Hi, Martin, It seems there are at least two ways to make large WAV files, and possibly three. (1) In the early 2000s, there was a format that Samplitude would use that made a WAV file and when that was full (2 GB, I believe), it made a W01 and then a W02 file, etc. These could be seamlessly used, but if one got lost... (2) According to a very thorough article at https://en.wikipedia.org/wiki/WAV the W64 format was created by Sound Forge (now Sony) with a 64 bit header. I don't know how widely that has been adapted. (3) since about 2010, programs have been adopting the RF64 and at least Samplitude would seamlessly transition from the WAV format to the RF64 format when needed. That created a few compatibility issues, but those seem to have vanished. Here is the Wikipedia article on RF64. Not as good as the WAV one, but it will give you the idea. https://en.wikipedia.org/wiki/RF64 The comment about the Fireface UFX neading FAT32 formatted USB sticks to record to (I found an SD card in a stick card reader to work more reliably) is valid for the Fireface UFX. The early (2017) manual for the UFXII confirms this as well and says there is a file size limit of 2 GB for the file on the USB drive. This is an artifact of the parallel recording system that is included in the interface while the signals fed to the computer do not have this limitation, but are rather limited by the DAW used to record the signals. The RME Digicheck program has a bare bones recorder function. The USB port records single files with as many channels as necessary while the Digicheck program can split files at save time, but the raw record is a multi-channel WAV file. I hope this helps. Cheers, Richard On 2020-12-09 5:06 p.m., Martin Fisher wrote: > !?!?!?!? > > Gary, you've given me something to think about and research. I thought it was a quirk in the OS. I'll have to check my drive formatting!! I do know that our server can handle files up to 4G and I can save .w64 files over 2G. The problem with .w64 is that apparently they are proprietary to Sony. > -- Richard L. Hess email: [log in to unmask] Aurora, Ontario, Canada 647 479 2800 http://www.richardhess.com/tape/contact.htm Track Format - Speed - Equalization - Azimuth - Noise Reduction Quality tape transfers -- even from hard-to-play tapes.