"Little Angel" - Super Simple PT2399 Mini Chorus

Pigyboy · July 31, 2011, 05:58:22 AM

It will latch up sometimes with a straight jumper but seems to be all right with the 1.2k....I just want to hear it next to one with a 330k so hear the difference...gonna play around and post what I find.
Thanks

merlinb · July 31, 2011, 05:59:56 AM

Quote from: Pigyboy on July 31, 2011, 05:58:22 AM
It will latch up sometimes with a straight jumper but seems to be all right with the 1.2k....I just want to hear it next to one with a 330k so hear the difference...gonna play around and post what I find.
Thanks

Whatever is causing it to latch up, it isn't that resistor! It's completely unrelated to the PT.

Pigyboy · July 31, 2011, 01:08:23 PM

Ok, I changed C5 & C6 to .47uf film caps and it really cleaned everything up. I jumpered R7 - 330k and on mictesters pin 6 fix I changed R1 from 47R to 1R2 and R2 from 2K2 to 68K and it has not got hot or latched up. It still has some background but it is acceptable I think. I don't have any other chorusy type boxes here to compare it to...success!

Pigyboy · July 31, 2011, 01:30:39 PM

Does this make sense...
I noticed when the PT latches up if I unplug it and short the +/- of the power jack then plug it back in it works every time. So I wired the red battery terminal lug of the power jack that I am not using to the ground lug. When the power jack is unplugged the + shorts to the - and resets the chip...seems to work everytime...this is using mictesters pin 6 fix set-up on the 1590A build.

Pigyboy · July 31, 2011, 01:51:03 PM

While I am thinking about it I recall people having problems with the sound being distorted or farty...I am pretty sure if you change C5 &C6 to .47uf film caps it will fix this. I have one here that sounded shite with ceramic .1's and totally cleaned up with the change. Hope this helps...

merlinb · July 31, 2011, 05:39:41 PM

Quote from: Pigyboy on July 31, 2011, 01:30:39 PM
Does this make sense...
I noticed when the PT latches up if I unplug it and short the +/- of the power jack then plug it back in it works every time. So I wired the red battery terminal lug of the power jack that I am not using to the ground lug. When the power jack is unplugged the + shorts to the - and resets the chip...seems to work everytime...this is using mictesters pin 6 fix set-up on the 1590A build.

Yes that would make sense. Mictesters fix only works provided you leave the unit unpowered for several seconds before powering up again, since the 47u doesn't discharge enough via the diode to allow immediate reset.

Also, when a PT goes into latch up once it will usually do it again even when the pin 6 resistor is more than 1k (something inside seems to burn out and it can't drive as much current at start up any more). You usually have to make it several k after that to avoid further latch ups, which explains why increasing R21 helped.

tuckster · August 03, 2011, 03:23:19 PM

Just finished my little angel (birthday edition). The effect works butit is very subtle like Pigyboy noticed first. Any suggestions on this?

askwho69 · August 04, 2011, 06:40:30 AM

Quote from: tuckster on August 03, 2011, 03:23:19 PM
Just finished my little angel (birthday edition). The effect works butit is very subtle like Pigyboy noticed first. Any suggestions on this?

wonderful layout! mine sharing ? i like on board stuff

tuckster · August 04, 2011, 07:05:29 AM

Yes od course but I don't know if there are any mistakes in it. Just wanted to wait until someone found out whats the problem with the new circuit

I only steal circuits, unfortunately I'm not able to fix designes by myself.

Pigyboy · August 09, 2011, 10:42:43 AM

Made a little discovery. All my angels always turn on without latching with the depth knob maxed. Any ideas?

~arph · August 09, 2011, 10:48:13 AM

A quick question.. if it latches, does it make a terrible noise?
Could be that I'm latching up one of my builds when the modulation gets out of hand or the input signal gets too high (too much feedback)
EDIT: I'm not talking about a LA

Pigyboy · August 09, 2011, 11:07:48 AM

^^
What are you referring to? When my angels latch they just sound a little different without the effect....and they get hot!

~arph · August 09, 2011, 11:16:08 AM

Quote from: Pigyboy on August 09, 2011, 11:07:48 AM
^^
What are you referring to? When my angels latch they just sound a little different without the effect....and they get hot!

Cool, that's the anwser I was looking for.. I was talking about a very noisy stuck oscillation kinda problem. Now I think of it.. I think I had a similar sounding issue with my belton reverb brick.. if the input level got too high it went into horrible oscillating noise.

Sorry for the interruption, please do continue...

askwho69 · August 09, 2011, 02:28:06 PM

so the one knob cheap chorus needs to be look?

rhcp_schipper · August 11, 2011, 11:34:33 AM

Quote from: Pigyboy on August 09, 2011, 10:42:43 AM
Made a little discovery. All my angels always turn on without latching with the depth knob maxed. Any ideas?

Hello Everybody,

My name is Tim and Chris from el musico loco introduced me to this forum. I bought one of the Angel choruses he sells. Unfortunately the one I have has the latching problem described above. I found out that when the depth knob is maxed out and you put the power on the angel will work fine(every-time you do that). But when I have my favorite setting (both knobs approximately at 12 o'clock), the angel will latch up.

I have allot of contact with Chris about this problem, but he said to me it is smart to post the problem here at the forum so maybe one of you guys could help us out here.

The first thing I'm going to do is putting a new PT2399 in, because maybe this is a bad chip, who knows?

Many thanks!

Tim

Govmnt_Lacky · August 11, 2011, 11:55:22 AM

Quote from: Pigyboy on August 09, 2011, 10:42:43 AM
Made a little discovery. All my angels always turn on without latching with the depth knob maxed. Any ideas?

Quote from: rhcp_schipper on August 11, 2011, 11:34:33 AM
...I found out that when the depth knob is maxed out and you put the power on the angel will work fine(every-time you do that). But when I have my favorite setting (both knobs approximately at 12 o'clock), the angel will latch up.

Has anyone bothered to probe Pin 2 of the PT to see what resistance/voltage range it falls into when it is working/latching?

Pigyboy · August 11, 2011, 12:10:16 PM

Welcome aboard Tim! How often is it latching?
I have one here that seems to start chorusing when I plug a 12volt adapter into it and keep chorusing when I swap it right over to a 9 volt...

rhcp_schipper · August 11, 2011, 12:22:47 PM

Quote from: Pigyboy on August 11, 2011, 12:10:16 PM
Welcome aboard Tim! How often is it latching?
I have one here that seems to start chorusing when I plug a 12volt adapter into it and keep chorusing when I swap it right over to a 9 volt...

Mine keeps latching every time I put power on it, with my own settings! Even when I power it up at 12 volts the angel latches!

The only way to make it chorus is to max out the depth knob, and than put the power on. There is no other way.

Pigyboy · August 11, 2011, 02:00:20 PM

After you power it on with the depth maxed then it works normally?

rhcp_schipper · August 11, 2011, 03:02:45 PM

Quote from: Pigyboy on August 11, 2011, 02:00:20 PM
After you power it on with the depth maxed then it works normally?

Yes! But when I dial in my own favorite setting, and power it off and back on again, it latches! So each time I power up the Angel I have to max out the depth knob, and than bring the power on to get it working properly! After I've done this I can dial in my own settings and use it.

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"Little Angel" - Super Simple PT2399 Mini Chorus