Labrat powers up and then dies.

[chongmagic]

Just to see if I can get a second or third set of eyes on this. I power up the circuit and it immediately dies, thought it might be a short but I can't see anything that would be shorting out. Maybe a bad cap?

 

[iamjackslackof]

I ran into this with a different Sushi Box project. Making sure you have sufficient voltage and amperage in your power supply is step 1. I honestly forget if I ever resolved my issue. Might have been the IRF740, as I seem to remember it's important in the circuit's power section.

 

[vigilante398]

Kudos on a very clean build. What power supply are you using with the pedal? As @iamjackslackof mentioned that's a common symptom of a power supply that can't deliver enough current; I recommend at least 400mA for single-tube pedals, but more is always better if you have it.

 

[chongmagic]

I am using a power supply on my work bench that has 500ma with selectable 9v - 12v- 16v options. I have used it in all of your other projects with no issues. It is strange the led on the tube socket is bright then greatly dims within a second after powering it up.

And thank you!

 

[vigilante398]

Ah, I found it, just needed a bigger screen. You used a NE5532 (dual opamp) instead of a NE555 (timer/oscillator). Your power supply is having a bad time.

 

[Tassieviking]

There might be a small solder bridge between pins 7 and 8 on the 555 timer on the bottom of the PCB.
It's very small and hard to see so I am not sure.

 

[chongmagic]

What a newbie fail from me, that fixed everything! Thank you vigilante.







I thought maybe drilling my own enclosure had jinxed me!

Thank you again!