Effect Engages But Little Distortion | IC3 Voltages Off | Aion FX Maelstrom

[Macca]

Hi everyone. I finished an Aion FX Maelstrom (Darkglass Vintage Microtubes) build and am having some trouble with it.

When bypassed, the signal flows through the pedal correctly. When on, the LED works, along with all the controls (Volume, Blend, Tone, Drive and the Low and High toggle switches). However, the amount of distortion is very little. I need to max the Drive + Blend control (fully wet) to get the smallest amount of distorting.

I checked all the voltages based on the chart below. Everything is good except for the 16-pin IC3 (CD4049UBE). On IC3, pins 5, 7, 9, 11, and 14 should read 0v. Instead, they all read ~9v. (The other pins are correct.)

IC3 - Pin 5 | Should read 0v | Reads ~9v
IC3 - Pin 7 | Should read 0v | Reads ~9v
IC3 - Pin 9 | Should read 0v | Reads ~9v
IC3 - Pin 11 | Should read 0v | Reads ~9v
IC3 - Pin 14 | Should read 0v | Reads ~9v

Here is a link to the build document:
Aion FX Maelstrom Documentation

I reflowed all the solder joints and checked every connection. It all looks okay. I'm unsure what to do next to address the IC3 readings above. Any help would be appreciated. Thank you!

 

[Nostradoomus]

Bad ground connection somewhere, post some pics of your build. Top and solder side, jack wiring etc.

 

[Feral Feline]

Post pics of your build, otherwise everybody is just...

Shot in the dark
As we guess which is the damaged part
Where to start
It's all part of the game that we call
Shot in the dark
As we play debugging-scenarios taking a shot (dark, dark)
Random sharts (dark, dark)
(dark, dark, dark)
Shot in the dark
Dark, Shot, Dark
Shot, Dark, Shot

You've checked the wiring on the DC-jack, I guess, or checked for solder-bridges under the IC-sockets — you did socket them?

Everything is good except for the 16-pin IC3 (CD4049UBE)

Download the CD4049UBE Datasheet (lots of places online to DL it from), you'll see that the pins you mentioned (5, 7, 9, 11, 14) are the inputs to the inverters:

The aforementioned pins aren't used in generating distortion, but they can't be left hanging either as that could unsettle the chip — so for the sake of the IC's stability they're tied to VA. (I always thought they needed to connect to ground .

Only the first inverter, "A", is being used in the pedal for clipping. You said though that pin 3&2 are okay. Maybe check again and make sure.
There's a warning on the datasheet: CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. So perhaps the chip got electro-borked.

I'd thoroughly check for shorts/solder-bridges before testing another chip in the place of the current CD4049UBE IC — you don't want to bork another chip.

Maybe you've got too high a resistor in R16 or maybe R17 is 470Ω instead of 470k or...


MAYBE...


Yeah, post pics.

 

[Nostradoomus]

on the aion schematic they are sent to ground

 

[DailyDovetails]

IC3 in backwards is my shot in the dark.