I tried the 4, but wasn't much of an improvement, to me. I like the 3X OS better too. I felt it didn't sound as rich, but that's my ears! I am looking forward to their next board. The EA-7 looks interesting. I'd like to give that a try.
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Yamaha 920 / Yamaha DGX-670 / Maui 5 Go (2) / Senn e935 / Sony C80 / Tascam DP24sd / ATEM Mini Pro switcher (studio)