So my 404(sx) works perfectly but when i put the sd card in my computer(macbook) and try to upload .wav files directly to it it always says that i cant import the file. This is happening with all my sd cards and all .wav files and i cant seem to find a solution. Any knowledge on how to potentially fix this would be much appreciated.

import problems are a b_tch!! It might be because of the filename, if you have a _ or if it starts by a number. Also, make sure the bitrate is right.

Thanks a lot for the advice, lets just hope one of those things is the problem.

When I have trouble, I open the file in http://audacity.sourceforge.net/, do File->Export and choose "WAV (Microsoft) signed 16 bit PCM".

If you're comfortable at the Terminal, you can check a file's format by running "file myaudio.wav". On my machine, it'll say "RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, stereo 44100 Hz" for files that will work with the SP-404SX.

If I remember right, the sampler will abort if it finds an unsupported WAV halfway into the import process, leaving the remainder in the IMPORT folder on the SD card. The manual talks about this.

That's a damn good idea man. It sucks having to find out what kilobytes per second(kbps) equals to what bitrate!