Phase 90 Output signal

[JRB]

Hello I am working on a phase 90 it seems to work but I ain't sure if the output signal is correct. For now I build it up on a breadboard cause I ain't sure if I like it enough to make it a keeper.

Here is the schematic I used:
http://www.generalguitargadgets.com/pdf/ggg_p90_sc.pdf

I changed C9 to a 10nF cap since it wouldn't let out any signal at all with the 47nF cap
I also removed R15 cause apparently it reduces distortion even tough I haven't really noticed any change so maybe I will put that back in.

I made some photo's of the scoped out signal.
http://s41.photobucket.com/albums/e294/jtheunknown/Phase90/

The thing I find strange is the UDC on the base pin of the output transistor Q5.

If anyone has any experience with this circuit and could tell me if I some how made a screw up I would be quite grateful.

[Mark Hammer]

R15 sets the amount of phase-shifted signal fed back to increase the resonance of the resulting sound.  If one uses too much feedback, then the sum of the input signal and feedback signal can sometimes exceed what either the op-amps or the FETs can tolerate.  But unless one is feeding the pedal a VERY hot signal, and using more feedback (where R15 would be noticeably less than 22k), those circumstances will be rare indeed.

Reducing the value of C9 will trim the bass response, in theory, though nothing you'd notice unless you played bass.

My sense is that whatever problems you are experiencing are not coming from the specific values of these components.

[JRB]

Then I guess the distortion is caused by my guitars humbuckers. And maybe the cap was broken or something was a ceramic but it felt like if you would blow against it it would fall apart. The ting is I ain't really experiencing a problem except for the slight distortion. Its just that what was shown as the output wasn't what I was expecting. I was expecting to see the original signal with the phased out signal together kinda like in a delay as that was the impression I got it would do.

[The_Armadillo]

Technically, there is dry signal at the output. With phasers, the signal is split into two. One part is sent onto a series of all-pass filters (4 in the case of the phase 90) which is slightly delayed (this is not the usual sort of delay, its just moving it out of phase) and the modulated. This causes vibrato when singled out. When its mixed back with the dry signal, the vibrato disappears an what we hear is the peaks and notches that the sum of the two signals produced, which is the whaaaeooo-whaaaeoo that we hear. At 50/50 (50% dry, 50% wet) these peaks and notches are the most noticeable.

[JRB]

I am back and I bring with me a nasty tick problem.

Since last time I have put the phase 90 from the breadboard to the prefboard.
Unfortunately one of the FETs decided to have one of its legs break off and I had to get a new set.

The problem is ever since I put it on the prefboard it developed a nasty tick and I suspect it has something to do with the layout.
I updated the album in the opening post with pictures from the front and the rear of the board so if someone could point me to some obvious error in my layout design I would appreciate it.

To try and get ride of the tick I already tried the resistor and cap as suggested in this thread.
http://www.diystompboxes.com/smfforum/index.php?topic=69638.msg559774#msg559774

Some explanation of what is what:
Looking at the component side of the board,

• The greenwires going off to the right are going to the Speed pot.
• The rigth black wire going down is the output.
• The other black wire going down is the LED.
• The red wire going down is the +DC.
• The green wire going to the left is the input.
• The blue wire going to the left is the -DC.
• All the other blue wires are the -DC.
• All the other red wires are the +DC except for the one at the top that connects the 1M to the gates  (I ran out of colours ).
• The other green wires are connection wires between the drain and the quadopamp and to connect the input of the Quadopamp with the buffer.

The LFO is on the right side of the board.

[JRB]

I did some more test with the scope and it seems the tick gets picked up in the collector of Q5.
I also applied the 100r and 100u to the other opamps with not a really noticeable change.
I change the LFO's opamp from a TL081 to a TL061, this reduced it a bit.

Does anyone roughly know how far the LFO needs to be to not be picked up by any of the other traces?

[JRB]

No one has any Idea how to fixed this? I even tried putting part of the circuit close to the LFO on the breadboard and it didn't do anything to reduce the ticking.