The EuroLine 6620 and the United 3151 are exactly the same player. Both these players can play the following formats:
They seem to be available in two versions, one that can play VCD/SVCD and one that can't. If the words VCD and SVCD appears on the box or above the DVD tray, it can play those formats. However, if the box and the text above the DVD tray does not mention VCD and SVCD, it may still play VCD/SVCD discs. There is no way of knowing if it does except to try it out with VCD/SVCD discs!
Here is a table summarizing which players that has actually been seen so we know that they exists:
| Cannot play VCD/SVCD | Can play VCD/SVCD | |
|---|---|---|
| EuroLine 6620, no VCD/SVCD marking | Exists | |
| EuroLine 6620, VCD/SVCD marking | - | Exists |
| United 3151, no VCD/SVCD marking | Exists | Exists |
| United 3151, VCD/SVCD marking | - | Exists |
If you own one of the players that is not verified to exist yet, please drop me a line and I'll update the table above. I have not yet heard of a player that is marked with VCD/SVCD, but cannot play VCD/SVCD. I doubt that such players exists so I have marked them with a "-" above.
The 6620/3151 has no built-in DolbyDigital decoder, and no built-in DTS decoder. So the only way of getting DD/DTS sound from this player is to connect it via the digital out connection (optical or coaxial) to an external DD/DTS-decoder.
The 6620 I have is also able to downmix DD to 2 channel stereo that can be listened to via the analog audio outputs on the back of the player. However, it cannot downmix DTS to 2 channel stereo!
If you want this player with built-in DolbyDigital decoder, the EuroLine 6650 and United 3155 are the way to go. The 6650/3155 are very similair to the 6620, but with a built-in DolbyDigital decoder. However, the 6620/3151 and the 6650/3155 have slightly different Video Processor chips, and I don't know which one that produces the best image quality.