madbeanpedals::forum

General => Open Discussion => Topic started by: claytushaywood on December 15, 2014, 06:47:30 AM

Title: Dirtbaby LED limiting
Post by: claytushaywood on December 15, 2014, 06:47:30 AM
I unfortunately missed out on the dirtbaby's short stock and I went ahead and tried the LED limiting mod on my deep blue delay... unfortunately I think its killing my pt2399's.

i am definitely going from pin 7 to pin4.

will this mod work on a deep blue clone?  or do i need to do something else to the circuit?
Title: Re: Dirtbaby LED limiting
Post by: Matt on December 15, 2014, 12:07:26 PM
Connect it to pin 3. Pin 4 is not ground on the deep blue
Title: Re: Dirtbaby LED limiting
Post by: sturgeo on December 15, 2014, 12:42:00 PM
Quote from: Matt on December 15, 2014, 12:07:26 PM
Pin 4 is not ground on the deep blue

Whilst that is strictly true for the original, a lot of people connect 3&4 to GND as this fixes an issue with certain PT2399 chips.
Title: Re: Dirtbaby LED limiting
Post by: midwayfair on December 15, 2014, 01:56:13 PM
Make sure you have the anode on pin 7, and make sure that your pin4 is actually connected to analog ground.
Title: Re: Dirtbaby LED limiting
Post by: Muadzin on December 15, 2014, 02:24:29 PM
*Checks upon Dirtbaby pdf*

*realizes what he has missed*

(https://www.drupal.org/files/images/nooooo.jpg)
Title: Re: Dirtbaby LED limiting
Post by: claytushaywood on December 16, 2014, 03:46:37 AM
well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone :(
Title: Re: Dirtbaby LED limiting
Post by: selfdestroyer on December 16, 2014, 03:58:08 AM
Quote from: claytushaywood on December 16, 2014, 03:46:37 AM
well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone :(

Chin up man, I get more than that bad in one tayda order :]

Cody
Title: Re: Dirtbaby LED limiting
Post by: madbean on December 16, 2014, 09:37:03 AM
Quote from: claytushaywood on December 16, 2014, 03:46:37 AM
well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone :(

I don't understand how this is possible. I don't doubt it, but are you sure they are fried and not temporarily locked up somehow? Have you tried grounding all the pins and re-checking it? What are the exact voltage measurements you get on pins 7, 3 and 4?
Title: Re: Dirtbaby LED limiting
Post by: claytushaywood on December 16, 2014, 09:39:34 AM
I have no idea about locking up pt2399s!  How exactly would I go about grounding each pin? Just individually connect.each pin to ground while powered on?
Title: Re: Dirtbaby LED limiting
Post by: Matt on December 16, 2014, 01:18:50 PM
Quote from: sturgeo on December 15, 2014, 12:42:00 PM
Quote from: Matt on December 15, 2014, 12:07:26 PM
Pin 4 is not ground on the deep blue

Whilst that is strictly true for the original, a lot of people connect 3&4 to GND as this fixes an issue with certain PT2399 chips.
I wasn't aware of this, thanks.
Title: Re: Dirtbaby LED limiting
Post by: claytushaywood on December 16, 2014, 09:06:40 PM
Quote from: madbean on December 16, 2014, 09:37:03 AM
Quote from: claytushaywood on December 16, 2014, 03:46:37 AM
well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone :(

I don't understand how this is possible. I don't doubt it, but are you sure they are fried and not temporarily locked up somehow? Have you tried grounding all the pins and re-checking it? What are the exact voltage measurements you get on pins 7, 3 and 4?

sorry I forgot to quote you on my last post-

how do i unlock the pt2399?  Do I just hook up the deep blue to my breadboard and power it then use a jumper cable to go to ground on the pins individually?
Title: Re: Dirtbaby LED limiting
Post by: midwayfair on December 16, 2014, 09:27:06 PM
Quote from: claytushaywood on December 16, 2014, 09:06:40 PM
Quote from: madbean on December 16, 2014, 09:37:03 AM
Quote from: claytushaywood on December 16, 2014, 03:46:37 AM
well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone :(

I don't understand how this is possible. I don't doubt it, but are you sure they are fried and not temporarily locked up somehow? Have you tried grounding all the pins and re-checking it? What are the exact voltage measurements you get on pins 7, 3 and 4?

sorry I forgot to quote you on my last post-

how do i unlock the pt2399?  Do I just hook up the deep blue to my breadboard and power it then use a jumper cable to go to ground on the pins individually?

Often the chips will unlock after a day or two on their own. Your breadboard idea would be fine. I don't think you necessarily have to ground all the pins simultaneously, it's just to remove any stored capacitance. (Which drains over time, hence why I said that they usually unlock on their own after a day or two.)

I can't think of anything about the LED mod that would do what you've described. It simply conducts when the voltage on pin 7 rises to ~1.8V or higher, and it's been done in about 5 different designs now.
Title: Re: Dirtbaby LED limiting
Post by: culturejam on December 17, 2014, 02:21:49 AM
Quote from: midwayfair on December 16, 2014, 09:27:06 PM
Often the chips will unlock after a day or two on their own.

Interesting.

