I’m making a 4 channel mixer for Daisy Patch. I’m having trouble because the audio inputs are normaled to one another. In this thread, @shensley mentions that this was an intentional design decision and it can be mitigated by plugging a dummy cable into each audio input. However, that would be a pretty darn bad user experience for my mixer
Therefore I am not happy with this solution. I’m currently trying to find a way to prevent Patch from audio input normaling on the software side. If there were some sort of way to detect whether or not an input jack was receiving a signal or had a cable plugged in, I could mute that input in my code. I haven’t been able to find a way, though.
Does anybody have thoughts on this?
I believe @antisvin asked a similar question int he aforementioned thread but it wasn’t answered.
It can’t be solved in software. So either set all levels to 0 by default or I guess you could hack your Patch to desolder normalization permanently.
Ah, that’s a bummer. Suppose I’ll just add a pop up message warning users about this behavior in the startup screen. Thank you for the reply!
Worth mentioning that on PCB revisions rev6 and up, there are 0R resistors that connect the normalization.
These are populated at the factory to maintain backwards compatibility with all previous versions of the hardware, but can be removed to disable the hardware normalization.
This does require removing some SMD components from the back of the PCB. So obviously not an easy thing for everyone to do, but figured it’d be worth bringing it up since it’s not obvious if you’re not looking at the back of the board.
The resistors would be visibly marked in the bottom right of the board when looking at it from the back, as shown below:
I would say it’s quite trivial and a very welcome addition. Maybe it’s time to add an officially blessed mods page for this sort of things i.e. removing AC coupling caps, soldering debug port to patch SM, patch.init() expansion port.