Aion Trivibe Trouble

[Carlinb17]

Howdy everyone, I'm a new user to this forum. I've build a couple dozen pedals and this one has me stumped. It's the AION TriVibe. All spec parts, I get power. I get sound both in bypass and on, I do not get modulation in any setting. The volume is about the same either way. I followed the audio signal path through the circuit and it is where it should be. I've swapped out the 13700 and TL022 with a known working one with no additional changes. I've reflowed and reflowed. If anyone has any suggestions, or thoughts it would be appreciated.

here are my readings for IC3 with both pots at max

7.96 doesn't vary
4.3 goes down to 0
4.36
0
7.6
3.97
8.14
8.73

[iainpunk]

welcome to the forum

have you checked out this thread:
https://www.diystompboxes.com/smfforum/index.php?topic=29816.0

if sound passes but without change, it could be that the LFO isn't working properly,

cheers, Iain

[Carlinb17]

if sound passes but without change, it could be that the LFO isn't working properly,

Thank you, I thought it was as well, but when I swapped out the LFO (IC3) with a known working one I had no change...

[Govmnt_Lacky]

Something in your LFO is not working properly. You should be getting a varying voltage on either Pin 1 or Pin 7 (excuse me as I do not have access to the schematic at this time)

Your Pin 7 seems very high at 8.14V.

When checking the LFO, recommend you set the Speed pot to mid-range otherwise the voltage readings will be hard to track on a meter.

Check for component values in the LFO circuit, capacitor vales and orientation, solder bridges, etc.

EDIT: Pin 5 of IC3 should be Vref. About 1/2 of your input voltage. Yours is at 7.6??

[Carlinb17]

thank you, I will check those and get back with more.

[Carlinb17]

EDIT: Pin 5 of IC3 should be Vref. About 1/2 of your input voltage. Yours is at 7.6??

So that is obviously an issue, if that is the input for the chip I believe I'm reading it correctly (please correct me if I'm wrong) then my problem could be IC2 or the parts leading from IC2 to IC3?

[Govmnt_Lacky]

So that is obviously an issue, if that is the input for the chip I believe I'm reading it correctly (please correct me if I'm wrong) then my problem could be IC2 or the parts leading from IC2 to IC3?

If I am reading the schematic correctly (runoffgroove):

Pin 5 of IC3 should have the exact same voltage as Pins 1 & 2 of IC2. Is this the case with your build? Also, what is the voltage at IC2 Pin 3?

[Carlinb17]

Thank you for the direction, I will check it as soon as I can here is the schematic I was going off of.

https://aionfx.com/app/files/docs/tri-vibe_documentation.pdf

[Carlinb17]

incoming voltage is 9.36

IC1. NE5532

4.19
4.18
2.09
0
4.42
4.43
4.43
8.86

IC2 TL062

4.42
4.42
4.22
0
3.9
3.9
1.54
8.86

IC3 TL022

2.89
4.36 drops to 0
4.36
0
7.61
3.97
8.13
8.73

IC4 13700

1.33
5.28
4.6
4.6
6
6
0
6
5
4.19
5.22
8.8
5.22
4.6
5.28
1.33


I did take the measurements of the 1N5817 before left to right it reads 9.07 after 9.35

I see a variable resistance on both sides of R31 and R28

Please let me know your thoughts and thank you in advance.

Ben

[Govmnt_Lacky]

I am still seeing what may be an issue with Vref coming out of IC2 and going to IC3.

I cannot get to Aion's site right now. Can someone take a look and verify? The voltages still look wrong.

[iainpunk]

does the little RED led flash at all? if it doesn't its definitely the LFO

its probably nothing, but solder side IC3 pin 7 has a little lump of solder, have you taken that off yet?
it would also be nice to see a picture of the solder side from the opposite angle so we can see what's going on behind the big red switch

cheers, Iain

[Carlinb17]

the led definitely does not flash. If I remove IC2 then the led will turn on but not flash. I just ordered another two sets of IC's, and pots for this pedal. I'm struggling a little with the concept though. If I have replaced IC3 (LFO) with a known working TL022 and it behaves the same (aka no modulation) I then put the known working IC3 back into my Luna pedal and the Luna works just fine leading me to believe that it's something more than the TL022.

