Silent, I used it initially to connect 2 scratch on my amp to switch from one to another, I have not tried the 2 together.
I'm using today to spend the normal channel on my AC30 top boost, or even 2 at the same time does not differ from chaining switch on the amp.
I have no problem as some poc.
-2 For the price because it really is not given. Off given the simplicity of the machine is a bit abused. But the quality is there. I do it again this election but certainly used after trying it here because it is affordable and definitely better than the new products at 45 €.