diyAB Amp The "Honey Badger" build thread

I am still using R23 = 47R. If it is taken too low it can affect stability.

Thank you...

I see that Rod uses no resistor here: 60-80W Power Amplifier

And Bigun does neither here: TGM8 - an amplifier based on Rod Elliot P3a

That is why I wondered about this resistor..... maybe we need lower gain in this VAS ??
Adding in VAS degeneration reduces stage gain and thus reduces open loop gain.
This will have a direct effect on the stability margins.
Removing the degeneration from an amplifier that has been designed to have adequate, but not excessive stability margins will perform differently and may shown signs of instability, or worse, complete oscillation.

The same argument applies to the Input LTP degeneration.
 
Member
Joined 2006
Paid Member
Adding in VAS degeneration reduces stage gain and thus reduces open loop gain.
This will have a direct effect on the stability margins.
Removing the degeneration from an amplifier that has been designed to have adequate, but not excessive stability margins will perform differently and may shown signs of instability, or worse, complete oscillation.

The same argument applies to the Input LTP degeneration.

Thank you Andrew.

Now I fully understand the issue.

I would also appreciate your comments about this other issue: http://www.diyaudio.com/forums/solid-state/258549-assemblage-power-amp-24.html#post5293354

Best
Ricardo
 
I believe the more popular opinion is to leave it out :) . I'm leaving it out of my build based on others experiences .

Edit: There is a discussion in this thread, or the general badger Thread. You could search the thread for LC, or lead compensation if you didn't want to sift through the 500-ish pages
 
Last edited: