Procastinator will not work (2nd try)

[Ariosto]

Hello there,
I am reviving this thread because I was a bit away from my workbench. OK, I bought the PCB for the second time in order to begin everything from scratch (the first attempt did not work neither). An user here recommended me to follow the signal with a tester -even if I am not an expert, it is a matter of logic and a minimum ability to read the circuit, uh?- OK, I started from IN to R1. It works. Then R1 to C1, works as well. But I lost the continuity in R2 and of course to Q1. I look for continuity in the rest of the circuit but nothing happens. Any clue? Later I could post some pictures if needed.


Thanks a lot

Ariosto

 

[Robert]

If you're measuring continuity from the Input you're only going to get a reading up to C1.

C1 is a capacitor (DC blocking) so there would be no continuity from that point forward in reference to the Input pad.

You'll have to take measurements in steps. Measure from Input to R1, then from the other side of R1 to C1, then from the other side of C1 to R2 / Base of Q1, etc.

What exactly is the Procrastinator doing wrong? If you're getting a clean signal but no swell effect the problem is most likely an out-of-spec (or fake) 2SK30 transistor.

 

[Ariosto]

LAST REPORT: OK, I changed C1 and now I become continuity. The pedal still don´t work. When I switch it off, the audio signal get through. Not bad, I can eliminate some suspicious switch wiring I guess. But accidentaly I discovered something weird that catch my eye: When I take out from sock the Q2 (2SK30A) with the pedal engaged I BECOME SIGNAL!(uneffected of course). I´ve found 3 replacements here at home -in fact they are marked "K30 A Y 3E but I suppose they are correct- And no one worked. Maybe it can help in the debugging process, if someone had any idea, please write me!

Ariosto

 

[Ariosto]

If you're measuring continuity from the Input you're only going to get a reading up to C1.

C1 is a capacitor (DC blocking) so there would be no continuity from that point forward in reference to the Input pad.

You'll have to take measurements in steps. Measure from Input to R1, then from the other side of R1 to C1, then from the other side of C1 to R2 / Base of Q1, etc.

What exactly is the Procrastinator doing wrong? If you're getting a clean signal but no swell effect the problem is most likely an out-of-spec (or fake) 2SK30 transistor.

Thanks for reading my last report. Can it be true that my 3 2SK30A are faulty or out of spec? If so, I must order some more and wait to see what happens then. I am thinking about a cold joint in the socket (I can measure continuity anyway).

Without the 2SK30A, am I able to measure continuity to be sure if everything is OK? Or is it a waste of time, taking in consideration that without it I become clean signal?

 

[zgrav]

you can measure continuity from where the transistor would connect to the PCB to the next part that it is supposed to connect to as shown in the circuit diagram.

I think you should go over the connections and part values on your PCB one by one to see if they are OK. if you find and fix something, it may make everything work. if not, keep looking for something else that is not right to fix. if everything eventually checks out, then it might be your transistor. as it is, though, you have multiple ones to try so it seems like that would not be the problem.

you also can use your circuit diagram and DMM to make sure you are getting your power at the different points in the circuit that need it.

if you are lost looking at your circuit diagram, do some google searches for "how to read a circuit diagram" so you have a better understanding of what you are looking at.

 

[Ariosto]

you can measure continuity from where the transistor would connect to the PCB to the next part that it is supposed to connect to as shown in the circuit diagram.

I think you should go over the connections and part values on your PCB one by one to see if they are OK. if you find and fix something, it may make everything work. if not, keep looking for something else that is not right to fix. if everything eventually checks out, then it might be your transistor. as it is, though, you have multiple ones to try so it seems like that would not be the problem.

you also can use your circuit diagram and DMM to make sure you are getting your power at the different points in the circuit that need it.

if you are lost looking at your circuit diagram, do some google searches for "how to read a circuit diagram" so you have a better understanding of what you are looking at.

Well, have checked ONE BY ONE the continuity with my DMM, and everything is fine. Last resource is ordering some 2SK30A´s and crossing my fingers that the focus of the problem lay there. I´ll be back again as soon as the post bring them!


Ariosto

 

[zgrav]

If you have confirmed you have continuity, I suggest you use your DMM to see if you have power everywhere on the board you should based on the circuit diagram, and check to make sure you have ground everywhere you are supposed to.

