- There are three main areas of balanced amplifiers and not all are incorporated in products. In fact, most products don't employ all three.
- Balanced input
- Balanced amplifier
- Balanced output
- Balanced inputs are common, usually connected to single ended amplifier topologies
- Balanced outputs are common, usually tacked on to single ended designs
- The big advantage of a balanced input is common mode rejection, where noise signals are squashed
- The big advantage of a fully balanced amplifier topology are many, including lower noise and distortion
Wrapping it up
We'll wrap up our series on balanced audio today. I think it's run its course and then some!
The last balanced piece I want to touch upon is the phono cartridge. Phono cartridges are all balanced. This is because a phono cartridge is a coil of wire with two ends—naturally balanced audio comes out. Unfortunately it's mostly connected as if it were a single ended device. What a great tragedy!
I have never really figured out why phono cartridges and their amplification devices are mostly single ended inputs. We are as guilty as the next manufacturer. Until recently, just about every phono stage we designed connected one side of the balanced output to ground. Our latest, the NPC is a balanced input. But that's rare.
So, what have we learned during this series?
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