isak wrote:Yes, the sequencer is fine.
Everything is working fine except the midi in.
That rules out the DAC.
isak wrote:More strange things just came up...
The the decay is not working as it should, it's working but very weak not as strong as it use to be.
It's getting out of tune the next day, strange, isn't it?
Only moving tm5 just a bit and it's in tune again.
These are very crazy symptoms. Seems something is happening to the MIDI-In signal as it travels down to the uC. It's difficult to check that without a scope. The other symptoms you are having... No idea. Really. Only a vague feeling that some shorts / bad (or wrong valued/mounted) caps end plenty other components could cause that. Let's hope someone more experienced can point you in the right direction.
But then again... You mentioned your reference 5.333 voltage to be drifting a tiny bit. And now it sounds like you need to touch a trimming pot to push the system back into balance? It *could* be related to some oscillation in the voltage regulators - but this is way out of my league.