Name for this sort of distortion ?

[N Cook]

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

 

[Arfa Daily]

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

Asymmetry is the term that springs to mind ...

Arfa

 

[CJT]

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

rectification

 

[N Cook]

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

 

[Ron(UK)]

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)

 

[tlbs]

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".

 

[Ron(UK)]

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)

 

[N Cook]

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.

 

[Arfa Daily]

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

 

[Meat Plow]

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

Unisymetricalnon-modularhyperbolichalfsinetoriodalimbalance?

 

[CJT]

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.

 

[Arfa Daily]

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.
Disproportion between two or more like parts; lack of symmetry.

Seems to pretty much cover the condition to me. I would also contest that we
are talking clipping here. Again, like crossover distortion, clipping is a
very specific form of ( sometimes intentional ) distortion, and tends to be
characterised by being symmetrical, although I will accept that it can be
asymmetric. The condition that is being discussed here is probably not even
strictly speaking "distortion" - rather, it's a severe corruption of the
intended performance, by virtue of a fault condition. I also don't follow
"level shifted". The reference level surely remains fixed at zero ?

I think that we're all in danger of over-complicating a straightforward
situation here ... :~)

Arfa

 

[[email protected]]

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.

 

[Eeyore]

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.

No. That's symmetrical.

Graham

 

[Arfa Daily]

No. That's symmetrical.

Graham

Correct !!

Arfa

 

[Ron(UK)]

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)