This amplifier has rather low distortion and is very fast.
All symmetric with JFET input and MOSFET output.
The supply is +/-12V because LSJ74 can only take 25V.
So max output is ~4.5 Watt which should be enough for most speakers.
All symmetric with JFET input and MOSFET output.
The supply is +/-12V because LSJ74 can only take 25V.
So max output is ~4.5 Watt which should be enough for most speakers.
This is the cascoded version.
Has +/-20V supply.
Max output is now 15 Watt in 8 Ohm.
Distortion THD 0.0008% 1kHz 1W.
Has +/-20V supply.
Max output is now 15 Watt in 8 Ohm.
Distortion THD 0.0008% 1kHz 1W.
How about retaining the original non-cascoded and explore a differential version. Kinda of like a simplified version of the AMB Beta 24 using laterals. That might be a fun design if if can be make to work. You'd probably need to add a common mode feedback circuits to stabilize the DC operating point. Even on 12V rails, it should be able to put out 25W. And with the low rails voltage you could probably run it in Class A with adequate heatsinking.
Maybe something like this? It's a rough idea. Power Supply bypass caps not shown. I'm not very familiar with Common-Mode Feedback circuits... what's shown is essentially a simplified version of the AMB B24 circuit. Also, I'm don't know how to test for stability in differential circuits. The compensation is just a guess, and no thermal stability analysis has been done. 1KHz / 1W distortion is similar to your design. I choose 16V rails as these are available from a readily available 12V transformers.
Check a usual common emitter amplifier from the 60:s or 70:s.
It was usual the time we had 2 transformers in our transistor amplifiers.
It was usual the time we had 2 transformers in our transistor amplifiers.