Troubleshooting vintage Phase 90

[Govmnt_Lacky]

All IC chip solder joints have been soldered. There are 2 large unsoldered holes in the board I am asking the seller about.

Those 2 large holes are for mounting the PCB in the enclosure by plastic standoffs.

I am guessing that you went through and re-flowed all solder points again since taking the above pictures. If not... you really need to.

[gordo]

In the meantime...cool to have an original board or a copy of it.

[mgalicki]

So the seller said the 2 holes in the board are to be left open. Nothing gets soldered to them.

[mgalicki]

From the Seller:
You do have the ICs oriented correctly?  ICs 2 3 4 and 5 are facing opposite direction from IC 1 and 6.  Let me know. 
I think you may be off in following the audio path.  The audio splits after IC1 and goes with a clean sound to R27 and the other split goes to C2 and R7 to go thru the 4 stage phasing process.( thru ICs 2, 3 4 and 5),  you should hear the phasing warble getting more intense on Pins 2 and output pin 6 of those ICs.  Then the clean and warbled sounds are mixed in the pnp transistor stage just before output.

You won't hear any sound anywhere on the FET Pins as they are there for the sole purpose to fluctuate the current going into the phasing ICs at whatever rate the LFO is set to be (LFO being the circuitry around IC6 and controlled by pot R21).    SO...if you are not getting any sound on the left side, not even to pin 2 of IC2, you would need to find out what's happening to the sound between pin 6 of IC 1 and pin 2 of IC2

[mgalicki]

So, great news! I guess resoldering all the joints fixed it! Praise to you all for your comments. My first DIY has become a success thanks to madebeenpedals Guru's.

[jimilee]

Woohoo!! Congratulations. That fixes about 98% of your issues.


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[mgalicki]

So what's the other 2% of my issues??

[Govmnt_Lacky]

So what's the other 2% of my issues??

He meant to say "Re-soldering your joints will fix your issue 98% of the time."

But... it's more like 50% 

[mgalicki]

Gotcha, so now that it's workin I'm thinkin about adding the script mod with a mini push button. Where would I get that?
Thanks

[jimilee]

So what's the other 2% of my issues??

He meant to say "Re-soldering your joints will fix your issue 98% of the time."

But... it's more like 50% 

I guess it's subjective. Either way, it's a good starting point for troubleshooting.


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[Govmnt_Lacky]

I guess it's subjective. Either way, it's a good starting point for troubleshooting.
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Agreed! As your skills with the iron progress from Padawan to Jedi, your chances of solder joints being the issue greatly decrease. Then, it becomes dumb mistakes like connecting Input and Output wires to the wrong sides of jacks.... take it from me 

[mgalicki]

So could  I put a potentiometer instead of an on/off switch on R28?

[mgalicki]

Well I did it, the effect does soften when dialed down about 25%. But I can only dial it back about 25% before the volume starts to drop along with the effect. cool stuff.

[jimilee]

Welcome to diy man. I love me some phasery goodness.


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