It works, but the pot doesn't seem to do anything...

[Outlaws]

So I just built the Tweak-O that is on Small Bear's website.  the thing works, and doesn't sound half bad, but only my 100K pot (volume) works right.  The 250k fuzz pot doesn't seem to do anything.

Now, before we go any further I have to inform everyone that I had a hell of a time tracking down a 250k audio taper pot, so I had to go with an AllParts 250k strat replacement pot.  I don't know if those are linear or audio, but I saw the thing at GuitarGagets.com about how linear will work, it will just have a different "feel" to it.

So is this the "feel"?  It only works as a 250k fixed resistor an no control?

Is a normal guitar pot even linear, or is it the right one and I just have some other issue I don't see?

[vdm]

guitar pot's can be either linear or audio (logarithmic) taper. if you use a 250k pot whether it is linear or audio, you will still get 0k at one end and 250k at the other, it just means the middle of the pot rotation may not be the 'middle' of the change in sound.

I would therefore suggest that you need to check offboard wiring to the pot, and/or all other components that would be affected in some way by the pot.

sorry i don't know the actual circuit, but good luck figuring it out.

trent

[Outlaws]

Theoredically, the circuit shouldn't work at all if I hooked it up wrong.  Right?

I mean, it sounds like I think it should sound, minus the Fuzz control.

I have been over and over the board and it just doesn't make sense.

[RjM]

Consider this... maybe you have a bad pot?

[petemoore]

Theoredically, the circuit shouldn't work at all if I hooked it up wrong.  Right?
 >>>Tweek-O was one of my first builds, and I had the same malfunction of the gain pot...but I can't remember the exact problem that made it work like that.

I mean, it sounds like I think it should sound, minus the Fuzz control.
>>>[ ok  ]

I have been over and over the board and it just doesn't make sense.

...
>>>see how many ways you can figure to apply the DMM...good excersize...lol   [really]
 Check grounds
 Check resistors...In cct. though, lower than R value code color reading may be showing the alternate path through the circuit...figure the ones you can, see if you can apply 'alternate path' math [or not] to the others.
  Take pin voltages
 Use Audio probe
 You can pull the pot and test it, without looking at the schem, can't say what you'd read there in Cct. I doubt it's a bad pot...just another thing you could do...
 Did you socket the transistor ?
 Can you post a link to the schem ?

[Outlaws]

see how many ways you can figure to apply the DMM...good excersize...lol   [really]

I have no idea what that is.  lol

Check resistors...In cct. though, lower than R value code color reading may be showing the alternate path through the circuit...figure the ones you can, see if you can apply 'alternate path' math [or not] to the others.

cct ?!?!?!  Again, no idea what that is.

Did you socket the transistor ?

Everything is just connected to perf board.

Here is the link.
http://www.smallbearelec.com/Projects/TweakO/TweakO.htm

[analog kid]

Dude, ... What Pete was saying was to take your MULTIMETER(and I"m SURE that you have one and know how to use it otherwise I can't imagine you would take out on a journey to build an effect) and just apply it everywhich way you can (continuity of the circuit traces, resistance of resistors and pots, voltages of battery and transistors, etc....)and that you might just uncover the problem in doing so or maybe more than one!
 cct=  CIRCUIT
good luck

[Somicide]

plus, you can have some parts in wrong (not terribly many) and have it still work, albeit not as great as you'd hoped.  perhaps the pot is wired wrong?

PnL,

Jeff

[petemoore]

Follow the directions RG posted in the thread "Debugging the Sparkle Boost"...fill in what you can....
 It's a good background knowledge test, what can't be figured out there ask questions and I'll try to help.
 These are the things one does to debug, by doing them answers start 'congealing' as you get more familiar with using them, and they let the more experienced debugger 'see' something...
 My guess tho, is that the gain pot isn't wired correctly, or just as likely signal isn't even going through the active...if you socketted the transistor...fire up the circuit [amp/battery/connections] and pull the transistor...report on the results of whappens when you do that.