One Last Attempt at Discrete Opamp in DIP8 Footprint

[EUVL]

I already made it clear at the beginning that I was doing this for the challenge.
Not with the intension to beat any IC solutions, especially in spec.

Whatever you prefer or think is scientific better is fine with me.
I have a lot of fun doing this, which is what matters.

And some other people think it is worth the trouble too :
"WHAMMY" Pass DIY headphone amp guide
(#1375)


Cheers,
Patrick

[dreamth]

I have no doubt about it, i might be wrong, but you'd probably better go back to Gray and Sedra for this effort to be better accomplished.
The biggest problem i see about this effort is that most of us here seem to be biased by Diyaudio topics which are on repeat mode most of the time.


We have about a few thousand pages on op-amps good for audio on this forum and Google can hardly find a damn thing about m5220,m5219, njm2043 and njm2041 which were used in most high end cassette players of the 90's and in early but very high quality I/V sections in early cd players that are still venerated, plus in countless good quality mixers, but people concentrated on ne5534 for some reason...njm2043 and njm2114 can beat ne5534 in any application. Even the "horrible" lm833 can beat ne5534 in i/v stages. Thank God for NOT listening to Diyaudio as they still sell the much discredited lm833.

Well... the best op amps were not made for audio, they were expensive and used in medical , metrology or military technology.
You would have INA117 or SSM2017 at 10 dollars each or at 100 dollars each in a different package with different specs.

The order of performance magnitude between the audio op-amps and those op amps developed by Analog Devices, Burr Brown, Intersil , Harris , Hitachi, Nec and others was simply high.


The most underrated spec was the thermal dissipation which actually improve by large the op-amp behavior cause even if you have some identical specs for both versions, like the industrial vs military chip, those specs are guaranteed either at 25 degrees Celsius or at 150 degrees Celsius and the difference is enormous for fast and powerful transients to be processed cleanly.


Now look at these two op-amps datasheets that i attached and, please, tell me what do you think about the audio op-amp plethora.
The datasheet tells that they are around at least since 1996...If i wouldn't log on Tapeheads i would've never knew this op-amp existed.


I asked for a few times here if anybody knows the reason why Denon and Nakamichi used in its most expensive players and dacs upc4570 in the i/v stage and ne5534 as a buffer after that...It clearly wasn't for the fact that upc was cheaper...they used two damn tarnsformers and a ton of very high quality capacitors and regulators plus a magnetic levitation transport in those models.


Do you see any talk about upc4570 qualities? The datasheet itself isn't very transparent but Denon knew something.
We still compare the whole op-amps world with ne5534 as the past and the new op-amp jewels of the present as the only solution that can only be beaten by dicrete op-amps.It's simply biased behavior.

[MarcelvdG]

What's the relation between those datasheets and the amount of fun involved in designing a discrete op-amp?

[dreamth]

Some might have some real fun replicating the internal guts of the Harris version
I've seen guys making tda2030 with discrete components...

[tsmith1315]

Originally Posted by EUVL

I have a lot of fun doing this, which is what matters.

And many of us have fun reading about it, I think it's pretty cool. Thanks for posting your efforts.

[EUVL]

I am not alone.

John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III
(post #17914, 17905)


Patrick

[BesPav]

Originally Posted by EUVL

Firstly a discussion about different basic opamp topologies.

For your interest:
http://cmosedu.com/jbaker/papers/tal...esentation.pdf

[BesPav]

Originally Posted by dreamth

We still compare the whole op-amps world with ne5534 as the past and the new op-amp jewels of the present as the only solution that can only be beaten by dicrete op-amps.

There are a completely clear reason - total lack of knowledge.
No one engineer wants real competition in his working area.

Who knows about - works and doesn't present there, who present there - couldn't cope with modern opamps loopgain.

[dreamth]

Originally Posted by BesPav

There are a completely clear reason - total lack of knowledge.
No one engineer wants real competition in his working area.

Who knows about - works and doesn't present there, who present there - couldn't cope with modern opamps loopgain.

YouTube

[dreamth]

Originally Posted by BesPav

For your interest:
http://cmosedu.com/jbaker/papers/tal...esentation.pdf

Thank you! Very good material!
YouTube
YouTube