I figured out what the problem is on my end: my notebook built-in audio default settings. But I still consider it a Steinberg DDP Player problem that should be looked into and fixed if possible, because it doesn’t happen with Hofa DDP, or iTunes with test tone WAVs, using the same default settings.
I have an inexpensive Windows 10 notebook computer with built in Realtek HD audio. I haven’t touched the settings for this, so they’re at defaults, no enhancements or processing. On the properties/advanced tab for the audio is a setting for “default format”, which defaults to 24 bit 48000 Hz. With this setting, the Steinberg DDP Player distorts as indicated in this thread. I’ve also made test DDPs with clean sine waves, and they also distort in the Steinberg player with the default setting. 1k @ -12db has a slight distorting “edge”, 10K @ -12db sounds like a buzzsaw, a sweep @ -12db goes crazy and has feedback.
The signals are playing at the right speed, but they’re distorted, and I can see how the distortion might not be immediately obvious on music, although Hesca116 caught it.
In the case of my notebook, this is all cured by changing the built in audio default format to 24 or 16 bit 44.1KHz.
But the point is you don’t have to do that with the Hofa player, or with iTunes. They’re not distorted even with the default 48KHz setting.
None of this happens with the Steinberg Player on the studio computer with another interface. But It might happen with some other interface, I don’t know. But I imagine this will come up again if nothing is done about it.