"Little Angel" - Super Simple PT2399 Mini Chorus

[haveyouseenhim]

Ah haaaa! It was r15. I used a 10m on accident. The blue and green striped om my resistors look so much alike. I wish there was a way i could thank you besides typing these words. But thank you so much.  It sounds great       Ive built quite a few effects, but i'm new to the whole stompbox forum thing. So its really awesome to talk directly to the designer.

[frequencycentral]

My pleasure. Though I'm not a designer I'm a pretengineer...

BTW, I've got a few spare LA PCBs available @ £10 GBP each (including shipping).

[haveyouseenhim]

you're an engineer under the age of 13?   wow    lol....oh thanks, i prefer to etch my own. its more satisfying that way. I have a veggie garden and the guy next door owns a plant nursery and is always trying to sell his pre-sprouted things to me. I guess he doesn't get that i like to start with nothing but a seed.   Hmm i think i just got a little philosophical 

[haveyouseenhim]

I have an idea for a mod now that i made that pleasant mistake. I'm going to put a switch on r15 that switches between 1 and 10m. I'm going to label it good/evil. Someone try this and tel me what you think of the tone.

[haveyouseenhim]

So through the magic of ms paint i made this:



Basically its just switching between the 1M and 10M and the red and blue leds. Since one led draws more than the other the switch just connects the two positive leads making them steal power from each other. I'm probably going to change it to a tpdt switch so i can add some clipping diodes to smooth out the randomness of the distortion. Let me know if any of you see anything wrong with what I'm doing.

Edit: i forgot the led resistor

[spampa]

Hello @ all,
I´m Zottel from germany, and I´m new here at the Diystompboxes.com, but i´ve built many effects the last time.
If you are interested you can visit my Blog: http://juicypedals.blogspot.de
Now I need to build The PT 2399 little Angel "Birthday edition", but I have some trouble with the scaling when i print the PCB because it is to big.
I want to use the layout from Page 33:http://www.diystompboxes.com/smfforum/index.php?topic=86297.660
Have anyone a Adobe PDF Document with the PCB or can me help in other ways?
With kind regards, - and sorry for the bad english,
Zottel

[karter2000]

Hi all,

Just built a LA from Rick's excellent pcb.  However, I must have done something wrong as it's not working right.  I'm not getting much of a chorus effect, rather a harsh loud fuzz on every note.  The pots don't seem to do anything, and occasionally the PT2399 locks up.  I've probed around and didn't see anything blatantly wrong.  My voltages are:

NE5532:

1. 3.06
2. 3.14
3. 2.82
4. 0
5. 3.40
6. 4.27
7. 4.70
8. 9.16

PT2399:

1. 5.00
2. 2.39
3. 0
4. 0
5. 5.00
6. 0.72
7. 0
8. 4.57
9. 4.82
10. 0.38
11 2.42
12 2.42
13. 2.42
14. 4.57
15. 2.42
16. 2.42

Thanks for looking!

[frequencycentral]

Yours:

NE5532:

1. 3.06
2. 3.14
3. 2.82
4. 0
5. 3.40
6. 4.27
7. 4.70
8. 9.16

PT2399:

1. 5.00
2. 2.39
3. 0
4. 0
5. 5.00
6. 0.72
7. 0
8. 4.57
9. 4.82
10. 0.38
11 2.42
12 2.42
13. 2.42
14. 4.57
15. 2.42
16. 2.42

Mine:

Here are voltages just taken from my Little Angel, which sounds the same as the breadboarded version I did you soundclips on. Speed at 3 o'clock, Depth at 12 o'clock:

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)


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

So it seems you have some way-off voltages at:

PT2399 pins 5, 7, 8, 9 ...you get 5V on pin 5? Pin 7 being ground is causing an issue elsewhere.

NE5532 pins 1, 2, 3 ...particularly concerning as these should be moving, which says the LFO isn't running.

NE5532 pins 5, 6, 7 ...pin 5 is way off, fix that and 6 and 7 might fall into line.

