No, even without the screw the hole is too small and deep for a 3.5mm plug to hook up.
But you can hook up the iPad to a bluetooth speaker which would be ideal so that there is no wire hindering the square stand from spinning.
@VanKalkerFarms - Great call out!
@marciejenay - You'll just want to keep in mind that audio won't work while the Square Register app is open, even if it's through bluetooth. 😕
Wow, I didn't even think of that. Thanks for calling that out.
As a background, the app/reader highjacks the headphone jack, and subsequent audio channels. If you happen to plug headphones in while Square Register is open, it's not pretty. It makes an awful screeching noise.
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