner, due to one or other of the devices not being lifted off the
non-linear part of the bottom end of its curve at the zero drive point. It
does not result in one half of the signal being missing.

When one half of the signal is going missing, due to either an output or
drive fault, I suppose at a pinch, you could apply the term 'rectification'
on the grounds that the resulting waveform would look like it had been
passed through a single diode, but to make this connection between a faulty
amplifier, and what is normally associated with being a power supply
function, is tenuous at best, and downright misleading at worst. I still say
that the only term that I have seen applied to this type of distortion
occuring in an amplifier, is asymmetry.

Arfa

Arfa Daily wrote:

"tlbs" wrote in message
ups.com...

N Cook wrote:

The term escapes me for when say negative going audio output is absent
and
only positive going is present, or vice versa. ?


If the audio voltage is "low level" -- under 1 volt peak, and the
amplifier output is a push-pull type especially class B, then it is
probably crossover distortion.

If the audio voltage you see is well over 1 volt peak (with no negative
voltage swing), then what the other guys above said is correct, but
there is no standard term for that kind of distortion I can think of
other than "rectification".


Crossover distortion is a very specific type of distortion that results from
incorrect bias in a class B output stage. That incorrect bias causes the
'handover' from one output device to the other, to not take place in a
smooth manner, due to one or other of the devices not being lifted off the
non-linear part of the bottom end of its curve at the zero drive point. It
does not result in one half of the signal being missing.

When one half of the signal is going missing, due to either an output or
drive fault, I suppose at a pinch, you could apply the term 'rectification'
on the grounds that the resulting waveform would look like it had been
passed through a single diode, but to make this connection between a faulty
amplifier, and what is normally associated with being a power supply
function, is tenuous at best, and downright misleading at worst. I still say
that the only term that I have seen applied to this type of distortion
occuring in an amplifier, is asymmetry.

Arfa


I suppose you could call it a level-shifted clip if you don't like
rectification. Asymmetry seems a bit broad to me.

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The e-mail address in our reply-to line is reversed in an attempt to
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"CJT" wrote in message
...
Arfa Daily wrote:

"tlbs" wrote in message
ups.com...

N Cook wrote:

The term escapes me for when say negative going audio output is absent
and
only positive going is present, or vice versa. ?


If the audio voltage is "low level" -- under 1 volt peak, and the
amplifier output is a push-pull type especially class B, then it is
probably crossover distortion.

If the audio voltage you see is well over 1 volt peak (with no negative
voltage swing), then what the other guys above said is correct, but
there is no standard term for that kind of distortion I can think of
other than "rectification".


Crossover distortion is a very specific type of distortion that results
from
incorrect bias in a class B output stage. That incorrect bias causes the
'handover' from one output device to the other, to not take place in a
smooth manner, due to one or other of the devices not being lifted off
the
non-linear part of the bottom end of its curve at the zero drive point.
It
does not result in one half of the signal being missing.

When one half of the signal is going missing, due to either an output or
drive fault, I suppose at a pinch, you could apply the term
'rectification'
on the grounds that the resulting waveform would look like it had been
passed through a single diode, but to make this connection between a
faulty
amplifier, and what is normally associated with being a power supply
function, is tenuous at best, and downright misleading at worst. I still
say
that the only term that I have seen applied to this type of distortion
occuring in an amplifier, is asymmetry.

Arfa


I suppose you could call it a level-shifted clip if you don't like
rectification. Asymmetry seems a bit broad to me.


Broad ? Where do you get "broad" from ? Two definitions from dictionary.com
a·sym·me·try (a-sim'i-tre)
n. Lack of balance or symmetry.

and

a·sym·me·try (-sm-tr)
n.

On Tue, 16 Jan 2007 12:41:12 -0000, "N Cook"
wrote:

The term escapes me for when say negative going audio output is absent and
only positive going is present, or vice versa. ?

This unbalance would be caused by failure of on half of a push pull
amplifier. It would become a single ended class B amplifier.

wrote:
On Tue, 16 Jan 2007 12:41:12 -0000, "N Cook"
wrote:

The term escapes me for when say negative going audio output is absent and
only positive going is present, or vice versa. ?

This unbalance would be caused by failure of on half of a push pull
amplifier. It would become a single ended class B amplifier.


Not really (IMO) because the waveform would have half cycle long periods
at 0 volts, the output would be chopped

Ron(UK)