A "reliable" source told me that the outputs are unbalanced. I believed this because the output amp and unbalanced line inputs(channels 4 and 6) share the same module. He went on to tell me that the accessory plug-in "transformers" on the rear panel that I have currently are actually jumpers. I guess your red circle is telling me otherwise.
Here's an easy one: What's the purpose of those bridging transformers in the context of the am-10?
Here's another: What's a line termination switch in the context of channels 4 and 6?
I don't think this post is any more clear than my prior one. Sorry!
outputs are balanced. 4 and 6 are line inputs are unbalanced if dummy plug(or call it jumpers, which what it is) are installed (plugged) (which you may have there) or can be balanced with optional input transformers. Which exactly transformers? I have no clue, you need to find part ##, if there's such thing as manual for am-10, I would imagin all the info there. All I could find was these docs.
Balanced or unbalanced (with or without transformer) the line input signal off slider of the channel 4(or 6) "goes" to preamp card (pin #4) where it sums with signal of the channel 3(or 5) after mic preamp/mic gain slider) and then "goes" to the mix amp (A or B, outputs of which are balanced with output transformers inside the "red circle" )
I have no clue about termination switches and terminators.
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