SOLVED AionFx Achilles (Prince of Tone) IC voltage 3 off?

[Asdrael]

Hi. Third pedal build, first one that does something wierd. I can't figure it out and thought I would turn to better knowing people (so basically, everyone but me).

- Pedal: AionFx Achilles, Prince of Clone single channel clone.
- Schematic:

- Picture (can take more if needed - c15 is now populated):


- Problem:
The pedal sounds "fine" and the pots do what they claim they do. It feels like I have to boost the volume to get to unity volume (like 2/3rd up) but it seems normal on this pedal. Maybe I don't have a huge headroom but that's hard to say considering I have never tried one, ever.
I was checking the voltages and Pin 3 is not reading what it should. 2.21V instead of the expected 4.25V.
All voltages of the power section are fine.
Voltage coming into R1 is 4.21V.
Voltage coming out of R1 is 2.21V (which makes no sense to me given the schematic).
Voltage into C1 is 2.21V. Out is 0V.
Voltage in and out of RPD are 0V with no audio input (so C1 is fine I suppose?).
There is no weird grounding around there that I could detect.
Edit: Also, R1, RPD values are correct. I have continuity between R1 and C1, C1 and RPD, R1 and R14/15.

Now it behaves like I have a voltage divider at the exit of R1 but I don't see it? Anyone has any clue?

 

[Nostradoomus]

What do pins 1 and 7 read?

 

[Asdrael]

1: 4.42V
2: 4.46V
3: 2.21V (?)
4: 0.00V
5: 4.25V
6: 4.27V
7: 4.25V
8: 8.58V

So not perfect, but within tolerance I'd say. All pins are what is expected, except pin 3.

 

[Nostradoomus]

What kind of multimeter do you have? Check the specs and see what the input impedance of your meter is. Most cheapy ones are 1M which will result in them being loaded down at this part in a circuit. Good ones have 10M Input impedance and display proper readings. I'd say nothing is wrong if it's a 1M meter.

 

[Asdrael]

I wouldn't be able to tell you as it's written nowhere on my old multimeter. Considering I have just found the new version of it on Alibaba for 1$ and it doesn't say anything about input impedance, I would say it's not a good sign.

Thanks a lot for the advice. I will order a proper one and pay attention to the input impedance. If you have any recommendations, I'll take those

Marking it resolved for now.

 

[Nostradoomus]

I have a Klein MM600 and it's been great. The cheaper MM400 looks good too if you don't need the extra functions, still has 10M impedance.

 

[Asdrael]

I'll grab one next time I'm at the hardware store then, cheers!