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RichD RichD is offline
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Who do MOSFET sound better than bipolar, as an audio amp output
driver?


--
Rich
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RichD wrote in news:b78fc9c2-fe9c-444c-8ac5-
:

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


They do? Seems like it's possible to design good amplifiers either
way.

--Damon

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On Sep 17, 6:12*pm, RichD wrote:
Who do MOSFET sound better than bipolar, as an audio amp output
driver?

--
Rich


MOSFETS HAVE WIDER BANDWIDTH ,less phase shift , lower odd harmonic
distortin. on and on.
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RichD wrote:

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


As a driver ?

Now if you said as an output stage it might make sense.

Graham

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"RichD" wrote in message
...
Who do MOSFET sound better than bipolar, as an audio amp output
driver?


**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device, operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs. Only when bias currents are elevated
(around 0.5A - 1A) do MOSFETs exhibit THD characteristics which are almost
as good as BJTs.

MOSFETs are very tough, have an exceptional ability to deliver high power,
high frequency audio (and RF), but distortion is very high. They require
lots of Global NFB in order to operate linearly.

MOSFETs do not sound better than BJTs. At best, they can sound as good. All
things being equal.


--
Trevor Wilson
www.rageaudio.com.au


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"Trevor Wilson"
"RichD"

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device,



** Same old red-herring ******** from know nothing Wilson.

It is totally irrelevant how DEVICES behave on their own.

Only when they are properly configured and suitably biased in a
complimentary output stage can performances be compared.


operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs.



** UTTER ******** !!!

When configured in typical amplifier topologies, THD is vanishingly small at
all power levels and with minimal bias current.

This is true for LATERAL mosfets as made by Hitachi and Semelab ( ie 2SK176,
BUZ905 etc ).

Switching mosfets ( ie IRFPxxx etc) are not the same.



...... Phil







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Kevin McMurtrie[_2_] Kevin McMurtrie[_2_] is offline
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In article ,
"Trevor Wilson" wrote:

"RichD" wrote in message
...
Who do MOSFET sound better than bipolar, as an audio amp output
driver?


**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device, operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs. Only when bias currents are elevated
(around 0.5A - 1A) do MOSFETs exhibit THD characteristics which are almost
as good as BJTs.

MOSFETs are very tough, have an exceptional ability to deliver high power,
high frequency audio (and RF), but distortion is very high. They require
lots of Global NFB in order to operate linearly.


That's nonsense. MOSFETs have a lower voltage gain, more capacitive
load, and infinite DC current gain. If you swap your bipolar
transistors for MOSFETs and crank up the bias voltage, yeah, it will run
like crap because the local feedback gain is totally wrong. It might
even incapacitate every radio within two blocks of your home then
violently explode. The circuits to drive MOSFETs and bipolars are a
little different.


MOSFETs do not sound better than BJTs. At best, they can sound as good. All
things being equal.


--
Google is a pro-spamming service. I will not see your reply if you use Google.
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"Phil Allison" writes:

"Trevor Wilson"
"RichD"

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device,



** Same old red-herring ******** from know nothing Wilson.

It is totally irrelevant how DEVICES behave on their own.

Only when they are properly configured and suitably biased in a
complimentary output stage can performances be compared.


operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs.



** UTTER ******** !!!


No it's not.

When configured in typical amplifier topologies, THD is vanishingly small at
all power levels and with minimal bias current.


That may be true, but only because of the negative feedback that Trevor
referred to. The basic device IS more nonlinear.

It comes down to device physics. MOSFETs, when operating in the
saturation region, have a square law relationship between Vgs and
Ids. It is only through either a) the application of negative feedback,
or b) the reduction of input level (the smaller the operating range, the
more approximating linear the Ids/Vgs relationship becomes) that the
device distortion is mitigated.
--
% Randy Yates % "Maybe one day I'll feel her cold embrace,
%% Fuquay-Varina, NC % and kiss her interface,
%%% 919-577-9882 % til then, I'll leave her alone."
%%%% % 'Yours Truly, 2095', *Time*, ELO
http://www.digitalsignallabs.com
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Default MOSFET output stage

RichD wrote:
Who do MOSFET sound better than bipolar, as an audio amp output
driver?


