Does the ASIO Buffer Size affect the tone?

Buffer size *can* have an effect on the tone if the plugin is coded badly. IE: If they're not accounting for variable buffer sizes, you can end up with extra aliasing, ring-modulation, frequency modulation, and bit crushing. It really depends on the architecture of the plugin, but I'd say nearly all the time if a plugin does this, it isn't working properly.
 
Exactly.
Especially there can be potential problem when buffer size is not the power of 2 (i.e. not 64, 128, 256, etc) if FFT is needed, but proper coding can remove this problem.
 
So xTomx, to add something else. There are other guys who think like me that there will be a sound difference in some badly coded drivers. I've experienced that once with ASIO4ALL drivers but never again with Focusrite own drivers.
 
You guys are talking about something faulty, if everything is working properly then there should be no difference at all.
 
Would be interesting to do a null test then to see exactly where the differences are.
Can you name 1 plugin that behaves like that ?

You guys are talking about something faulty, if everything is working properly then there should be no difference at all.

As I said:

Buffer size *can* have an effect on the tone if the plugin is coded badly