Aion Refractor (Klon clone)Issues

[Big mike 1100]

Hi- It's my first post, and this is my 4th or 5th build.  I've purchased a few boards from AION and love the product.  Just wish I could get them to work!

I put together an Aion Refractor.  The mods I made (based on what I had were-
-I initially socketed the diodes, but thought they were faulty so I soldered them in
-I believe I changed C14 to a 6n8

https://aionelectronics.com/project/refractor-centaur-overdrive/


IC1 (LF353P)
1-   6.73
2-   6.73
3-   5.79
4-   0
5-   6.7
6-   6.69
7-   5.94
8-   9.36

IC2 (LF353P)
1-   8.24
2-   6.88
3-   6.73
4-   7.27
5-   6.74
6-   6.98
7-   8.25
8-   8.86

IC3- TC1044SPCA
1-   9.36
2-   9.36
3-   8.4 (fluxuates 8.4-8.1 up and down)
4-   7.28
5-   7.28
6-   7.93
7-   7.93
8-   9.36

I tried measuring D1, D2, D3 and D4, but not sure if I'm testing correctly.  Sometimes they read 0 and other times they read -3 or -2.93

Regarding the sound- when the pedal is not turned on, there is clear working signal.  When the pedal is engaged, the light turns on and there is clear guitar sound, but its noticeably quieter than the bypassed volume and there is no gain whatsoever.  The volume pot works as it should but neither the tone nor dual gain pots work at all.

[Aph]

Did you insulate the bottom of that dual pot?
I haven't built the Refractor, but I've built the Nimbus which also uses a dual pot, and it sits right on the circuit board.
If I didn't isolate it with two layers of electrical tape, it certainly would have shorted out the board.

[DIY Bass]

Not an expert by any means, but it looks to me as if the place to look first is around IC3.  That and the surrounding circuitry should be generating all your power supply voltages.  Those voltages don't look right, and the power supply pins to your op amps do not measure what the schematic says they should.  IC1 power pins look about the same as the schematic, but IC2 should have -9V on pin 4 and +18V on pin 8.  That -9V looks like it should be coming from IC3 pin 5, and the +18V comes from D4 and the circuitry around pins 1, 2 and 4 of IC3, so I would be looking for problems around there.  Maybe shorted solder connections or similar.

[Big mike 1100]

Thanks for the replies- Here's the update.  I actually removed the dual gain pot thinking it might be part of the problem.  I replaced with two 250KB pots.  Same problem- volume works, gain and tone do not. 

I also took a look around IC3 as DIY Bass suggested and didn't see any solder issues, but maybe I'll try with a better magnifying glass. 

[Big mike 1100]

I just looked back at the schematic.  If I used a 500K pot instead of the 100k pot suggested, could that be the issue??

[Aph]

No.
If you have a voltage on pin 3 of the TC1044, you do not have a good ground. Pin 3 should be going directly to ground.
Make sure your IC socket for IC3 has good solder connections and that the IC is seated in the socket firmly.

[Big mike 1100]

Thanks Aph.  I checked IC3 and it seems to be seated correctly.  I'll remove the socket later and maybe try a different socket and IC.

[Big mike 1100]

I tried a different socket, seated it well,  and  a new IC and checked for solder bridges.  As stated above, I assume there's a grounding issue somewhere.  Would an audio probe be the next step?  I'm pretty new to this and not sure how to continue.  Thanks!

[Aph]

If you are decent at reading schematics, you could make continuity checks between the chassis and the ground points on the PCB (with power not connected). It looks like you have all the grounds going to the ground lug of your input jack, so connect one lead (with an alligator clip) to the stomp chassis and use the other lead to touch the ground points on the PCB, which can be done from the top. The first thing I'd do is touch the actual pin 3 of IC3. If you don't get zero ohms, there is a break somewhere. You could then try soldering an insulated thin wire under the PCB from pin 3 to a known good ground.

[DIY Bass]

Yep, you aren't up to an audio probe yet.  Get the power supply voltages correct first.  A lot of what is currently wrong will then come good.

[Big mike 1100]

Ok- All that should go to ground goes to ground according to the continuity test.  I had to run a wire from IC3 pin3 to ground as APH suggested and got the following numbers so far.  I think it's an improvement. 

IC1
1-1.4
2-1.4
3-1.38
4 -1.8
5 -5
6 -.47
7 8.73
8 9.36

IC2
1 16.03
2 -5
3 1.37
4 -8.7
5 1.37
6 .62
7 16.04
8 16.72

IC3
1 9.36
2 4.82
3 .3
4 -4.25
5 -8.68
6 4.3
7 5.8
8 9.35

Still no gain, but one of the two gain pots at least adjusts sound now.  Nothing on tone pot.  Volume pot still works

[DIY Bass]

VB (pins 3 and 5 of IC2) should be half of the +9V value, which comes from pin 8 of IC3.  So you are looking for about 4.6V on those pins, not 1.3 as you have now.  Check R29 and R30 and make sure they are the correct values and that there are no solder problems around them. If they are both the same and soldered correctly you should be getting 4.5 to 4.6 V for VB easily.

[Aph]

Yeah, like DIY says ^^^.
You may also have other grounding problems. Go back to the schematic and check all the ground points on the PCB.

[Big mike 1100]

Ok- as mentioned, I substituted the dual gain pot for two single 250k pots.  When the "top row" pot is at the halfway point and the "bottom row"  pot is fully turned the voltages are at the following points.

iC 1
1 3.27
2 3.27
3 2.47
4 0
5 -.53
6 -.48
7 8.72
8 9.36

IC2
1 16
2 -5.5
3 3.27
4 -8.78
5 3.27
6 2.36
7 16
8 16.72

IC3
1 9.36
2 4.82
3 0
4 -4.25
5 -8.72
6 4.32
7 5.8
8 9.36

The gain significantly affect the voltages- I can adjust IC2 pin 3 from 3 volts to .8v by turning the bottom gain pot. 

Am I getting closer?

[DIY Bass]

If you look at the schematic, IC2 pin 3 is supposed to be a fixed voltage.  It should not adjust.  I would be looking for a solder bridge somewhere.  Sounds as if that gain pot may be connected somewhere it shouldn't.  Also - recheck the network around R29 and R30 and all the points where that network is connected to the circuit.  You need a steady 4.5-ish volts on that pin.

[Big mike 1100]

I took all of the suggestions above into account-  checking for solder bridges and rechecking to ensure proper grounding.  The puzzler to me is that the gain pots affect IC2 pin 3, but the gain pot also affects IC1 pins 1,2. &3.  I know that pin 3 of IC2 should have fixed voltage, but I'm at a loss as to what to do next. I checked the R29 area and actually replaced the resistors just in case.

[DIY Bass]

Maybe post some photos of the top and bottom of your board and see if somebody else can spot any issues?

[Big mike 1100]

Here are some pics.  I tried to scrape between the solder joints to ensure no bridges. I'm not sure how to test for solder bridges other than visually.  Would a multimeter help with that?

The only addition is a black wire that runs from IC3 pin 3 to ground (connected to ground lug of the output jack)

[Aph]

Thanks for pix, mike... but unfortunately, it's really hard to see anything clearly. For me, I'd need much higher resolution pix.

[Slowpoke101]

I have to ask just because I'm curious and I have noted that other builders have had this problem with this exact unit.

Is C16 (1uF Tantalum) installed with the correct polarity?