Well, I had some time this evening so I popped the cover off the Omni VI+ and pulled that plug 52. With and without headphones I sent a few 'test de KD2E V V V" At about 22 to 25 wpm, I could not detect any difference. Perhaps the improvement happens at higher speeds, but I had no reason to test that. I left #52 plugged in! Just my findings! ...Dave