 

[Ariosto]

If you have confirmed you have continuity, I suggest you use your DMM to see if you have power everywhere on the board you should based on the circuit diagram, and check to make sure you have ground everywhere you are supposed to.

Alright, but, must I wait ´til I get the new 2SK30A ? Or am I able to do without it?

 

[zgrav]

The easiest thing to do would be to set this aside until you get the new transistor and see if everything works when you put it in the board. if it does you will have saved yourself some time, and if it does not work you can start doing the other testing.

 

[Ariosto]

If you have confirmed you have continuity, I suggest you use your DMM to see if you have power everywhere on the board you should based on the circuit diagram, and check to make sure you have ground everywhere you are supposed to.

Well, I received yesterday 5 2SK30A per mail (marked "K 30A"). I put it and......... NOTHING. I replaced all the BC549s as well, and no reults. Only an almost inaudible (and uneffected) audio signal. I checked voltage according with the little schematic under the another schematic and I become power everywhere. I touched de pins of the TL071 as well and every transistor and I become power too. I did not wrote the values because I have made that in my previous post that was misteriously deleted. I am dry of solutions now and I find the task not so amusing....

 

[Robert]

Just to clarify the situation hasn't changed...

With the FET installed you have no audio.
If you remove the FET you do have audio.

Correct?

The next step will be to measure the control voltage coming from the envelope detector circuit. I'm not at my computer right now but will post more info later today.

 

[Ariosto]

Just to clarify the situation hasn't changed...

With the FET installed you have no audio.
If you remove the FET you do have audio.

Correct?

The next step will be to measure the control voltage coming from the envelope detector circuit. I'm not at my computer right now but will post more info later today.

I did not understood the part "voltage coming from the envelope detector circuit."

 

[zgrav]

if you look at your circuit diagram for the project, it is all of the parts that connect to the "sensitivity" pot. probably worth your time to get some understanding of what is going on in the different parts of that circuit diagram. start with a google search about "circuit diagrams" or something like that.

 

[Ariosto]

if you look at your circuit diagram for the project, it is all of the parts that connect to the "sensitivity" pot. probably worth your time to get some understanding of what is going on in the different parts of that circuit diagram. start with a google search about "circuit diagrams" or something like that.

I am checking with my DMM (only continuity in the moment). From the "Sensitivity" pot (1, 2, 3) to:

1 to R14: YES
2 to C9: YES, C9 to IC1 3: YES, but 2 to IC1 2 NO, Ic1 3 YES
3 to C8: YES, C8 to Q1 YES..... but 3 to Q1 NO

I tried with the potentiometer in both positions, and the potentiometer itself is working OK. It is very difficult as newbie to understand such behaviour.

 

[Kelmark1]

Try using audio probe and find out where your signal is and isn’t getting getting to, troubleshooting can be very trying as you know

 

[zgrav]

and if you need a break, set is aside while you build another pedal.... : ^ )

 

[Kelmark1]

We’ve all been through it

 

[Ariosto]

and if you need a break, set is aside while you build another pedal.... : ^ )

We’ve all been through it

.............. Or directly:



22 euros in eBay

 

[chongmagic]

I remember when I first started out, I built two of these from BYOC, neither one would work. I fried the pads on the first PCB and the second one didn't work either. About a year later I got another PCB and finally had some success. So don't fret, we have all been there. Sometimes you just need a break.

 

[Ariosto]

Well, a new report direct from my desk..! This time I followed the audio path with an audio probe (I am not an expert neither, truth must be told). Anyway I´ve found some "curiosities" during the task:

a) Now I detected that, with the effect engaged, a very weak audio signal comes thru (approx. 50% and uneffected). With the Q2 out -again- I become normal audio volume obviously unneffected too.
b) In the path C6 - Q2 - R6 I become a weak audio signal, as well in the C2, C11, and the sensitivity pot tip 1.
c)NO SIGNAL in the tip 1 of the Attack pot, c3, c4, and the path between R13, C7, D1.

Maybe a more seasoned pedal builder could recognize some "symptoms" when reading such information. I cannot do much more at the while. Thanks for reading


Ariosto