First build - help needed debugging

[rankine]

I built the Tweako fuzz pedal recently and I had it working but then it stopped. After some fiddling I had it working again but when I went to test it just now it's not working. The pedal works when the effect is bypassed but when the effect is on there is no sound produced.
I used a multimeter to test the voltages at the Collecter, Base and Emitter of the transistor and they all read the same; roughly 3v. I looked on the tweako build instructions and it says I need the voltages as follows;
Collector 2.8 volts
Base 1.5 volts
Emitter .95 volts

Please could someone give me possible reasons why all the voltages are the same? If this helps to pin-point the problem the schematic is here- http://www.smallbearelec.com/Projects/TweakO/TweakO.htm

Thanks

[DryRoasted]

First of all welcome to the club!

To help us to help you debug, we have a sort of standard form we use when we post questions like this.  You can see it here http://www.diystompboxes.com/smfforum/index.php?topic=29816.0.  Make another post with 1)=Doesnt work! 2) Name=Tweeko 3) etc etc following the headings shown.  It makes helping a lot easier.  Its a simple circuit so we shouldnt have too much trouble sorting you out.

Have you put the circuit in a case yet?  Are you using perf board or strip board?  Also did you buy a kit of parts from Smallbear or did you buy the parts seperately?  If so what transistor are you using?


cheers,

Jim

[rankine]

3) I followed the layout perfectly
It's not in a case yet and I'm using 'pad-per-hole' perf board which was supplied with the kit. I bought it straight from SmallBear so it shouldn't be any component trouble.

[DryRoasted]

Ok, the next thing to do is check every wire is going to the right place, Its very easy to overlook something and assume its correct, I do it at least once a week.  After the wires if that doesnt clear it up, check that the wires linking each component on the board is not touching somewhere it shouldn't.  With pad per hole is very easy to get a little sliver of solder in the wrong place and short.

good luck

[rankine]

Thanks, I checked against the layout and I spotted I didn't connect R4 correctly. I now have the correct voltages at each leg of the transistor but I still don't have any sound when the effect is on. Any ideas anyone?
Thanks again

[aron]

OK, start looking at your wiring from the jacks to the switch to board.

[rankine]

  I've sorted it now. It was connection to one of the switch terminals which turns the effect on and off.
Thanks for the help I've learnt alot from this.

[8mileshigh]

Rakine,

I use a dab of flux when soldering wire to switches and jacks.  I built the Tweako as well, it's a rewarding first built.

Chris