Prismatic Distortion - Can I use a UA 741?

[HamishR]

I just built a Prismatic Distortion and I don't have an LM741 - can I use a UA741 which I do have? Thing is, I have tried the UA741 and am getting no signal through. If I turn the volume up I am getting some hiss but no guitar.

 

[Cybercow]

The UA741 has the same pinout as the LM741, but higher performance. Should be no problem there.

Good clear photos of the build with details on the soldering & wiring?

 

[HamishR]

I know how to troubleshoot, but thanks! The soldering is all fine, wiring is clean... Maybe it's the BC182L? There's no schematic as yet so I can't check the transistor orientation. The voltages on the IC seem good, the collector on the transistor is getting the full VCC but I don't know if it supposed to because I have no schematic. I also can't check resistor values because of the lack of build docs. Kinda frustrating!

 

[benny_profane]

Maybe it's the BC182L

The BC182L is ECB; the BC182 has the typical EBC BC series CBE pinout.

 

[Robert]

This is my fault, I apologize! The L was supposed to be dropped from the part number since BC182 has similar specs (but different pinout, as @benny_profane noted) and is still in production.

You need a CBE pinout. (BC182, BC549, etc)

It's just an input buffer so most anything with a similar pinout should be fine.

 

[HamishR]

I knew it!! Thanks! I was aware that the 182L was a different pinout so made sure to use it...

Next question then - Should I go by the outline of the transistor if I used a BC549?

 

[HamishR]

I answered my own question by removing the BC182L and measuring where the voltage was coming from. So a BC549B has been installed and it works the way the outline is printed on the PCB. And it works! Yay! It sounds exactly like the demo. Not a hugely versatile pedal but I like it. Very much a cocked wah kinda sound. Very glam rock. It actually sounds amazing with a truckload of delay on top.

So glad to get it working...