Using DMA as a beginner

Am attempting to construct a triggerable function (envelope for synthesisers) generator using a Pi Pico and Micropython. The Pico has a 7bit R2R DAC across GPIO 16-22.

Have been successful using while loops and utime.sleep to play back lists of voltages but I find that there is an annoyingly low limit to the sample rate I can achieve, even though the unit is clocked at 125 MHz? I would like to get close to that value.

Have seen some posts that suggest using DMA is the answer but my Python is pretty basic and I don't know where to start.

Any help would be hugely appreciated!!!