Just make your own tones. https://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling#Keypad

The distinction isn't actually digital vs. analog but in-band vs. out-of-band. For dialing, it might as well be in-band, since the end user has to have control over it. They used to also do things like authorizing long-distance calls through in-band signalling, which is why phreaking worked. Phone company equipment sent audio signals to other phone company equipment over the same line that you were talking over, so if you made the same audio signals, the target equipment would respond in the normal way. That's all out-of-band now (the equipment communicates over lines that you don't have access to), so that's why you can't phreak that way anymore. If they had kept it in-band but just switched to digital, you could still phreak; it would just need something more sophisticated than a whistle from a box of Captain Crunch.