now i need to buy the capacitors since there is no way im putting shitcons(crappy capacitors such us chengx sinecon and so on) near my headphones.
Here is one model
IRF540/9540 are excellent MOSFETS
Code:
.model IRF540 NMOS(Level=3 Gamma=0 Delta=0 Eta=0 Theta=0 Kappa=0.2 Vmax=0 Xj=0
+ Tox=100n Uo=600 Phi=.6 Rs=21.34m Kp=20.71u W=.94 L=2u Vto=3.136
+ Rd=22.52m Rds=444.4K Cbd=2.408n Pb=.8 Mj=.5 Fc=.5 Cgso=1.153n
+ Cgdo=445.7p Rg=5.557 Is=2.859p N=1 Tt=142n)Quick comment on that circuit I posted earlier. Once you bias the thing up to some useful operating point, the MOSFET will have a gate voltage of (guessing) 1-2 volts. That means the opamp is also running at 1-2 volts output. Thus, at low levels like headphones are typically at, the signal doesn't cross zero. If there's even the slightest issue around zero, it won't be seen until the signal is large enough for it not to matter. I suspect this is a key as to why it sounds so good.
i already have a phisical prototype so it may be only useful for measurments. im also intrested in lowering the source resistor to around 1.5ohms.
gave it my first(mono) headphone listen with an 22uF input cap. the main issue is noise caused by the power supply and other issues like grounding, heatsinking,an probably fake fet and the input device. it sounds really well and the bass extends very far with no issues in the treble/mids region.
i think im gonna mount an lm340/lm7815 voltage regulator onto the same board as the amplifiers(one per channel).
i finished incorporating the voltagr regulator, now all i need to do is buy another 22ohm resistor.
yes i will but not now since i dont want to waste thermal grease before finishing everything. i also realised how noisy my pc's output is. i need to buy myself a dac to combine with it.
update mounted them using these little silicon pads. also the amplifier is dead silent after adding the regulator and sounds amazing.
It will be pretty limited in output power driving a speaker but it will drive headphones louder than you could ever need.