"Little Angel" - Super Simple PT2399 Mini Chorus

[Govmnt_Lacky]

Another nice layout GSM. You might want to edit your Capacitor values as some of them look to be missing information OR are labeled wrong (pF instead of uF)

[GodSaveMetal]

Awesome man, thank you so much, did you build it yet with your PCB
Does everything work OK

I don't build this yet but is based on the idea of Earthscum!!!!!! but the version whit two potentiometers it's great; prove this a notice what happends!!!!!!!!!!!!

[GodSaveMetal]

Another oops!!!!! some tipping error labeled on C6 is 0.1uF the correction is in this layout:

Thanks Govmnt_Lacky for your observations!!! something else please!!!!!

[ppaappoo]

Hi, i make the chorus but don't works, only sound the clean guitar. I used this PCB by Slade on page 8



This is may board



And this are my values compared to the frecuency central ones.

Power supply 8.93V
Tester range 20VDC

TL072

1: 1.4 to 7.3
2: 2.7 to 3.3
3: 2.6 to 3.3
4: 0v
5: 4.79
6. 4.95
7: 4.95
8: 8.93


PT2399

1: 4.95
2: 2.2 to 2.5
3: 0
4: 0
5: 4.94
6: 0.55
7: 0
8: 4.55
9: 4.78
10: 0.33
11 through to 16:  2.4 (slight movement)

Frecuency central

NE5532

1:  0.13 to 4.9
2:  2.9 to 3.2
3:  2.7 to 3.1
4:  0v
5:  4.79
6.  4.9
7:  5.14
8:  9


PT2399

1:  5
2:  2.38 to 2.42
3:  0
4:  0
5:  2.75
6:  0.61
7:  0.88
8:  0.88
9 through to 16:  2.41 (slight movement)

[Govmnt_Lacky]

This is may board

My advice would be to GET RID of that 100 ohm resistor off of Pin 6 of the PT2399 (the one between the 2399 and the voltage regulator) and replace it with a 1K ohm resistor. There has been discussion in this thread about the 100 ohm resistor causing problems.

Good Luck 

[GodSaveMetal]

OK that's 100R resistor causes problems?? if i changes with the 1K you proposed will work fine?? I probe the original layout and changes the PT2399 and It's fine with the 100R resistor!!!! the IC will be that causes problem?? It is wright o no?

[Govmnt_Lacky]

OK that's 100R resistor causes problems?? if i changes with the 1K you proposed will work fine?? I probe the original layout and changes the PT2399 and It's fine with the 100R resistor!!!! the IC will be that causes problem?? It is wright o no?

You need to go back and read Replys 435 through 450. Might clear it up for you.

Good Luck 

[bluesman1218]

Hi, i make the chorus but don't works, only sound the clean guitar.
And this are my values compared to the frecuency central ones.

Power supply 8.93V
Tester range 20VDC

TL072

1: 1.4 to 7.3
2: 2.7 to 3.3
3: 2.6 to 3.3
4: 0v
5: 4.79
6. 4.95
7: 4.95
8: 8.93


PT2399

1: 4.95
2: 2.2 to 2.5
3: 0
4: 0
5: 4.94
6: 0.55
7: 0
8: 4.55
9: 4.78
10: 0.33
11 through to 16:  2.4 (slight movement)

Frecuency central

NE5532

1:  0.13 to 4.9
2:  2.9 to 3.2
3:  2.7 to 3.1
4:  0v
5:  4.79
6.  4.9
7:  5.14
8:  9


PT2399

1:  5
2:  2.38 to 2.42
3:  0
4:  0
5:  2.75
6:  0.61
7:  0.88
8:  0.88
9 through to 16:  2.41 (slight movement)

I had a similar problem with my last build. Here's what it boiled down to for me -
1. make sure the 100R is 1k - it has to do with the PT2399 locking up
2. check the 330K behind the voltage regulator - mine drifted in value
3. check the 1meg from pin 7 on the opamp

In bypass. everything was fine, but no signal at all with the effect on. I found that when I touched the back of the PCB in the output path, I got hum .
I also a - touched up my solder connections
        b - checked every solder joint and trace for continuity and solder bridges
The end result was #3 above
#2 above took care of my voltage readings

Hope this helps. I was very pleased with the build once it was working.

