"Little Angel" - Super Simple PT2399 Mini Chorus

Post by **GodSaveMetal** » 19 May 2013, 00:46

dthurstan wrote:Hey

Here is my Little Angel build;

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Built for my mates 30th. The batch of enclosures I did last weekend that included this one is the best I've made.

I too am having trouble with the PT locking up. Changing the timing cap to 47uF made it worst, so I'm keeping it at 10uF. Using it on its own is fine. Its when I daisy it with other pedals were it locks up. I don't really have many chips to audition for it. I bought 3 off ebay. I'm giving him the pedal tomorrow so don't have time to mess with it much more.

Has anyone figured out what it is about the chip which causes lock up? I was thinking of getting some more chips and testing them when I find a good one I can send it to him to replace. I guess a good test would be to breadboard a simple delay circuit with a small timing resistor and see which chips don't lock up?

Also has anyone else noticed the popping? I put a 2.2M from input to ground on the reverse of the board but it hasn't helped.

Dave

Put the IN to ground by a yellow cable I draw in yor photo; you see it?? it makes the input to ground wen you shot OFF; it makes discharge the condensers to ground and no POP wen you shot ON the pedal!!!

dthurstan · Post by **dthurstan** » 22 May 2013, 09:59

Cheers for the tip GodSavesMetal.

Input grounding the circuit in bypass, I may have to look at some of my other builds.

Duckman · Post by **Duckman** » 08 Jul 2013, 23:16

rocklander wrote:thanks for the suggestion. I've now got a 4K7 in there and get some wild depth, but the 500K pot still leaves plenty of room to drop it down to almost nothing...

I managed that today, changing the 500k pot to 50k... seems to work fine

shiflet · Post by **shiflet** » 19 Aug 2013, 06:50

Boys, i have a small problem with this pedal, i assembled and the effect is very low listening,that is to say, listening is very in the background the effect of the chorus, is not strong, it is not in unity, review the components and are all ok, use the layout version of the birthday, will be that one cannot give me a hand? Now change the IC's and the transistor, but the same thing is heard under, used everything that requests the scheme ...

shiflet · Post by **shiflet** » 22 Aug 2013, 06:29

Anyone?

Cannibal · Post by **Cannibal** » 22 Aug 2013, 20:55

my first guess is that you've put a wrong value resistor in the mixing stage (the two 10k resistors before the output).

Rax89 · Post by **Rax89** » 01 Sep 2013, 01:53

Can you get John Scofield chorus sound out of it?

otsismi · Post by **otsismi** » 13 Dec 2013, 07:13

I breadboarded this today but sometimes when I move the pots the chorus stops and then starts again. Is this the locking up problem?

fuzz_germanium · Post by **fuzz_germanium** » 13 Apr 2014, 14:28

hello guys, i'm gonna build this pedal, but is necessary have a capacitor MKP? or condenser polyester is the same?

Thank you!

IvIark · Post by **IvIark** » 13 Apr 2014, 15:05

Just use anything that fits, they will all work fine

fuzz_germanium · Post by **fuzz_germanium** » 14 Apr 2014, 01:08

IvIark wrote:Just use anything that fits, they will all work fine

Thank you very much!

commathe · Post by **commathe** » 14 Apr 2014, 06:07

Can anyone help me understand how this chorus works? I don't understand how the PT2399 is working in this circuit and I don't get how it even creates the chorus sound

grrrunge · Post by **grrrunge** » 14 Apr 2014, 09:09

commathe wrote:Can anyone help me understand how this chorus works? I don't understand how the PT2399 is working in this circuit and I don't get how it even creates the chorus sound

Then PT2399's pin 6 is grounded for the shortest possible delay time. Modulating the supply voltage then varies the delay time, giving you the wet side of the chorus effect. It's all pretty well documented throughout this thread.

frequencycentral · Post by **frequencycentral** » 14 Apr 2014, 09:13

When I was breadboarding using the PT2399 with delay set very short, I noticed that the delay time 'swooped' down if I disconnected power to the PT2399. Plugging an LFO into the chip's vref pin simulates power being disconnected/reconnected very quickly. It's cheating really.

commathe · Post by **commathe** » 16 Apr 2014, 03:09

Isn't the Vref pin into the op-amps? How come that simulates the power being switched on and off?

copachino · Post by **copachino** » 08 Jun 2014, 03:14

i have search but i cant figure out, the sizes from the original PCB, its not specified, can anyone tell me the size?? im really interested on this chorus sounds amazing on the videos

RenéF · Post by **RenéF** » 01 Aug 2014, 19:15

Hi

Does anyone have the original pcb-transfer PNG-file? The proportions are way off on the picture on page 1.

If you have the original file I would really like to get a hold of it

Thank in advance

René

frequencycentral · Post by **frequencycentral** » 19 Aug 2014, 12:30

Resize to 48%.

"Little Angel" - Super Simple PT2399 Mini Chorus [documentation]