Re: Excuses excuses
The article from Elektor last summer points the way. ("Compact 200W Output Stage", Elektor, July-August 2005). If you don't subscribe to Elektor (you should) , you can purchase a PDF of the article from their website.
glennb said:You Hooking up a SAP-15N/P or SAP-16N/P pair of darlingtons is actually quite easy. I make no apologies for the blunders of people who don't actually know what they are doing, but learning by practical experience is a great tool.
The article from Elektor last summer points the way. ("Compact 200W Output Stage", Elektor, July-August 2005). If you don't subscribe to Elektor (you should) , you can purchase a PDF of the article from their website.
Rigid Engineering Topologies And Subjective Philosophy
Hi,
Just a simple minded idea. According to Peavey at
www.peavey.com/support/technotes/poweramps/classact.cfm
there is also design philosophy quoted from page 2 MOSFETS
"properly designed and used within design parameters, an amplifier will not have a characteristic sound -- the positive sound qualities attributed to vacuum tubes are actually artifacts of non-ideal preformance and musical sounding overload beyond electrical clipping".
With this design philosophy in mind
www.genzbenz.com/?fa=detail&mid=1839&sid=422&cid=95
states "with seperate FET and 12AX7 tube channels that can be selected independently or mixed togeather creating endless tonal possibilities".
So just the rigid topologies of A, B, AB et all and rigid electronics
theory and application, can still leave room for design philosophy
while investigating output stages, even odd FET and TUBE
parallel output stages philosophy.
Mark
Hi,
Just a simple minded idea. According to Peavey at
www.peavey.com/support/technotes/poweramps/classact.cfm
there is also design philosophy quoted from page 2 MOSFETS
"properly designed and used within design parameters, an amplifier will not have a characteristic sound -- the positive sound qualities attributed to vacuum tubes are actually artifacts of non-ideal preformance and musical sounding overload beyond electrical clipping".
With this design philosophy in mind
www.genzbenz.com/?fa=detail&mid=1839&sid=422&cid=95
states "with seperate FET and 12AX7 tube channels that can be selected independently or mixed togeather creating endless tonal possibilities".
So just the rigid topologies of A, B, AB et all and rigid electronics
theory and application, can still leave room for design philosophy
while investigating output stages, even odd FET and TUBE
parallel output stages philosophy.
Mark
LM4702 Audio Philosophy
Hi,
Written by Nelson Pass of Pass Labs
www.passlabs.com/downloads/articles/seclassa.pdf
We've heard Triodes, Pentodes, Bipolars, VFMET, MOSFET, IGBT ...
and appreciation of audio is a completely subjective human
experience ... we should no more let numbers define audio
quality than we would let chemical anaylsis be the arbiter of fine
wines ... why are we looking to reduce subjective experience to
objective criteria anyway?
Mark
Hi,
Written by Nelson Pass of Pass Labs
www.passlabs.com/downloads/articles/seclassa.pdf
We've heard Triodes, Pentodes, Bipolars, VFMET, MOSFET, IGBT ...
and appreciation of audio is a completely subjective human
experience ... we should no more let numbers define audio
quality than we would let chemical anaylsis be the arbiter of fine
wines ... why are we looking to reduce subjective experience to
objective criteria anyway?
Mark
LM4702 Output Stages And Amp Simulators
Hi,
With a GN X 3000 from www.digitech.com a musician can
simulate 40 amp models and 25 speaker cabinets and with a POD
X Live from www.line6.com a musician can simulate 36 amp
models and 24 speaker cabinets. So why should the LM4702
driver be limited to the subjective sound of 1 output stage,
expecially calling this 1 output stage the "best"? Some like TUBE
flavor. Some like BIPOLAR flavor. Some like MOSFET flavor. Some
like hybrid flavors. So why 1 "best" ouput stage for all subjective
human listening experience?
