egodriver more gain

[bs_ane]

Hi.I built the egodriver with Tl072.the pedal has very good sound but I want a little more gain.I have LEDs for clipping.

[stecykmi]

Try increasing R5. The higher you go, the more clipping you'll get. Sorta hard to say the best value without testing, but start at perhaps 47k. You can also increase the 1Meg Gain pot, but the next largest common value (2Meg) would likely be too big. In a way, the pot is a better solution since you don't loose any of the low-gain range.

You can also decrease R4, but you may find it will change the frequency response of the circuit.

[oldhousescott]

I'm guessing any change in R5 would be swallowed up by the 1M pot at max (assuming as you stated, you want more gain and maxing the pot doesn't get it for you). In this case, reduce R4 to 1k and increase C3 to 120n or 150n, to keep the same approximate corner frequency as stecykmi eluded to. If that still doesn't get you there, cut R4 to 470r (not k) and raise C3 to 270n.

[mgwhit]

Hi.I built the egodriver with Tl072.the pedal has very good sound but I want a little more gain.I have LEDs for clipping.

When you say "gain" do you mean loudness or distortion?  More gain (i.e. loudness) from the first op amp should give you more distortion from your clipping stage, but if all you want is more distortion you could try going with clipping diodes with a lower forward voltage than what you're currently using.  Do you have the specs for your LEDs?

[bs_ane]

Hi.I built the egodriver with Tl072.the pedal has very good sound but I want a little more gain.I have LEDs for clipping.

When you say "gain" do you mean loudness or distortion?  More gain (i.e. loudness) from the first op amp should give you more distortion from your clipping stage, but if all you want is more distortion you could try going with clipping diodes with a lower forward voltage than what you're currently using.  Do you have the specs for your LEDs?
[/q

I mean distortion.I dont have the specs from leds.it does matter the specs?

[mgwhit]

I mean distortion.I dont have the specs from leds.it does matter the specs?

Yep.  Lower forward voltage == more wave clipping == more distortion.  Check out this page for a simplified explanation.  Different diodes (including LEDs) have different forward voltages.  Usually diffused LED's have less forward voltage than clears or ultrabrights.  And the character of the distortion might be different, too.  If you're planning to experiment, you may want to socket.

Also note that when you lower the forward voltage of the clipping diodes to add more distortion to this circuit, the overall loudness of the pedal will decrease.  That shouldn't be a big deal -- just adjust the Volume knob to taste.  Good luck!