Wednesday, August 12, 2015
Little Angel Chorus
Here's a simple, fairly low parts count chorus based around a PT2399, designed by Rick Holt (aka Frequency Central) from the DIYStompboxes forum. I've drawn 2 versions, one with board-mounted pots, and one off-board pots. The 2nd IC (NE5532 in the layout) can be any dual op-amp (a TL072 works well), just socket and experiment. The board is fairly large, so you might want to use long leg right angle PCB mount pots and mount them from the component side to save space. Here's a quick sound sample.
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Hi,
ReplyDeleteThe PCB on the top - the second pins of the parts from 6,7,8 pins of "PT" must go to ground.
Verifed
reg.
Martin
Thanks for catching that and verifying. Fixed!
DeleteI Builded this pedal but doesn't work!!!
ReplyDeletewhich PCB you uesd?
ReplyDeleteThe second.
ReplyDeleteI made base on the top pcb and it is ok
DeleteDid you like this chorus, Marcin?
DeleteI will try!
ReplyDeleteThe second pcb says that depth 1 and speed 1 are not connect, but the first are connected.
ReplyDeleteEither way will work the same. They're just being used as variable resistors and either method is acceptable.
DeleteMaybe my ic doesn't work. Thanks.
DeleteI found error in my pcb, i fixed and works great. Very nice pedal, thank for Effects Layouts!!!
DeleteHi Could you please share what the error was? If it was a common one
DeleteI build this, its working, but the depth is like not many effect, somebody can modified for the depth ?
ReplyDeletewhich PCB?? the 1st one or the 2nd one ?
Deletethe 2nd one
DeleteIs there any replacement for the pt2399? I cant find it anywhere
ReplyDeleteAfraid not. It's a really common chip though now. I got 50 of them off eBay for like $10 US.
DeleteEmilio - try HT8970 as a substitute
Deleteyeah I figured it would be plenty of those around since it is a pretty popular pedal in the diy community here (argentina) I guess it is just bad timing with the stores stock. Thanks anyway!
ReplyDeleteSimple good chorus, vibrato tone there. Slightly lacks depth, but in general everything is great. Thank you very much. Checked with the LM4558, jrc4558,LM833,TL072.
ReplyDeletewhich of the layouts work ? The first or second
ReplyDeleteI try this pcb, it's working. But, i get many hiss in sound :(
ReplyDeleteI did it today, very good Chorus, not better than Small Clone, but you can have a nice tone. Thanks!
ReplyDeleteI try to build this Chorus. It's working ! But, the hiss sound "sssssssssssss" very big. :(
ReplyDeleteI have the same. what is the solution?
DeleteTry replacing the PT or up the value of the power filter cap.
DeleteThis comment has been removed by the author.
ReplyDeleteBoard mounted PC works great. However I did have a failed IC which caught me out for a few mins! I'd post a picture but can't work out how.
ReplyDeletePerfect chorus, perfect sound for soloing and some clean tones too. First I tried with Entropy chorus which seemed more interesting, but after two tryings I did this design at first attempt. Great job!!! Nice PCB layout!!! Greetings from Balearic islands!!!
ReplyDeleteNote: I don't know why but it sound better with TL072 than 4558, less effect... our maybe less gain, but I kept 072 ;)
ReplyDeleteI built it for three times, but i got same problem. it work but sometimes doesnt work. what the solution?
ReplyDeletei faced similar type of problem with a Delay pedal made with PT2399.
DeleteProbably its the same here. Try different PT2399
Built this today, I am getting sound through the effect but no chorus effect. Went through and triple checked component values and traces for errors, couldn't find any. Has anyone else experienced this problem? Any idea where to go from here?
ReplyDeletePower is checking out at all locations, getting 5v at the regulator, op amp is working fine, clean signal comes through but no chorus effect. :/
Me too. Same problem. Passes signal, but no chorus effect, just some unwanted gain...
DeleteThe same problem.. any of you can resolved this?
DeleteI can't speak english.
DeleteBut you can translate my instruction word by word. I hope you understand what i mean.
"IC PT2399 tidak semuanya sama. Saya membeli IC PT2399 ditoko yang berbeda. Keduanya berfungsi dengan baik. Hanya saja, salah satunya tidak bisa dipakai untuk efek chorus. Saya telah memasang socket di papan efek saya untuk test IC. Agar saya segera mengetahui manakah IC yang berfungsi dan manakah yang rusak"
Thank you very much. Sorry for my english
Did you know any mod to increase the Depth of the effect?
ReplyDeleteIn the onboard pots PCB, the "Underside (reversed) image is not mirrored.
ReplyDeletedoes it make any difference ?
DeleteI've build this today.
ReplyDeleteOnly problem is the output is amplified and distorting,
And it has no high frequencies in it.
Checked component values and traces.
If i pull out the PT2399 it sounds fine but no effect.
Tested with multiple IC's
can i make a request for a daughterboard of this chorus to solve the lock ups of PT2399 and its pin outs?
