Bad Stone Q (callin StephenGiles)

[Zero the hero]

Hello everybody, I've almost finished the Bad Stone layout.
I used this schemo http://www.generalguitargadgets.com/diagrams/badstone_2.jpg but I got some questions about this project...

The first thing i have to ask is about this symbol used in the schematic:

Code Select Expand


   I
   I
----------
/  /  /  /


I assumed that this is NOT ground, but it's +4.5 bias and both C3, and the voltage divider section around R3, R4, R38 and R39 confirm my thesis (am I wrong?)

But...
look at the output jack: it's connected the "K", and "K" is connected to C13 and +4.5 bias via a 470 ohms resistor... why should I feed the ooutput with 4.5 volts?
And why pin 8 of CD4009 is not to ground?

Even the input section seems very strange to me...

Any suggestion and help is welcome...
Thanks!
alex.

[puretube]

I got an un-corrected version of that "same" drawing:
it does not have that 470 ohm resistor south of the cap marked with point "K", but is rather floating.
My guess: that resistor was inserted later, and ought to be a (470k) anti-plop pulldown resistor, and that fork-sign in the "corrected" version should rather be the ground-sign.

Also the un-corrected schemo shows point "A" at the tip of the input-jack,
which makes sense for bypass...

the other drawing shows the first opamp "B1" wired differently, but also quite doubtful...

[Zero the hero]

Even the fork on C1 makes not much sense... I believe that is a ground too.
Thanks for the guess!

[B Tremblay]

The earliest version of the Bad Stone used two 9v batteries.  Maybe that schematic just contains "artifacts" relating to a bipolar power supply.

[Zero the hero]

puretube, can you send me the "uncorrected" version of the schematic?
My email is:
offramp.uno AT tiscali.it

I think I'll build the LFO and phase shifting section with my layout and breadboard the rest of the circuit.
I found a couple of pics of the original Bad Stone circuit on home-wrecker. According to these pics, all the op-amp ICs are fed with +9 / 0 supply, so each pin 4 is on true ground and pin 8 is to +9.
The input section is correct, all the forks are right.
ICB-2 is correct too!
Now I'm stuck cause in the picture I've got, the interesting stuff (C1, R16 etc.) is hidden by the "Feedback" pot...

[StephenGiles]

Puretube is correct - this is an "old" corrected circuit diagram. Plenty of water under the bridge since then! I fell foul of the 470ohms resistor without thinking, and of course lost most of the volume.
Stephen

[puretube]

Zero: I finally found the schem
(I only had a small printout, but no scanner, and couldn`t find it on my PC...);
the un-corrected schematic I got, is the same as this:
http://www.muzique.com/schem/badstone.gif

(but without the "courtesy of www.m*usic.com" imprint and the watermark, which itself is rather a case for the more ethical people... :? ).

[Zero the hero]

Thanks everybody!
I hope to get this thing working during the week-end!
Alex.