Phozer not working

[ninoman123]

Built a phozer using the ROG perfboard, i subbed mpf102s for the j201s though, all i get is buzz, no phozing. the LED blinks. I picked a green LED, would it matter which color? Probably wouldnt make much difference I think.  Should i change the speed resistor to a higher value? Maybe lower the depth resistor? When i turn the speed pot all the way down and turn it back up it takes awhile for the LED to start blinking again. Thanks for any help you can give.

-Steve

[ninoman123]

And also, when the effect is turned on the hum that i get has the tremolo effect, not the guitar signal. odd very odd

[B Tremblay]

If the LED is blinking, then the LFO is working properly.  The color doesn't really matter.

The 510 resistor is too low for your LFO transistor, that's why the oscillation stops when the Speed pot is at minimum.  Try a 1k in place of it and it should take care of it.

The next step is to build an audio probe and determine where the signal is being lost: http://www.diystompboxes.com/pedals/debug.html

[ninoman123]

Well signal goes through, theres just no effect. Ill try changing that resistor

[B Tremblay]

First you said that there is no signal, just effected hum.  Now you say that the signal does go through?

When I say signal, I'm referring to the signal from the guitar that's plugged into the circuit, not just the presence of something audible.

[ninoman123]

lol sorry, i meant to say no effect. There IS signal, just no effect. I measured voltages on the transistors and Q2-Q4 have no power. So, I need to figure out what I did wrong. And that 1k resistor worked, the LED doesnt stop blinking now. So somewhere the circuit isnt getting power. Either that or I fried a transistor.

[ninoman123]

Ok! Got it working. I changed the 1M5 to 100k. the 180K to 220K. Only problem is that when Depth and Rate are both at max theres no effect, just straight guitar. Otherwise it works just fine. So would you suggest maybe increasing the value of the 100k, maybe to a 560k or something like the EA trem? Thanks for the help! Its an AWESOME effect ROG