Loading Sysex files:
The sysex files are raw dumps from the synths. Most will load them back without having you to set any parameter.
Some must be in a special “sysex mode” to work. An example is the MKS-80. Consult your manual for details.

Loading wave files:
These are just recorded from the tape outputs of the instruments, you load them back just as if they were coming from a real cassette player.
Loading presets from “cassette” can be more or less tricky. Some synths have a reliable interface (Korg Polysix) and some are very bad… (Roland JP-6).
If you’re having problems, try different volumes. Most synths prefer a non-distorted, high level signal.
It might help to run it through your mixer and adjust the level there. Try using a headphone output, some synths need a pretty hot signal (OB-8).

All banks on this page have been loaded previously with success.
One way of verifying your setup is to sample a dump from your instrument and load it back again.
If this works the the patches found here should also work as long as you use the same volume during playback.

Saving wave files:
If you already have a patchfile on an audio cassette, load it to the synth first and then sample directly from the synth’s cassette output. Sampling directly from the cassette will add a “generation” and reduce quality.
Some synths have a very weak cassette output and it might be necessary to run the signal through your mixer to get an acceptable S/N ratio. Maximize volume in your wave editor.
Most synths will be happy with an 11k 8 bit file. If you want to reduce the filesize, trim off unnecessary header/trailer signals. For most synths only a second or so header is sufficient.
However, certain models requires the load button to be pressed after the tape interface has received the header, and it’s then necessary to make it a bit longer.

Compressed formats like MP3 are not recommended.