[ppaappoo]

i changed R1 (100R) to 1K and the effect becomes to work but the depth pot only acts at the end, i used a 470k one

[Govmnt_Lacky]

i change R1 (100R) to 1K and the effect became work but the depth pot only acts at the end. i use a 470k one

This was also addressed in this thread. Some people (including me) opted to use a 100K pot because the effect was only working during the last little bit of the 470K pot rotation (the last 100K or so)
Rick however, voiced his opinion about this saying that he liked the "doubling" effect that the 470K pot gave when it was in use.
It is all in this thread.... just gotta find it.  

Good to hear you got it working though 

[ppaappoo]

yes, i'll change the depth pot and adjust R1 to my teste.

So, for the next builders:
DEPTH POT ---> 100k
R1 ---> 1k to 10k or 22k

[GodSaveMetal]

yes, I'll change the depth pot and adjust R1 to my taste.

So, for the next builders:
DEPTH POT ---> 100k
R1 ---> 1k to 10k or 22k

OK OK!!! that's fine are you sure for change the 100R for that's values??? what happends??? now your pedal is in functions???

[ppaappoo]

1K for R1 it's ok,you olso can use a 5k pot in series with 1k resistor to make a delay control.

the chorus works! thanks to all

[ppaappoo]

I have a question, what type of wave generated by lfo?
if someone had a function generator may inject a specific signal on pin 2 of the pt2399, and compare how respond the chorus.

[GodSaveMetal]

1K for R1 it's ok,you olso can use a 5k pot in series with 1k resistor to make a delay control.

the chorus works! thanks to all

thank ppaappoo I made other PCB for probe this and other modes; my 5 pot mode!!!!!!!!!!!!

[ppaappoo]

today I will inject a triangular signal on pin 2 of pt2399, but I have a doubt about the voltage range supported by the ic.

[LaceSensor]

Hi, i make the chorus but don't works, only sound the clean guitar.
And this are my values compared to the frecuency central ones.

Power supply 8.93V
Tester range 20VDC

TL072

1: 1.4 to 7.3
2: 2.7 to 3.3
3: 2.6 to 3.3
4: 0v
5: 4.79
6. 4.95
7: 4.95
8: 8.93


PT2399

1: 4.95
2: 2.2 to 2.5
3: 0
4: 0
5: 4.94
6: 0.55
7: 0
8: 4.55
9: 4.78
10: 0.33
11 through to 16:  2.4 (slight movement)

Frecuency central

NE5532

1:  0.13 to 4.9
2:  2.9 to 3.2
3:  2.7 to 3.1
4:  0v
5:  4.79
6.  4.9
7:  5.14
8:  9


PT2399

1:  5
2:  2.38 to 2.42
3:  0
4:  0
5:  2.75
6:  0.61
7:  0.88
8:  0.88
9 through to 16:  2.41 (slight movement)

I had a similar problem with my last build. Here's what it boiled down to for me -
1. make sure the 100R is 1k - it has to do with the PT2399 locking up
2. check the 330K behind the voltage regulator - mine drifted in value
3. check the 1meg from pin 7 on the opamp

In bypass. everything was fine, but no signal at all with the effect on. I found that when I touched the back of the PCB in the output path, I got hum .
I also a - touched up my solder connections
        b - checked every solder joint and trace for continuity and solder bridges
The end result was #3 above
#2 above took care of my voltage readings

Hope this helps. I was very pleased with the build once it was working.

Hi thanks for your input
Can you clarify what you mean by checking the 1M and the 330K? Do you simply mean checking their resistance is accurate?
I did indeed use a 1k rather than the 100R resistor mentioned.

[bluesman1218]

I had a similar problem with my last build. Here's what it boiled down to for me -
1. make sure the 100R is 1k - it has to do with the PT2399 locking up
2. check the 330K behind the voltage regulator - mine drifted in value
3. check the 1meg from pin 7 on the opamp

In bypass. everything was fine, but no signal at all with the effect on. I found that when I touched the back of the PCB in the output path, I got hum .
I also a - touched up my solder connections
        b - checked every solder joint and trace for continuity and solder bridges
The end result was #3 above
#2 above took care of my voltage readings

Hope this helps. I was very pleased with the build once it was working.
[/quote]
Hi thanks for your input
Can you clarify what you mean by checking the 1M and the 330K? Do you simply mean checking their resistance is accurate?
I did indeed use a 1k rather than the 100R resistor mentioned.
[/quote]

Yes, that's what I meant.

[ppaappoo]

it's possible a softless lfo? like a sine wave or just modify the current lfo to make it more soft on the peaks?

thanks

[ppaappoo]

hello, how I can do to increase the volume of the signal delay? o maybe add a mix control.