My phase 90 clone isn't working

[Kevin Mitchell]

I didn't see any mention of your JFets, are they matched?

i think so yea

So what's the story on these jfets?

Where did you get them?
Were they actually tested and/or matched?
-Did you purchased them as a matched set for this project?
-If you had tested and/or matched them, what method did you use and how many did you purchase to do this?

Again, jfets are commonly counterfeited. These parts are no longer manufactured in TO-92 packages so everything is either old stock or absolutely fake.

I got a 20 pack off of Amazon.

I'm guessing you were dishonest the first time you were asked about matching as you've neglected to answer it adequately once again. There's plenty of folks here who want to help you but they need you to be upfront, vigilant and observant of your work.

Follow the build notes. You can't afford to take shortcuts. Hell, you might learn a thing or two along the way.

Best of luck moving forward.

[andy-h-h]

I didn't see any mention of your JFets, are they matched?

Again, jfets are commonly counterfeited. These parts are no longer manufactured in TO-92 packages so everything is either old stock or absolutely fake.

You can still buy proper JFETS from reputable suppliers - they are still widely available from Mouser and others.    Amazon on the cheap....  Not recommended.   

There's even a run of through hole J201 about to become available on Mouser.   Expensive, but they will be the real deal.   

[snow123]

I didn't see any mention of your JFets, are they matched?

Again, jfets are commonly counterfeited. These parts are no longer manufactured in TO-92 packages so everything is either old stock or absolutely fake.

You can still buy proper JFETS from reputable suppliers - they are still widely available from Mouser and others.    Amazon on the cheap....  Not recommended.   

There's even a run of through hole J201 about to become available on Mouser.   Expensive, but they will be the real deal.

is jameco good?

[bushidov]

Usually Jameco is good. I have obtained some 8 bit computing ICs from them a few times.

[andy-h-h]

Any big supplier is fine.  Just have to watch what appears to be mainly small Chinese suppliers on ebay, Amazon, Ali etc. 

[snow123]

i just matched the jfets and im getting the same results as before.

[snow123]

i just build this jfet matcher:


and i just tested a bunch of the 2n5457s that i got from that bundle off of amazon, and used 4 of them that had the same voltage.

[snow123]

and i also just ordered some 2n5457s off of jameco just in case

[snow123]

im still not getting a phaser effect tho

[snow123]

heres the transistor voltages:


Q1
D = 4.7
S = 4.8
G = 1.8


Q2
D = 4.7
S = 4.8
G = 1.8


Q3
D = 4.7
S = 4.8
G = 1.8

Q4
D= 3.6
S= 4.8
G= 1.8

Q5
C = 3.6
B = 4.2
E = 4.8

[snow123]

anyone still here?

[snow123]

well while the pedal is on it takes out a little bit of low end but thats it.

[snow123]

and ive checked the soldering and stuff and everything looks good.

[snow123]

Here's the soldering and stuff:















I also did replace those electrolytics with a 10uf and 4.7uf in parallel, and my Russian big muff that I was working on is working now.

[snow123]

ok, here:

P5 = 0.0
P6 = 2.2
P7 = 0.0

So...no sign of the voltages varying at all then?

Those look terrible if they're fixed numbers. You should be able to see pin 7 switch from a high state (close to 9V, but not 9V) to a low state (close to 0V but not 0V - how close in both cases depends on which op-amp you use). The pin 6 voltage should follow the voltage on the 15uF cap, a triangle wave going linearly up and down - and the triangle frequency should be affected by that 500K rate pot.

Check the component connections for the LFO carefully, and not just the joints, but *where* they're joined. Looks like something is wrong there somewhere.

and the voltage on ic3 is working correctly, so thats not the issue.

[Kevin Mitchell]

What can the kind folks of this community do for you to start fixing your shorted connections?

And don't tell me there's no shorts because I'm looking right at them *more than one*.

[antonis]

And don't tell me there's no shorts because I'm looking right at them *more than one*.

edit: There is more than one unshorted track..!!

[Kevin Mitchell]

And don't tell me there's no shorts because I'm looking right at them *more than one*.

edit: There is more than one unshorted track..!!

LOL barely.... I started circling obvious shorts and suspicious spots. There's way too many once you really glance at it all.

Snow, CONTINUITY CHECK. Watch a youtube video if you haven't figured it out by now.

Use your soldering iron to clear them out ONCE YOU KNOW THEY ARE SHORTED, don't just gouge at them with a screwdriver and pray it does something.  With the iron wick them away without making it worse by spreading it out.

[snow123]

And don't tell me there's no shorts because I'm looking right at them *more than one*.

edit: There is more than one unshorted track..!!

LOL barely.... I started circling obvious shorts and suspicious spots. There's way too many once you really glance at it all.

Snow, CONTINUITY CHECK. Watch a youtube video if you haven't figured it out by now.

Use your soldering iron to clear them out ONCE YOU KNOW THEY ARE SHORTED, don't just gouge at them with a screwdriver and pray it does something.  With the iron wick them away without making it worse by spreading it out.

ok, im pretty sure i fixed all of the shorts and im still getting a dry signal when i turn the pedal on..

[antonis]

ok, im pretty sure i fixed all of the shorts and im still getting a dry signal when i turn the pedal on..

In such a case we are pretty sure you have to consult an exorcist..