Whenever I've had a PT lock up, I kill power to the whole circuit, wait 10-15 seconds, and power back up. Seems to solve the issue.
Title: Re: Dirtbaby LED limiting
Post by: atreidesheir on December 17, 2014, 02:25:07 AM
Quote from: Muadzin on December 15, 2014, 02:24:29 PM
*Checks upon Dirtbaby pdf*

*realizes what he has missed*

(https://www.drupal.org/files/images/nooooo.jpg)
me toooooooo!
Title: Re: Dirtbaby LED limiting
Post by: claytushaywood on December 17, 2014, 02:48:28 AM
Quote from: culturejam on December 17, 2014, 02:21:49 AM
Quote from: midwayfair on December 16, 2014, 09:27:06 PM
Often the chips will unlock after a day or two on their own.

Interesting.

Whenever I've had a PT lock up, I kill power to the whole circuit, wait 10-15 seconds, and power back up. Seems to solve the issue.

thanks.  i promise you i am doing everything correctly.  i've tried it 4 times over about 3 days checking connections, checking LED's, having working pt2399's to begin with, checking voltages, everything.  its not exactly a difficult thing to do.

and now my pt2399s dont work.  ill check em tomorrow to see if theyve unlocked or if theyre donezo. 

I believe I'm using those terribly dim LED's that tayda used to carry (maybe still does) and I used a 3mm diffused green LED.
Title: Re: Dirtbaby LED limiting
Post by: madbean on December 17, 2014, 12:33:55 PM
For unlocking I always found just grounding each pin on my testing rig seemed to do the trick. You probably don't even need to do that---just pins 1 - 8.
Title: Re: Dirtbaby LED limiting
Post by: Muadzin on December 17, 2014, 01:58:01 PM
Quote from: atreidesheir on December 17, 2014, 02:25:07 AM
Quote from: Muadzin on December 15, 2014, 02:24:29 PM
*Checks upon Dirtbaby pdf*

*realizes what he has missed*

(https://www.drupal.org/files/images/nooooo.jpg)
me toooooooo!

Somebody made a vero layout here:

http://guitar-fx-layouts.42897.x6.nabble.com/Madbean-Dirtbaby-tp15783.html

It boggles the mind why something as awesome as this was just a temporary project.
Title: Re: Dirtbaby LED limiting
Post by: Luke51411 on December 17, 2014, 02:15:23 PM
I believe he is planning on making it a regular project or at least doing a larger limited release at some point.
Also, I saw the vero... I enjoy vero but this is one of those cases I would opt for a pcb. Gotta hand it to the people building crazy large veros though.
Title: Re: Dirtbaby LED limiting
Post by: Muadzin on December 20, 2014, 12:01:03 PM
Quote from: Luke51411 on December 17, 2014, 02:15:23 PM
I believe he is planning on making it a regular project or at least doing a larger limited release at some point.
Also, I saw the vero... I enjoy vero but this is one of those cases I would opt for a pcb. Gotta hand it to the people building crazy large veros though.

It's been moved from short runs to the delay section on the projects page, with a release date of jan 2. Happy days!
Title: Re: Dirtbaby LED limiting
Post by: claytushaywood on December 20, 2014, 08:18:08 PM
this project is just prone to locking up my pt2399's- ive never had this problem before but I guess its common.  I changed the opamp and it locked up a chip.  I did unlock one, but then I went and changed the opamp- power disconnected and everything and locked it up again but now I cant get it unlocked.  i've got a few that I cant unlock actually... I've been putting the pcb on my bread board and using an alligator jumper to connect pins to ground.  Can I unlock them without power?

maybe the project I'm using is the culprit?  I'm using rullwowr's deep blue delay board... it looked like a straight deep blue delay copy- but ive historically had all sorts of troubles with the deep blue delay... i mean all sorts.

i do have a sparklehorn has anyone tried the LED trick on that project?
Title: Re: Dirtbaby LED limiting
Post by: sturgeo on December 20, 2014, 10:22:04 PM
Have you connected pins 3 & 4 together permanently?? I've checked the Rullywow build doc and the schematic hasn't got them connected?


Edit: I'd leave the LED out for now, try to get the circuit working reliably as it should first.
Title: Re: Dirtbaby LED limiting
Post by: claytushaywood on December 21, 2014, 07:49:01 PM
No, I havent connected pins 3 and 4 permanently... should i do that?

I do have the circuit working, itd be reliable as long as I dont mess with it, but like I said, changing the opamp has caused the pt2399's to lock up on several occassions.
Title: Re: Dirtbaby LED limiting
Post by: sturgeo on December 23, 2014, 10:20:54 AM
Yup, i do on all of mine.
It seems some PT2399s lock up randomly, mostly those sourced form tayda...

It doesn't appear to have any adverse affects, the first dbd i built on vero had the link: http://tagboardeffects.blogspot.co.uk/2012/02/mad-professor-deep-blue-delay.html (http://tagboardeffects.blogspot.co.uk/2012/02/mad-professor-deep-blue-delay.html)
Title: Re: Dirtbaby LED limiting
Post by: gtr2 on December 23, 2014, 11:33:46 AM
Quote from: claytushaywood on December 21, 2014, 07:49:01 PM
No, I havent connected pins 3 and 4 permanently... should i do that?

I do have the circuit working, itd be reliable as long as I dont mess with it, but like I said, changing the opamp has caused the pt2399's to lock up on several occassions.

Yes, connect them.
Title: Re: Dirtbaby LED limiting
Post by: claytushaywood on January 04, 2015, 10:48:19 PM
connecting pins 3 and 4 together fixed all my problems!  they both showed continuity to ground but since ive hard wired them together i havent had a pt2399 lock up yet and i was able to use the LED limiting.  Now i've got a deep blue delay running at 18v with a charge pump.  killer