The device properties of BJTs are superior to those of MOSFETs in all
respects, except for offset - there MOSFETs have the advantage. Whether you
will actually hear this depends on many more factors.




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Randy Yates writes:

"Phil Allison" writes:

"Trevor Wilson"
"RichD"

Who do MOSFET sound better than bipolar, as an audio amp output
driver?

**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device,



** Same old red-herring ******** from know nothing Wilson.

It is totally irrelevant how DEVICES behave on their own.

Only when they are properly configured and suitably biased in a
complimentary output stage can performances be compared.


operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs.



** UTTER ******** !!!


No it's not.

When configured in typical amplifier topologies, THD is vanishingly small at
all power levels and with minimal bias current.


That may be true, but only because of the negative feedback that Trevor
referred to. The basic device IS more nonlinear.

It comes down to device physics. MOSFETs, when operating in the
saturation region, have a square law relationship between Vgs and
Ids. It is only through either a) the application of negative feedback,
or b) the reduction of input level (the smaller the operating range, the
more approximating linear the Ids/Vgs relationship becomes) that the
device distortion is mitigated.


PS: See, e.g., [gray] and [razavi].

--Randy


@book{gray,
title = "Analysis and Design of Analog Integrated Circuits",
author = "Paul R. Gray and Paul J. Hurst and Stephen H. Lewis and Robert G. Meyer",
publisher = "Wiley",
edition = "fourth",
year = "2001"}
@book{razavi,
title = "Design of Analog CMOS Integrated Circuits",
author = "Behzad Razavi",
publisher = "McGraw-Hill",
year = "2001"}

--
% Randy Yates % "So now it's getting late,
%% Fuquay-Varina, NC % and those who hesitate
%%% 919-577-9882 % got no one..."
%%%% % 'Waterfall', *Face The Music*, ELO
http://www.digitalsignallabs.com
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"RichD" wrote in message
...
Who do MOSFET sound better than bipolar, as an audio amp output
driver?


--
Rich



Well this is probably an urban myth/load of ********, but years ago lots of
people were talking about power Mosfets exhibiting different distortion
characteristics than BJT's in the same way thermionic valves distort with
differening harmonics and sound nicer.

Fact or crapology?



Gareth.


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Trevor Wilson wrote:

"RichD" wrote

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device, operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs. Only when bias currents are elevated
(around 0.5A - 1A) do MOSFETs exhibit THD characteristics which are almost
as good as BJTs.

MOSFETs are very tough, have an exceptional ability to deliver high power,
high frequency audio (and RF), but distortion is very high. They require
lots of Global NFB in order to operate linearly.

MOSFETs do not sound better than BJTs. At best, they can sound as good. All
things being equal.


With the required amount of feedback (which isn't rocket science - just good
design) they have no trouble meeting VERY low THDs such as one I designed with
0.0008% THD @ 1 kHz.

They sound better because of the predominance of 2nd harmonic distortion and
almost complete absence of 3rd and ditto up the range AIUI with even and odd
harmonics.

GRaham

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"Kevin McMurtrie" wrote in message
...
In article ,
"Trevor Wilson" wrote:

"RichD" wrote in message
...
Who do MOSFET sound better than bipolar, as an audio amp output
driver?


**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device, operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs. Only when bias currents are elevated
(around 0.5A - 1A) do MOSFETs exhibit THD characteristics which are
almost
as good as BJTs.

MOSFETs are very tough, have an exceptional ability to deliver high
power,
high frequency audio (and RF), but distortion is very high. They require
lots of Global NFB in order to operate linearly.


That's nonsense.


**Er, nope. Here are the specs for a modern high power BJT:

http://www.toshiba.com/taec/componen...c//66/7890.pdf

Note the hFE vs. Ic. Particularly at elevated temps. It is almost a straight
line, from less than 10mA to several Amps. I call that spectacular
linearity.

Now, I draw your attention to a high power MOSFET:

http://www.magnatec-uk.com/pdf/magnatec/BUZ900.pdf

Note the characteristics of this device. They're pretty good, but as good as
a modern BJT.

