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VSSA Lateral MosFet Amplifier

:)
 

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I said it is not something new, just SSA/TSSA derivative. :)

Well for those folks who like to simulate here's my contribution so far to the Lazy Cat VSSA, a file to play with.... :D
 

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Nice, second harmonic almost -100dB down. :cool:

yes, it looks very nice !

The Simplified thread started off with something simple like this and then wandered off to something not at all simple. Let's keep this one simple :D

for temp stability the drain current through laterals must be above some threshold, I think it's 100mA, depending on which FET.
 
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yes, it looks very nice !

The Simplified thread started off with something simple like this and then wandered off to something not at all simple. Let's keep this one simple :D

for temp stability the drain current through laterals must be above some threshold, I think it's 100mA, depending on which FET.

OK deal, I won't mess with more parts on this one (values optimization only) I promise hehe, although it can be rocketed to complex version in any time :D

Yes, normally Id should be 100 mA or more, sweetspotted too I suppose.
 
VSSA - Very Simple Symmetrical Amplifier, something in between SSA and TSSA. Similar schematics posted a lot of times but not exactly the same. :)

With only six transistors you can get genuine current feedback, high bandwidth amplifier, capable of driving 4 ohm speakers. PCB can be very simple and small too. ;)
I setup the circuit from your diagram.
The DC-offset is very small, 12 mV.

The first thing I noticed is that circuit needs some compensation to be stable.
This was fixed with one 22pF from base to collector of KSA1381 and likewise 22pF around KSC3503.

The THD distortion at 1 Watt is remarkably low for such a simple amplifier:
THD 0.0002% at 1 Watt RMS.

Very nice amplifier :)