Recently, I've got a phase 90 built from tonepad-pez90. Unfortunately, it didn't work. I wasn't able to hear anything from my built, so I tried several debugging with audio probe. I changed 5n value to 4n7 and 15uF to 22uF electrolytic cap. I look for bad solder joint, but I didn't find it, and tried to triple check my pedal. right now I pretty stuck and don't know how does the exact value of tht transistor and IC pins.
I've been tried to get it working, but it won't until today, so I need help. Here are some information about my TL072 and transistor pins. I used matched 2n5952 on 1.901V.
and I don't have 250k trim on hand so I changed it into 200k trim
IC1 TL072
1-5.22v
2-5.23v
3-5.21v
4- -0.001v
5-4.22v
6-4.47v-5.9v
7-8.41v
8-9.04v
IC2 TL072
1-5.22v
2-5.22v
3-5.21v
4-0v
5-5..23v
6-5.23v
7-5.22v
8-9.04v
IC3 TL072
1-5.23v
2-5.59v
3-5.22v
4-0v
5-5.23v
6-5.45v
7-5.23v
8-9.05v
2n4125
E-2.75v-3.00v
B-5.23v
C-5.22v
2n5952
Q2
G-2.703-2.979v
S-5..23v
D-5.22v
Q3
G-2.703-2.979v
S-5.22v
D-5.23v
Q4
G-2.704v-2.98v
S-5.22v
D-5.23v
Q5
G-5.23v
S-4.56v
D-4.55v
Zener- 5.23 V
I really need any suggestion and information about this pedal. I'm curious about my phase 90 problem, I've also tried to change IC1,2,and 3 to a new TL072 but it still didn't change the result. I've got nothing on my amps. So please help me to figure it out.
Cheers all
A few suggestions:
1) Ensure that your FETs (5952s) are properly oriented (turned the right way)
2) The change from 15uF to 22uF is pretty steep (usually want to go +/- 10%) You may want to try 10uF instead. Not within 10% but closer than 22uF ;D
3) Post some pics of your build.
Quote from: Govmnt_Lacky on March 26, 2012, 02:49:53 PM
A few suggestions:
1) Ensure that your FETs (5952s) are properly oriented (turned the right way)
2) The change from 15uF to 22uF is pretty steep (usually want to go +/- 10%) You may want to try 10uF instead. Not within 10% but closer than 22uF ;D
3) Post some pics of your build.
Hey mate,
thank you for your quick suggestion and here some quick pictures of my board. I rolled on my board by myself. I've read about other issue about this problem and some of them said that I should change the 200k trim, should I do it ?
(http://farm8.staticflickr.com/7213/7018482663_5fd5ced1e6_z.jpg) (http://www.flickr.com/photos/75813062@N05/7018482663/)
IMG_0572 (http://www.flickr.com/photos/75813062@N05/7018482663/) by DIY Parts + PCB Center (http://www.flickr.com/people/75813062@N05/), on Flickr
(http://farm8.staticflickr.com/7090/6872377136_7007cfbbea_z.jpg) (http://www.flickr.com/photos/75813062@N05/6872377136/)
IMG_0574 (http://www.flickr.com/photos/75813062@N05/6872377136/) by DIY Parts + PCB Center (http://www.flickr.com/people/75813062@N05/), on Flickr
1) Check that your Output wiring at the PCB. It looks like it may be shorted to ground.
2) Check that your Rate pot Lugs 1 & 2 (shorted together via the PCB) are NOT shorted to Lug 3. It looks like it might be in your pics.
Quote from: Govmnt_Lacky on March 26, 2012, 03:27:07 PM
1) Check that your Output wiring at the PCB. It looks like it may be shorted to ground.
2) Check that your Rate pot Lugs 1 & 2 (shorted together via the PCB) are NOT shorted to Lug 3. It looks like it might be in your pics.
nothing shorted between output and ground and lugs 3 are not to lugs 1&2, so any other suggestion ?
Thank you for your concern
Cheers all
Double and triple check ALL resistor color codes.
Might have to move up to the 250K trimmer.
Quote from: Govmnt_Lacky on March 26, 2012, 03:47:30 PM
Double and triple check ALL resistor color codes.
Might have to move up to the 250K trimmer.
Here some guts of our discussion, I moved up 22uF and change to 10uF , as your suggestion to lower 22uF cap to 10uF, and check again about 500kC lugs, and output lugs
(http://farm8.staticflickr.com/7050/7018657915_3a26987cb8_z.jpg) (http://www.flickr.com/photos/75813062@N05/7018657915/)
IMG_0579 (http://www.flickr.com/photos/75813062@N05/7018657915/) by DIY Parts + PCB Center (http://www.flickr.com/people/75813062@N05/), on Flickr
(http://farm8.staticflickr.com/7042/7018655911_fff35a6d27_z.jpg) (http://www.flickr.com/photos/75813062@N05/7018655911/)
IMG_0578 (http://www.flickr.com/photos/75813062@N05/7018655911/) by DIY Parts + PCB Center (http://www.flickr.com/people/75813062@N05/), on Flickr
(http://farm8.staticflickr.com/7207/7018654397_a5989141a2_z.jpg) (http://www.flickr.com/photos/75813062@N05/7018654397/)
IMG_0577 (http://www.flickr.com/photos/75813062@N05/7018654397/) by DIY Parts + PCB Center (http://www.flickr.com/people/75813062@N05/), on Flickr
(http://farm8.staticflickr.com/7226/6872545868_bf8e2fec3d_z.jpg) (http://www.flickr.com/photos/75813062@N05/6872545868/)
IMG_0576 (http://www.flickr.com/photos/75813062@N05/6872545868/) by DIY Parts + PCB Center (http://www.flickr.com/people/75813062@N05/), on Flickr
About move up to 250k, in my town, the don't have 250k trim, they just have 200k trim. That's all for the largest value of trimmer, so what should I supposed to do ? I think about change it to Bourns 200k trimme.
Hey mate,
Seems the problem has been solved here, I've got now my phaser working, it PHASING finally, yeayyyy :icon_razz: :icon_razz: :icon_razz:
but I'll think to give more depth on it, could you please tell me how to do it ? like in MXR Phase 90 evh series.
I decided to used new 200k trim, and it's working, I turn left a bit and it comes the phaser sound,
Thank you all
Cheers
I don't know if it gives you more depth, but when I built it, i like it more without the the feedback R (22k).
The depth can be controlled by the trimmer. Try turning it with a fast rate position, it's easier this way.