Here is another, older, worse example:

http://www.datasheetarchive.com/pdf-...SA-158541.html

Quite ordinary lineariy.

MOSFETs have a lower voltage gain, more capacitive
load, and infinite DC current gain. If you swap your bipolar
transistors for MOSFETs and crank up the bias voltage, yeah, it will run
like crap because the local feedback gain is totally wrong.


**I never suggested anything of the sort. I mentioned ONLY the intrinsic
linearity of the devices. MOSFETs are inferior to BJTs. For now. When
installed in an appropriate topology, it is likely that there will be little
audible, nor measurable difference between a MOSFET amp and a BJT amp.
Device linearity is another story.

It might
even incapacitate every radio within two blocks of your home then
violently explode. The circuits to drive MOSFETs and bipolars are a
little different.


**Again, not in dispute. The intrinsic linearity, is what I refer to.


--
Trevor Wilson
www.rageaudio.com.au




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Phil Allison wrote:

"Trevor Wilson"
"RichD"

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device,


** Same old red-herring ******** from know nothing Wilson.

It is totally irrelevant how DEVICES behave on their own.

Only when they are properly configured and suitably biased in a
complimentary output stage can performances be compared.

operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs.


** UTTER ******** !!!

When configured in typical amplifier topologies, THD is vanishingly small at
all power levels and with minimal bias current.

This is true for LATERAL mosfets as made by Hitachi and Semelab ( ie 2SK176,
BUZ905 etc ).

Switching mosfets ( ie IRFPxxx etc) are not the same.


Yes.

Just for fun once I configured a lateral mosfet output stage with zero feedback.
Its THD at almost all power levels was ~ 1%. From that you can get a good idea
of the negative feedback required to obtain any THD you like.

Lateral mosfets, correctly biased also exhibit virtually NO crossover
distortion. This is all but impossible with bipolars due to their inherent
transfer characteristics unless operated in pure Class A.

Graham

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Kevin McMurtrie wrote:

That's nonsense. MOSFETs have a lower voltage gain


Mosfets are used as source followers in an audio output stage you inane idiot.

Voltage gain is NOT AN ISSUE, regardless of whether or not your statement is true.

Graham

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Randy Yates wrote:

"Phil Allison" writes:

When configured in typical amplifier topologies, THD is vanishingly small at
all power levels and with minimal bias current.


That may be true, but only because of the negative feedback that Trevor
referred to. The basic device IS more nonlinear.


But when given suitable NFB, the transfer characteristic IS 'cleaner'. Very little
odd harmonic distortion (the nasty stuff) and very very low crossover distortion
(which makes a big difference).

I know, I've designed audio amps with both types. As in designed from the ground
up for commercial pro-audio sale.

Graham

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Jorden Verwer wrote:

RichD wrote:
Who do MOSFET sound better than bipolar, as an audio amp output
driver?


The device properties of BJTs are superior to those of MOSFETs in all
respects,


How about SOA for one you UTTER MORON ?

Do you even know what SOA is ?

except for offset - there MOSFETs have the advantage. Whether you
will actually hear this depends on many more factors.


YET MORE INSANE ********

Is this all down to techs not knowing their chops ?


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Gareth Magennis wrote:

"RichD" wrote

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


Well this is probably an urban myth/load of ********, but years ago lots of
people were talking about power Mosfets exhibiting different distortion
characteristics than BJT's in the same way thermionic valves distort with
differening harmonics and sound nicer.

Fact or crapology?


Fact. Different transfer characteristics. Fundamental device physics.

Graham



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Eeyore a écrit :

Trevor Wilson wrote:

"RichD" wrote

Who do MOSFET sound better than bipolar, as an audio amp output
driver?

**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device, operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs. Only when bias currents are elevated
(around 0.5A - 1A) do MOSFETs exhibit THD characteristics which are almost
as good as BJTs.

MOSFETs are very tough, have an exceptional ability to deliver high power,
high frequency audio (and RF), but distortion is very high. They require
lots of Global NFB in order to operate linearly.

