Grounding stuff to Vref

[Hatredman]

(Mental note: experiment with LFOs as Vref...)

[duck_arse]

hatred, I posted this somewhere a while ago.
http://i.imgur.com/HVzhSVm.png

[ashcat_lt]

(Mental note: experiment with LFOs as Vref...)

I've messed with this a bit in digital.  It can be pretty cool, but like a lot of things in distortion it's pretty subtle unless its extreme and if it's extreme it has limited uses.  Not trying to discourage your experimentation!

Interesting to note that not all opamps really "want" to be biased at half the supply.  If you're looking for the most headroom in a given circuit (or symmetrical clipping), then you really need to look at the datasheet.  The LM324, for example, will swing its output all the way to the bottom rail, but will only go to about a silicon diode drop of the top.  On a 9V supply, that means like 8.4V.  So the "ideal" Vref would have to be like 4.2V, right?  Course, it will also run on a 3V rail, in which case the output will only go to 2.4V.  Bias it at 1.2V and you get symmetrical clipping much like LEDs to ground. 

But who says we always want symmetrical clipping?  In fact, it seems like all of the most popular mods involve asymmetry, don't they?  Yes, we've covered that...