"Little Angel" - Super Simple PT2399 Mini Chorus

p_wats · January 27, 2011, 09:36:45 AM

I finally built one of these (on a board from gutiarpcb.com). Very subtle, but I like the thickening of the sound almost more than the outright chorus. Combine that with a delay pot instead of R1 (I used 25K, because I don't mind very dirty repeats) and it's a lot of fun.

Otherwise, I ditched the depth pot (jumpered the connection), as it's already subtle enough.

I also messed around with the value of R18 (a pot was suggested, but I found a really low value resistor was all I needed here).

I'm hoping to box it up tonight with a "Noise Ensemble" (another PT2399 circuit posted here recently). Woo!

Gordo · January 27, 2011, 11:24:56 AM

Quote from: frequencycentral on August 09, 2010, 09:05:42 AM
I'm using a NE5532 dual opamp. I used a 470k because here in the UK that's what we use, 500k seemingly being a value available in the US but not here. 500k will work just fine.

Is that metric electronics vs US Imperial electronics? Or do we just have controls here that "go to 500..."

p_wats · January 27, 2011, 07:25:03 PM

This is strange, but while I was messing around with mine today I swear I had it doing multpiple repeats. Then when I finished the soldering it was back to a single repeat.

Anyone else found that too or any ideas on how to keep the multiple repeats?

rmachado · February 07, 2011, 11:35:39 PM

Hello, someone can sell me 2 or 3 1590A?
I live in Brazil and has nowhere to buy here.
Thanks, sorry my english.

bdevlin · February 08, 2011, 04:59:13 PM

Quote from: frequencycentral on December 02, 2010, 02:09:08 PM
Sounds like the PT2399 has locked up. Switch it off and on again and it'll probably work. Also try a 1k resistor for R1 instead of 100R.

What is the procedure to switch off and back on. Are you just referring to removing power?

frequencycentral · February 08, 2011, 05:02:38 PM

Quote from: bdevlin on February 08, 2011, 04:59:13 PM
Quote from: frequencycentral on December 02, 2010, 02:09:08 PM
Sounds like the PT2399 has locked up. Switch it off and on again and it'll probably work. Also try a 1k resistor for R1 instead of 100R.

What is the procedure to switch off and back on. Are you just referring to removing power?

Yeah! For a couple of seconds.......

bdevlin · February 08, 2011, 05:17:03 PM

Quote from: frequencycentral on February 08, 2011, 05:02:38 PM
Quote from: bdevlin on February 08, 2011, 04:59:13 PM
Quote from: frequencycentral on December 02, 2010, 02:09:08 PM
Sounds like the PT2399 has locked up. Switch it off and on again and it'll probably work. Also try a 1k resistor for R1 instead of 100R.

What is the procedure to switch off and back on. Are you just referring to removing power?

Yeah! For a couple of seconds.......

Okay then. Maybe we have some factual evidence to help some people with issues. My chips from eBay do not work. But I just popped in the chip out of my PT80 which came from SmallBear and it works. Pin 5 on the Small Bear reads 2.4V but on the eBay chip (Raycon??) it reads 5v.

bdevlin · February 09, 2011, 12:15:24 AM

And oddly enough, the eBay chips work in my PT80.

p_wats · February 09, 2011, 09:43:58 AM

I definitely recommend trying several PT2399s. The first one I used didn't modulate that well, but the second was great!

Also, I found it very ditch R13 entirely, as it seems to increase the depth available---from drunken sailor warble to slight shimmer (FC, does that make sense?).

However, mine is a little noisy. Anyone else experience this?

juansolo · February 09, 2011, 09:51:45 AM

I've had a batch of 3 PTs that dont modulate in a LA. They do work in an Echobase, so a little swapping was required.

bluesman1218 · February 09, 2011, 11:08:02 AM

So glad I found this thread! I perform as a solo acoustic act and love the chorus in my Fender Acoustasonic Jr, but don't use it for most gigs. Just bought a Fishman SA 220 and love it but have been looking for a Chorus pedal to add in. Gonna check my inventory and get this puppy built.

bluesman1218 · February 09, 2011, 01:51:41 PM

Quote from: dylar on January 20, 2011, 02:18:50 AM
Quick question:
I built a Little Angel using the vero layout http://www.sabrodesign.com/wp-content/uploads/2010/10/Little-Angel.gif and it worked fine for a minute, but then it stopped working altogether.
The only deviation I made from the original design was to use a 1n4007 diode instead of a 1n4001. Don't think this should matter, but maybe?
Voltages check out on the PT2399 except pin 5, which reads much lower than it should (about .5v instead of the 2.6 or so that it should be).
I have no idea what happened. Any guesses?

I found a few errors in the Parts List for the following: C6 & C8 should be 100nF/.1uF

Renegadrian · February 09, 2011, 02:14:21 PM

Quote from: bluesman1218 on February 09, 2011, 01:51:41 PM
I found a few errors in the Parts List for the following: C6 & C8 should be 100nF/.1uF

The original schem at the first page calls for 10nf, so it it correct. I used the same layout and it works fine.

bdevlin · February 10, 2011, 05:10:34 PM

Concern so called Depth issues. As an experiment I put a 50k trimpot in parallel with R13. There are some interesting results as you lower the trimpot. I also wired in a Mix pot off of R18 but as of now I find it seeming sort of redundant with the Depth control.

rmachado · February 11, 2011, 01:24:46 AM

My little angel work.
Pedal simple with great sound.
I put a 1k pot in place of the 100R resistor to control the delay time, did not see much difference, tomorrow replace for a pot of 10k. (any ideas??)
Now I need to get a cabinet.
Thanks to all who participated in this project.
Sorry my english.

rmachado · February 11, 2011, 01:44:24 AM

Does it matter if I use all of cps of 100nF ceramic?
The polyester caps are very large.

Perrow · February 11, 2011, 01:54:09 AM

Quote from: rmachado on February 11, 2011, 01:44:24 AM
Does it matter if I use all of cps of 100nF ceramic?
The polyester caps are very large.

You should be ok, as long as you don't care about the cork-sniffers frowning at you. When that happens give them this link and tell them those shells were used hunting their kind.

Although to be fair, there are times when ceramic versus film will change the sound of a circuit, not always for the worse though.

Renegadrian · February 11, 2011, 06:41:41 AM

All the caps I used are ceramics! it works so good! I have a 20k linear pot for the delay with a 1k in series (so when the pot is at 0 the minimum value is still 1k)

Pigyboy · February 11, 2011, 07:44:25 AM

I'm not a cork sniffer but I do think using ceramic caps make the circuit have a lot of hiss. At least it did in the last one I built. I had used all film caps in the others and the latest seems more hissy with the ceramics. I did have to change the amp I test my stuff thru as the Peavey Classic 50 went back to our practice studio and now now I am using a Marshall Artist 30 tube amp to test at home. I would like to know it anyone else has this experience with the hiss.
Cheers,
Chris

p_wats · February 11, 2011, 10:19:07 AM

Quote from: Pigyboy on February 11, 2011, 07:44:25 AM
I'm not a cork sniffer but I do think using ceramic caps make the circuit have a lot of hiss. At least it did in the last one I built. I had used all film caps in the others and the latest seems more hissy with the ceramics. I did have to change the amp I test my stuff thru as the Peavey Classic 50 went back to our practice studio and now now I am using a Marshall Artist 30 tube amp to test at home. I would like to know it anyone else has this experience with the hiss.
Cheers,
Chris

I've got hiss without the use of ceramic caps.

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"Little Angel" - Super Simple PT2399 Mini Chorus