member Ostripper or Pete V. was commisioned by diyaudio to design this amp.....
i hope he recovers well from his health issues so he can continue to do a fine job at
designing amps for diy'ers...
i hope he recovers well from his health issues so he can continue to do a fine job at
designing amps for diy'ers...
Ost recovered well enough to go an a long term cycling expedition across the USA.
That's why we so rarely hear from him.
As far as I know he is in good enough health to have taken on that epic journey.
That's why we so rarely hear from him.
As far as I know he is in good enough health to have taken on that epic journey.
That journey may have been made for his health. Not to mention the fact that he needs to clear his mind.
He's a really good guy and deserves to recover fully. Let's hope that happens.
-Chris
He's a really good guy and deserves to recover fully. Let's hope that happens.
-Chris
In my simulation, lowering R23 will lower THD dramatically.
What is the purpose of this resistor ?
can I reduce it's value from 33 to 10ohm ?
What is the purpose of this resistor ?
can I reduce it's value from 33 to 10ohm ?
the resistor set the collector current of the VAS...
the change increased the VAS current a little bit....
that is why distortion decreased...
limit is the VAS and big CCS collector dissipation and heat...
So if the vas transistor is chosen to be able to cope with the power, we can remove the resistor right ?
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.
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
LC cap
I'm curious if many builders have added the lead compensation capacitor and if they consider it a "necessary" option. I've looked at the comments in the build guide but would like to know what other builders think.
Thanks
I'm curious if many builders have added the lead compensation capacitor and if they consider it a "necessary" option. I've looked at the comments in the build guide but would like to know what other builders think.
Thanks
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
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
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I have tried with the LC cap, using different values. It sounded best to my ears without the LC cap.