Arcam has given more insight into its new high-end DiVA AVR350 home cinema receiver (pictured above, along with the brand’s DV137 DVD player), and specifically the unit’s lack of an internal scaler.
Brand manager Geoff Meads explains: “Firstly we should define the purpose of a scaler in a home entertainment system: The purpose of a scaler is to match the resolution of a video source (PAL, NTSC etc.) to the number of pixels in a digital display device (768×1024 for example). Because screen construction varies widely, each has its own scaler to fill the screen from any given input resolution. The resulting picture quality will be dependant on the quality of the scaler fitted to the display.”
“Cheap displays tend to use poor scalers and high performance displays use better ones,” he adds, “There are clearly obvious advantages to putting a scaler in a receiver. All sources can be scaled by the same device and be seamlessly switched. However, this is only an advantage if the scaler in the receiver is of good enough quality and the screen can accept the scaled signal in exactly the format of its construction.
“This way the scaler in the display may be by-passed completely and the user can get the full benefit of the superior scaler inside the receiver. Sadly, it is often the case that the screen itself will not accept the right resolution.
“For example, the majority of 768 horizontal line plasmas and projectors will not accept a 768 line signal over the HDMI input. Even those that do, rarely accept the right horizontal resolution. Often the result of scaled images into digital display devices is two sets of scaling, once in a source (e.g. a DVD player to say 720p) then again in the display (720p to 768p…).
“Since all scalers are basically guessing what the extra lines would have contained, scaling twice thus is guess work based on guess work, which is clearly not ideal. With this in mind we currently leave it to the display to scale up regular sources and only offer scaling in our DV137 DVD player, which is the best quality source. Once display construction stabilizes on a standard (1080 is possible in the next few years) things may look different.”