op amp problem

[joehill]

Hi guys, my first post here, having problems with first op amp build. Have only done fuzzes before.

Im working on http://www.generalguitargadgets.com/richardo/distortion/opamp.gif
from this page:http://www.generalguitargadgets.com/richardo/distortion/index.html
with this bias supply: http://www.generalguitargadgets.com/richardo/distortion/bias2.gif
but with a muff tone control.

Doesn't work, have probed it an signal stops at non-inverted input on TL071 OP. It seems powered correctly, +9V on VCC+, ground to VCC- and somewhere above 4V on input+. Output voltage is maby ½ V below VCC+. Only way to get it sending the signal through the whole circuit is by setting voltage on DC supply to 3V. Without power=no sound. 4.5V or above = no sound.

Please help me, getting frustrated.

kind regards, Joe

[petemoore]

  RG's required read  "Debugging: What to do when it doesn't work" sticky thread.
   For us to figure it out, we'll need what we need, ^ lays out how to do it. 

[joehill]

  well I forgot to connect the feedback wire...

now its working at least. thanks anyway

[familyortiz]

Joe,
  Does it behave the same way for either position of S1? You might double check the installation of the diodes as to polarity. It sounds like the opamp output is responding such that the noninverting input is always higher than the inverting input when V+ > 4.5V.

[joehill]

problem fixed, thank you anyway