Beavis 555 modifier

[Gregory Kollins]

I'm having some issues with the Beavis Audio 555 modifier circuit. Bewildering, mind numbing, ball-grasping issues.
Diagram on this page:
http://www.beavisaudio.com/projects/ArmageddonProcessor/

The effect is weak in volume and sounds incorrect... though I do have to say I don't know what it IS supposed to sound like...
When engaged it acts mainly as a free running oscillator, with almost no guitar coming through at all, and the volume is so low I have to jack the amp up to hear this at all.
Next, THERE IS NO SIGNAL IN BYPASS...
?!?!?!?!???!?!?
I have eliminated all of the following possibilities:
Circuit layout (compared to the one on the beavis website)
Solder joints
Component values
Component orientation
guitar and amp cables
power supply
broken switch
input and output jacks... somehow....? again, I'm confused so I'm trying everything...

I have not tried the 9 volt jack but.... HOOOOOOW would any of this disrupt the bypass signal? AgGh.

So fustrated

[MikeH]

The only thing that seems possible is that you've made a mistake in your switch wiring.  Otherwise it would work in bypass.

[soggybag]

Beavis comes up with great stuff. But, in this case though I would recommend building an UglyFace or the Crash Sync. The Uglyface is easier of the two.

[Gregory Kollins]

Checked my switch wiring against the data sheet, wiring's good. Wired in a third 3pdt. Same thing.
Going to try 9 volt jack.

[Gregory Kollins]

Going to ask a few slightly dumb, unnecessary questions to clear up any other possibilities:

In a "-|(-" symbol, the curved side is negative, correct?
"Vcc" is positive supply voltage, right?
The positive LED lead can be connected directly to the 9 v jack right? Will not draw excess current or something (I have a 1.5 k resistor on it)?
On an 8 pin ic, a little dot on one end can be considered the same as one of those half moon indents, for orientation, right?
IC pinouts are counted like this, correct? (this is, looking down at the top side of the chip)

   8  7 6  5
_|_|_|_|
|            |
D            |
|_______|
   |  |  |  |
  1   2  3  4

That's all I got...

[Ripthorn]

You need a resistor with the LED because it will draw excess current and burn up if you just hook it up to +9V.  Other than that, your answers to your own questions are valid.

[MikeH]

Can you post a pic or a diagram of how your 3pdt is wired?  Make sure that you trace the wires all the way back to where they come from- don't just replace the switch with the same wires going to the same place- I had the same problem once (no sound in bypass), and I swore for almost 6 months that my 3pdt was wired correctly but I had switched the output and effect output wires.  Which gave me signal when the effect was engaged, but no signal in bypass.

On a separate note, I also built that beavis 555 circuit and ended up prefering the crashsync in the end.

[Gregory Kollins]

<------------------------->          <Empty>

<In>               <OUT>             <LED ->

<Circuit In>  <Circuit out>   <Board ground>



Can you tell what I mean?

And another piece of information: the LED does work.

[MikeH]

And you've tried how many 3pdts?  Is it possible you have the switch turned 90 degrees?

Lugs should look like this:

_  _  _
_  _  _
_  _  _

Not like this:

l   l   l
l   l   l
l   l   l

Based on yourdiagram above

[aziltz]

And you've tried how many 3pdts?  Is it possible you have the switch turned 90 degrees?

Lugs should look like this:

_  _  _
_  _  _
_  _  _

Not like this:

l   l   l
l   l   l
l   l   l

Based on yourdiagram above

word.

[Gregory Kollins]

I've checked this against the switch's data sheet and other projects where I have used the same switches. And if this was the problem, the LED would not function, and it does.

And I've tried three 3pdt's. So far...

[MikeH]

Use your continuity tester.  Set the pedal for bypass and start at the input jack on the soldered lug of the jack tip, and test for continuity from there to the switch and at every solder joint until you get to the output jack.


Oh yeah, and check that you haven't reversed your wiring on your input or output jacks (I mean mixed up the sleeve and the tip.  Sleeve is ground, tip is signal, as I'm sure you know)

[fuzzo]

Take off the 3PDT and see if only the circuit works. Wire the input jack to the input circuit and the output jack to the ouput jack.

[Gregory Kollins]

Something bizarre and troubling:

Note: My "continuity tester" is an extra jack with free wires soldered to tip and sleeve. I did not de-solder anything on the 555 modifier, switch or anything.

Testing from the input, the signal goes dead... AT THE INPUT. While in contact with the rest of the circuit there is NO SIGNAL, PERIOD, FROM ANYWHERE. !@>:!@@#LO@#%??

The amp doesn't even get "the sound" if you touch the tip on the output jack.

[kvb]

Are you using a meter and an "audio probe"?
if not, you must.

there may be something grounded that should not be.

[MikeH]

<------------------------->          <Empty>

<In>               <OUT>             <LED ->

<Circuit In>  <Circuit out>   <Board ground>



Can you tell what I mean?

And another piece of information: the LED does work.

You've got your LED hooked up to the ground on the board, but do you also have the board grounded to the input jack?  This of course won't solve your 'no signal in bypass' problem which is the first thing you need to track down.  I'd remove the circuit entirely and work out your bypass first.

[Gregory Kollins]

OK, done. When the circuit is removed, and the negative contacts from each jack are directly connected, bypass works. When the circuit is connected, everything goes dead.

[Gregory Kollins]

I found it. Both the original and replacement output jacks were shorting out. When I cut out the circuit, I soldered in a different one and thusly did not catch that the old ones were broken...
anyways, thanks for all the help and input. 

[MikeH]

Bewildering, mind numbing, ball-grasping issues.

I bet your balls are a lot happier.

[biggy boy]

The effect is weak in volume and sounds incorrect... though I do have to say I don't know what it IS supposed to sound like...
 

OK now that you have it working what does it sound like?
I'm curious about the circuit myself, is it a good effect?

Glen