MOSFETs do not sound better than BJTs. At best, they can sound as good. All
things being equal.


With the required amount of feedback (which isn't rocket science - just good
design) they have no trouble meeting VERY low THDs such as one I designed with
0.0008% THD @ 1 kHz.

They sound better because of the predominance of 2nd harmonic distortion and
almost complete absence of 3rd and ditto up the range AIUI with even and odd
harmonics.


Uhhh.

Please explain how you obtain even distortion products from a
symmetrical (suppose paired mosfets) push-pull.

Any symmetrical function produces odd (and no even) harmonics.

:-) ...unless you used single ended output stages.


--
Thanks,
Fred.
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"Randy Yates"
"Phil Allison"

**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device,



** Same old red-herring ******** from know nothing Wilson.

It is totally irrelevant how DEVICES behave on their own.

Only when they are properly configured and suitably biased in a
complimentary output stage can performances be compared.


operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs.



** UTTER ******** !!!


No it's not.



** Yes it is you pathetic, know nothing MORON,



When configured in typical amplifier topologies, THD is vanishingly small
at
all power levels and with minimal bias current.


That may be true, but only because of the negative feedback that Trevor
referred to.


** Bull.

The basic device IS more nonlinear.



** Irrelevant.

Can't you read - dickhead.



..... Phil







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"Eeyore" wrote in message
...


Gareth Magennis wrote:

"RichD" wrote

Who do MOSFET sound better than bipolar, as an audio amp output
driver?


Well this is probably an urban myth/load of ********, but years ago lots
of
people were talking about power Mosfets exhibiting different distortion
characteristics than BJT's in the same way thermionic valves distort with
differening harmonics and sound nicer.

Fact or crapology?


Fact. Different transfer characteristics. Fundamental device physics.

Graham




Well in that case the OP's question is thus answered, as far as I can tell.
It sure is noisy in here.



Gareth.


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"Gareth Magennis"


Well this is probably an urban myth/load of ********, but years ago lots
of people were talking about power Mosfets exhibiting different distortion
characteristics than BJT's in the same way thermionic valves distort with
differening harmonics and sound nicer.

Fact or crapology?



** Audiophool crapology - repeated parrot fashion, ad nauseam.

The THD residual of even the simplest topology, lateral mosfet audio
amplifiers is vanishingly small.

Sub the threshold of audibility.



..... Phil








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"Gareth Magennis"


Well in that case the OP's question is thus answered, as far as I can
tell.



** It can never be answered.

Since it was a UTTERLY meaningless TROLL.

You pathetic fool.




..... Phil






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"Phil Allison" wrote in message
...

"Gareth Magennis"


Well this is probably an urban myth/load of ********, but years ago lots
of people were talking about power Mosfets exhibiting different
distortion characteristics than BJT's in the same way thermionic valves
distort with differening harmonics and sound nicer.

Fact or crapology?



** Audiophool crapology - repeated parrot fashion, ad nauseam.

The THD residual of even the simplest topology, lateral mosfet audio
amplifiers is vanishingly small.

Sub the threshold of audibility.



.... Phil


Not if you clip them like you might a valve amp for example. Would a Mosfet
amp clip more "nicely" than a BJT amp? I'm thinking driving bass speakers.
Is this what some of these "audiophools" or pehaps PA guys are getting at by
saying they sound better?



Gareth.


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"Gareth Magennis"
"Phil Allison"

Well this is probably an urban myth/load of ********, but years ago lots
of people were talking about power Mosfets exhibiting different
distortion characteristics than BJT's in the same way thermionic valves
distort with differening harmonics and sound nicer.

Fact or crapology?



** Audiophool crapology - repeated parrot fashion, ad nauseam.

The THD residual of even the simplest topology, lateral mosfet audio
amplifiers is vanishingly small.

Sub the threshold of audibility.


Not if you clip them like you might a valve amp for example.



** Only ****ing half-wits listen to clipped audio from a home hi-fi.


Would a Mosfet amp clip more "nicely" than a BJT amp?



** No.

Any more ****wit MOSFET myths you want to give an airing here ?