Solder bridges and/or incorrect resistor values is my guess.

[Maik]

Hello @ all,
I´m Zottel from germany, ..............................but I have some trouble with the scaling when i print the PCB because it is to big.
I want to use the layout from Page 33

Hi Zottel

die Maße sind 54,7x34,05mm
Kannste mit DIY Layout testen (Raster auf 2,54 stellen und Zeichnung (BMP) importieren...

Sorry for german, but this will go quicker then...

[karter2000]

So it seems you have some way-off voltages at:

PT2399 pins 5, 7, 8, 9 ...you get 5V on pin 5? Pin 7 being ground is causing an issue elsewhere.

NE5532 pins 1, 2, 3 ...particularly concerning as these should be moving, which says the LFO isn't running.

NE5532 pins 5, 6, 7 ...pin 5 is way off, fix that and 6 and 7 might fall into line.

Solder bridges and/or incorrect resistor values is my guess.

I've checked the values of everything, and there are no solder bridges.  I'm guessing my build is really jacked beyond fixing.  Probably put it down before I smash it into a thousand pieces on my workbench.

[frequencycentral]

Ah, the old 'smash it into a thousand pieces on my workbench' debugging technique, never fails to satisfy. 

[karter2000]

Yeah, I promise I won't do anything drastic.  I've learned to come back to debugging after a bit of a break. 

Thanks for your help Rick!

[Kunfuz]

Got the same fuzzbuzz lawnmover action from mine sadly 
Thanks for the voltages Rick, will check em out again...

[tuckster]

Yeah, I promise I won't do anything drastic.  I've learned to come back to debugging after a bit of a break. 

Thanks for your help Rick!

Mine is in a big box of unfinished pedals time to get it out again I think I can fix it now......

[Jerem]

Hi everybody, I have finished my little angel chorus but I think the output volume is too small. I want to push up the output gain so witch resistor I have to change? Thank for your answer!!

[frequencycentral]

Hi everybody, I have finished my little angel chorus but I think the output volume is too small. I want to push up the output gain so witch resistor I have to change? Thank for your answer!!

The output should be at unity with the input. Perhaps you have an error? How much too low is it? You could try taking voltages from your build and comparing them to mine, that way you may be able to identify where the error occurs.

[Jerem]

Thank for your answer. The sound volume is the same when I push up the volume of my gear.

I just test the Ic of the circuit :

NE5532
pin1 : 5.14v
pin2 : 4.78v
pin3 : 4.62v
pin4 : 0.5mV
pin5 : 8.74v
pin6 : 2.9v
pin7 : 2.95v
pin8 : 2.82v

PT2399

pin1 : 4.94v
pin2 : 2.38v
pin3 : 0.5mV
pin4 : 0.5mV
pin5 : 2.48v
pin6 : 0.433v
pin7 : 0.847v
pin8 : 0.849v
pin9 : 2.38v
pin10 : 2.38v
pin11 : 2.38v
pin12 : 2.38v
pin13 : 2.38v
pin14 : 2.37v
pin15 : 2.38v
pin16 : 2.38v

[axeltrance]

Hi to all, this is my first post.

First of all sorry for my english, i'm italian.

I made an eagle layout and board of the project, here we are:





In the next days, i made the pcb and all the rest.

If someone is interested to the Eagle files, i can post on the forum.


Bye.
Axeltrance

[herrdoktor]

Hi,
I finished and it works, but I've some issues
1) When I turn on the pedal I hear the oscillation of LFO in my amp
2) I hear a strange response to low frequencies (low E) with some setting of Depth and rate.

Could you say me something?
the point 1) is really important to solve.

[garcho]

@Jimi P

if i plug in the input jack a couple times, it will catch and work fine until it's powered down, but then if i plug it in again, i gotta plug it in several times again.

I have the exact same issue! Figured I made a mistake somewhere so I'm about to put it back on the breadboard and try again, probably with some mods and somewhat controllable space madness (hopefully). Any up luck with the lock up?