Hello all,
This is my new test poweramp which have differential VAS, compensated with shunt capacitor from output to ground.
The loop gain is 86dB and phase margin 36dB.
In the searching of a solution to decrease VAS capacitive load, I came to this schematic which have the same loop gain but more phase margin (49dB)
What is your opinion about this compensation type ?
Unmodified amp
This is my new test poweramp which have differential VAS, compensated with shunt capacitor from output to ground.
The loop gain is 86dB and phase margin 36dB.
In the searching of a solution to decrease VAS capacitive load, I came to this schematic which have the same loop gain but more phase margin (49dB)
What is your opinion about this compensation type ?
Unmodified amp
Attachments
Hi,
that 150pF from VAS to inverting input is quite conventional.
used by many British designers (JLH, Crimson, Sugden that I know about) for reputedly improved sound quality.
The phase of your connection seems reversed from the norm.
Can you eliminate C8 & C9 completely and use 150pF//(R+C) to stabilise and tune the phase margin?
that 150pF from VAS to inverting input is quite conventional.
used by many British designers (JLH, Crimson, Sugden that I know about) for reputedly improved sound quality.
The phase of your connection seems reversed from the norm.
Can you eliminate C8 & C9 completely and use 150pF//(R+C) to stabilise and tune the phase margin?
Very similar to Bob Cordell amps compensation scheme. In Your amp C8 and C9 plays role C3 and R14 in Bob amp (which is better, because less VAS loading).
And no furher posta thoroug so many years ....?
And no furher posta thoroug so many years ....?
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