Mark
Hi,
With a GN X 3000 from www.digitech.com a musician can
simulate 40 amp models and 25 speaker cabinets and with a POD
X Live from www.line6.com a musician can simulate 36 amp
models and 24 speaker cabinets. So why should the LM4702
driver be limited to the subjective sound of 1 output stage,
expecially calling this 1 output stage the "best"? Some like TUBE
flavor. Some like BIPOLAR flavor. Some like MOSFET flavor. Some
like hybrid flavors. So why 1 "best" ouput stage for all subjective
human listening experience?
Mark
Lm 4702 Philosophy
Hi,
National Semiconductor writes some philosophy on LM4702:
"Sound quality can be a very heated and subjective debate.
However, some feel that there are differences that can be heard
between different pieces of equipment and that almost all of
these can be quantified ... a significant amount has been written
in the audiophile press about how different types of passive
components affect perceived sound quality ... [in our prototype]
all of the passive components used in the demo amplifier are
standard".
www.national.com/an/AN/AN-1490.pdf#page=7
at topical subdivisions sound quality and parts selection.
So I guess one philosopy of ouput design, is to start with the
stardard parts and then evolve into the more esoteric parts,
while always listening to the subjective sound output and then
double checking the subjective with the objective quantified.
Mark
Hi,
National Semiconductor writes some philosophy on LM4702:
"Sound quality can be a very heated and subjective debate.
However, some feel that there are differences that can be heard
between different pieces of equipment and that almost all of
these can be quantified ... a significant amount has been written
in the audiophile press about how different types of passive
components affect perceived sound quality ... [in our prototype]
all of the passive components used in the demo amplifier are
standard".
www.national.com/an/AN/AN-1490.pdf#page=7
at topical subdivisions sound quality and parts selection.
So I guess one philosopy of ouput design, is to start with the
stardard parts and then evolve into the more esoteric parts,
while always listening to the subjective sound output and then
double checking the subjective with the objective quantified.
Mark
National Semicondutor Output Philosophy
Hi,
NS has already made an output stage philosophy at the FAQ
question entitled "How do I get an ouput power of 300 watts or
more per channel for the LM4702".
NS's answer: The output stage will need to be composed of 3
NPN/PNP output pairs.
It is also possible to get 100 watts with 1 output pair and 100-
200 watts with 2 NPN/PNP output pairs.
This philosophy is 1 pair then 2 pair then 3 pair or 2 transistors
per channel then 4 transistors per channel then 6 transistors per
channel, which is a standard design philosophy.
http://search.national.com/iphrase/query?query=LM4702&render&1&categories=1phrase
Mark
Hi,
NS has already made an output stage philosophy at the FAQ
question entitled "How do I get an ouput power of 300 watts or
more per channel for the LM4702".
NS's answer: The output stage will need to be composed of 3
NPN/PNP output pairs.
It is also possible to get 100 watts with 1 output pair and 100-
200 watts with 2 NPN/PNP output pairs.
This philosophy is 1 pair then 2 pair then 3 pair or 2 transistors
per channel then 4 transistors per channel then 6 transistors per
channel, which is a standard design philosophy.
http://search.national.com/iphrase/query?query=LM4702&render&1&categories=1phrase
Mark
Alan Blumlein
Hi,
Alan Blumlein earned 128 patents including British 394325 for
stereo audio by the time he died at age 39.
What would AB do with LM4702, just another conventional 2
channel stereo circuit?
www.ieee-virtual-museum.org/collection/people.php?id=1234681&lid=1
Mark
Hi,
Alan Blumlein earned 128 patents including British 394325 for
stereo audio by the time he died at age 39.
What would AB do with LM4702, just another conventional 2
channel stereo circuit?
www.ieee-virtual-museum.org/collection/people.php?id=1234681&lid=1
Mark
1992 Electronics World IGBT Output Stage
Hi,
This old May 1992 Electronics World image showing part of
Tosbiba's application note X3504 may be one of the first DIY
notes available for use of IGBT in audio output stages citing use
with a GT20D101.
