The OCD and VLO both tie the diodes (or MOSFETs wired as diodes) to the reference voltage instead of ground.
The OCD folks claim it adds dynamics because thr input signal affects how much clipping occurs.
Funny thing is, the output of the first op amp stage reads 4.5 v dc, which happens to be the reference voltage.
So unless I am wrong (a possibility I admit) both sides of the clipping diodes see the same voltage and the voltage difference between cathode and anode is 0V dc. How can the diodes clip? Is all the distortion from the second op amp stage?
I yanked thr MOSFETs out of my OCD build and it sounded the same as with the clipping stage.
Am I missing something, or is the diode clipping stage superfluous?
Quote from: texcaster on January 03, 2011, 11:17:18 PM
Funny thing is, the output of the first op amp stage reads 4.5 v dc, which happens to be the reference voltage.
So unless I am wrong (a possibility I admit) both sides of the clipping diodes see the same voltage and the voltage difference between cathode and anode is 0V dc.
now look at what happens with AC.
Quote from: texcaster on January 03, 2011, 11:17:18 PM
The OCD folks claim it adds dynamics because thr input signal affects how much clipping occurs.
This is marketing crap. The whole point of
any clipper is that the higher the input signal, the more it clips! If the MOSFET thing makes it confusing, imagine they're a pair of 1N4148s. They're tied to Vref because of the lack of an input cap between the first opamp and the diodes.
If your build sounds the same with the clippers removed, then I suggest that your build wasn't right in the first place!
Quote from: texcaster on January 03, 2011, 11:17:18 PM
Funny thing is, the output of the first op amp stage reads 4.5 v dc, which happens to be the reference voltage.
So unless I am wrong (a possibility I admit) both sides of the clipping diodes see the same voltage and the voltage difference between cathode and anode is 0V dc. How can the diodes clip? Is all the distortion from the second op amp stage?
I yanked thr MOSFETs out of my OCD build and it sounded the same as with the clipping stage.
Am I missing something, or is the diode clipping stage superfluous?
Seems you did your homework lad! Please point all users at TGP to this post and prepare thine castle for armageddon.