Please, read the following instructions carefully. Before sending audio material, make sure it meets all the technical requirements. The audio we receive goes into the production queue and only when its turn comes, it is checked by our technical department, so you might be notified about any incompatibility with the required criteria even several days after placing an order.


Approved file formats for cassette:
We approve .wav files of at least 44.1 KHz sampling frequencies and 16-bit depth.

All masters should be supplied with single files for each side (two files per single double-sided cassette) along with the MD5 checksum file. If the delivered master is divided into individual tracks, the engineering studio will have to prepare the new single-side files by merging single files for an additional fee (25 €). In this case send us a tracklist document (AVAILABLE HERE). All tracks should be put in the correct sequence (named alphabetically per side and in a right sequence e.g. A_01 A_02 B_01 B_02) and separated with proper pauses between them, so in result all tracks are mounted together, there is suitable pause(s) between them.

The maximum lenght of one side is 45 minutes and must not be exceeded. It is required that side A duration should be a bit longer than side B, otherwise we won’t be able to duplicate the material. If side A is shorter, you have to add the necessary amount of silence to match the side B. If you’re unable to do it, the engineering studio is able to do it for you for an additional fee (15 €).

Before the master is supplied, the customer is obliged to check its sound, potential errors, track sequence and completion.

Audio masters can be supplied:
– on an external carrier such as CD/DVD, pendrive, HDD, SD card,
– electronically – Wetransfer, DropBox etc.; when sending the audio material this way, it must be compressed (e.g. as a ZIP file). Files should have a MD5 checksum attached, otherwise, if any problems with the end product arise, it may not be possible to file a complaint.

MD5 checksum is one of the most effective ways to verify the integrity of digital data. It allows you to make sure that the file has been correctly transferred from one computer to another. There are many programs for both Mac and PC that can generate a MD5 checksum file, some are free, some require a license, e.g. MD5summer, Sophos, PowerShell, Hash Generator, MD5 & SHA Checksum Utility and others.

If the Customer notices errors that may have been introduced during the transfer of digital files, but did not attach a MD5 checksum to them, any claims in this respect will not be considered.


The MC production has a tolerance of -/+ 5%, ie. you may receive slightly more or slightly less discs (but no more than 5% of the overall quantity).