Class AB amp clipping at 55v under no load, help

[Audio1Man]

I always do. I don’t want to fix them as the customer will surely do it. I use a 0.1 Ohm, 25Amp bridge and 2 FETs (my manual test was 2 Grayhill pushbuttons).

 

[dungdochi1978]

one more question .
Compare between VAS stage using Bootstrap & Current source which one is good ?.
https://www.google.com/url?sa=t&rct...usg=AOvVaw03s4AoL1MjWnzlg_FrzrxX&opi=89978449

 

[mjona]

Hey everyone,


I’ve built a 1000W RMS amplifier designed to drive a 2Ω load. I'm supplying it with ±80V rails. However, when I check the output voltage (without any load connected), the signal starts clipping at only 55V peak.


I was expecting a higher swing, given the rail voltage. Could this be due to a weak driver ? Would adding a predriver help improve the voltage swing?


Any insights or suggestions would be appreciated

View attachment 1459979

R5 suggests a constant current of 6 m.a. for the Vas do you think that is enough to drive the following buffer stages through to the output. What is the voltage across R16 and apply Ohms law to deduce the current and is that sufficient also.