Imbecile.



...... Phil


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"Phil Allison" wrote in message
...

"Gareth Magennis"
"Phil Allison"

Well this is probably an urban myth/load of ********, but years ago
lots of people were talking about power Mosfets exhibiting different
distortion characteristics than BJT's in the same way thermionic valves
distort with differening harmonics and sound nicer.

Fact or crapology?


** Audiophool crapology - repeated parrot fashion, ad nauseam.

The THD residual of even the simplest topology, lateral mosfet audio
amplifiers is vanishingly small.

Sub the threshold of audibility.


Not if you clip them like you might a valve amp for example.



** Only ****ing half-wits listen to clipped audio from a home hi-fi.


Would a Mosfet amp clip more "nicely" than a BJT amp?



** No.

Any more ****wit MOSFET myths you want to give an airing here ?

Imbecile.



..... Phil





Er, perhaps. Mosfets don't have the same thermal characteristics as BJT's,
which are more prone to thermal runaway. So perhaps when you are runing
Mosfets hard, there is some kind of compression thing going on which sounds
nicer than a BJT amp exploding after clipping a lot.




Gareth.


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Fred Bartoli wrote:

Eeyore a écrit :
Trevor Wilson wrote:
"RichD" wrote

Who do MOSFET sound better than bipolar, as an audio amp output
driver?
**Non-sequitur. If you're saying that MOSFET outputs sound better, they
don't.

As a device, operating at typical bias currents (say) 10-50mA, MOSFETs
exhibit VASTLY more THD than BJTs. Only when bias currents are elevated
(around 0.5A - 1A) do MOSFETs exhibit THD characteristics which are almost
as good as BJTs.

MOSFETs are very tough, have an exceptional ability to deliver high power,
high frequency audio (and RF), but distortion is very high. They require
lots of Global NFB in order to operate linearly.

MOSFETs do not sound better than BJTs. At best, they can sound as good. All
things being equal.


With the required amount of feedback (which isn't rocket science - just good
design) they have no trouble meeting VERY low THDs such as one I designed with
0.0008% THD @ 1 kHz.

They sound better because of the predominance of 2nd harmonic distortion and
almost complete absence of 3rd and ditto up the range AIUI with even and odd
harmonics.


Uhhh.

Please explain how you obtain even distortion products from a
symmetrical (suppose paired mosfets) push-pull.


If you're such an expert, built one and see for yourself. And use LATERAL mosfets
designed for audio.

TWIT.

Graham

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Gareth Magennis wrote:

"Eeyore" wrote
Gareth Magennis wrote:
"RichD" wrote

Who do MOSFET sound better than bipolar, as an audio amp output
driver?

Well this is probably an urban myth/load of ********, but years ago lots
of people were talking about power Mosfets exhibiting different distortion
characteristics than BJT's in the same way thermionic valves distort with
differening harmonics and sound nicer.

Fact or crapology?


Fact. Different transfer characteristics. Fundamental device physics.


Well in that case the OP's question is thus answered, as far as I can tell.
It sure is noisy in here.


It is indeed, with a whole bunch of nutcases spouting nonsense.

It's a fact that 'open loop' with no NFB, a mosfet output stage will indeed
distort more than a bipolar one, but the distortion characteristics are
different. Put some gain on the front and close the loop and the mosfet wins
every time (admittedly requiring more overall NFB but it can take it).

That 0.0008% THD amp I mentioned, you could not see ANY vestiges of crossover
distortion on an Audio Precision analyser output, and what you could see was
mainly 2nd harmonic.

Oh and its THD floor is 0.0007%, so doubtless the amp was rather better than the
display said.

Graham



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Default MOSFET output stage



Gareth Magennis wrote:

Not if you clip them like you might a valve amp for example. Would a Mosfet
amp clip more "nicely" than a BJT amp?


Not really.


I'm thinking driving bass speakers.
Is this what some of these "audiophools" or pehaps PA guys are getting at by
saying they sound better?


I know of no 'PA' amps currently using mosfets. Everyone wants cheap these days
and bipolars are cheaper.

