SOLVED Obsidius Preamp no anything

[FamousAmos]

Howdy,

Just finished an Obsidius preamp which I though I was being pretty careful with building, however upon trying to power on the completed build the first time I get nothing. Already cleaned with IPA and reflowed solder but still nothing.

Any common issues with these guys you folks are aware of that I'm overlooking?

I'm new I don't know what to do

Thanks

 

[steviejr92]

Your soldering looks fine I would check continuity throughout the board and then check the voltages on your ic’s
Edit: are you getting bypass at all?

 

[FamousAmos]

So I get just a clean signal passing through to the amp when the pedal is what I believe to be switched on. (led doesn't power on though. tested led before install). Even cranking all the knobs it's still just dead clean.

No odd warbling or squealing hissing or buzz either.

When I switch the pedal off. All signal cuts off/no passthrough.

 

[steviejr92]

So I get just a clean signal passing through to the amp when the pedal is what I believe to be switched on. (led doesn't power on though. tested led before install). Even cranking all the knobs it's still just dead clean.

No odd warbling or squealing hissing or buzz either.

When I switch the pedal off. All signal cuts off/no passthrough.

Sounds like you might have a jack wiring issue

 

[FamousAmos]

Sounds like you might have a jack wiring issue

Input/output jacks or power jack itself?

If the in/out jacks were the problem wouldn't I at least still get the led powering on? Or could something be grounding out?

 

[steviejr92]

Input/output jacks or power jack itself?

If the in/out jacks were the problem wouldn't I at least still get the led powering on? Or could something be grounding out?

Yes or you could have the led wired backwards I would check all jacks look for any wiring issues

 

[steviejr92]

So that breaker board for the foot switch looks a little different is that a normal 3pdt breaker board?
Update:

Notice mine do not have those numbers

 

[fig]

it's upside down...maybe?. Great catch @steviejr92 !

 

[steviejr92]

it's upside down

Not sure if it’s upside down the other side should have what I call the “caution” side cause it looks like caution tape haha it might be a different board all together

 

[fig]

Hmm...could that be for a particular board maybe?...oh you just said that...I feel like a parrot...got a cracker?

 

[steviejr92]

Hmm...could that be for a particular board maybe?

I’m really not sure I’m about to look at the store for it and confirm
Update: couldn’t find it it might just be part of a batch that had those number on it? Again not sure but it look different.

 

[fig]

The silkscreen lines up, but the numbers are probably a run# from the pcb-printer.
This is a different issue I think.

 

[Robert]

The breakout board is fine, that's just a production code that is printed on a few of the boards.

Turn Blend all the way up, Level all the way down. If you still have sound you are in "Bypass" mode.

The LED could be installed backwards, or there may be a power issue affecting the entire circuit.

Got a DMM? If so measure the voltage on Pin 8 of one of the TL072 ICs.

 

[FamousAmos]

So that breaker board for the foot switch looks a little different is that a normal 3pdt breaker board?
Update:
View attachment 32722
Notice mine do not have those numbers

Yeah it's a standard breakout, not one of the different ones they have for like a kliche or anything. No idea why it has all the extra numbers. I've only ever ordered these:

3PDT Latching Footswitch - Solder Lugs - PedalPCB.com

Footswitch

www.pedalpcb.com

I have extras though should I try another one?

LEDs wired right though it's one of those pre-built deals from Lovemyswitches.

 

[steviejr92]

Yeah it's a standard breakout, not one of the different ones they have for like a kliche or anything. No idea why it has all the extra numbers. I've only ever ordered these:

3PDT Latching Footswitch - Solder Lugs - PedalPCB.com

Footswitch

www.pedalpcb.com

I have extras though should I try another one?

LEDs wired right though it's one of those pre-built deals from Lovemyswitches.

Before soldering anything new I would check the voltages on your ics and post for each let’s narrow this down before we go jumping to more permanent actions!

 

[FamousAmos]

Before soldering anything new I would check the voltages on your ics and post for each let’s narrow this down before we go jumping to more permanent actions!

Will do soon here, thank you standby lol

 

[steviejr92]

Also I would do the test @Robert has suggested that will let you know if you in bypass or not.

 

[FamousAmos]

The breakout board is fine, that's just a production code that is printed on a few of the boards.

Turn Blend all the way up, Level all the way down. If you still have sound you are in "Bypass" mode.

The LED could be installed backwards, or there may be a power issue affecting the entire circuit.

Got a DMM? If so measure the voltage on Pin 8 of one of the TL072 ICs.

Blend all the way up, level all the way down and I still have sound in one of the switch positions. Click it again and sound gone. So sound gone must be on.

 

[FamousAmos]

Well got it fixed and working now. Tested all the ic's they were fine. So as was mentioned I checked power. Opted to just replace the whole DC jack and sure enough that was it. It was a lumberg DC jack too. Oh well glad it wasn't something like a single resistor. Thanks a bunch for your help gents!

 

[xefned]

Power jack was my guess after reading the LED wasn't lighting. Congrats on the quick fix!

Just want to mention that "Lumberg" jacks are often faked. The ones from Amazon are often garbage. I threw away a pack of 10 after an unusually high failure rate. The ones from LMS have proven high quality.