Does anyone have any newer IGBT audio ampflier output stage
schematics?
www.audiodesignguide.com/tra/igbtsch.jpg
Mark
Hi,
This old May 1992 Electronics World image showing part of
Tosbiba's application note X3504 may be one of the first DIY
notes available for use of IGBT in audio output stages citing use
with a GT20D101.
Does anyone have any newer IGBT audio ampflier output stage
schematics?
www.audiodesignguide.com/tra/igbtsch.jpg
Mark
Newer IGBT Application Note
Hi,
UNETTO minimal power amplifier uses class A driver (which
LM4702 is) and class AB push pull output stage.
Note says IGBTs are voltage sensitive devices and a small change
in the input voltage generates a large change in the output
current. This would be an odd mixture with LM4702 semi-constant
current (for low noise) with large voltage change to next drive
a low voltage sensitive IGBT output stage with a high current out
put swing. The "odd couple amp".
http://digilander.libero.it/essentialaudio/unetto_home.htm
Mark
Hi,
UNETTO minimal power amplifier uses class A driver (which
LM4702 is) and class AB push pull output stage.
Note says IGBTs are voltage sensitive devices and a small change
in the input voltage generates a large change in the output
current. This would be an odd mixture with LM4702 semi-constant
current (for low noise) with large voltage change to next drive
a low voltage sensitive IGBT output stage with a high current out
put swing. The "odd couple amp".
http://digilander.libero.it/essentialaudio/unetto_home.htm
Mark
IGBT
Hi,
I guess I am supposed to be at www.4hv.org
FOR HIGH VOLTAGE
under the fourm heading General Science And Electronics for the
audio amplifier design discussions and start with Toshiba GT-20D-
101 and GT-20D-201. The IGBT posts via search on DIYAUDIO are
just fine yet incomplete at this time.
Mark
Hi,
I guess I am supposed to be at www.4hv.org
FOR HIGH VOLTAGE
under the fourm heading General Science And Electronics for the
audio amplifier design discussions and start with Toshiba GT-20D-
101 and GT-20D-201. The IGBT posts via search on DIYAUDIO are
just fine yet incomplete at this time.
Mark
Strict Moderators
Hi,
Just spent 4 hours with www.4hv.org HIGH POWER.
One poor guy peeped "I am wondering about the [IGBT] for audio
amplifier and joined the site on 02-09-06.
On 02-13-06 the moderator cut the thread off for no more
General Science And Electronics forum and transfered the thread
to the chat room by suggesting link a Las Vegas gambling
program design to predict Aces entitled: "How to ace caculate on
the street" from University of California, Davis, mathematics
department.
We are lucky for the open minded DIYaudio moderators, since
these pro engineer guys at the other HIGH POWER forum are
much sticter on the (1) forum rules and (2) topic rules.
Thanks for the free speech oppertunity,
Mark St. Denis
Hi,
Just spent 4 hours with www.4hv.org HIGH POWER.
One poor guy peeped "I am wondering about the [IGBT] for audio
amplifier and joined the site on 02-09-06.
On 02-13-06 the moderator cut the thread off for no more
General Science And Electronics forum and transfered the thread
to the chat room by suggesting link a Las Vegas gambling
program design to predict Aces entitled: "How to ace caculate on
the street" from University of California, Davis, mathematics
department.
We are lucky for the open minded DIYaudio moderators, since
these pro engineer guys at the other HIGH POWER forum are
much sticter on the (1) forum rules and (2) topic rules.
Thanks for the free speech oppertunity,
Mark St. Denis
To Jackinnj
Hi,
Thank you for your reply.
I less than 2 months that I have been part time reading
DIYAUDIO, I have gone from just any amp that I could design was
a good beginners start -- into this amp worship egomanic design
guru philosophy.
I am presently questioning my own motives to prototype an amp
to begin with.
Maybe subconsciously I wanted to be another Nelson Pass with
world wide audience.
