Doug Selfs NE5532 Power Amp. Thoughts anyone !

Mooly · 30th September 2010, 07:41 AM

While browsing the bookstands yesterday I saw this in Elektor,
The 5532 OpAmplifier, part 1 - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement

All the specs are in the link. Doug mentioned this amp in his new book but it was a surprise to see a "real developed version"

300ma quiescent... so how much output is available in class A I wonder when each individual device is a class ab stage.

Wonder how it sounds... this could be an opamp tweakers ultimate challenge, never mind using different devices, how about "mix and match".

I'd love to know how it sounds compared to say Dougs blameless amp.

abraxalito · 08:11 AM

My first question about this is - is it designed to run from a regulated supply? The specifications for the rails (+/-18.3V) look especially tight if not. Next would be - how did he manage to degrade the slew rate for the 5532 which is typically 9V/uS? Given the relatively modest output power, I think a bridged version using 128 chips is going to be a reasonable upgrade.

steph_tsf · 30th September 2010, 09:16 AM

I think Douglas Self started a quiet revolution with this seminal design. Seeing something like this from the "Blameless" creator caused a shock in my mind. Now, after one week or so, I'm realizing that Elektor made it available to the masses, for evaluation purposes.
As said above, this is a quiet revolution.
Imagine a small PCB having the same footprint as an Intel CPU. Using SMT quad-opamps. You then can apply an inexpensive CPU cooler. Imagine regulated switched-mode power supplies, kind of laptop power supplies. Imagine a bridged amp using a single 36V regulated switched-mode power supply. Imagine a 1ppm THD figure. Could it be we just entred the 1ppm Blameless gridAmp era ? More about this here : 1ppm gridAMP

nmiljac · 30th September 2010, 10:18 AM

I saw something like this before:

HeadWize - Project: A Precision Preamplifier-Power Amplifier System with Natural Crossfeed Processing by Jan Meier

so there *is* prior art ...

Mooly · 30th September 2010, 11:10 AM

Thanks steph_tsf
I did a forum search but it didn't throw that one up of yours

I'll have a read.

wahab · 30th September 2010, 11:17 AM

Quote:

Originally Posted by steph_tsf

. Seeing something like this from the "Blameless" creator

Beg to differ...
The "blameless" topology, that is, a LIN with an enhanced Vas
did exist well before Self popularized it...

AndrewT · 30th September 2010, 11:22 AM

It is a philosophy.
Design and assemble the amplifier properly and the distortion becomes so low that one cannot blame the amplifier for what one hears.

It's that philosophy, that draws criticism of D. Self's designs/writings from many.

wahab · 30th September 2010, 11:29 AM

Quote:

Originally Posted by AndrewT

It is a philosophy.
Design and assemble the amplifier properly and the distortion becomes so low that one cannot blame the amplifier for what one hears.

It's that philosophy, that draws criticism of D. Self's designs/writings from many.

Yet, his own "blameless" has an awful design when it comes
to the VAS and LTP respective CCS...

blueskynis · 30th September 2010, 11:58 AM

Quote:

Originally Posted by wahab

Yet, his own "blameless" has an awful design when it comes
to the VAS and LTP respective CCS...

Changing compensation scheme from simple Miller to Edmond's TMC would have much bigger impact on performances than changing CC sources.

Mooly · 30th September 2010, 12:04 PM

Any chance we can keep this to the original topic... multiple paralled opamps as a power amplifier... thanks

30th September 2010, 07:41 AM	#1
Mooly diyAudio Member Join Date: Sep 2007	Doug Selfs NE5532 Power Amp. Thoughts anyone ! While browsing the bookstands yesterday I saw this in Elektor, The 5532 OpAmplifier, part 1 - ELEKTOR.com \| Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement All the specs are in the link. Doug mentioned this amp in his new book but it was a surprise to see a "real developed version" 300ma quiescent... so how much output is available in class A I wonder when each individual device is a class ab stage. Wonder how it sounds... this could be an opamp tweakers ultimate challenge, never mind using different devices, how about "mix and match". I'd love to know how it sounds compared to say Dougs blameless amp. __________________ ------------------------------------------------------- *A simulation free zone.* *Design it, build it, test it.*

30th September 2010, 07:59 AM	#2
abraxalito diyAudio Member Join Date: Sep 2007 Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though... Blog Entries: 46	My first question about this is - is it designed to run from a regulated supply? The specifications for the rails (+/-18.3V) look especially tight if not. Next would be - how did he manage to degrade the slew rate for the 5532 which is typically 9V/uS? Given the relatively modest output power, I think a bridged version using 128 chips is going to be a reasonable upgrade. __________________ I think ideas are what you want to get rid of. I don't really like songs with ideas. - Leonard Cohen Last edited by abraxalito; 30th September 2010 at 08:11 AM.

30th September 2010, 11:10 AM	#5
Mooly diyAudio Member Join Date: Sep 2007	Thanks steph_tsf I did a forum search but it didn't throw that one up of yours I'll have a read. __________________ ------------------------------------------------------- *A simulation free zone.* *Design it, build it, test it.*

30th September 2010, 11:22 AM	#7
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	"blameless" is not a topology. It is a philosophy. Design and assemble the amplifier properly and the distortion becomes so low that one cannot blame the amplifier for what one hears. It's that philosophy, that draws criticism of D. Self's designs/writings from many. __________________ regards Andrew T.

30th September 2010, 12:04 PM	#10
Mooly diyAudio Member Join Date: Sep 2007	Any chance we can keep this to the original topic... multiple paralled opamps as a power amplifier... thanks __________________ ------------------------------------------------------- *A simulation free zone.* *Design it, build it, test it.*


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30th September 2010, 09:16 AM	#3
steph_tsf diyAudio Member Join Date: Mar 2008	I think Douglas Self started a quiet revolution with this seminal design. Seeing something like this from the "Blameless" creator caused a shock in my mind. Now, after one week or so, I'm realizing that Elektor made it available to the masses, for evaluation purposes. As said above, this is a quiet revolution. Imagine a small PCB having the same footprint as an Intel CPU. Using SMT quad-opamps. You then can apply an inexpensive CPU cooler. Imagine regulated switched-mode power supplies, kind of laptop power supplies. Imagine a bridged amp using a single 36V regulated switched-mode power supply. Imagine a 1ppm THD figure. Could it be we just entred the 1ppm Blameless gridAmp era ? More about this here : 1ppm gridAMP

30th September 2010, 10:18 AM	#4
nmiljac diyAudio Member Join Date: Dec 2005 Location: Germany	I saw something like this before: HeadWize - Project: A Precision Preamplifier-Power Amplifier System with Natural Crossfeed Processing by Jan Meier so there is prior art ...

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