Can someone school me on diode placement feedback loop vs post transistor?

[chumbox]

What sound differences should I expect and what are some example production pedals for reference?

Does anyone have diodes in the feedback loop and post transistor as well?

Thanks

[R.G.]

In a classical "opamp" style feedback the elements in the feedback are driven by what amounts to a constant current source. In a diodes-to-ground setup, the currents are limited by whatever resistance is put in series with the diodes, often 1K - 10K. The difference between these two drives makes the feedback connection a little softer in clipping.

[brett]

Hi
my mental image of a diode in a feedback loop is that the gain is high (10 to 1000) until the diode conducts. Once conducting - even a tiny bit - the gain  sharts falling, so the clipping starts early and ends late and is "soft" to the ears. A capacitor in the feedback path also softens the tone by allowing high frequencies through.

As RG said, the post-transistor diode starts conducting at the same voltage, but it ramps up fast because a diode can go from 0 uA to hundreds of uA for a small rise in the signal (say 0.05V).
cheers