Bo Deadly
Well-known member
I want to try TPA6120A2. Here's my schematic (click to enlarge):
Some parts are optional. The mono input and volume control is just for making a quick and dirty bench amp. The output inductors are just to see how heavy of a load I can drive without it becoming unstable. I will refine this when I figure out how I'm going to use this exactly.
The problem is this chip is a little too powerful for headphones. It's nice to have that power but it scares me a little to think I am attaching speakers to my ears with an amp that can put out more than 1 watt per channel. Eventually something is going to break and I don't want to loose an ear in the process.
So the question is, is there a simple way to make the output power adjustable or just limit it to a certain level like say 250mW?
I'm using +-15V in my designs but I could regulate down to +-5V. That would significantly limit the damage it could do but I think it could still do damage nevertheless.
What if I put diodes in the feedback path of the op amp (meaning parallel to the 1n cap)? Like back to back zeners or a bidirectional TVS diode like SMBJ5.0CA?
Or would that ruin the wonderful specs of this chip?
Some parts are optional. The mono input and volume control is just for making a quick and dirty bench amp. The output inductors are just to see how heavy of a load I can drive without it becoming unstable. I will refine this when I figure out how I'm going to use this exactly.
The problem is this chip is a little too powerful for headphones. It's nice to have that power but it scares me a little to think I am attaching speakers to my ears with an amp that can put out more than 1 watt per channel. Eventually something is going to break and I don't want to loose an ear in the process.
So the question is, is there a simple way to make the output power adjustable or just limit it to a certain level like say 250mW?
I'm using +-15V in my designs but I could regulate down to +-5V. That would significantly limit the damage it could do but I think it could still do damage nevertheless.
What if I put diodes in the feedback path of the op amp (meaning parallel to the 1n cap)? Like back to back zeners or a bidirectional TVS diode like SMBJ5.0CA?
Or would that ruin the wonderful specs of this chip?