Phase II too subtle

[Ludovic]

As a beginner with poor knowledge in electronic, I built the Phase II from a Musikding kit. I'm not that happy with the result.

1/ I have to fully close the 10K trimpot for the yellow LED to start blinking, and fully open the 1K trim to have a decent sweep.
In the end, the phase effect is very subtle, even with depth maxed out.
Is it possible the LED specs is not adapted to the circuit? How can I double check that? Is it worth trying to pair the led with an extra resistor? Which value? Or maybe I should replace the 10K trim by an higher one?

2/ I was expecting the phaser to periodically gently boost low ends during the sweep. That never happens. It this the normal behavior?

Thank you for any suggestion!

 

[DGWVI]

While it can definitely do subtle sounds, with the depth and feedback maxed you should be getting some heavy whoosh with a bit of throb.

Any way you could post some pics of the component side so we could see if maybe a part or two is off?

 

[DGWVI]

Here's one that's mostly stock. The trimpots are made external, and I used 9203 LDRs. But I wouldn't call it subtle

 

[Ludovic]

What do you think about the behavior described? (10K trim at 0 or no blinking, 1K trim at almost 100% or no sweep)

Here's a sound with 5 parts:
1- Guitar with Phase II off
2- Guitar with Phase II on, depth and feedback at 0
3- Guitar with Phase II on, depth 100% and feedback at 0
4- Guitar with Phase II on, depth 100% and feedback 100%
5- Guitar with Phase II on, depth 100% and feedback 100%, increased rate

https://soundcloud.com/ekovah%2F20230624-phase-ii-kit

Ringing a bell on something to anyone?

 

[DGWVI]

What do you think about the behavior described? (10K trim at 0 or no blinking, 1K trim at almost 100% or no sweep)

Here a sound with 4 parts:
1- Guitar with Phase II off
2- Guitar with Phase II on, depth and feedback at 0
3- Guitar with Phase II on, depth 100% and feedback at 0
4- Guitar with Phase II on, depth 100% and feedback 100%
5- Guitar with Phase II on, depth 100% and feedback 100%, increased rate

https://soundcloud.com/ekovah%2F20230624-phase-ii-kit

Ringing a bell on something to anyone?

It sounds right, but definitely not as intense as it should be. Verify all component values from R37-R46

Could we see pics of the component side of the board?

 

[mkstewartesq]

What do you think about the behavior described? (10K trim at 0 or no blinking, 1K trim at almost 100% or no sweep)

Here a sound with 4 parts:
1- Guitar with Phase II off
2- Guitar with Phase II on, depth and feedback at 0
3- Guitar with Phase II on, depth 100% and feedback at 0
4- Guitar with Phase II on, depth 100% and feedback 100%
5- Guitar with Phase II on, depth 100% and feedback 100%, increased rate

https://soundcloud.com/ekovah%2F20230624-phase-ii-kit

Ringing a bell on something to anyone?

Oddly, this is about how my XC Phase sounds (everything seems to be soldered and wired correctly, and the jfets are matched). I opened a troubleshooting thread here but no solution was found, and, as you feel with your build, I feel certain that mine isn’t phasing nearly to the extent it is supposed to either. I hope you find a solution to your problem. Perhaps it will be something that I can apply to my own build to get an improvement.

Mike

 

[Ludovic]

Here is a pic of the components side of the PCB if it helps.

 

[Nic]

Top right chip is upside down

 

[DGWVI]

Top right chip is upside down

No, it's right side up. That's the voltage converter

 

[Betty Wont]

Two things, first are you testing it in the dark? This pedal will not work with light hitting the inside of the enclosure. Secondly, what you’re describing sounds more like what would happen if you had swapped the trimpots.

 

[DGWVI]

Here is a pic of the components side of the PCB if it helps.View attachment 51037

I'll give this a good look when I return home. Can you confirm the values of the trimpots?

 

[Ludovic]

Secondly, what you’re describing sounds more like what would happen if you had swapped the trimpots.

Thought the same, double checked, not the case, left one on the pic is 1K, right one is 10K, DMM tested.
I'm currently checking resistors R37-R44 as suggested. Will update once completed.

 

[music6000]

Should say on the side of Trimmers 102 for 1K on the Left, 103 for 10K on the Right.

 

[Ludovic]

Is R39 4k7 instead of expected 47k?

 

[DGWVI]

Is R39 4k7 instead of expected 47k?View attachment 51040

Definitely reads as 4.7k

 

[Nic]

No, it's right side up. That's the voltage converter

Well, I started with the assumption Robert always had all the IC with pin 1 top left !!! Thanks for correcting me, I should have looked at the build doc.

 

[Ludovic]

Definitely reads as 4.7k

And is R20 47k instead of expected 4k7?
Feel like I need to heat the soldering iron...

 

[DGWVI]

And is R20 47k instead of expected 4k7?
Feel like I need to heat the soldering iron...
View attachment 51047

Yep

Looks like you got those two values swapped. Easy enough fix, though

 

[Ludovic]

Easy spotting and guidance for you! Hard time to remove and resolder resistors for me
But now we talk!

Thank you very much DGWVI, you're the man. You made my week-end! Thanks all.

PedalPCB Phase II Kit fixed, 5 parts:
1- Guitar with Phase II off
2- Guitar with Phase II on, depth and feedback at 0
3- Guitar with Phase II on, depth 100% and feedback at 0
4- Guitar with Phase II on, depth 100% and feedback 100%
5- Guitar with Phase II on, depth 100% and feedback 100%, increased rate

https://soundcloud.com/ekovah%2F20230624-phase-ii-kit-fixed

 

[DGWVI]

Easy spotting and guidance for you! Hard time to remove and resolder resistors for me
But now we talk!

Thank you very much DGWVI, you're the man. You made my week-end! Thanks all.

PedalPCB Phase II Kit fixed, 5 parts:
1- Guitar with Phase II off
2- Guitar with Phase II on, depth and feedback at 0
3- Guitar with Phase II on, depth 100% and feedback at 0
4- Guitar with Phase II on, depth 100% and feedback 100%
5- Guitar with Phase II on, depth 100% and feedback 100%, increased rate

https://soundcloud.com/ekovah%2F20230624-phase-ii-kit-fixed

Rad!!

Glad you got this one working. This is still my favorite phaser circuit, so I love seeing others' builds out there