Thing modulator

[joer0952]

I just made this pedal today and it works except the volume is really low.  Are there any common causes for this?  Also, there is a constant hum from the pedal, is this normal and is there any way to get rid of it?

[Jhouse]

It might be a grounding problem if you get an ungodly amount of hum. Post the voltages of your parts and we could give you better answers.

[joer0952]

its not an ungodly amount of hum just alittle.  I assume you want me to use a multimeter, but im not exactly sure what you you want me to do.

[Jhouse]

Read THIS. It should answer any questions. Post all of the information it tells you to.

[joer0952]

ok  here is a copy of the schematic I used, I followed it exactly:


I put the multimeter on the battery and got 9.67v, I got the same reading on the circuit board connected the the red wire.  I git 0.00 on the black wire.
on the ic (LMC567) I got:
pin 1 = .80
pin 2 = .66
pin 3 = 0
pin 4 = 1.07
pin 5 .53
pin 6 = .53
pin 7 = 0
pin 8 = 0
on D1 I got
K = 9.67
A = 0

[Jhouse]

Pin 1 isn't supposed to be connected to anything, is it? It shouldn't have any voltage on it then.

[joer0952]

your right, its not hooked up to anything, and there r no solder bridges, so I dont know why its getting a voltage.  you think I should try a new ic?

[Jhouse]

If you're sure that there are not any bridges, I think it might be a good idea.

[joer0952]

i put in a new chip and im getting the same reading.  Im new to this and i dont totally understand ic chips, but isnt pin 1 connected to other pins internally.  Could that be causing the voltage?

[joer0952]

sound wise it works, it sounds like a telephone lol, i just have to turn the volume all the way up to get it to be as load as the clean guitar is.  I would think it should be loader

[Jhouse]

I'm not too familiar with that IC actually. What did you make it with: veroboard, pcb?

[joer0952]

veroboard