The original post :
https://www.diyaudio.com/forums/pass-labs/376445-update-pas-f5-post6797286.html
All credit to him.
Happy reading,
Patrick
.
https://www.diyaudio.com/forums/pass-labs/376445-update-pas-f5-post6797286.html
All credit to him.
Happy reading,
Patrick
.
"Earlier, Lynn Quam posted an alternative feedback circuit for the standard F5 power amplifier [1]
, which
I thought was really clever. But he asserted that all he wanted was to achieve bias stabilisation, so
that he could get rid of the MOSFET source resistors.
"
that is not how I understood him, having some reading of his prior work, and even from these few posts
lhquam is too clever to not know that resistance in source is what is working in temperature/bias stabilisation domain
he's also too clever to not know difference of resistances in source vs. drain
kudos to him, agree, to investigate that
though, here it is even in Aleph, MF A1, and few more amps of Yore
, which
I thought was really clever. But he asserted that all he wanted was to achieve bias stabilisation, so
that he could get rid of the MOSFET source resistors.
"
that is not how I understood him, having some reading of his prior work, and even from these few posts
lhquam is too clever to not know that resistance in source is what is working in temperature/bias stabilisation domain
he's also too clever to not know difference of resistances in source vs. drain
kudos to him, agree, to investigate that
though, here it is even in Aleph, MF A1, and few more amps of Yore
So did he mentioned earlier anything about AC performance, in particular even harmonics ?
Cheers,
Patrick
Cheers,
Patrick
....... on the other hand, he was maybe chasing one thing, while finding another one ..........
not happening for first time, for sure
though, I'm especially successful in chasing, without clever results ........
not happening for first time, for sure
though, I'm especially successful in chasing, without clever results ........
I am not so good at reading someone else's mind, especially someone I do not know, thousands of mile away.
Nice evening,
Patrick
Nice evening,
Patrick
Someone asked about the voltage across R9,10.
This is a plot of 1W 1kHz into 8R.
As you can see the voltage is largely constant (good match between push and pull).
But some 1kHz fundamental is still visible (push-pull not 100% perfect).
And 2nd harmonics is clearly visible, as also confirmed by the FFT.
Patrick
.
This is a plot of 1W 1kHz into 8R.
As you can see the voltage is largely constant (good match between push and pull).
But some 1kHz fundamental is still visible (push-pull not 100% perfect).
And 2nd harmonics is clearly visible, as also confirmed by the FFT.
Patrick
.
