I bought used kb37 to record guitar, bass and vocal. I use macbook pro 2012 mid and OS version is 10.9.1(Mavericks), Garageband version is v10. But I have not record anything yet because of popup noise when I connect guitar via toneport kb37 on garageband. I installed latest software like monkeys, gearbox and pod farm2 and I changed audio input/output setup to toneport kb37. I can hear guitar sound on garageband but also can hear pop up noise to play and record. I'd like to solve this problem.