I want to know your priority if you design an amplifier. Please sort these specification for most importance to the least importance:
- THD
- IMD
- specific harmonic profile of the distortion
- slew rate
- signal to noise ratio
- reliability (use many protection)
- damping factor
- other (please name it)
- THD
- IMD
- specific harmonic profile of the distortion
- slew rate
- signal to noise ratio
- reliability (use many protection)
- damping factor
- other (please name it)
Seems like it's still easier to make an actual CD reader if you have the time and money to make a system that can scan the pits and lands of a CD.
I agree that we won't find ourselves 50 years from now unable to read a CD.
Bill: Cool. Presumably larger groove shellacs? Only a matter of scale to get to microgroove, but resolution of the smallest possible signals is currently challenging. "Wavelength of a hydrogen atom" is an exaggeration, but the wiggles at -50 to -60dB VU (ref: 0VU = 5cm/sec lateral) are pretty small. Not at all out of the reach of visible light lasers, say unnamed sources in the Government.
For your eyes only,
Chris
For your eyes only,
Chris
After the Rapture, we'll all be playing in the Heavenly Band. In the meantime, CDs are looking to be reasonably archival. The hated cases actually encourage good archival storage. Nothing magnetic or charged-capacitor feels very leave-it-half-a-century-and-come-back to me. I won't be here anyway; don't care.
But all modern bulk storage depends on continual updating. Is there any modern music that actually needs preservation? Separate question.
All good fortune,
Chris
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Are-you joking ?
In the history of art, all disciplines combined, the 70s represent a summit that, unfortunately, I think incomparable.
Hi Bimo,
You seem to be someone who listens very carefully, and who is strongly opinionated about amplifier design. Since your English appears limited it can be hard for some of us to know how to converse in response to your statements.
I haven't designed a power amplifier yet, although that may happen at some point (if my friend Jam has his way). For now I am still working on DACs. Have you built any DACs yourself?
Do you mean does anyone design dac chips from discrete components or in FPGAs? A few do that. Either way, it can be viewed as connecting chips together (since FPGA schematic design entry is possible), just more chips involved (and maybe a vacuum tube now and then).
Problem with those things is that it is very hard (essentially impossible) to do as well as teams of professionals who design more complex building blocks in the form of dac chips.
Even then, a really good design can be quite challenging. After all, the dac chip manufacturers don't appear to know how to use their own chips to best end results judging by evaluation board designs and the lack of good user design application support.
Mark,
He is asking questions about importance of individual items he has listed, to amplifier design and sound. I do not think it has something in common with level of English knowledge.
No complaints about AKM. Follow the script and it all comes down to layout skills. How do you think they get to their specs. Of course, improvements may be possible. Like Victor's clever analog solution for ESS. Requires a DAC that likes to push against zero Ohms. Should work for AK4099 as well.
All are proprietary that I know of. For ESS, Benchmark DAC-3 is one example. I know of a few more things people have figured out, but not published.
An example of a evaluation board type ESS design would be Oppo's last CD player that many people (not all, of course) found not up to their expectations. Also, ESS did not provide a suggested explanation/solution for the hump problem in the data sheet or since then. People are still trying to figure it out.
Since I only know in detail about one AKM dac chip and evaluation board, I can talk about a few details. AKM opted to design the Reference Voltage supply with filtering that they plainly state produces more than minimal LF harmonic distortion. Why? Apparently because it sounds better that way in otherwise mediocre dac system design implementations. AKM also included an AK4137 ASRC on the board, but only designed the board to give an option to use the ASRC with SPDIF input. They also did not populate the reference clock for the ASRC, and the board layout only provides pads for adding a rather mediocre clock if one can find a source for one (not pads for commonly used good quality audio grade clocks). There is more, but enough for now.
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Bill,
Mediocre, of course in the context of a high end dac chip such as AK4499.
EDIT: It appears AKM has a problem in that AK4499 is complex in terms of its support circuitry requirements. Some manufactures are shying away because of it. At its best (that I know about so far), is where the complexity pays real dividends. Unfortunately, its best seems to require even more complexity and cost.
From what I hear, they seem to understand the market needs a less complex chip, but one still good enough to justify switching from ESS Swiss-Army-Knife parts.
Mediocre, of course in the context of a high end dac chip such as AK4499.
EDIT: It appears AKM has a problem in that AK4499 is complex in terms of its support circuitry requirements. Some manufactures are shying away because of it. At its best (that I know about so far), is where the complexity pays real dividends. Unfortunately, its best seems to require even more complexity and cost.
From what I hear, they seem to understand the market needs a less complex chip, but one still good enough to justify switching from ESS Swiss-Army-Knife parts.
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