Aion Refractor (Klone) Troubleshooting Help

[versayce]

Hey everyone, I just recently purchased and built Aion Fx's refractor pedal and ran into some problems.

Firstly, I had problems shortly after plugging the unit in. I was able to play with it for a short while before the led started blinking intermittently and a popping noise started at an interval equal to the blinking of the led.
I figured it was a power issue and was able to narrow it down to diodes D1, D2, and Z1. I found that they were shorted and replacing these solved my power issue. the unit is able to start up and each knob is functioning as they should (or at least it seems like it) and there is no intermittent popping.

The unit is able to power on and the overdrive is definitely working, but now my issue has turned into a squealing noise while the unit is on (everything seems to be functioning properly aside from this high pitched squeal).

Also worth mentioning that the squeal isn't constant, its more like an oscillation (Can make a video if necessary)

I turned to the troubleshooting page in the build documentation and was advised to take voltage measurements from the IC chip legs.

Here are the readings I measured for each chip:

IC1

• 3.93v
• 3.93v
• 0.88v
• 0.00v
• 3.87v
• 3.93v
• 3.93v
• 7.83v

IC2

• 3.93v
• 3.93v
• 3.27v
• -6.41v
• 3.93v
• 3.93v
• 3.95v
• 14.75v

IC3

• 8.14v
• 4.15v
• 0.00v
• -3.87v
• -7.9v
• 3.79v
• 3.41v
• 8.15v

One other thing to note: After recording these values, I ran through each chip again and each reading was pretty different (up to a volt or more difference). I repeated this a few times (making sure I was going in pin order 1,2,3....etc) to confirm that I was getting different measurements. Not sure if this helps or not but I felt it was worth mentioning.

Clearly the voltages I was getting are out of spec for every chip and I was wondering if someone could help direct me to the next spot I should be looking for circuit issues. I'm pretty new to soldering this many components onto a bare circuit board and my knowledge of circuits is pretty limited. I was thinking my first course of action would be to get new chips to test in the current circuit but wanted to know what someone with more experience doing pedal wiring thinks. If more information/photos are needed to help me out let me know and I'll do my best to send them quickly!

THANKS!

Build Documentation: https://aionfx.com/app/files/docs/refractor_kit_documentation.pdf
[/list][/list][/list]

[idy]

What kind of chip did you use for the charge pump? These are notoriously whiny.

[versayce]

What kind of chip did you use for the charge pump? These are notoriously whiny.

So I believe IC3 is for the charge pump which is using: TC1044S.

The other two sockets are using TL072

[idy]

Do some googling and reading on the forum about the charge pump. There are also 1044scpa that are less noisy.

as to proper voltages for the ICs, yours are not too bad, maybe your supply is a bit less than 9v?

on this thread "lmkv15" posts some good voltages.
https://www.diystompboxes.com/smfforum/index.php?topic=118310.msg1101193#msg1101193

it's towards the bottom of the page, not the "bad" ones earlier.

[versayce]

Do some googling and reading on the forum about the charge pump. There are also 1044scpa that are less noisy.

as to proper voltages for the ICs, yours are not too bad, maybe your supply is a bit less than 9v?

on this thread "lmkv15" posts some good voltages.
https://www.diystompboxes.com/smfforum/index.php?topic=118310.msg1101193#msg1101193

it's towards the bottom of the page, not the "bad" ones earlier.

Thanks for the post. I read the documentation and I was supposed to be within .5v of what is recorded in the PDF, but my measurements are off by over that amount. I'm using an old cheapo multimeter which I was a little nervous about using so that could be resulting in my readings varying by more than expected.

Comparing my values to the post you linked, I can see an obvious trend that the chips follow as far as voltage and it does seem that mine follow a similar trend albeit with lower voltage. I measured the voltage of both 9v power supplies I'm using and they both are around 8v, again, I'm not sure if the multimeter is giving me error.  I'll try to see if I can find my other multimeter or purchase a new one to be sure I'm getting a proper measurement. I've done some reading on the charge pump chip and it seems like this problem is very common. I ordered multiple new chips from different manufacturers to see if that fixes the problem.

I apologize if I'm a bit slow. There's a lot more I need to learn and I'm a car guy so putting together mechanical parts is my specialty, not so much electronics. Luckily that's given me lots of patience so I'm positive I can work out this issue with a little bit of guidance!

[versayce]

Update: I swapped the TL072 chips in IC1 and IC2 and have noticed a huge improvement on the whining/squealing sound. It no longer oscillates and is constant, but the pedal is now useable, the sound gets louder as I turn up the treble pot. I'm hoping the new chips I've ordered completely solve my problem.

[duck_arse]

welcome to the forum.

please post your new voltage measures from the good/working IC's, just for completeness.

[versayce]

welcome to the forum.

please post your new voltage measures from the good/working IC's, just for completeness.

Sure thing. As soon as they come in I'll take some new measurements.