moog taurus filter problem

[tomg]

> From: Janne Heikkarainen 

> > > i'm tring to get tomg's moog taurus vcf circuit to work but everytime i power
> > > it the 3906 and the ca3046 gets real hot and fries.any ideas what's wrong 
> > > with it? i've trashed two 3046s and 3906s already :( everything seems to 
> > > be in place...
> 
> > That sounds bad. I've never seen one do that. Did you use the vcf2b_pc.gif
> > to do your pcb layout?
> > 
> yeah exactly that gif...i've been over and over the parts and pcb and 
> everything seems to exactly like in the gif file.
> 
> .biotek

>From your description it sounds like the 3906 is pulling all of the current. I would
look very carefully at the way the 3904 is wired up. Possibly check the pinout
of your transistor type...just to make sure. Did you make a pcb or hand-wire?

Why are you blowing up chips? The 3046 would be smoldering by the time it
goes. What sort of supply are you using? Are you running it on +/-12 or what?

If you need further help email me and I'll try. I could scan mine and you 
could do a one-2-one? I could remove my 3904 and we could compare voltages?

What happens if you remove the 3904? Does the 3046 still heat up? <- Unplug
it from the PS before it blows if it does. Likewise what happens if you remove the 
3906? 

I have decided to put the sequencer off a little while longer. I'll post another mail
addressing the details. I have the diode/tranny filter ready to go, so if you wanted
you could probably get a board from me (10-15$??) within the next 20 working 
days.....If you wanted to buy a board,  I'll still help you try to fix yours regardless
....if you like.

-tg (shrugging in Atlanta)