I can definitely send some more pictures of the solder area and I will go through and touch it up.

I read another thread on here where another person was having a similar issue with a Tri-vibe they made (not Aion) as of the last post they were unsuccessful but one of the causes was thought to be the depth pot. I have continuity through it but I just wanted to throw that out there to incase it makes any sense to someone who knows far more about these designs than I do.

Thank you again for all your help I will get the pictures tonight and the new iC's when ever they arrive .

[Govmnt_Lacky]

Are you sure that ALL 10uF capacitors are installed correctly?

** Sorry... troubleshooting blind as I can only see the runoffgroove schematic right now **

[DrAlx]

Look at IC3.
Pin 7 should be a square wave that toggles between high and low levels. (Lets say 8.1v to 0.6v) according to whether voltage at pin 5 is higher or lower than at the reference at pin 6.
Confirm you pin 7 is indeed stuck at the high level. I guess it is.

Now considerr the voltage divider...

Pin7-----R25-----Pin5------R26---------Pin1

Write in the end voltages and R values

8.13V-----220k------Pin5------68k-------2.89V

Now just looking at the R values, Pin5 has lower resistance to the 2.89V so it should be closer to that voltage than the 8.13V on the other side.
You measured 7.6V being input to Pin 5.  That is way off.

So either...

The schematic in their document does not match the pin numbering of the board IC
OR
You did not measure voltages with enough attention as to whether things were changing in time or not
OR
You used wrong values for R25/R26.  The measured voltages suggest you have R25 lower than R26.
OR
Some other build error.

[DrAlx]

Resistors in photo look correct, so must be something else in the build.
General principle about that voltage divider still applies though.

What happens in a non stuck LFO is that as the triangle voltage (pin 1) varies, it will at some point drag the voltage at Pin5 across the Pin6 reference voltage and so make the square wave at pin7 to toggle.

With no power applied to the board, confirm those two R values with a multi meter.
Then power on again and check voltage measures at pins on that IC. If anything varies say how.

[Carlinb17]

First off, thank you both for the help. I will start the measuring when I get home and report back. I've attached a picture of the Aion schematic so hopefully your not trouble shooting in the dark as much.

All the capacitors are in the correct orientation. Thankfully Kevin at Aion orients things more or less the same way across builds.

So I understand correctly you want me to measure the R value both on and off of R25 and R26 correct. I will also double and triple check voltages on the pins.

Thank you

[DrAlx]

Yes. That's the schematic I looked at.
Yes first measure R25 and R26 resistances to confirm they are as marked. Also measure across them together and confirm it is the sum (i.e. measure resistance between pin5 and pin7 of the IC3 socket)  Take out IC3 and remove power too when you do that.
If all OK then please retake voltages on IC3.

[DrAlx]

Hang on, you have posted inconsistent IC3 voltages. Earlier post mentions much higher voltage at pin1. First post said it was 7.96V and stuck. If you use that value in the voltage divider then the voltages at pins 5,7,1 look OK and are consistent with each other. So resistances probably are ok.I
... EDIT: or maybe not. The pin5 voltage should be between the pin7 and  pin1 voltages and closer to the pin 1 voltage than pin7.

Pin 6 voltage should be closer to Pin 3 voltage though.
I would temporarily short out R24. That should make the voltages the same for sure.

The triangle voltage at pin 1 should never go as high as it is. I have had LFOs reach a stuck state before on start up. One thing to do before you power things up is to short out the pins on caps C9 and C10 with a screwdriver to discharge them so circuit starts with uncharged caps.  Then fire up the circuit.

[Carlinb17]

yes, I did the same process for reading the voltages both times. I use an allagator clip to ground the meter and attach it to the grounding wire on the output jack which is connected to the ground on the input jack. I set the meter to 20 and measure. 

[DrAlx]

Try discharge the caps first like I say above.