Here's a strange one:
I used to use my old Keystep with my iPhone, connected by a 3-way camera adapter (USB, 3.5mm jack, lightning power input) with no issues -- audio from various soft synth apps routed directly from the headphone output on the adapter to my Elektron Digitone input
I've updated to the Keystep 37 -- I need a low C -- but when I connect the Keystep to my iPhone now, it forces the iPhone to use speakers instead of the headphone output. If I connect the Digitone to the iPhone directly and send a midi track, I still get headphone output, it's just the Keystep that's changing the audio routing
Anyone able to test this for me to see if they can replicate the problem. I havent' tried powering the Keystep separately yet, so that might fix it...
Cheers,
James