Using a Dying Battery Simulation power supply

[mojo321]

I just built another Cornish buffer for a friend, and I noticed that when I disconnect the power plug, it continues to function for quite a few seconds before the charges in the caps finally starts to die.  Playing on a clean channel, it slowly starts to go into distorted fuzz like....really cool.  I never understood why someone would want a power supply with a "dying battery simulator" but now I wish I had one!  

So, does anyone have one?  What do you do with it?  I am imagining trying out a circuit and then tweaking with the power, and when you find the sweet spot, measure the voltages all over the board and then add or change components to achieve the same result from 9V.  Is that right?  Or would you just have to put a resistor right on the tip of the power rail?

[dexxyy]

I`ve done this on a couple of builds. Basically its just a sag pot. 10k pot, 9v from dc socket to lug 3, lug 2 takes the power to your board, lug 3 to ground. great in some circuits, shit in others.

[Vince]

Works great on Fuzz Faces and also good on some modulation effects as it can slow the modulation right down.

[mojo321]

So, Dex takes one end of the taper to ground. Vince binds two lugs to make a rheostat on just the power rail.  

Is there an advantage or disadvantage to one over the other? I'm not trying to start a battle here, but I would think taking voltage to ground would drain the battery pretty quick.  

[dexxyy]

I never use batteries in my builds, the sag pot gives the effect of a dying battery to a 9v psu

[dexxyy]

And forgot to add  I also use a 2k2 resistor in series to ground

[Vince]

I never use batteries either. I just wire as is without the battery clip. I suppose either way would work. I just find it less messing about.

[mojo321]

Ah, the 2.2k makes me feel a lot better about it!  :)