So, in my years studying amplifiers and preamplifier (still learning ) I've only seen single ended preamplifiers if you might believe it; but lately I've dived a little bit into class d amplifiers, and i'm beginning to notice that many class d amplifiers if not all, have differential inputs, how do i build a filtered preamplifier for these differential inputs? :/
It is only the front end that is balanced, after the first op amp the signal is then unbalanced. +ve signal goes to +ve input and -ve signal to inverting input. The reason for balanced signal leads is to help with noise pickup with leads.
What do you mean by only the front end might i ask?
Oh, so these balanced inputs serve to eliminate noise from ground currents?
Its not essential to have differential output to feed a differential input. Balanced ins do work OK when fed unbalanced outs. Yes having a balanced input can help rejection noise currents in grounds, unbalanced ins are particularly susceptible to that.
Thank you
Have you read Jensen's app note 003?
http://www.jensen-transformers.com/an/an003.pdf
section2.4 shows a cheap mod to allow every unbalanced Source to properly drive a balanced input and get the full benefit of the interference rejection of a balanced impedance connection.
If you are really interested in balanced connections then read the whole site:
http://www.jensen-transformers.com/apps_wp.html
and read all the balanced papers/articles of D.Self, Rane, Cordell, ESP, Pass
http://www.jensen-transformers.com/an/an003.pdf
section2.4 shows a cheap mod to allow every unbalanced Source to properly drive a balanced input and get the full benefit of the interference rejection of a balanced impedance connection.
If you are really interested in balanced connections then read the whole site:
http://www.jensen-transformers.com/apps_wp.html
and read all the balanced papers/articles of D.Self, Rane, Cordell, ESP, Pass
Take a look at the OPA1632 datasheet -- all you need to know.
uhh.. i may be naive but i can't seem to find it :/
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