Hi People!
I'm thinking about building a headamp for IEMs. I want to protect them from being fried by DC in case something breaks. I think that MOSFET based solutions have advantage, so I'm here to see what do you think.
First questions is as follows. Is it better to use MOSFET with floating driver rather than drive them from eg opamp out? Using dual DC precision opamps would be super easy. Photovoltaic drivers are expensive and harder to get. Currents in headphone circuit will be real small, so I guess no need to go for a strong driver? I'm looking at PVI1050N in dual mode.
What kind of MOSFET should we use? I guess RDS(on) together with VGS are important here. IRF7301 is a dual, logic level (driven by 5V to max conductance), so it looks perfect. (it's kinda big though (SO8). Add opamp and filter and it is a quite a big circuit.
IEM headphones depend on very low noise and they work on very low voltages so anything else we should look at?
I'm thinking about building a headamp for IEMs. I want to protect them from being fried by DC in case something breaks. I think that MOSFET based solutions have advantage, so I'm here to see what do you think.
First questions is as follows. Is it better to use MOSFET with floating driver rather than drive them from eg opamp out? Using dual DC precision opamps would be super easy. Photovoltaic drivers are expensive and harder to get. Currents in headphone circuit will be real small, so I guess no need to go for a strong driver? I'm looking at PVI1050N in dual mode.
What kind of MOSFET should we use? I guess RDS(on) together with VGS are important here. IRF7301 is a dual, logic level (driven by 5V to max conductance), so it looks perfect. (it's kinda big though (SO8). Add opamp and filter and it is a quite a big circuit.
IEM headphones depend on very low noise and they work on very low voltages so anything else we should look at?
The easiest way to get it done is to get a usb dac donggle that can achieve low noise and able to drive 32 ohm.
Apple dongle should fit in nicely.
Any amp after the DAC will increase it's noise and not reduce it.
For another low noise amp solution is going composite amp. Nope, I'm not familiar with discrete. 😛
Apple dongle should fit in nicely.
Any amp after the DAC will increase it's noise and not reduce it.
For another low noise amp solution is going composite amp. Nope, I'm not familiar with discrete. 😛
I have a FiiO M11 PLUS II, so no dongle is needed really. It's for my desktop setup, including DAC and an AMP. Actually some IEMs are kind of difficult to drive. Campfire Audio Mammoth is 8 Ohm power-hungry monster. Shuoer S12 is a planar IEM and it plays good only with a powerful amplifier despite being smartphone friendly on paper.
Since some of IEMs can cost hundreds if not thousands of $ I'd like to have a good protection circuit 😛
Since some of IEMs can cost hundreds if not thousands of $ I'd like to have a good protection circuit 😛
