Bowser, going through your notes here, I wasn't sure what you mean with the term "root frequency", and "high frequency". I want to make sure I understand exactly what you said before I perform some experiments. That way, I can confirm your readings, as well as extend the scope of data collection.BowserB61 wrote: ↑Sun Sep 20, 2020 10:05 amI thought it was very interesting how the 921 had very pronounced drift on the root frequency during warmup, but rock steady high frequency response, while the 921Bs had the opposite; very steady root frequency, but dramatically changing high frequency. So the 921 has solid scaling and easily compensated drift in tuning with temperature, whereas the 921B has sold tuning, but the scaling drifts with temperature in a way that can’t be compensated with the front panel controls. As many have already found, this makes the 921 the better choice for perfectly accurate playing.
I noted that my 921B went about 23 cents sharp over the course of the early morning. I haven't changed any trimmers yet, so I can take factory measurements to for writing up any quick-start procedures.