SOLVED cetus preamp - no signal when engaged

[maertz13]

Hey all, first post, first build. i've done some much simpler circuits and mods, but this is the first big one.

i have good bypass, but as soon as i turn on the pedal, it mutes. LED comes on. volume is up. cables are good. i have reflowed every connection, checked the orientation of every polarized part, swapped the jacks around to ensure i am plugging in correctly, and at this point i am out of my depth. the only suspicions i have are that i have a bad component somewhere (i've read that there are bad batches of op amps), or that there is an error in the build doc that i'm unaware of. i found a picture of someone else's build and they've got the zener diode at D2 flipped. a backwards diode would certainly stop a signal dead in it's tracks.

i'm open to any ideas and any criticism at this point. i know my soldering is a little sloppy. reflowing a couple dozen components in a magnifying glass has made a flux mess. bad vision, shaky hands. there's a reason i don't do this for a living . also attached is a picture of the (much cleaner) build that was being sold on reverb (so it's safe to say it works) with that diode flipped

 

[jhaneyzz]

Ok, so what power supply ARE you using?

Wait, you just answered that…

I’ve had bad power supplies give me noise like that, I’d suspect that.

 

[jhaneyzz]

What is a “headdesk” power supply?

 

[maertz13]

sorry. that may have been a little too millennial cringe for this forum. head desk. like face palm. only your head into the desk.

at my disposal i have

a 9-12v switching adaptor from radio shack (read: old). that turns the pedal on but gives me the gnarly noise. reading 10.4v

another 9v radioshack power supply that only turns the LED on. 800ma

ANOTHER 9v radioshack power supply that is 300ma that won't even turn the LED on

duh dude, don't use those crappy old radioshack wall warts. of course. my 9v 800ma godlyke powerall turns the LED on only. i've trusted that power supply with every pedal i've ever thrown at it for 15 years.

so i borrowed a buddy's 1spot. it's reading 20v from the wall despite being a 9v power supply. sounds amazing. horrible noise is gone. except the LED isn't turning on with this one. this is the best result i've gotten so far, though not ideal. 2 of these power supplies are specifically made for pedals, and only one works.

 

[Dirty_Boogie]

Ok, forget all these power supplies (who knows what you have there!) and try a new 9V battery. That’s a known voltage, and not susceptible to any noisy house wiring. Take one of those old Radio Shack power supplies, cut off the plug side (leaving about 6 inches of wire), throw out the PS, strip the ends, and attach to the battery, making 100% sure you connect the negative terminal to the center pin of the 2.1mm jack (verify with your multimeter).

Connect to pedal, and report back.

 

[Nic]

sorry. that may have been a little too millennial cringe for this forum. head desk. like face palm. only your head into the desk.

at my disposal i have

a 9-12v switching adaptor from radio shack (read: old). that turns the pedal on but gives me the gnarly noise. reading 10.4v

another 9v radioshack power supply that only turns the LED on. 800ma

ANOTHER 9v radioshack power supply that is 300ma that won't even turn the LED on

duh dude, don't use those crappy old radioshack wall warts. of course. my 9v 800ma godlyke powerall turns the LED on only. i've trusted that power supply with every pedal i've ever thrown at it for 15 years.

so i borrowed a buddy's 1spot. it's reading 20v from the wall despite being a 9v power supply. sounds amazing. horrible noise is gone. except the LED isn't turning on with this one. this is the best result i've gotten so far, though not ideal. 2 of these power supplies are specifically made for pedals, and only one works.

All those are center negative ?

 

[maertz13]

All those are center negative ?

2 of the radioshack adaptors can be switched. the godlyke is center pin negative. as is the 1spot.

 

[maertz13]

slight update. it seems that my testing of the godlyke power supply didn't make it past seeing if the LED came on. tried it again. works. quiet. no horrible noise. but also the LED isn't on. so 2 power supplies work and sound good but won't turn the light on, and some power supplies will turn the light on but not power the pedal.