I plugged in a headphone amp this morning to the pre-out terminals and the sound is fine.
So, it's destiny as a preamp is still secure.
Thank you for warning me about the clipping danger. I did it for about a minute total, do you think any damage was done?
So, I'll get the amps on Monday or Tuesday and hook everything up and see how it works.
BTW, is it difficult to fix a broken amplifier?