I have had the most success by following these steps:

1.) CLOAD the program into the MC10 then CSAVE it directly to the PC (with the shortest possible leads), using your favourite audio capture program saving as WAV file. 44.1KHz 8Bit Mono

2.) CLOAD saved file into the
emulator (don't worry about editing the WAV file)

3.) CSAVE the program

4.) Use the
C10TOWAV conversion tool to convert the C10 file to a WAV file

For machine language programs use this method:

1) Use
BACKUP or
ID.CSAVE and CSAVE directly to the PC

2) Use the BACKUP program loaded into the emulator following step 4 of the BASIC conversion
The saved program in WAV format can be downloaded to a real MC-10 by plugging your audio input lead into the speaker output of the pc's sound card
If you are experiencing difficulties try these ideas:

1) Ensure cables are as short as possible between cassette player and PC, roll up excessive leads to prevent unwanted noise from being picked up

2) Change the cassette players power source to another socket (so that it is on a different outlet to that of the PC)