AionFX Polaris troubles, no output

[Stasis]

Recently worked through soldering up an Aion Polaris pedal (adapted from Human Gear Animato) and everything looks good.

The issue I'm having is that on the output you can hear distortion itself like white noise, and raw guitar (as if it's being just passed through opposed to modified?) instead of affecting the guitar sound itself. I hope this makes sense.

When not active, the pass-through works as expected. When active you get what's described above.

I was very meticulous when assembling, product number matching for each part down to the resistors. I've checked for shorts or solder bridges. Reflowed a couple of bits and pieces. But no joy.

I've also soldered up a spare jack, soldered to ground, and have been trying to trace through where the signal doesn't seem to make it through. It seems to stop before even getting to Q1:


If I jump directly onto R7 I get sweet sweet distorted sound, but before Q1 input I seemingly get nothing:


An interesting observation is playing with the tone adjustment feeds radio audio out at the right setting lol, based on this and some diode mode testing of the transistors i'd say the they're both working as expected.

Apologies if this is not the right place or I'm lacking any details.

I'm not really sure where to go from here, any help or advice is greatly appreciated 🙏

Schematic:
https://aionfx.com/app/files/docs/polaris_documentation.pdf

Photos:

[antonis]

Same issue stands for both BIAS A & BIAS B settings..??

[Stasis]

Same issue stands for both BIAS A & BIAS B settings..??

That's right, just triple checked now and same issue with either setting

[antonis]

That said, R2 is exonerated..

Could you take measurement of Q1 & Q2 Base voltage..??
(both for A & B setting, if it isn't too much trouble..)

[Stasis]

Was going to edit my post but I've reflowed as basically every solder join, ensuring I have used enough flux etc, to triple check that all the welds are tight. No joy though.

That said, R2 is exonerated..

Could you take measurement of Q1 & Q2 Base voltage..??
(both for A & B setting, if it isn't too much trouble..)

Sure, can try my best, this is my first time fiddling with measuring germanium transistors. I've measured Base -> Emitter for both Q1 and Q2 in both settings:

Code Select Expand


┌────┬──────┬──────┐
│    │ A    │ B    │
├────┼──────┼──────┤
│ Q1 │ 1.01 │ 0.71 │
│    │      │      │
│ Q2 │ 0.11 │ 0.12 │
└────┴──────┴──────┘


Hopefully this makes sense, if not there's a non-zero chance I haven't measured correctly. Thanks in advanced

[Govmnt_Lacky]

Hopefully this makes sense, if not there's a non-zero chance I haven't measured correctly. Thanks in advanced

What you need to do is measure the voltage at the Collector, Base, and Emitter of BOTH transistors while in BOTH modes. Maybe post it like this:

BIAS A
C: X.XX
B: X.XX
E: X.XX

BIAS B
C: X.XX
B: X.XX
E: X.XX

[Stasis]

Thanks for that, how does this look:
BIAS A
Q1
C: 2.77
B: 1.55
E: 2.81

Q2
C: 2.81
B: 2.76
E: 2.91

BIAS B
Q1
C: 1.63
B: 0.85
E: 1.67

Q2
C: 1.67
B: 1.63
E: 1.78

[Govmnt_Lacky]

Just to make sure... you did use an NPN transistor for Q1 and a PNP for Q2... right?

[antonis]

I think you mixed pinouts up..

[Stasis]

Just to make sure... you did use an NPN transistor for Q1 and a PNP for Q2... right?

That's right, NTE103 for Q1, NTE102 for Q2:


Where the NTE102 is Q2, towards the middle of the board:

I think you mixed pinouts up..

I hope it's this, and that I'm grossly misreading the design lol

I used the data sheet to identify the pins for both: https://www.farnell.com/datasheets/201871.pdf


Then on the board:


I retook the measurements:
BIAS A
Q1: NTE103
C: 2.76
B: 1.37
E: 2.79

Q2: NTE102
C: 2.79
B: 2.76
E: 2.94

BIAS B
Q1: NTE103
C: 1.64
B: 0.75
E: 1.63

Q2: NTE102
C: 1.63
B: 1.64
E: 1.94

[antonis]

For a happy n-p-n, Emitter can't sit higher than Base..
(opposite stands for p-n-p, but here Q2 Collector is forced to particular voltage due to Q1 Emitter direct coupling..)

[Stasis]

For a happy n-p-n, Emitter can't sit higher than Base..
(opposite stands for p-n-p, but here Q2 Collector is forced to particular voltage due to Q1 Emitter direct coupling..)

Hmm that kind of leaves me a bit more lost, would that imply that a component prior to q1 is not correct?

I've just gone through and checked the components prior to Q1 again, their solder, their values (resistors, caps, etc), etc and all seem correct to the schematic so not sure where to from there

Am I thinking about this wrong? 🤔🤔 should the components off the emitter be pulling the voltage lower than they are?

EDIT: Made a futile attempt to reflow all components again just in case something wasn't soldered through correctly, same result, disappointingly

[Stasis]

Tonight's attempt was using a voltmeter in continuity and following through the whole schematic to see if any component couldn't talk to any other component as expected.

I also experimented more with the trimmer to see if that would help alleviate the issue in some way.

In addition to this, I soldered on entirely different jacks and new cabling for them to bypass the aion io kit just in case there was an issue there (had sort of done this but did it more so)

Sadly nothing.

I'm wondering if at this point if the NTE103 is dodgy or the 102. Although I got both new unused sort of thing so that would be a shame.

[Stasis]

Good news, replaced the NTE103 and NTE102 and suddenly it works 

So went through and checked which it was, turns out the NTE102 wasn't working as expected.

Got a happy pedal now, thanks for the help everyone <3

[danfrank]

I'm a little late to the party, but a couple of things I'd like to note:
Germanium transistors are really sensitive to heat and soldering them in without some sort of heatsink (cliplead) between the transistor and PCB lots of times results in a damaged transistor. As a rule of thumb, when I solder germanium transistors I will put a cliplead on the lead I'm soldering to the PCB. This means that the transistor being soldered is spaced  at least 3mm off of the PCB, so I can get a cliplead in there.
I saw that the OP had the transistors soldered flush with the PCB, this will pretty much guarantee transistor damage from soldering heat.
Anyway, glad you got it working...
This is an FYI to anyone who may solder germanium transistors in the future.