To measure distortion, you can use a notch filter to "cut" the first harmonic.
For distortion measurements, I use a Picotech 4262 DSO, as this provides 96 dB dynamic range already without any tricks.
This scope is confused by a bandwidth of only 5 MHz.
A 5000 series picoscope with switchable vertical resolution ADC is not suitable for this purpose?
It has bandwidth of 5MHz, more than enough for audio, vibration measurements etc..
It also has a noise floor of 8 uV rms... !!!
SFDR: 96 dB typical @ 10 kHz, –1 dBfs input. Around 0,002% distortion.
It also includes low distortion DC to 20 kHz AWG. (102 dB typical @ 10 kHz, -1 dBfs output).
It is actually pretty unique instrument..
5000 Series is excellent general purpose scope that has better resolution than even average 12 bit scope. But higher resolutions come at cost:
16 bit mode comes with lower sample rate of 62.5 MS/s and on single channel only. So in 16 bit you have 30MHz single channel scope.
SFDR in14 to 16-bit modes: 70 dB at 100 kHz full scale input. (around 0,03% distortion)
That one too is pretty unique instrument, that can serve as general purpose scope and have higher resolution when needed with some compromises.
5000 is good enough to service and check on audio equipment for musicians (PA, instrument amplifiers). You just cannot measure very low distortion. Probably good enough for normal musical equipment. It is just that 4262 is order of magnitude better.