Lampie519,
what do these files have to do with the discussion of the analog oscillator?Instead of downloading most of these files, it's easier to download and install the WeveGene1.50e program, which can generate a lot of signals through your sound card.
Moreover, instead of a sound card, it can output them to files (wav), and you will get the same files which can be burned to CD-R, if you want to check CD-player.
Here the specifications of a 14 bit cd player:
Frequency range: 20 hZ - 20kHz, ±0.3dB
Phase linearity: ±0.5º
Signal to noise ratio: >90dB
Channel separation: >90dB (at 1kHz)
T.H.D. (incl noise): <0.005%, <0.004%(at 1Hz)
Intermodulation distortion: <-86dB(at max. output level)
Specifications Philips cd100
Playback system: Compact Disc Digital Audio
Audio performance: (20Hz - 20kHz)Frequency range: 20 hZ - 20kHz, ±0.3dB
Phase linearity: ±0.5º
Signal to noise ratio: >90dB
Channel separation: >90dB (at 1kHz)
T.H.D. (incl noise): <0.005%, <0.004%(at 1Hz)
Intermodulation distortion: <-86dB(at max. output level)
It depends of "how low". 0.000x% and 0.0000x% - very different things.
Many people uses "Victor's" oscillator, which is analog and fixed frequency.
To get it's THD from digital generated waveforms is not so easy.
And in general - not possible.
Just also for the fixed frequencies, using BandPass or LowPass filter after the digitally generated sinus.
You are right/
But in the 1st message mentioned "-140dB THD" (=0.00001%), which absolutely not possible to obtain from digital generated waveforms without BPF/LPF.
And if to see on a components, it's quantity, PCB size, this BPF/LPF will be comparable with the Victor's oscillator.
I thought you didn’t want a digital one, so here you have an analog one as requested with ultra low distortion.
This is not true.
I have both analog (1 kHz and 10 kHz "Victor") and also digital: https://www.altor.co/products/test-equipment/jkgen-2
But I use them for a different tasks.