A lot of output current, but the rest of the specs are pretty bad. I'd probably avoid that one...
A more modern beast:
https://www.analog.com/media/en/technical-documentation/data-sheets/ada4870.pdf
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I would suppose that one to be squirrley.
If I wanted a headphone amp, I'd use something akin to :
https://www.onsemi.com/pub/Collateral/EN3309-D.PDF
That's just a crap power amp?
Are you listening to AKG K1000? I'll take an OPA1622 or a ADA4898 + BUF634/LME49600 or something like that...
I probably wouldn't use the ADA4870 directly, but in the feedback loop of another op-amp, and you would certainly need to make sure it's stable with capacitive load or make the needed changes so it is... but you need to do that with almost everything high performance.
Are you listening to AKG K1000? I'll take an OPA1622 or a ADA4898 + BUF634/LME49600 or something like that...
I probably wouldn't use the ADA4870 directly, but in the feedback loop of another op-amp, and you would certainly need to make sure it's stable with capacitive load or make the needed changes so it is... but you need to do that with almost everything high performance.
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Have listened to a couple devices with TPA6120, sounds fine to me. A long time ago I built a discrete Class A amplifier to test. It sits collecting dust now. http://www.djgardner.com/headphone/gilmore/dynahi/schematics/dynahi2.gif
Note - didn't use LM78xx for PS or OP27 for servo.
An opamp + buffer in the loop sounds good enough for Benchmark, apparently. LME49860 + LME49600.
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This will be my last response to you and chris719.Is RNMarsh your family member or relative? You seem very protective of him, so I'm wondering...
Yes, Mr. Marsh and I are from the same family, despite being born in distant countries, with different cultures, speaking different languages, not having the same standard of living and very different life paths.
Curiously, it turns out that we get, most of the time, the same opinions, and reach the same conclusions about "hifi". Strange, isn't it ?
A family far removed from yours, indeed.
The family of those who consider things with humility and an open mind. The family of those who seek to understand and learn without ever being satisfied. The family of those who listen to the opinions of others with kindness, especially when they are based on a life of passion in their area of expertise. And never take for granted things that they have not verified by themselves.
The family of those who commit the deadly sin of listening in Audio, to look in photography, to choose their cars by trying them rather than reading the catalogs. The family of those who, in your opinion, are wallowing in illusion, swimming in snake oil, forging their opinions by reading audiophile magazines, etc.
The family of those who prefer to share our bread and wine rather than vomit bile.
It turns out that we, he and I, are old gents, having spent their professional lives in this area of creation and musical reproduction through electronics. To read to you, I doubt that it is your case and that you have as much experience in this field of which you think to be a referee of elegance, politically correct and the unique thought.
As you only print the same line, "sighted, flawed, measurements, etc.", only based on prejudices and motives of intent, as it turns out that he and I have had to spend a lot more time in our lives measuring and trying to understand the more scientific ways we could what's behind what we're listening to, the measures of which, as always, are only narrow bands in a volume of things more complex than I believe you imagine, we are, indeed very different from you.
As I have no pleasure in holding conversations with aggressive parrots, I leave you to your primary and childish certainties and your witch crusade.
Above all, do not change your certainty of having a kindergarten truth, you might learn one of two things.
PS: I apologize for being so aggressive, but this constant aggression coming from a bunch of bounded so calling objectivists must stop, because it is boring, disrespectful and unproductive.
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Am I wrong to think LM3886 and the likes still fits the definition of an op amp?
Best possible with discrete includes :
- Complementary differential JFET input stage,
- MOSFET output stage,
- JFET output stage,
- Class A output stage biasing,
- Non degenerated output stage,
- Electron tubes,
which I am not aware have been implemented in an IC.
Could anybody help me by pointing out ICs that do have these features, or any references why said features are cows?
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I was like the "other guys" in the mid-70's, fresh out of school: "whatever I did not know how to measure did not exist" (careful wording). Then I met JC who showed me "sometimes you can hear things you don't know how to measure". Now I'm a believer, I grew up listening to and playing music anyway, so it's a natural for me.
Enough said, it a fine day for skiing... Till later.
JC is not getting any younger. I hope younger generation keep pushing the measurement envelope. It is very difficult to make progress on subjective evaluation alone.
I am going to build this phone amp in SMT, practically no distortion at all level or phone loads.
Damir
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Actually, that's probably not the most important difference. Most likely it is the external digital interpolation filter in FPGA that DAC-3 has. Oppo uses the built-in Sabre filter. In DAC-3 the FPGA filter also has a more gradual transition band due to upsampling to 211kHz of all audio before going into the FPGA filter. Its easier to make a good sounding filter that way. In my view, that is the primary thing about DAC-3 that none of the competition have had, and that makes it sound especially good. The upsampling in SRC4392 also helps attenuate any jitter from SPDIF or USB asynchronous inputs.
Some Sabre dacs that only use USB or a Raspberry Pi streaming audio source (no SPDIF variants) are able to achieve improved sound quality by operating in synchronous digital input mode. The built-in dac ASRC may not be entirely transparent.
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This is intriguing. And suggests that, at normal listening levels on the sofa none of this matters?
Not quite. It doesn't matter if two dacs are similar enough and the same high quality power amp is used with both. Katana is much lower cost than DAC-3, but that's because it is a Raspberry Pi hat dac without a case or power supply. It only sounds its best with good linear power supplies, which adds a minimum of around $150 additional diy cost. It has no SPDIF or USB inputs (although a USB memory stick can import audio files). It is a synchronous mode dac with ultra-low jitter. Primarily, the sound suffers somewhat from not having an external interpolation filter. The difference in the near field or with headphones is easy to hear, but not with both diffuse room sound and higher SPL levels (and possibly dependent on speaker and room characteristics).
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