Ice Vendor low volume

[CraigL]

Hi, I just built the Ice Vendor and it sounds really good but I have to max the volume to make it louder than the clean signal. It says to use a LM741CN but I used a UA741CP instead. Would that make any difference? It's an easy circuit and the components I believe are correct, I tried different transistors. Does anyone see anything funny in the pics?
Thanks!

 

[chris.knudson]

There's nothing obviously wrong, and as you have said, there's not much to the circuit. I don't see any wrong resistor values, which is where I'd start with low volume. I don't see any reason why you couldn't use a UA741CP instead of an LM741CN. Having said that -- there isn't much to this one, and given that all the rest of the parts seem to be correct. I think it may be your op amp. There are a lot of bad Op Amps in the marketplace.

First, I'd try reflowing the solder (especially R1). If that doesn't work, do you have another Op Amp you can try?

 

[CraigL]

Hi Chris, thanks for the speedy reply!
I reflowed all the solder joints.
I was mistaken when I said I tried different transistors, there are none, I meant op amps. I tried a couple of different ones, same deal. I guess I'll try some non-Tayda IC's.
I did notice that when I turned the tone control all the way counter-clockwise, it got louder. Maybe a different value pot? I have no idea what part of the circuit controls the tone.

 

[chris.knudson]

Your pot values should be correct from what I can tell (unless you have a bad pot). If you got the ICs from Tayda, chances are they're decent. I've heard a random story here or there about a bad part from Tayda. If you had said that you got them from Ebay or Amazon, then I would be more suspect. Looking at the data sheets for the LM741CN and the UA741CP, I don't see anything that makes me think that you couldn't swap one out for the other, but they do have slightly different operating voltages, and maybe (I'm just guessing) that could be enough to cause a difference in volume. If you have a TL071, you could try that.

I don't know. I'm at a loss. I don't see anything wrong with the build.

 

[CraigL]

I never played a real tonebender, that could just be the way the pedal works? I found the LM741CN's somewhere else, I'll try those and also the TL071.
Thanks again for your help! I'll let you know what happens.

 

[chris.knudson]

I never played a real tonebender, that could just be the way the pedal works? I found the LM741CN's somewhere else, I'll try those and also the TL071.
Thanks again for your help! I'll let you know what happens.

Yep, keep me posted. There's nothing more satisfying than fixing a pedal that isn't working right.