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New "mini" Chorus project!!
Posted: Wed Aug 11, 2010 5:03 pm
by culturejam
Mr FrequencyCentral recently whipped up a simple chorus-like circuit from a PT2399 delay chip and a dual op amp. The simplicity is astounding, and the sound is fantastic. All the project details are here:
http://circuitworkshop.com/forum/index.php?topic=565.0There are some really cool sounds in this thing, although I probably wouldn't classify it as true chorus. It's got chorus settings, and it's got vibe settings. And it also does some other stuff.
With both Depth and Speed at minimum, it just makes the guitar sound a little bigger and fuller/fatter.
I volunteered to test/verify the PCB layout, and I did that earlier today. I also had a partially gutted enclosure already painted and it had two knob holes drilled, and it was just sitting there, so....
All I had to do was solder a few wires, slap on some stamp artwork, and take photos. :icon_mrgreen:


Not my neatest work inside, but half of it was already wired up for a different project, so I just made do with what was there.

Re: New "mini" Chorus project!!
Posted: Wed Aug 11, 2010 7:15 pm
by Jero
Love the color! Sounds like a cool pedal.
Re: New "mini" Chorus project!!
Posted: Wed Aug 11, 2010 9:37 pm
by culturejam
Clip!
http://www.archive.org/details/LittleAn ... asedChorusHere's what's up:
Same basic progression each time.
First clean >
Speed 12:00 / Depth 2:00 >
Speed 12:00 / Depth MAX >
Speed turned from min to much higher / Depth MAX >
And then I just move around and try to show the main types of tones you can get. I think I did a total of maybe 8 settings or so.
And then clean again.
Straight into Garage Band through a UX1 with a hint of (software) reverb.
Re: New "mini" Chorus project!!
Posted: Thu Aug 12, 2010 11:46 pm
by sevenSHARPnine
I like it

Re: New "mini" Chorus project!!
Posted: Fri Aug 13, 2010 8:46 am
by deadbeatriot
sounds awesome
Re: New "mini" Chorus project!!
Posted: Thu Aug 19, 2010 10:47 am
by spacelordmother
Awesome.
Easy = cheap?

Re: New "mini" Chorus project!!
Posted: Thu Aug 19, 2010 11:29 am
by culturejam
spacelordmother wrote:Easy = cheap?

Pretty much. The delay IC is cheap and there are no exotic components.
Let's see here:
PT2399 Delay IC - $2
Dual Op Amp - $0.50
(20) Resistors @ 5 cents - $1
(15) capacitors @ 20 cents - $3
(2) Potentiometers @ $1.50 - $3
So that's about $10 for circuit. The jacks, stomp switch, LED/bezel, and enclosure should run another $15 - $20, depending on several factors.
As a side note, I've built a second Little Angel to test out some mods. I've added a pot to control the max delay time, so it can also function as a short slap-back type echo as well as a chorus-vibe. And also I added a wet/dry mix pot, but I settled on just using a switch to toggle between what I'll call moist/wet.

Re: New "mini" Chorus project!!
Posted: Thu Aug 19, 2010 2:44 pm
by Jero
Can I get the parts (at least the IC and board) for this from you? The 2nd modded one sounds like something I want.
Re: New "mini" Chorus project!!
Posted: Thu Aug 19, 2010 4:10 pm
by sevenSHARPnine
Jero wrote:The 2nd modded one sounds like something I want.
Me too!
And in case anybody's wondering, this dude's builds are quality. I've got a Fuzzface from him that's pretty spectacular.
Re: New "mini" Chorus project!!
Posted: Thu Aug 19, 2010 6:31 pm
by culturejam
Jero wrote:Can I get the parts (at least the IC and board) for this from you?
I've got the PT2399 and a couple different dual op amps (NE5532 is on order but not in stock yet). Oh, and the 5v voltage regulator you'll need for the delay chip. Most of the other stuff (except for a few of the resistor values) is also available in the shop. I can probably dig out the missing values from my personal stash, if you don't have them already (like 220K, 330K, etc).
The PCB you can get from Barry at GuitarPCB.com:
http://www.guitarpcb.com/apps/webstore/ ... ow/1690146The boards I make usually aren't quite "perfect". I wouldn't feel comfortable selling them, especially when there are already really nice boards ready to go.

Adding the Delay Time control is just as simple as leaving off one resistor and soldering in wires to the pot. It's really simple. Same for the Wet control.
Re: New "mini" Chorus project!!
Posted: Thu Aug 19, 2010 6:33 pm
by culturejam
sevenSHARPnine wrote:And in case anybody's wondering, this dude's builds are quality. I've got a Fuzzface from him that's pretty spectacular.
Thanks for the kind words.

Re: New "mini" Chorus project!!
Posted: Fri Aug 20, 2010 5:17 am
by Jero
Oh, good deal buddy! This is certainly one of the next builds I'd like to do. I'm in the middle of finishing that mojo'd FF right now.
frequencycentral "Little Angel" Chorus
Posted: Tue Oct 26, 2010 6:35 pm
by frequencycentral
Re: New "mini" Chorus project!!
Posted: Tue Oct 26, 2010 7:50 pm
by culturejam
The man himself!

Re: New "mini" Chorus project!!
Posted: Tue Oct 26, 2010 9:13 pm
by nbabmf
Oh snap! It's the Perfmaster!