hurray it works!..quietly

[Chef]

I have deigned and built a tweako (from small bear) on breadboard.  I now have it working but the output is really quiet.  I have to turn my amp right up to get anything like a decent level.  Why could this be?

Adam

[Chef]

I would really appreciate any input on this one.

Thanks

Adam

[The Tone God]

Read the "What to do when it doesn't work" sticky and report back.

Andrew

[AdamB]

I tend to find it's a bad solder joint somewhere when there's a really low output level.

-Adam

[Joecool85]

Or a reversed cap.

[Chef]

ok sorry, just read the what to do if it doesn't work thing.

Here's all the info.

I am using the schematic from smallbearelec.com for a "tweak-o" and redesigning it on Breadboard to do some experiments on it for a uni project. 

I have swapped R1, R2 and R4 for equivalent potentiometers and measured them to make sure they are the correct value whilst i am testing.

I have gotten rid of the bypass switch and am now using a mono input jack (the stereo one on the original was just for power on/off)

I am reading 3V at the collector, 1.5v at the base and 1v at the emmitter when the battery is plugged in.

I have checked my connections and they all seem fine.  My cap is in the right way round.

still getting a really quiet output.

Cheers

Adam

[Chef]

http://aronnelson.com/gallery/Schematics-etc/tweak_o_breadboard_2
That should take you to a scan of my breadboard design.  Please bare in mind that i've never done this before and it may look a bit amateurish.

[Chef]

http://aronnelson.com/gallery/Schematics-etc/breadboard_wiring

the lines on the above picture indicate how the board is wired

http://www.smallbearelec.com/Projects/TweakO/TweakO.htm

And here's the original schematic

[jrem]

trace it through again, don't take it off the breadboard until it works.  recheck everything.  if you still can't figure it out, put it down for a couple of days then come back to it with a fresh mind.

or try this:  pull all that distortion stuff out above the collector and see if it works, debug it without that diode circuit first, then add it back in.

[Chef]

Thanks Jrem, I'll try taking the distortion stuff out. 

If anyone can see anything that stands out in my design as being wrong It would save me many hours of wasted fault finding.

Thanks again

Adam

[psiico]

Try these changes:



All the changes I made are in the lower right corner.  I moved your connection to 9v to the other side of R5 and C6, I moved R5 up and removed the jumper to C7, I moved C7 down and make sure you have it's other end past where C6 and R5 go to then I moved R7 to connect to C7.

Ignore the C7 and R5 in the upper left off the board, I forgot to remove those when I was done copying and pasting to modify your drawing.

Let me know if that works better.

[Chef]

Thankyou very much,  I'll get on that right away.

Adam

[Chef]

That has significantly improved things, thanks.  It also has a lot more body to it now. 

Adam

[Chef]

actually, that was an understatement, now it works perfectly.  I never thought this pedal would sound as good as it does.  Better start experimenting then. 

Thanks a million

Adam

[psiico]

Glad to be of service.