I'm analysing a particular schematic, an audio compressor: https://www.soundskulptor.com/en/proddetail.php?prod=LA502
The schematic is here: https://www.soundskulptor.com/docs/la502-schematic-03.pdf
My goal is not a specific issue with a product (I'd just ask the creator), but rather finding out how it works and learning in the process of doing so. Because it wouldn't make sense to just ask about explanation in one go, I decided to analyse it on my own and just try to ask specific questions whenever I feel blocked.
My first question is on the stage where input signal (line level, balanced) is transformed to the unbalanced one:
What I understand of it:
IN+ and IN- are the voltages carried by the input. They're essentially the same signal (sans noise) with opposite phases. That's just what balanced input is.
The transformer T1 is used to go from balanced to unbalanced. Because the left coil is connected to both sources, this means the changes of the voltage across it are twice as big as the original signal (either IN+ or IN-) so the output of the transformer is double the voltage of the input (and here is where noise-cancellation happens).
- What is the role of the capacitors C1, C2 and C5?
- What is the difference of the ground connected to C5 and the "empty" (unlabelled) triangle under right coil? If that's just some schematic peculiarity and not general knowledge then it's fine, I might reach author, but I think this has to do something with the fact the transformer isolates those grounds, so they're not common.
- What's the role of the R1 and R2 resistors? I'm only intereste in the "output" of the transformer stage, so the unbalanced signal - would that be a signal denoted by the voltage across R1 ? And then R2 would be just part of the further stages which are not the part of this question?
Hope this is fine to ask questions in such manner here!