Graham

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Gareth Magennis wrote:

Er, perhaps. Mosfets don't have the same thermal characteristics as BJT's,
which are more prone to thermal runaway. So perhaps when you are runing
Mosfets hard, there is some kind of compression thing going on which sounds
nicer than a BJT amp exploding after clipping a lot.


Competently designed BJT amps don't 'explode'. It's not difficult, but the
Chinese haven't quite mastered it yet.

Graham

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"Gareth Magennis"
"Phil Allison"


Not if you clip them like you might a valve amp for example.



** Only ****ing half-wits listen to clipped audio from a home hi-fi.


Would a Mosfet amp clip more "nicely" than a BJT amp?



** No.

Any more ****wit MOSFET myths you want to give an airing here ?

Imbecile.



Er, perhaps.



** Wot a glutton for punishment we have here - folks.


Mosfets don't have the same thermal characteristics as BJT's, which are
more prone to thermal runaway. So perhaps when you are runing Mosfets
hard, there is some kind of compression thing going on which sounds nicer
than a BJT amp exploding after clipping a lot.



** Another 100% ****wit MOSFET myth.............

Go away - you IDIOT !!!



....... Phil




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"Eeyore" wrote in message
...


Gareth Magennis wrote:

Er, perhaps. Mosfets don't have the same thermal characteristics as
BJT's,
which are more prone to thermal runaway. So perhaps when you are runing
Mosfets hard, there is some kind of compression thing going on which
sounds
nicer than a BJT amp exploding after clipping a lot.


Competently designed BJT amps don't 'explode'. It's not difficult, but the
Chinese haven't quite mastered it yet.

Graham





The point is that when people prefer one amp over another it may not be easy
to tell technically what it is they prefer. If a Mosfet amp compresses the
bottom end slightly over a BJT, for example, this might in the long term be
a nicer sounding amp. Maybe absolutely nothing to do with crossover
distorion, linearity, feedback blah blah blah.



Gareth.


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"Phil Allison" wrote in message
...

"Gareth Magennis"
"Phil Allison"


Not if you clip them like you might a valve amp for example.


** Only ****ing half-wits listen to clipped audio from a home hi-fi.


Would a Mosfet amp clip more "nicely" than a BJT amp?


** No.

Any more ****wit MOSFET myths you want to give an airing here ?

Imbecile.



Er, perhaps.



** Wot a glutton for punishment we have here - folks.


Mosfets don't have the same thermal characteristics as BJT's, which are
more prone to thermal runaway. So perhaps when you are runing Mosfets
hard, there is some kind of compression thing going on which sounds nicer
than a BJT amp exploding after clipping a lot.



** Another 100% ****wit MOSFET myth.............

Go away - you IDIOT !!!



...... Phil



No, this is good fun, and you might eventually tell me why my supposition is
untrue.



Gareth.




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"RichD" wrote in message


Who do MOSFET sound better than bipolar, as an audio amp
output driver?


Who do? That's voodoo!


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wrote in message

On Sep 17, 6:12 pm, RichD wrote:
Who do MOSFET sound better than bipolar, as an audio amp
output driver?


MOSFETS HAVE WIDER BANDWIDTH ,less phase shift , lower
odd harmonic distortin. on and on.


Not in any relevant way for audio power amps.


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"Eeysore"

I know of no 'PA' amps currently using mosfets.



** Huh ????

All those hundreds of thousands of MOSFET audio power amps made since the
mid 1980s have not justs disappeared you know - power amps made by H-H &
Harrison Electronics plus C-Audio in the UK , Perreaux and ZPE of NZ,
Australian Monitor and ARX (still in full production) and Jands here in
Aussie - plus many other less well known brands.

The majority are STILL in use, maybe looking just a bit the worse for wear.

Even in the UK - Chevin Research ( based in Yorkshire) A-series amps are
all lateral mosfet designs.

http://www.chevin-research.com/products_a_series.php



...... Phil


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"Gareth Magennis"

** Bugger off - ******.



Gareth Magennis wrote:


If a Mosfet amp compresses the bottom end slightly over a BJT,



..... blah, blah , blah .....






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