"Little Angel" - Super Simple PT2399 Mini Chorus

[clamup1]

its ok, i got it to work.

[Barcode80]

You can also do it in MS Publisher, I just tested it. I made a grid 0.254mm (= 0.1") and scaled the pad spacings to that. Worked a treat.

Sorry about my first reply.... Here goes again...

I also do not have MS Publisher. As you can tell from my login, I work for the government. They do not give us cool software tools like MS Publisher. Any other ideas? Sorry to be a pain. Can anyone tell me a % to shrink this down to in order to get the sizes correct?
Any other ideas would be appreciated.

Just an FYI for everyone, all pcb transfers generated out of DIY layout creator are properly sized when printed at 72 dpi. You can use irfan picture viewer to print at different resolutions if you don't have a program to do so.

[Barcode80]

oh well i got more coming.

5532 opamps are highly recommended (a little low on the input impedance, but a great driver on output).  Not to start a debate or anything, but between these and TL072 you are pretty well covered for anything you would want to build.  Someone is selling 50 5532's on Ebay for 10.99 (including shipping) at the moment.  If you plan to continue building DIY stompboxes, I would just order a nice supply.

This is good advice, but bear in mind that in LFO's and modulation especially, as mentioned before, the two can't be used interchangeably. I can say that due to the number of tremolos I have built with NE5532 that didn't work until I popped in a TL072. Not all duals are created equal...

[boog]

I tried adding a 50K pot between the 100R and pin 6 of the 2399. Though this does work, you get a delayed signal, the sound was not very exciting. There is a single short delay and the modulation seems less obvious. The best sounds seem to be at the shortest delay times. There might be use for a smaller pot say 1K to 10K to adjust the delay length a small amount for different sorts of sounds.

I wonder if a regeneration pot might be more useful as a sort of resonance control?

25k was i ended up using, after it falls out of 'chorus' it seemed pretty cool, though there was a snare like echo to the circuits echo. i liked the 'somethin aint right sound.' i too wondered about a resonance control, figured i'd try something out in the winter.

[culturejam]

Just an FYI for everyone, all pcb transfers generated out of DIY layout creator are properly sized when printed at 72 dpi. You can use irfan picture viewer to print at different resolutions if you don't have a program to do so.

This is not my experience. For the older version, the output files are properly sized at 200 dpi. The new version (beta) outputs at 166 dpi. At least that's how it works with Photoshop.

[Barcode80]

Sorry, I mistyped. The old version outputs the image at 72 dpi. The print size I've found to be best is 200.25 dpi. Perfect fit every time. Thanks for the correction, don't know where my mind was!

[Earthscum]

So, I built a second LAC... this one has a horrible LFO thump!

Word of advice: choose your pot and board locations carefully. I am getting LFO bleedthrough from the pots to one of the audio paths in the board. Fun fun fun! 

I'm lazy, so I'll probably just do a ground plane shield between the back of the pots and the board... worked decent on testing, we'll try it tomorrow, along with some shielded cable in/out. I'm tired of soldering on this thing, hehe. I wanna move on to my next project (probably a wah).

[Barcode80]

I took a risk since some people have verified the layout and built it up completely without testing. I will play through tomorrow and ensure it wasn't a mistake!

[Pigyboy]

Hi,
Ok I went thru the whole thread and I think if I want to build the standard two knob version I use the layout on page 9. Yes Rick?
Thank you

[juansolo]

Super, smashing, lovely.

[frequencycentral]

Hi,
Ok I went thru the whole thread and I think if I want to build the standard two knob version I use the layout on page 9. Yes Rick?
Thank you

Yeah, that's the 1590A layout. Both layouts I've posted follow the schematic and part values in post #1.

Nice to see some finished build photos!

[Govmnt_Lacky]

Still unsure about good pot values for this build.

Can someone help me out with what potentiometer values work best in this circuit? I know Rick used 100K for Speed and 470K for Depth but I have also read that some poeple liked 100K for both.

[Pigyboy]

I am getting ready to build this too and Rick suggests the 470K. I should have it done tomorrow sometime I hope so I will post my results.

[Barcode80]

Strangely enough, I used the NE5532 with a 500k pot for depth and a 100k spot for speed, but I'm experiencing that all the depth and speed both are bunched at the end of the pot's rotation. I'm assuming I will need to go with the 100k depth. THoughts?

[waltk]

but I'm experiencing that all the depth and speed both are bunched at the end of the pot's rotation. I'm assuming I will need to go with the 100k depth. THoughts?

