Many Brown Software titles are over 30 years old, and the original storage media was audio tape. Unfortunately these audio tapes become less reliable over time, and the hardware to play them is now all but obsolete.

Later Brown Software titles used 3-inch floppy disks, which are also now an obsolete format.

In order to preserve these titles, they need to be converted to an electronic format, and the process used is detailed below.

Software on disk is loaded into a Spectrum +3. The software is saved from the Spectrum onto a blank C20 tape. If the software already exists on tape, the Spectrum is not required.
The tape is played into a laptop, running Sony Vegas SoundForge, and the audio captured.
The audio is recorded as a mono track at the highest quality available.
The volume on the tape deck is adjusted to ensure maximum volume without distorting.
The recorder WAV file is loaded into MakeTZX for interpretation and conversion to a TZX file.
MakeTZX hopefully manages to decipher the WAV file. If not, try again with different volume settings or attempt to clean the audio in SoundForge.
Load the TZX file into WinZ80, by starting the emulator and setting the emulated machine to load.
Once Z80 has successfully loaded the TZX file, you can save the state of the emulated spectrum as a .z80 file. Various emulators will load this and can be used to convert it to other formats, e.g. sna snapshots( (if required).