Anyway, if you have any fundamental must read IGBT data,
please let me know.
www.audia.it/pages/e/100.html
Thanks,
Mark
Hi,
Thank you for your reply.
I less than 2 months that I have been part time reading
DIYAUDIO, I have gone from just any amp that I could design was
a good beginners start -- into this amp worship egomanic design
guru philosophy.
I am presently questioning my own motives to prototype an amp
to begin with.
Maybe subconsciously I wanted to be another Nelson Pass with
world wide audience.
Anyway, if you have any fundamental must read IGBT data,
please let me know.
www.audia.it/pages/e/100.html
Thanks,
Mark
More Homework
Hi,
Best I can find so far is Elektor Electronics Magazine's book titled
"Build Your Own High End Audio Equipment" 1995 and 2002
Edition at Chapter 5 named 90 Watt IGBT Power Amplifier.
I am at a low level of basic homework right now, so I am not
ready for prototype yet.
www.audioxpress.com/bksprods/books/bkee38.htm
Hope this post helps another find faster one of the few DIY IGBT
amp design books.
Mark
Hi,
Best I can find so far is Elektor Electronics Magazine's book titled
"Build Your Own High End Audio Equipment" 1995 and 2002
Edition at Chapter 5 named 90 Watt IGBT Power Amplifier.
I am at a low level of basic homework right now, so I am not
ready for prototype yet.
www.audioxpress.com/bksprods/books/bkee38.htm
Hope this post helps another find faster one of the few DIY IGBT
amp design books.
Mark
National Needs New Trademark?
Hi,
When Intel finished a high priced legal transaction, the
intellectual property law judge ruled P5 is a genetic term.
Intel then spent $300,000 at a speciality company to replace P5
with the trademark-able name Pentium.
Why is LM4702 still generic name?
Why not name the circuit COOL HOT POWER (TM) so that OEMs
can say COOL HOT POWER INSIDE (TM).
It costs about $400 a year for a trademark.
How are OEMs supposed to market and sales the LM4702 with a
generic name?
Any suggestions on trademark name for LM4702, besides
somewhere in the so called Overture (TM) Serries including
complete chip amps as divided from class A drivers?
http://tess2.uspto.gov/bin/gate.exe?f=tes&state=9nrbe4.1.1
Mark
Hi,
When Intel finished a high priced legal transaction, the
intellectual property law judge ruled P5 is a genetic term.
Intel then spent $300,000 at a speciality company to replace P5
with the trademark-able name Pentium.
Why is LM4702 still generic name?
Why not name the circuit COOL HOT POWER (TM) so that OEMs
can say COOL HOT POWER INSIDE (TM).
It costs about $400 a year for a trademark.
How are OEMs supposed to market and sales the LM4702 with a
generic name?
Any suggestions on trademark name for LM4702, besides
somewhere in the so called Overture (TM) Serries including
complete chip amps as divided from class A drivers?
http://tess2.uspto.gov/bin/gate.exe?f=tes&state=9nrbe4.1.1
Mark
Re: National Needs New Trademark?
Logo-rhea
Mark St. Denis said:Hi,
When Intel finished a high priced legal transaction, the
intellectual property law judge ruled P5 is a genetic term.
Intel then spent $300,000 at a speciality company to replace P5
with the trademark-able name Pentium.
Why is LM4702 still generic name?
Why not name the circuit COOL HOT POWER (TM) so that OEMs
can say COOL HOT POWER INSIDE (TM).
It costs about $400 a year for a trademark.
How are OEMs supposed to market and sales the LM4702 with a
generic name?
Any suggestions on trademark name for LM4702, besides
somewhere in the so called Overture (TM) Serries including
complete chip amps as divided from class A drivers?
http://tess2.uspto.gov/bin/gate.exe?f=tes&state=9nrbe4.1.1
Mark
Logo-rhea
LM4702 prototype with Sanken SAP16P and SAP16N -- heat sink is 11.3125 * 4 inches:
An externally hosted image should be here but it was not working when we last tested it.
Member
Joined 2004
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