LTSPICE HELP! strange simulation results

cucicu

Member
2011-10-25 10:42 pm
Italy
Hi at all, I have a strange problem with LTSPICE when simulating a sugden a48mk2 amplifier.
I attach the simulation file for someone who wanna have a look at.
the problem is that changing R24 (bias adjustement) or R11 (sets the mid voltage point on the positive side of the output capacitor C1), sim gets slow or gives some thick lines as sinusoidal curve.
hope someone can explain what's going on.
thank you all.
regards
 

Attachments

  • SUGDEN a48mkii.asc
    7.4 KB · Views: 19

cucicu

Member
2011-10-25 10:42 pm
Italy
Thanks for the reply. My scope is noto so good, it measures just to 200khz so I can't see that oscillation if it is in the Mhz range.
I attach the simulation, removing your resistor and replacing C2 from 470pF to 1000pF because I have not the place in the pcb to add that resistor. It seems to block the oscillation the same way than the resistor. Could it be also a good solution?
thanks a lot
BR
 

Attachments

  • SUGDEN a48mkii_ABC.asc
    7.7 KB · Views: 12