True, but an ON MOSFET is just a low value resistance so I see no reason is should add any significant distortion.The datasheet of the opto-mosfets switch does not mention distortion or polarity of the signal. It also does not mention any audio application.
MOSFETs conduct equally well in the forward and reverse direction when biased on (they look like an Ohmic, non-polar resistance), so I wouldn't expect that to be a problem.Doesn't the polarity of the drain and source of the N-channel Mosfets affect their on-resistance? Don't they cause crossover distortion as one Mosfet turns on then the second Mosfet turns on as the polarity across them switches?
You are correct. I had it backwards.n the AC application of the IC, the Mosfets are in series, source to source.
Beats me, but it's probably because not many people need to switch speaker connections with relays, so it's not a big market.Then why doesn't the manufacturer mention that the opto Mosfets make a perfect audio switch?
Probably because they don't?, adding extra semiconductors in the audio path (and outside the feedback loop) can only decrease quality.Then why doesn't the manufacturer mention that the opto Mosfets make a perfect audio switch?
Yes, I would be interested in seeing that.Be interesting to see what effect it actually has?
No. Are you not familiar with the fact the MOSFETS conduct equally well in both directions when ON?If the MOSFET's are in series, then they are relying on the internal diode across the opposite MOSFET to conduct the signal, so it's like putting two parallel diodes in series with your speaker.
That seems to be a rather archaic and condescending view.I've no interest in the 'guesses' that simulators provide
So like a linear resistor?The datasheet for the opto Mosfets shows a perfectly linear low voltage drop at the output when the load current increases. Then the distortion might be "only" 0.5% like an old vacuum tubes geetar amplifier at low output power.
Not sure what you are seeing.I can see that your simulation sinewave has distortion at about +3.3V and -3.7V, something like crossover distortion. I cannot see distortion when it is less than about 1% so yours is pretty bad, maybe 1 or 2%. I can hear when distortion is 0.2% or more.
i've had much the same experience. i wish there had been such tools available in the 1960s through the 1980s, might have saved me a lot of burned components (and burned fingertips)...That seems to be a rather archaic and condescending view.
Simulators don't provide "guesses", they provide a simulation of the circuit operation based upon the models used.
I've use SPICE simulators for over 30 years to help me design circuits, and they've often spotted errors in my design before I built them.
The built circuits almost always operated very close to what the simulator predicted.
They've also help me trouble-shoot circuits already built which where not operating as intended.
I would never build a circuit without simulating it first.