Deep Blue Delay issues; is this the PT2399?

[jfrabat]

OK, I am in need of a delay, and since I got a bunch of PT2399 for my Little Angel Chorus (which I have yet to get to work right!), I decided to breadboard this delay to give it a try.  This is the schematic I am using:



Changes from the schematics is a TL082 instead of the 072, and a 2.2K resistor instead of a 2K resistor (I was out of 2K, but I measured the 2.2K reistors I had, and picked theone with the lowest reading, which was 2.1K, so I figured I was good).

Anyway, I have checked everything, and I am pretty sure everything is in the right place.  But since I am having issues with the Little Angel Chorus, as well as the basic delay tested for the PT2399's I have, I am suspecting that the issue is the PT2399's I have are fried.  This was the last unused one I had, and I have bought from 3 sources (locally, amazon and smallbear), but I wanted your opinion on the matter.  Here is a short video of me trying the audio probe on the circuit:

As you can see, the dry signal makes it through just fine, but the wet signal is not there, and instead there is this percussion sound where the wet signal should be.  Is my assumption correct?

This is the breadboard, in case you spot anything off:



Using the Ditto as a sound source...











I have not yet tried other PT2399's I have about 6 more of them, but I do not know if I should.  I used the last one that I had not tried on any board on this project...  The others I have tried ether on the delay test rig or on the little angel chorus.

Voltages are:

Battery:
9.02V*

*I noticed after taking all the voltages that the battery had dropped to below 9V to 8.88V, so some readings could be affected by this; I am out of 9V bats, though!)

TL082:
1 - 3.24V
2- 3.24V
3 - 3.24V
4 - 0V
5 - 3.23V
6 - 3.23V
7 - 323V
8 - 9V

PT2399:
1 - 4.91V
2- 3.71V
3 - 16mV
4 - 0.256V
5 - 0.64V
6 - 3.48V
7 - 3.59V
8 - 0.669V
9 - 3.6V
10 - 2.45V
11- 0.935V
12 - 0.944V
13 - 3.89V
14 - 2.55V
15 - 3.27V
16 - 3.67V

78L05
I - 6.6V
G - 0V
O - 4.91V

[jfrabat]

It seems I answered my own question...  Took out the PT, grounded the new one prior to inserting, and the delay works as advertized!

[thermionix]

Nice granite!  My sister has pretty much the same pattern/color in her kitchen.

[EBK]

It seems I answered my own question...  Took out the PT, grounded the new one prior to inserting, and the delay works as advertized!

Great! Now verify whether the other PT2399s in your stockpile work as well.

[jfrabat]

Great! Now verify whether the other PT2399s in your stockpile work as well.

Yup.  The plan now is to sort which PT's work and which don't.  Knowing that, I will take the ones that do work and try to run them in the Little Angel Chorus and try to troubleshoot that pedal (which out of all the pedals I have given a shot, is the only one I have yet to get to work!).

By the way, here's the video of the breadboard working (using the same Ditto recording as a source):

[duck_arse]

jfra - on ALL your PT2399 circuits (even if not shown on the circuit diagram), connect both pin 3 and pin 4 to ground. always! your voltages show a small voltage at pin 4 that should not be there. this may be an occasional cause of the dreaded latch-up.

and about those voltages you posted - your 78L05 is connected to the battery via a 33R resistor, so the input to the regular should measure verr close to the full 9V, not the 6V6 you are showing. can you re-measure that voltage on your working build? and yes, I know you have it working now, but it might save you headaches in the future if you can find why your PT's are so intractable.

[anotherjim]

In those pictures, the PT2399 appears to be fitted backwards. Obvious in the 5th picture from top.

The semi-circle notch in the package denotes the pin1 end.

[jfrabat]

jfra - on ALL your PT2399 circuits (even if not shown on the circuit diagram), connect both pin 3 and pin 4 to ground. always! your voltages show a small voltage at pin 4 that should not be there. this may be an occasional cause of the dreaded latch-up.

and about those voltages you posted - your 78L05 is connected to the battery via a 33R resistor, so the input to the regular should measure verr close to the full 9V, not the 6V6 you are showing. can you re-measure that voltage on your working build? and yes, I know you have it working now, but it might save you headaches in the future if you can find why your PT's are so intractable.

Pin 3 is grounded.  Pin 4 is not, though.  It goes to the delay pot.  Should I ground it anyway?

I'll retake the voltage for the 78L05.

In those pictures, the PT2399 appears to be fitted backwards. Obvious in the 5th picture from top.

The semi-circle notch in the package denotes the pin1 end.

You know, I did not notice I had it on backwards until I went to test the other PT's...  I took the one I had out, and I looked at the picture and then looked at the + in (from the 78L05), and I said to myseld "how did you not see THAT!"

Great! Now verify whether the other PT2399s in your stockpile work as well.

OK, the good news is that only one PT was toasted.  I have 7 that are good to go.  The bad news is that the one that was in my Little Angel was not the one that was bad, so now I REALLY have no clue as to what's going on there! 

[duck_arse]

Pin 3 is grounded.  Pin 4 is not, though.  It goes to the delay pot.  Should I ground it anyway?

yes. easiest to just add a jumper between pins 3 & 4.

and Jim's well spotted backward IC may well be the reason the regulator input voltage was so low.

[anotherjim]

Very easy to plug chips in wrong on a BB. My more usual sin is to place them 1 row out - have fried a few op-amps doing that 
It can pay to put a link (just to fill the holes) across the row next to pin 1 end, so you have a guide and "end stop".

I'm pretty sure the troublesome, naughty little angels had the PT2399 pins3 & 4 connected?

[jfrabat]

Actually, none of them had pin 4 grounded.  I will put a jumper in today, but I already threw out the one bad PT.  I still got a bunch of them, though, and apart from using one in the Little Angel, one in the Deep Blue Delay, and two for a Equinox Reverb, I have no clue what I will do with the rest.