Preferred file formats
Upload WAV, AIFF or FLAC wherever possible. High-quality lossless files are preferred over MP3 or M4A because compressed audio can already contain distortion and high-frequency artefacts.
Leave sensible headroom
Do not intentionally clip the master. A clean file with modest headroom is easier to assess than a master pushed beyond 0 dBFS. Excessive brick-wall limiting cannot be undone during cutting.
Control low frequencies
Very deep bass uses substantial groove space. Keep sub-bass controlled and centre the lowest frequencies where possible, because wide stereo bass can be difficult to track on vinyl playback systems.
Consider playing time
Longer sides require tighter groove spacing and usually a lower cutting level. Shorter sides allow more space. The calculator provides format limits, but final suitability depends on the programme material.
Sequence files clearly
Upload tracks in the exact order you want them listed. Use clear filenames such as 01 Track Name.wav, 02 Track Name.wav and identify Side A and Side B in the track information and project notes.
Do not add vinyl simulation
Supply the clean master rather than adding artificial crackle, rumble or aggressive vinyl-emulation processing unless those sounds are an intentional part of the production.