12 Volt MOSFET SE Class A Hi-Fi HeadPhone Amp

[lineup]

Good hifi

Intended for High Fidelity 32 Ohms Headphones.

- 12 Volt DC, preferably regulated 78M12 or LM317
- 2N3819 JFET high impedance input
- ZVP3306A, TO-92 PMOS, VAS Voltage amp stage
- IRF610 Single End 125 mA Class A output
- Internal Bandwidth is 8 MHz ( Closed Loop without RF input filter )
- Gain +10 dB ( x3.1 )
- Distortion in 32 Ohm/1 mW is below -100 dB, 0.001%

I attach my simplified concept diagram.
If anyone wants, I post my full, tweaked and optimized working simulated tested circuit.

Lineup Audio

 

[lineup]

hi

If you use for example Grado Hi-Fi Headphones 32 Ohm
http://www.gradolabs.com/
you have a specification: Sensitivity, SPL at 1 mWatt = XX dB
This means, at 1 mW you will have Sound Pressure Level of XX dB in your ears.

Say we have headphones with SPL = 98 dB / 1 mW
At 10 mWatt we will have another +10 dB
Which in this case give a sound pressure of 108 dB ... !!!
... dangerous, yes .. I have tinitus .. a damage caused by headphones
... be very careful, my friends

I attach the very nice Fourier spectrum of this Class A MOSFET amplifier.
In fact the harmonics are like this at any output level .. until overdriven/clipping.

FFT at 10 milliWatt, +10 dB

 

[Salas]

If anyone wants, I post my full, tweaked and optimized working simulated tested circuit.

Lineup Audio

Very nice! Give us the full thing! We like.

 

[d to the g]

2nd.

motion passes, gives us the precious schematic.