Questions about amp camp amp and linear power supply

[AndrewT]

Those high measurement values must be at the PSU.
It would help you and us a lot to also see the measurement values at the speaker output terminals. With the inputs shorted and with the source connected.

 

[kking85743]

Sorry, should have specified: the measurements were taken at the power supply with the amp on, no input (pre-amp off) and speakers plugged in. As close to nominal use case as possible. Also, Amp was warmed up.

I will check what it looks like at the speaker's early next week.

 

[kking85743]

Sorry, should have specified: the measurements were taken at the power supply with the amp on, no input (pre-amp off) and speakers plugged in. As close to nominal use case as possible. Also, Amp was warmed up.

I will check what it looks like at the speaker's early next week.

Ok, the data is pretty simple. Almost no variance between sides, or between inputs (present w/ preamp off, shorted, open), and almost no difference with or without speakers plugged in. I am also including self-noise values for the cheap USB scope (probe attached, but not shorted) for comparison:

My guess is that this is beyond good enough (15mV peak to peak above self-noise, and no RMS difference over self-noise), and that I should put my effort into building speakers rather than building a Power Supply filter. Or saving for a better scope...