Warbling phaser

[Luke51411]

The first link is 75 percent rotation the second is full. I found a set of better matching fets with just one a bit further out so I'm going to break out the soldering iron and make a fixed stage.
https://www.dropbox.com/s/je043696ywxlnph/New%20Recording%202.m4a
https://www.dropbox.com/s/fgvv5rcw7a72j2y/New%20Recording%203.m4a

[Luke51411]

It's always the simple things... One of the 150k resistors had a bad solder joint. Now it sounds right. I feel slightly like an idiot. I did learn a lot though!

[armdnrdy]

I just listened to the sound samples and I was going to post....

The problem is not the JFETs, LFO, or the zener. You have to look for a wrong value component or a solder bridge.

It's good that you found the problem.

[Luke51411]

The good news is I have a couple sets of fets for the next phaser build!

[GibsonGM]

Good deal, Luke! Glad to hear that, as usual, you've found the issue )   You can always use some FETs! 
Eventually this will become second nature. You just KNOW there's something wrong like that resistor, and fixate on it...just takes experience.
On to the next one!

[Luke51411]

Yeah this one threw me off because it worked and didn't exactly sound bad and I knew that matching fets important so I just fixated on that side of it. Now I need to look over my p45 I think I have a similar issue there. I also built it on a pcb and I'm used to vero. It's easier to solder so I glossed over that possibility.

[Luke51411]

I must forget how to solder on pcb... I looked at my p45 and found several solder bridges... Chalk it up to being used to vero I guess. Oh well... Works great now. Now I have two phasers. Lesson learned... Always check the small stuff first. And buy a magnifying glass perhaps.

[GibsonGM]

I must forget how to solder on pcb... I looked at my p45 and found several solder bridges... Chalk it up to being used to vero I guess. Oh well... Works great now. Now I have two phasers. Lesson learned... Always check the small stuff first. And buy a magnifying glass perhaps.

Ha ha, great advice man! I use a magnifying glass and a bright desk lamp a lot...really helps!   Plus, sometimes giving it a break for a few helps you come back at it fresh.  We all do it...

[Luke51411]

Dumb question (probably). Could I just take the suggestion mark gives to build 2 new phase shift sections by removing the fet and changing the 22k resistor value?

[Mark Hammer]

Yes.  The 22k sets the lowest point in the sweep.  Just remember, such stages will not sweep, even though their phase-shift is added to the phase-shift of the swept stages.

[Luke51411]

Would it be worthwhile to add 2 fixed stages?

[Luke51411]

And if so, where would be the best place to patch them in? or would it matter?

[Mark Hammer]

Give this thread a read, and it may answer your questions as well as provide useful examples:  http://www.diystompboxes.com/smfforum/index.php?topic=80456.0

[Luke51411]

Thanks Mark, your input is always greatly appreciated! I think I'm going to try the fixed stages on a daughter board and just see what happens! Not too many components. It should be fun and will definitely be educational!