Rick had a good point with this post:

Re. Depth pot value debate:

The more minimum settings shouldn't be dismissed out of hand. Take away (most of) the modulation and you've got automatic double tracking, which we don't seem to talk about much around here. ADT has the effect of thickening the sound as if two people were playing the same part in unison. You might not notice the thickening until you bypass it - then your sound will seem thin and weedy by comparison!    Process your vocalist through the Little Angel at minimum settings - he/she/it will love you forever.

The ADT you get with the depth pot turned down all the way is a cool effect in it's own right.  Yet you don't seem to significant chorus effect 'til you get to the last 20% of the pot rotation.  My solution was to change the depth pot to 100K, and add an SPDT switch and a 470K resistor - so that in one switch position, it's like having the 470K depth pot turned down all the way (you get ADT).  In the other switch position it's like having the full rotation of the depth pot cover the top 20% of the 470K pot (from the original schematic).

[frequencycentral]

but I'm experiencing that all the depth and speed both are bunched at the end of the pot's rotation. I'm assuming I will need to go with the 100k depth. THoughts?

Rick had a good point with this post:

Re. Depth pot value debate:

The more minimum settings shouldn't be dismissed out of hand. Take away (most of) the modulation and you've got automatic double tracking, which we don't seem to talk about much around here. ADT has the effect of thickening the sound as if two people were playing the same part in unison. You might not notice the thickening until you bypass it - then your sound will seem thin and weedy by comparison!    Process your vocalist through the Little Angel at minimum settings - he/she/it will love you forever.

The ADT you get with the depth pot turned down all the way is a cool effect in it's own right.  Yet you don't seem to significant chorus effect 'til you get to the last 20% of the pot rotation.  My solution was to change the depth pot to 100K, and add an SPDT switch and a 470K resistor - so that in one switch position, it's like having the 470K depth pot turned down all the way (you get ADT).  In the other switch position it's like having the full rotation of the depth pot cover the top 20% of the 470K pot (from the original schematic).

Phew! At least someone read my ADT post!    Nice mod Walt!

[Earthscum]

Phew! At least someone read my ADT post!    Nice mod Walt!

That's basically the trick I take advantage of with the added 5k delay pot. The effect disappears on the lower notes on bass, so increasing the delay a small amount covers a bit more range of effect.

I gotta get pics up for ya... even though I'm not done. I think I gotta re-etch a new board. I yanked the whole thing out and found I'm getting LFO thumping through the board itself. ugh!

[Govmnt_Lacky]

The ADT you get with the depth pot turned down all the way is a cool effect in it's own right.  Yet you don't seem to significant chorus effect 'til you get to the last 20% of the pot rotation.  My solution was to change the depth pot to 100K, and add an SPDT switch and a 470K resistor - so that in one switch position, it's like having the 470K depth pot turned down all the way (you get ADT).  In the other switch position it's like having the full rotation of the depth pot cover the top 20% of the 470K pot (from the original schematic).

I am a bit confused 

So, the way that the 470K depth pot is wired on the Little Angel, (with lugs 2 & 3 connected and Lug 1 open) as the pot is turned CCW or down, does the resistance go UP or DOWN?

 

[waltk]

So, the way that the 470K depth pot is wired on the Little Angel, (with lugs 2 & 3 connected and Lug 1 open) as the pot is turned CCW or down, does the resistance go UP or DOWN?

As you turn the pot "down" (CCW), the resistance goes up - to 470K ohms if you're using a 470K pot; to 100K if you're using a 100K pot.  As you turn the pot "up" (CW), the resistance goes down to zero ohms - regardless of what value pot you are using.  So simply replacing the 470K pot with a 100K pot (wired the same way - lugs 2 and 3), and using the full rotation, is exactly like using the top (CW) ~20% of the 470K pot.

The switch on my build is wired so that the resistance is either 470K (simulating having a 470K pot turned all the way down), or somewhere between 0 and 100K depending on the rotation of the pot.

[Govmnt_Lacky]

The switch on my build is wired so that the resistance is either 470K (simulating having a 470K pot turned all the way down), or somewhere between 0 and 100K depending on the rotation of the pot.

I see now. I originally thought you were putting the 470K resistor IN SERIES with the 100K pot. I see now that it is EITHER/OR.

So you get the max ADT with one side of the switch, and the FULL pot rotation of the 100K with the other side of the switch. Good deal!