newbie says "it doesn't work" #40314

[flies]

hi, i'm new here so thanks for your trouble,

i am breadboarding my first pedal, the tweak-o from small bear http://www.smallbearelec.com/Projects/TweakO/TweakO.htm .  (direct link to schem: http://www.smallbearelec.com/Projects/TweakO/Schem.gif )  I have a background in physics so my understanding of electronics is at a basic level (as opposed to non-existent). 

I was playing my discman through it into a crate practice amp, both of which work fine on their own.  I have all the parts as specified in the build instructions.  Am I 100% positive that i did the schem right? Nope, I did my best to look it over but i would not be surprised if there were still a few mismatched connections.

symptom:  the output does not sound distorted, and the CD bleeds through even when the volume pot is all the way down.  Therefore my guess is that the problem is that i haven't grounded anything.  All the ground connections are together, but i have no groud connection to attach to my breadboard.  do you think that could be the problem?  the bleed through sounds very thin and filtered.

Another weirdness is that if I remove Q1 the output sounds exactly the same.  I tried connecting the input 'tip' directly to R6 to see if the volume pot would work then, and, well, no there was no change whatsoever.  the output sounds the same with tip connected to C1 or R6.  I suppose i could also mention that there was an awful lot of hum, which dissipated significantly if i touched one of the leads attached to ground.

thanks!

[Arn C.]

Since you have all your grounds together, now attach them to the negative side of the battery.  Anything that should be grounded should be grounded to the negative of the battery.

Peace!
Arn C.

[flies]

Since you have all your grounds together, now attach them to the negative side of the battery.  Anything that should be grounded should be grounded to the negative of the battery.

thanks for the reply  
In the schem, the 'ring' of the input jack is connected to the ground, and the 'sleeve' is connected to the - battery terminal.  with a plug in the jack, sleeve and ring are connected, right?  if so then grounds are connected to the - terminal, if not so then i'll have to correct that when i get home

[Arn C.]

Yes, run "all" your ground wires to the ring,  and the battery  (-) to the sleeve. 

Peace!
Arn C.

[johngreene]

When you play your diskman through it, are you using a mono or stereo plug?

You have to use a mono plug in order to connect the negative side of the battery to ground.

--john

[flies]

ok, then i am doing what arn says, which is same as in the schem.  As to the cord i'm using, it's mono input, as you say (to be precise, it's a stereo mini to dual 1/4", so the input is a mono plug).

As far as my suspicions about the grounding, what you're saying is, i don't need any external ground so long as all the "ground" connections are together and the - terminal of the battery is connected to the same ground via the jack.  If that's so, then my suspicion that the ground was causing the toruble was wrong, since i seem to be doing that part right.

So why does it make no difference when i turn the volume pot?  why does it make no difference when i remove the transistor? or when i connect the input right in to R6? 

I'll just have to double check all the connections tonight...

[flies]

Well, i fixed a major problem, and now the volume knob works.  Yea, well, i guess it's been a long time since i used a breadboard, cuz i had been under the impression that the grid is connected vertically instead of horizontally

so now the volume knob works, but there's still no fuzz! changing the fuzz pot does exactly jack.  ugh.