Some prototype THD curves at 50W in 8 ohms (except the red one). Red = EC element, yellow and blue are the front end and output stage.
Remember, this is with NO global feedback, and an OL gain that essentially is equal to the CL gain (about 21 times).
Seems that the limiting factor is the EC element, so there's where the money is to be made.
Jan Didden
Remember, this is with NO global feedback, and an OL gain that essentially is equal to the CL gain (about 21 times).
Seems that the limiting factor is the EC element, so there's where the money is to be made.
Jan Didden
Cordell paper: error correction
Hello all,
I am comming into this tread a bit late, and found that the web urls posted earlier (posts #5, #12 by Mandat), for the paper by Cordell showing error correction, no longer exists.
But Mr Cordell has kindly put this on his own website here:
http://www.cordellaudio.com/poweramp/mosfet.shtml
Hello all,
I am comming into this tread a bit late, and found that the web urls posted earlier (posts #5, #12 by Mandat), for the paper by Cordell showing error correction, no longer exists.
But Mr Cordell has kindly put this on his own website here:
http://www.cordellaudio.com/poweramp/mosfet.shtml
Loading the Vas with resistance to ground is a perfectly good technique, used in the Aleph 0, 0s, and 1.0. Yes, it increased the distortion figure slightly by anchoring down the load impedance that the VAS saw, and thus limiting the open loop gain figure, but I liked what I heard, which was more spectral consistency and less variation with load impedance.
It's not always appropriate, but I always at least try it to see.
Hello
Loading the VAS with a resistor (20 k to 50 k) to ground, are good because it's made it more load tolerant and others reasons, but I think it also because that by reducing the OLG it's also reduce the memory distortion in the vas transistor, because that the memory distortion in the VAS are partially link to the OLG.
What do you think of that ?
Thank
Bye
Gaetan
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