"Little Angel" - Super Simple PT2399 Mini Chorus

[Barcode80]

I've read from previous pages and I found to avoid the lockup from PT2399 is by substituting the value of resistor R1, capacitor C1 and C3 with the value that I mentioned above. Is there another trick that I missed? please let me know .... 

here:

http://www.diystompboxes.com/smfforum/index.php?topic=86297.msg774512#msg774512

[cobexonly]

Don't know if anyone else has mentioned this, but if you are getting intermittent operation out of your LA, check what your power is reading. I found out the hard way on a used pedal board that someone had tried the 100r + huge cap trick for a noisy cheap wall wart that ended up with 8.1 vdc with only four pedals hooked up. At that voltage level both my LA and Echobase lfo's quit. Worked just fine when the One Spot powering the internal power strip did not get loaded down by the R/cap mentioned above. It went from 8.1 vdc to 9.54 vdc just eliminating that cludge. This worked both for the original with the pin 6 fix daughter board, and the birthday edition I built just to have everything on one board.

nice info bro...  I will measure voltage reading off my Power supply, and maybe I'll try to use battery first. Thanks

I've read from previous pages and I found to avoid the lockup from PT2399 is by substituting the value of resistor R1, capacitor C1 and C3 with the value that I mentioned above. Is there another trick that I missed? please let me know .... 

here:

http://www.diystompboxes.com/smfforum/index.php?topic=86297.msg774512#msg774512

OMG  . how could I miss something as important as this. thanks for telling me, maybe I'll try advice from bhill first, if not successful I will try this one. thank you 

[mr_deadmaxxx]

how is this as compared to the one-chip chorus?
http://www.diystompboxes.com/smfforum/index.php?topic=92872.0

[mr_deadmaxxx]

is the birthday edition verified and working?

[bhill]

Many times.

[juanjuin]

excuse me
i'm a new member here
sorry for out of topic here
sorry for my bad english

i want to ask this, please

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!!!!!

i want to ask C12 and C14
in my country, Indonesia, i didn't find 0.1pf
is that right capasitor? i just found 1pf in electronic component store in my town,or i must make 10 of 1pf strung together a series
and is that right R1 is 100k?

sorry for my bad english
and sorry for out of topic
i was excited about 5 pot little chorus

thankyou

[frequencycentral]

C12 and C14 are 0.1uF (otherwise known as 100nF).

R1 is 100R (otherwise known as 100 ohm). Not 100K!

[juanjuin]

C12 and C14 are 0.1uF (otherwise known as 100nF).

R1 is 100R (otherwise known as 100 ohm). Not 100K!

woo, thankyou sir

[mr_deadmaxxx]

@frequency central

I built your LA Birthday Edition and I cant tell why there is a very huge amount of volume loss/drop. Around 10 to 20% only of the input signal comes out at the output. Is this normal?
BTW, I used an Ipod for the input as I dont have an electrical guitar on hand. Did that affect the volume loss?

Thanks.

[garcho]

Around 10 to 20% only of the input signal comes out at the output. Is this normal?

No.

I used an Ipod for the input as I dont have an electrical guitar on hand. Did that affect the volume loss?

Try with a guitar before troubleshooting. Pickups are much different than what comes out of your iPod's headphone jack.

[Willybomb]

Here's mine.  It's actually my first pedal build - thanks to Haberdasher on the madbean forums for the PCB.

Gutshot (yes, it's messy):



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[acepepper]

Sorry to be late to the party on this one, I don't get over here very often. Is anyone still making PCBs for the Little Angel?

[frequencycentral]

Is anyone still making PCBs for the Little Angel?

Yep!

[mr_deadmaxxx]

@chris

did your original page 4 version work ok?..still waiting to build this...

The one from page 9 for the 1590A's definitely works with the pin 6 fix (like the one pictured above)  I am not sure if anyone got the BDay version to work totally right yet. Turns out the sound out of mine is really weak compared to the one above.

Same problem. Weak output signal.

[frequencycentral]

I've gotta build another one myself in a few weeks, we'll see how it turns out.

[mr_deadmaxxx]

I guess I'll just wait then..

[bacanador]

I am about to build this one

I noticed one thing, that there is no capacitor to ground between the two resistors that go to the opamp on the pt2399, most circuits with the pt2399 have it, so it seems this is only a 1st order low pass filter




Which is equivalent to this:




So maybe there is an opportunity to eliminate a couple of resistors, (1 at the input and 1 at the output), since it seems to work fine with a 1st order filter

I simulated this in ltspice, to make sure and I got the same freq response

[bacanador]

So in other words, it would look like this



I put 33K, because it is a common on value, but 30K would be the right value to keep the frequency response exacly the same. I have not tried this, but seems like it makes sense?.

I hope it is OK to use Frecuency central's artwork, (partially), I'll take it down if it is a problem

[garcho]

I moved this to Little Angel Space Madness Mod, sorry for the clutter!

[deadastronaut]

i'm going to breadboard this today , as it seems the most logical thing to do...

is this the final schematic with the pin 6 fix?..

http://www.diystompboxes.com/smfforum/index.php?topic=86297.msg815570#msg815570

is this a working model?...even when unplugged and plugged back in...or is there still gremlins?...cheers guys.


edit: hmmmm i have sound but no lfo at all ......ive gone over it a few times?...i'll check it over again...i hope this schematic is the working one..