Krill - The Next Generation

[Steve Dunlap]

Originally Posted by scott wurcer

I have hate mail now so I turn this over to andy_c who I trust totally to be objective.

That is unfortunate. I welcome your input here. I do think Andy will be totally objective. We are getting different results and are trying to establish why. I don't feel like I am being picked on by either you or Andy.

[andy_c]

Okay, I'll have a look at this latest one and see how it goes.

[Steve Dunlap]

Guess what? I forgot to attach the file.

[scott wurcer]

Originally Posted by Steve Dunlap

That is unfortunate. I welcome your input here. I do think Andy will be totally objective. We are getting different results and are trying to establish why. I don't feel like I am being picked on by either you or Andy.

No worries, I'm leaving tomorrow for a while anyway. I would like to see some convergence of results too.

[Steve Dunlap]

Originally Posted by scott wurcer

No worries, I'm leaving tomorrow for a while anyway. I would like to see some convergence of results too.

I am trying to be cooperative this time around. I very much want to know where the discrepancies occur. I am open to the possibility (some here would say certainty) that I am wrong about this. If that turns out to be the case, then it has been a learning experience for me. Is it possible that my simulation package could be that incorrect even at DC? If that is the case, then this will be great advertising for Intusoft.

[scott wurcer]

Originally Posted by Steve Dunlap

I am trying to be cooperative this time around. I very much want to know where the discrepancies occur. I am open to the possibility (some here would say certainty) that I am wrong about this. If that turns out to be the case, then it has been a learning experience for me. Is it possible that my simulation package could be that incorrect even at DC? If that is the case, then this will be great advertising for Intusoft.

It's more likely that no one is "wrong" and there is some out of bounds quirk handled in two different ways. That is where real human intervention is needed.

[Steve Dunlap]

Here is the output stage only. I simply deleted the VGS. Some of the node numbers were changed by the program when I did this. I have always used a higher voltage regulated supply on everything but the drivers and outputs, so I have left the 40V supplies in. If you choose to use only the 34V supplies, you will need to add the connections so the front of the OPS gets voltage. This will change the measurements I posted earlier, but not much. The DC on the input is to adjust the output offset. This was done before in the VGS. The 277 ohm resistor in series with the input represents the output impedance of the VGS. I put it there to be complete, it is not needed.

[jkeny]

Has any consensus yet been reached on this output stage or convergence of opinion yet taken place?

[Steve Dunlap]

Originally Posted by jkeny

Has any consensus yet been reached on this output stage or convergence of opinion yet taken place?

Andy hasn't reported back yet, if that is what you are asking. I assume he is being thorough.

[AKSA]

Steve,

I'm having issues getting emails through to you - so, could I ask a question?

Your stage either softens the landing of output devices as they switch, OR, prevents them switching altogether, Andy's simulations may give some sort of resolution on this one. Either way, will it account for the reported lovely sound of this topology?

Have you thought much about the large, compressive non-linearities due to Vbe creep and emitter resistor losses in the formation of odd order harmonics? If these could be reduced, presumably with error correction, would not the spray of odd, high order harmonics found in almost all Class AB output stages be drastically reduced?

Hugh