I know tuning can be a bit of a bear on these, but actually I've got it to a really good place overall - tuning is solid on both oscs and stays rock solid in tune all day all the way up the keyboard except one spot!
The problem is just one key - the first, low F.
It's a tiny bit sharp compared to all the other keys. And then if I add glide - the low F goes quite a bit sharper.. the more I increase the glide, the more sharp the low F goes. But it doesn't seem to affect the other keys at all. Even with full on glide, all the keys eventually reach the correct pitch.. just not that low F.
This happens equally on both oscs.
I checked the 100ohm resistor on the F key on the keyboard itself, it reads exactly 100ohms. And all the other resistors do also.
I checked the keyboard scale: I get 0v for low F, 1.00v for F2, and 2.02V for F3.
Anyone heard of anything like this before? any help is much appreciated. thank you!!