[. . . ] In order to keep superb digital transfer quality by REAC, please make sure to use following optional cables Before using USB memory for the M-400/M-380, please format the memory on the M-400/M-380. [. . . ] This might cause some damage to the data of the USB memory or dificit. We recommend to format USB memory before doing mixing operation on the M-400/M-380. We recommend to use USB memory exclusively for the M-400/M-380 without storing any other files or You might find some noises when you control followings. When multiple REAC products are connected to either REAC A or REAC B on the M-400/M-380 via REAC splitter or switching hub , please set up REAC mode on each product correctly. [. . . ] No part of this publication may be reproduced in any form without the written permission of ROLAND CORPORATION. [. . . ]