SOLVED First try using audio probe

[Dali]

Newbie Xtreme here.

I just "build" this high end audio probe (100nf) on the tip.



I first tested on a working pedal because every article in the Universe says to use the other wire (red-then-black-alligator in my case to GROUND) and I was not sure about what is ground... (see my level? )

Then I've checked the schematic (https://docs.pedalpcb.com/project/Delegate-Boneyard.pdf) of the Boneyard Delegate and tried to use some logic. (cough, cough)

Got a loop going in so I don't have to touch a guitar and started using the probe on R1, C1, C2, R2,R3, C104, R101.

Got sound to the amp until I reached C104 (any side of it produced no sound).

Does it means the Electrolyte Capacitor at C104 is "at least" the first culprit to swap/change?

 

[fig]

I'm just bummed it isn't working for you. It's a really great pedal. I'm certain someone will help you get it functioning soon.

 

[Dali]

Recap: Audio sound up to R3 then nothing on C104

IC1 voltage
1 = 15,96
2 = 15,68
3 = 0
4 = 0
5 = 16,12 <--- Changed R102, now 8v as expected!
6 = 15,22
7 = 16,08
8 = 16,89

Is that correct/normal?

 

[PJS]

C104 is part of the power supply. You should never have audio there.

Your voltages for the IC are way off. The one to examine is pin 5. That is connected directly to Vref, which is supposed to be half way between gnd and the positive voltage, so in this case you would expect about 8.4V. Vref is created by R101 and R102. Either one of them is faulty or the wrong value, or you have a short between the Vref line and the +ve voltage somewhere. Fix the Vref and most of your voltages should go to normal

 

[EGRENIER]

Based on the picture posted here:

Delegate Boneyard has LED turning OFF

I just finish a Delegate Boneyard Edition. When I turn on 9v, the 5mm Transparent LED goes on for 2 seconds then fade out. Same thing for the sound. If I play during those 2 seconds with the pedal engage, I got sound for those 2 seconds then it vanish. If 3PDT is OFF the pedal being bypassed...

forum.pedalpcb.com

And assuming the second band is violet, R101 and R102 seems to be correct at 47K.

So replacing them might be an easy step.

 

[Dali]

I changed R102 yesterday and now Pin 5 on IC1 is ok. But it was not sufficient to make the pedal work...

 

[Chuck D. Bones]

Let's go back to the DC voltage measurements.

Recap: Audio sound up to R3 then nothing on C104

IC1 voltage
1 = 15,96 bad - should be around 8V
2 = 15,68 bad - should be around 8V
3 = 0 bad - should be around 8V
4 = 0
5 = 16,12 <--- Changed R102, now 8v as expected!
6 = 15,22 bad - should be around 8V
7 = 16,08 bad - should be around 8V
8 = 16,89

Is that correct/normal?

Please recheck all of them and tell us what DMM you are using. Depending on the meter, you might get bogus readings on pins 2 & 3. Are you sure IC1 is a real OPA2134? If it's socketed, you can try a TL072.

It's hard to explain why there are so many bad readings. Your workmanship is usually very good.

 

[Dali]

Please recheck all of them and tell us what DMM you are using. Depending on the meter, you might get bogus readings on pins 2 & 3. Are you sure IC1 is a real OPA2134? If it's socketed, you can try a TL072.

Sadly, got the same thing today:
1-15.82
2-15.26
3- 5.25
4-0
5-15.22
6-15.53
7-15.92
8-16.73

DMM is this one: XL830L



As for the OPA2134, it was taken from a working Magnetron Delay as a test.

Both bought at Tayda on one year apart.

Both giving me around 16v on 1,2,5,6,7,8 and 5.25 on pin 3.

Tested with 9V connected. The number don't really change between the pedal at on or off.

It's hard to explain why there are so many bad readings. Your workmanship is usually very good.

Maybe I'm just bad at testing/debugging.

Seriously, I'm very grateful for all the help!

 

[Chuck D. Bones]

Seems like Vref is messed up. Pull the OPA2134 out of the socket, turn the power on and measure the voltage on pin 5. Should be close to 8V.

Apparently the input resistance of the XL830L is a secret. Your measurements tell me that it's 1MΩ. Not great, but usable for most measurements as long as we correct the readings.

 

[Dali]

Seems like Vref is messed up. Pull the OPA2134 out of the socket, turn the power on and measure the voltage on pin 5. Should be close to 8V.

8.53v on pin 5 ic-less and power on.

 

[Chuck D. Bones]

You said in your previous post that you measured around 16V with the IC installed. Tells me that the OPA2134 is broken. Try another IC.

 

[Dali]

You said in your previous post that you measured around 16V with the IC installed. Tells me that the OPA2134 is broken. Try another IC.

Sadly no more OPA2134.

I just tried back both in my Magnetron Delay and now it looks both are fried, my Magnetron don't work anymore...

I will get some new ones and test back (in about a month).

Thanks to @fig, @Chuck D. Bones @EGRENIER and others for all the help! I've learned a lot in the last 2 days!

 

[Chuck D. Bones]

Most other dual opamps will work. If you have a TL072, try that. Any chance you have plugged the OPA2134 in backwards at any time?

 

[Dali]

Most other dual opamps will work. If you have a TL072, try that. Any chance you have plugged the OPA2134 in backwards at any time?

It is a possibility. Knowing myself I'm eager to believe I removed or put back those IC while it was powered On (more likely than backward but I didn't film myself )

So I tried a TL072 and voltage seems way more like we want it.

And... the pedal now WORKS!

 

[Chuck D. Bones]

YAY!
Plugging and unplugging ICs with the power on is dangerous. Sometimes you get away with it, sometimes you don't. Putting a dual opamp in backwards will kill it instantly when the power is turned on.

 

[Dali]

YAY!
Plugging and unplugging ICs with the power on is dangerous. Sometimes you get away with it, sometimes you don't. Putting a dual opamp in backwards will kill it instantly when the power is turned on.

I assure you it was not because I was lazy (but I do that all the time with USB on PC, on purpose).

Again, a million thanks! Being such a newbie (builder-by-docs) I started my journey with no knowledge of electronics at all.

Having build around 30 pedals with so few basic knowledge is just a great testimony on how great @PedalPCB stuff is!

 

[EGRENIER]

So was it all that time R101/ R102 ? Could pushing 16V to pin 5 fry the Opamp ?

or do you suspect that you fried both Opamp ?

 

[Chuck D. Bones]

So was it all that time R101/ R102 ? Could pushing 16V to pin 5 fry the Opamp ?

That would not hurt the OPA2134. It had to be something else.

 

[EGRENIER]

I guess this will remain a mistery!

now where‘s the artwork and how do you like it ?

 

[fig]

I was involved...that's always suspect

 

[Dali]

now where‘s the artwork and how do you like it ?

Golgotha Compressor (Delegate Boneyard)

Well, I did finish the enclosure *before* testing, hence the May 8th date inside... If I knew I would blow 2 ICs once it didn't work at first. Now it's working. My surprise was with the Sustain control. Over 12 O'clock, it turns into an Overdrive pedal. I don't know if it's on purpose or...

forum.pedalpcb.com

I'm not sure it compete against my Pigtronix Philosopher's Tone 18v but I built the Golgotha so it's a win in my book!