Yes, exactly, only in SMD.
If you do not request for higher output drive capability and unity gain ultimate stability+high slew rate, then AD797 is still better regarding lower distortion.
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I looked at the LME49990 but the spec sheet shows a Zobel on the output (also only SOIC IIRC)
This will not be the first Natsemi part that seemed to require special attention to the output. I built my first phono amp using a dedicated chip from them in the late 70's and it had a terrible hissing sound - my buddies also had the same problem (circuit straight from the data sheet). I helped a guy here on the forum a year or two ago who also had HF oscillation on another Natsemi part - fixed it with a Zobel also.
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What I find interesting in all of this is that no one (as far as I can tell) has offered an opinion of what the devices in the test actually sound like 
You have two hugely differing distortion spectra, two totally dissimilar devices... and so at this point I have no choice but to draw my own conclusions based on the lack of listener feedback Fair comment ?
You have two hugely differing distortion spectra, two totally dissimilar devices... and so at this point I have no choice but to draw my own conclusions based on the lack of listener feedback
Fair comment ?
What I find interesting in all of this is that no one (as far as I can tell) has offered an opinion of what the devices in the test actually sound like
You have two hugely differing distortion spectra, two totally dissimilar devices... and so at this point I have no choice but to draw my own conclusions based on the lack of listener feedback
Karl, I still assume that recording chain may have a great influence to test result and quality of the sound files provided.
During the last year, I have been improving both line stage and power amplifier to get the best possible S/N and distortion, also with a nice and clean step response. IMO this effort makes sense and leads to better and more accurate sound (both is valid). But I have no chance to make an ADC sound recording that would just approach to quality of preamp + power amplifier. I do not own a professional SOTA 24-bit recording sound system.
I don't care. I sum the 20 output currents in an inverting stage and have
up to 60 dB post gain, so the contribution of the 20 parallel stages is
effectively nil. (But probably audible if one can see them.)
We had this amplifier already in this thread at 51771, in the
homebrew opamp thread, and where I presented the findings
about battery noise, so the claim of never having seen an ADA4898
in action is
< http://www.hoffmann-hochfrequenz.de/downloads/lono.pdf >
The circuit block with the one opamp pair is repeated 10 times
by the cad system because of the rep(xxx, 1, 10) statement in the
root sheet. The block is also automagically repeated 10 times in the
layout.
I have added the missing WIMAs in the meantime, but dead bug style
since I could not get enough of those that fit the layout. Does not
look pretty anymore.
< www.hoffmann-hochfrequenz.de/downloads/NoiseMeasurementsOnChemicalBatteries.pdf >
(measured with this preamp)
You could play with the AD8009 if you want speed & current.
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Karl, sorry I haven't got back to you yet, but I got burnt by rushing a quickie evaluation to you in the previous round, - the hookup of the PC had been optimised to suit the Yamaha keyboard, and it was making a mess of the sound of the straight PC playback - the piano samples made that very obvious. I've done a preliminary round of evaluation, and the two "sounds" are quite clear, but it's been a hot day, so I'll leave until tomorrow and run them through a second time, to confirm my assessment. Interestingly, SY's samples were easier to rank than the piano, the latter showed clearly that my PC was not in good shape initially ...
- the hookup of the PC had been optimised to suit the Yamaha keyboard, and it was making a mess of the sound of the straight PC playback - the piano samples made that very obvious. I've done a preliminary round of evaluation, and the two "sounds" are quite clear, but it's been a hot day, so I'll leave until tomorrow and run them through a second time, to confirm my assessment. Interestingly, SY's samples were easier to rank than the piano, the latter showed clearly that my PC was not in good shape initially ...
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Hi Pavel, that is undoubtedly true, but equally you have to say the recording process and method used clearly shows the difference in the distortion between the two samples.
Who does
and yet we still argue that we can discern differences (sometimes big differences) in the amplification chain, and that using far from perfect source equipment and material.
Karl, sorry I haven't got back to you yet, but I got burnt by rushing a quickie evaluation to you in the previous round,
No problem Frank, take your time
You are one of the few here that actually enters into these kind of tests in the spirit in which they are offered
That is as a fun, and hopefully informative listening experience. There is no right and wrong in any of this.
hi Gerhard,
What is the cause of the various peaks in the noise measurements?
The right question would be "Why are there places without noise peaks?"
That's lab noise, 50 Hz line & overtones. It took fat Hammond aluminium
cast boxes, semi rigid coax cable, floating battery supply and a second
large alu box with BNC feedthroughs to enclose everything to get to this
level. The numbers on the y-axis are _really_ small.
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Aluminium?The right question would be "Why are there places without noise peaks?"
That's lab noise, 50 Hz line & overtones. It took fat Hammond aluminium
cast boxes, semi rigid coax cable, floating battery supply and a second
large alu box to enclose everything with BNC feedthroughs to get to this
level. The numbers on the y-axis are _really_ small.
I was more thinking of Jim Williams' cookie box....
Who does
And I am sure we can
If I make a 48kHz/24bit recording from vinyl, then I play analog vinyl and digital data through preamp with switchable inputs, levels matched - I can tell the difference. Same if I make a CD from vinyl and compare it directly to vinyl. It never sounds the same. What is my ADC good for if I can tell the difference, from imperfect sound source?
Well, at the very least you have a reasonably accurate facsimile, , whose integrity is guaranteed forever, provided you deal with it intelligently - which will allow you to fiddle with the contents and alter them to suit, with the ever more sophisticated DSP developed in the years to come ... not such a bad option, really ...
, whose integrity is guaranteed forever, provided you deal with it intelligently - which will allow you to fiddle with the contents and alter them to suit, with the ever more sophisticated DSP developed in the years to come ... not such a bad option, really ... 
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