Amazing opamp measurement shoot-out

[Wavebourn]

Originally posted by syn08


LM4562 is (AC) identical to the already tested LME49860. The slightly higher supply voltage allowed by the LME49860 is most likely the result of sorting the chips.

Thanks! $2.10 if a good price for such device.

[scott wurcer]

Can't of course, just a light hearted comment. This looks like a lot of work and pretty good writeup.

[scott wurcer]

Originally posted by forr
I was interested by the bootstrapped current mirror in the one stage topology mentionned in appendix B. Are there discrete implementations of it ?

Someone here was building one, they emailed me a schematic.

[QSerraTico_Tico]

I sorely miss the correlation between measurements results and sound quality....

[QSerraTico_Tico]

Originally posted by Bonsai

....

I might be wrong, but it looks like the AD749 comes out tops overall and the LME4xxx from Natsemi a creditable 2nd place.

...

Again you mean probably the AD797....
No offence!

[KSTR]

Originally posted by scott wurcer
This explains a call I got the other day. Did anyone notice the unbiased and unbypassed 6800uF caps in the test circuits?

I noticed this too, at a closer look. The question is, how much would a slightly varying noise gain from parasitic cap effects disturb the results? From the photos it is not clear also if all DUT's used the identical same cap for the measurements. If so, at least the DUT's had idential conditions.

Still it is a great effort and an enthusiasm to applaud to...

- Klaus

[KSTR]

Originally posted by QSerraTico_Tico
I sorely miss the correlation between measurements results and sound quality....

In this type of investigation any personal comments on "how they sound" are not to be expected. Also we already know it:
AD797, top performer, some like it, some don't.
OPA604, poor performer in this test, some like it, some don't.
Pick you choice!

- Klaus

[QSerraTico_Tico]

Originally posted by KSTR
In this type of investigation any personal comments on "how they sound" are not to be expected. Also we already know it:
AD797, top performer, some like it, some don't.
OPA604, poor performer in this test, some like it, some don't.
Pick you choice!

- Klaus

Then may I ask what is the use of these measurements for audiophiles?

[destroyer X]

those op amps into power amplifier input, say, substituting differential amplifier and maybe VAS too (not when using as error correction).

I am perceiving this as a new approach (not so need) into the most expensive and sophisticated audiophile grade amplifiers... this seems to me has advantages to use them.... well.... i think discrete may be even better, but maybe mine ignorance..for sure... as i do not know them (have not the experience building with them) and i cannot conclude nothing.

Really, i am not a data addicted...no patience enougth to read 222 pages of datasheet.... if you have some conclusion..... some audibility tests made (not charts), or some opinions about, i will be happy to listen your thougths about.

http://www.sg-acoustics.ch/analogue_...distortion.pdf

Tem que ter muita paciência Tico tico, pra lêr tôda essa coisa...haja Seiko pra isso!...podes me dar um "diagnóstico"... tipo....isso soa bem....ou tipo "outra conversa fiada" pra vender pra boboca.

We need to find a lot of time and patience to read all this thing.... too much patience!... can you give me some "diagnosis"... some final result of audibility testing.... audio is to listen, not to read papers with graphics..they sound nothing.... can you tell me "this sound fine"...or "another bill shot to make you spend money and destroy your hopes for perfection"

I continue to believe, and this seems to me very logic, that simple is better..the most simple solutions will be always better in sonics (Nelson Pass, JLH and others prove that).... we can have, of course, a lot of surrounding auxiliary circuits, CCS, sinks, mirrors and all that stuff, to help..but inside audio chain, the most simple is much better when listening... i am watching, perceiving and testing this stuff during last 48 years..no doubts about that.... those op amps are complicated...some of them have an entire amplifier circuit, with differential, sophisticated Vas and drivers and output and a lot of "inside audio chain" circuits...in my belief "this cannot sound good!" when you can just use a single differential and a single transistor VAS..less parts distorting and producing errors, phase errors, intermodulation errors is better than a lot of circuits disturbing.

Please..someone... tell me i am wrong... this gonna be great... i will try to buy all them and test all them to check and will be happy using something better than my simple beloved discrete circuits.

How they measure says nothing to me... absolutelly nothing.... i am human and not a computer to be analising graphics...to me, a human beeing, what really interests are "how they sound".... the rest may be number competition between factory, things not interesting to us, audiophiles, humans that loves to build and to listen good music with good amplifiers, good speakers.... graphics?... nice to put into a frame or into an office... to sell products maybe, to compete between them.. non usefull to humans that loves music.

regards,

Carlos

[weissi]

what's up with njm4556, njm4580 and all that stuff that populates modern digital low- to high grade digital interfaces?
still searching for some upgrades that comes in MSOP8....