Marinus……Foobar is an excellent music player and has become my favourite way of playing to the Qute. AlbumArt size will not affect playback by Foobar, but may if you use the Qute’s remote to select and play music directly from your NAS. You may need a tag editor if the artwork is embedded in each file to establish/change its file size. If you have a ripping program already you may well have a tag editor. I tend to limit file size to 200K max, many of mine are much smaller than this and work fine.
As for Foobar, you need to setup your preferences under Tools/Server/Streaming Profiles. Here you tell Foobar’s UPnP server how to handle your files for streaming to the Qute. At the top of the page you set the ‘Renderer Capabilities’…..44100…to….96000…….Max bit depth 24
By setting these options Foobar will play your files up to 24/96 as they are, but should you have or get any 24/192kHz files it will automatically downsample them to 24/96 and allow the Qute to play them without any further action from you.
Towards the bottom of the page ‘Decoding to PMC’. If you set this option to ‘always’….and ….’WAV’, Foobar with transcode your files to WAV before sending them to the Qute; from your description of what the Qute screen reads it sounds as though this is already selected. I would suggest you leave it set that way as Naim products are optimised for WAV.
Hope that helps
Peter