Impact of HDMI switching in amps

[admin_exported]

Magazines such as What Hi Fi have always reviewed cables and made clear the impact that they can have on the overall system performance. If cables can have a significant impact on audio and video performance, why is no mention ever made of the impact of switching audio and video within an AV amp? When I use my amp to switch multiple HDMI inputs does the amp have no impact at all? If it does have an impact does this vary from amp model to model? If it does vary why does it not form a part of product reviews?

I may be missing an important point but I can't help feeling that if the type of wire can make such a big difference so must feeding the signal through a big black box of electronics..........

 

[d4v3pum4]

Usually any problems manifest themselves as EDID/HDCP issues and the amp will simply not pass a certain resolution e.g. 1080p/24fps or be incompatible with a certain piece of kit and this is usually only discovered once the amps/switching devices hit the streets and get installed at the user end. HDMI has been a nightmare since the start but most amps seem to pass the video unscathed to the TV.

However, the Yamaha DSP-AX763/863SE, RX-V1800/RX-V3800/Z11 suffered from 'RGB clipping' whereby the full signal wasn't passed resulting in BTB (below 16) and WTW (above 235) clipping/crushing. This isn't mentioned in the reviews AFAIK. Yamaha corrected it via fimware for the RX-V1800 and above models but left 763/863 owners to put up with it, although it's only 'seen' if you calibrate your display by all accounts.