I just got the PO-137 (and I love it). I had understood that this was basically the same as the PO-35, but I can't seem to get the build-up effect to work properly. Does FX #12 work differently on the PO-137 than on the PO-35?

Effect 12 is indeed different on the PO-137. It is called "FM Bend". Fun fact: when you transfer data between PO-137 and PO-35 the effect configurations are transferred as well. This means you can get the build-up effect on the PO-137 too if you just download a PO-35 dump. Let me know if you want me to upload one here.

Oh, yeah, I wouldn't mind that if it's no trouble, Magnus! Thank you so much, and thanks also for all your hard work. After being aware of them for many years, I just started buying Pocket Operators a month or two ago, and they're addictive. I bought the Ultimate Punch bundle with PO-12 Rhythm, PO-20 Arcade & PO-33 K.O!, and then I got PO-28 Robot and PO-137 R&M. Going to take a bit of a break now and just work with these five for a bit. Thanks again!

TOTALLY no hurry, but I'm just nudging you in case you've forgotten, Magnus. I'd love a PO-35 dump (one with your own stuff on it would be even better, haha!). Thank you so much.