Questions about my bad phaser design

[Josh?]

Hey everyone! I'm currently designing a phaser for a friend. It's essentially a phase 45 with anotherJim's LFO from this thread: https://www.diystompboxes.com/smfforum/index.php?topic=107962.0, and with the remaining cd4049 stages used as input and output buffers. Here's my schematic:

Phaser1.png

The LFO

[Josh?]

whoops didn't finish typing.

To be continued in a couple minutes...

[Josh?]

So I can't figure out how to post my schematic at the moment, but here's what's wrong so far on my breadboard:

The LFO works great (thanks Jim!), but introduces a clicking sound into the audio path. Is this because I'm also using the LFO IC for buffer stages, or is it because of something else?

My phase shift stages are just passing dry audio, so that I just get an unaffected guitar sound with a rhythmic clicking noise when I turn on the pedal. I've tried J201s and 2N5485s, both matched, with no difference. What might cause this?

Thanks in advance, everyone, and I'll try and find a way to post my schematic soon.

[patrick398]

Have you tried adjusting the bias trimmer? Sounds like the fets are mis-biased to me.

[duck_arse]

you need to upload your image, after you've reasonably resized it as needed, to a hosting site, like imgur or that little blue P button. the hosting site gives you a link address to your image, which will usually have the "img" tags start and end - you just past their url in the page and we all gawp at it.

[PRR]

> at 10:04:32 PM
> at 10:05:31 PM
> whoops didn't finish typing.

You have about 15 minutes after a Post to hit the Modify button and fix/add words.

> find a way to post my schematic soon.

[Josh?]

Alrighty, update after too long. Thanks for being patient with me!

First of all, I got the phaser working on breadboard, and mostly removed the ticking, but it's still there. Here's my schematic:
https://imgur.com/a/raT6KBz

My JFETs are 2N5485, opamps are both TL071, and the inverters are all on a single CD4049UBE ic. (Putting my 100uF cap to ground as close as possible to vcc on the 4049 helped a ton with the ticking, but it's still there.) Any suggestions for further removing the lfo tick?

Also, sorry I didn't notice the modify button and had so much trouble formatting everything

[duck_arse]

it's possible that the oscillator invertors are producing the clicking, and the two invertors in the audio path use the same internal supply connections. no way around that. try inserting a small value resistor - 100R? 470R? 2k2?  dunno? - before the 10k zener resistor, between the invertors supply pin and supply, keeping your added electro cap on the IC side of the added resistor.

[Josh?]

it's possible that the oscillator invertors are producing the clicking, and the two invertors in the audio path use the same internal supply connections. no way around that. try inserting a small value resistor - 100R? 470R? 2k2?  dunno? - before the 10k zener resistor, between the invertors supply pin and supply, keeping your added electro cap on the IC side of the added resistor.

Hey thanks for the help! I was worried my space-saving trick with the leftover stages was the problem, and it seems like it is. I tried keeping the electro cap from vcc of the 4049 to ground, and separating vcc and v+ with a variety of resistors from 10R to 1k5, and all of them interestingly made the the clicking louder and bassier. Also, anything above around 800R made the LFO stop altogether. Any ideas why these things might happen?

Second, I've noticed the duty cycle of the LFO isn't exactly 50%, it's around a 45% to 55% ratio. Any ideas why?