Phoenix, agree with what you say, but let me add that 19VDC is the voltage at which the part is known to meet spec. With obvious consequences - which, to an engineer such as yourself, pose no issues.
Battery noise was measured by someone in Germany some years back. I think they were looking at powering phono stages. He found that all technologies made a fair bit of noise, except NiCd, which measured at the noise floor of his HP instrumentation.
Anyway, I'm in the process of designing a new phono power supply based on NiCd's for listening and a linear PS for warming, and the unexpected issue is charging. Seems that no-one does it right - i.e. warning at 1.1VDC per cell to avoid memory effect and separate current source for each cell.
Expect to start building in a couple of weeks, will let you know if it makes a perceptible improvement over alkaline with LC filter.
Battery noise was measured by someone in Germany some years back. I think they were looking at powering phono stages. He found that all technologies made a fair bit of noise, except NiCd, which measured at the noise floor of his HP instrumentation.
Anyway, I'm in the process of designing a new phono power supply based on NiCd's for listening and a linear PS for warming, and the unexpected issue is charging. Seems that no-one does it right - i.e. warning at 1.1VDC per cell to avoid memory effect and separate current source for each cell.
Expect to start building in a couple of weeks, will let you know if it makes a perceptible improvement over alkaline with LC filter.