Hi all, I will start by saying what a great community this is and the help I have recieved has been fantastic so thanks a lot everyone.
I have built a stage fright phaser and I cannot get it to work for me.
When I turn the trimpot manually whilst a chord is ringing out the phaser works but only while I turn the trimpot.
The LED flashes in time with the speed knob as it should.
Does anyone have any ideas about what I have done wrong here?
Thanks again
Jules
Jules,
Are you getting no sound when you aren't turning the trimpot? Or just no phaser effect?
Try reflowing the solder where that trimpot is. You may have a bad solder joint there. It's an easy attempt at fixing this issue. If it doesn't work, we can look deeper into the circuit.
Steve.
Steve, when I turn the trimpot it gives me the phase effect as I turn it.
I am getting sound when not turning the pot, just no phase effect. Thanks for your suggestion will try that
reflowed a few solder joints and now working perfectly.
Quote from: Jules on February 09, 2015, 07:42:58 AM
reflowed a few solder joints and now working perfectly.
Awesome! Enjoy....
Steve
I am having this exact same problem. I also tried reflowing the solder on the trim pot with no luck. What else should I look for to try and fix this issue?
Hi Tony. Your phasing only works when you are turning the trimpot also?
Do you get the guitar sound, but no phasing?
Steve.
That's correct. I get the signal without phasing. when I turn the trimpot, it effects the signal, but I don't actually get the phasing with the lfo.
Ok. This is a little different. Do you have a Digital Multimeter? Are you able to take voltage readings on all your IC's? Also, sometimes a picture is really worth a thousand words. This info would go a long way in narrowing down the problem.
Steve.
I do have a DMM. Here are the voltages
on all LM13700
Pins 1 and 16- 1.2V
Pins 3 and 14- 4.2V
TL074
Pins 5, 7 and 8- 4.2V
pin 10- 3.5V
Tl062
Pins 3 and 5- 4.2V
pin2- 3.8V
Here are a couple pics
http://i357.photobucket.com/albums/oo13/whamola_man/sf%20front_zpszw5vvxcd.jpg
http://i357.photobucket.com/albums/oo13/whamola_man/sf%20back_zpsvhhqeiax.jpg
thanks for the help!
I can't really see it, but make sure q1,q2 and q3 are the correct transistors and oriented properly on the board.
Steve.
The transistors were in correctly. I reflowed all of the solder joints on the board and the pedal came to life. :D
Thanks for your help!!
So glad Tony! I'm going to have to build this one myself. Have fun.
Steve.