ReplyDeleteand also can i request for the little angel chorus with lock fix and noise reduction measures from rick holt's design? extra pad for space/warbler switch and chorus/vibe switch? thanks and more power..
ReplyDeleteHello,
ReplyDeleteHow could I add a volume pot at the Little Angel circuit ? Is it possible to do just changing some resistor by a pot ?
You could just tack on an A100k pot to the output. Lug 3 to the out pad, lug 2 to out, lug 1 to ground.
DeleteIt´s a good idea, however this A100K pot to the output will not be only a volume attenuator ? I mean, I would like to control the unity gain of the circuit.
DeleteSo, to Adjust the volume (unity gain), the output volume must to be (very) higher when the pot is rotated clockwise in the maximum position.
DeleteTry adjusting the value of the 1M resistor by the 5532. Or make that a trimmer/pot.
DeleteThis comment has been removed by the author.
ReplyDeletewhen I turn on the pedal the overall volume goes down...can you help me?
ReplyDeleteHi , modificando la resistencia de 33k próxima al pot de depth podría aumentar o disminuir la depth ? Es necesario aumentar la depth un poco más
ReplyDeleter12 = 10k y aumentas la depth!
DeleteI build the second layout, but there is no effect, only a volume lotion.
ReplyDeleteI replaced PT, NE5532 and 7805 ... What do I do? Can you help me?
I did the second layout and it worked very well. nothing inverted or bad; it would be interesting to have more depth. and about the sound, it is perceptible to be based on a delay circuit, sometimes it sounds like a metal echo / delay. brazil vibrations.
ReplyDeleteps: nice chorus, nice effect, nice layout, thanks!
Deletefala aí, td bm? eu fiz um com o segundo layout e funcionou, troquei o resistor 33k por 100k e melhorou o volume com efeito ligado, deixo a dica caso tenha tido este problema tb de volume baixo quando ligado. Semana passada fiz outro tb com o segundo layout, porem este nao funcionou, o som passa clean...ja chequei trilhas, pots e chave.....teve este mesmo problema tb?
DeleteI've built 3 and all of them work great. i use 1st PCB. Thanks to Effects Layouts :)
ReplyDeletedid you build yours using 5532? i did mine with tl072..because 5532 are not easy to come by here in philippines
Deletegreetings from philippines..can i request the GLAM CHORUS layout? thanks in advance :)
ReplyDeletecan i requeat GLAM CHORUS in perf board layout? i really love building using perfboards..thanks for your effort,great site by the way..have built a few effects from this site and all worked first time..and also..any way to add more depth in this LAC? it would be really nice to have more depth to this..thanks a lot..greetings from philippines..
ReplyDeletehow can i fix distorted chorus sound...thank you
ReplyDeletedistorted output problem please help
ReplyDeleteI tried the first board when the effect is on the guitar signal went through but no chorus effect. what to do?
ReplyDeletewithout any kind of modifications the first plate should work ??? greetings from Argentina
ReplyDeletemantap bung
ReplyDeleteIt is heating too much
ReplyDeleteI didnt heat this much in deep blue delqy.
Got two diy chorus already( mxr micro chorus and p dimension chorus).
ReplyDeleteAnd im going to build this one for sure just to compare them in terms of output responses.
Tnx guyz and more power!!
Hi to all. I build first version (with mounted pots). 1 of 7 PT2399 i bought wasn't hot after turning on (so only one was good ;) ). Power supply is very simple bench supplu 24v module down do 9V (very noisy but for tests it's OK). Now the werdiest thing. When turned on, only clean signal with mearly effect on pots turning. I start to mesure voltage on each pt2399 legs, and when i tuched 2 leg (2,4v or pin 2) i heard some kind disortion (click) on amp (3W, battery supply Orange Micro Crunch) and effect starts to work . Until power off. Power On, and no effect again, until i touch 2 leg (or solder joint, or even second end of path - before 33K) with something metal (isolated on end, to prevent body interfer) , then disortion click sound on amp and everything starts working perfect. I don't use any force, just light touch is enought to start effect to work.
ReplyDeleteI'm electrician, i build electronics for fun, and i known how to solder, I checked all joints 3 times, checked all elements. Can enyone can tell me what is going on ?? is pt2399 broken ?? I have only one working so I can't check it. I have PT on stand , and i check it for connections and its OK. Can enyone can help me with this ??
Hello! I have the same problem. Have you solved it? do you have a piece of advice?
DeleteThis comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteHow would I get more depth?
ReplyDeletethanks.
from chile
How are you friends, for those who have not worked or changing the ic pt2399 there is a solution, which is to place a 10nf capacitor from pin 2 of the ic to the negative, for some reason most of the ic they sell are blocked but Making this arrangement works 100% and I already tried several ic that I had discarded thinking that they were damaged but when adding the capacitor they worked
ReplyDeletedo you have the schematic?
ReplyDeleteMay i know that voltage used in the capacitors? Like is it 2kv 1kv and so on. Thank you!
ReplyDelete