AionFX Redshift Phaser issues

[Quirkey]

Damn, I seem to be struggling lately! Trying not to get too discouraged since I did complete some other working things recently that I have yet to post (Hydra, Syncrohwah).

My AionFX Redshift build is not working as in there is no sound when engaged. LEDs light up, secondary switch switches between the two phases. Audio trace shows the signal dying when it hits the first IC (LM13700N). I don't _think_ it's the IC's themselves as they're from a reputable source (Jameco). I have a feeling this is voltage/IC related, but not sure what the correct voltages should be here.

I know there have been some others building this who got it working so any help would be appreciated!
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[szukalski]

My money is on the LM13700N.

Have a look at my build report and see the IC casing difference:

[Aion] Redshift

I've had a bit of a hiatus from building thought-out pedals whilst I worked on my supply chain tool and filled my lust with vero and raw enclosures. When my Tayda order came in, the first up on my build list was a Phase II. Unfortunately, muggins here forgot to get 1/8W resistors so it got...

forum.pedalpcb.com

I bought a bunch of LM13700N from Aliexpress and they were not the real deal. Either failed to work, or (in a compressor) worked for about 3 minutes before they got too hot and stopped.
I don't have them around, they got thrown in the bin, but I am pretty damn sure that they ended with "KE3".

I could be completely wrong, if you have another pedal to test them in then try that.

On a side note, if you need a UV print for it...

diy-pedal/graphics/aion-redshift.final.pdf at main · szukalski/diy-pedal

DIY Pedal Resources. Contribute to szukalski/diy-pedal development by creating an account on GitHub.

github.com

 

[Quirkey]

Haw man, that would suck. I thought jameco was supposed to be reliable.

 

[Dan M]

My ICs also have a dot on the case at pin 1 like @szukalski

Mine came from Tayda. I’m not saying yours are bad, it could be something else. But I do see a difference. Not sure if it means anything.

 

[music6000]

Haw man, that would suck. I thought jameco was supposed to be reliable.

There have been reports of suspect components purchased at Jameco!?
google ''jameco counterfeit''

 

[music6000]

Here is one I found on Ebay from China, Different digits up front but ends in KE3, has all the dots?

 

[szukalski]

Here is one I found on Ebay from China, Different digits up front but ends in KE3, has all the dots?
View attachment 34469

The more dots, the less counterfeit!

What surprised me most is when I read of counterfeit SMD. Mouser prices don't look so bad anymore..

 

[szukalski]

Haw man, that would suck. I thought jameco was supposed to be reliable.

Purchasing departments are people, maybe someone messed up.

You can always breadboard a tester for them if you can't sub them in another pedal:

LM13700 tester circuits? - MOD WIGGLER

 

[Quirkey]

Tried to breadboard the test circuit but the only issue is that I don't have a working IC to test with to know if my circuit works or its just the IC. I think I'll order some from mouser and come back to this when they eventually arrive.

 

[Quirkey]

Actually (still up and tinkering even though I have to be up at 5 …) I tried referencing the madbean docs which have the voltage readouts and mine are wildly different. Anyone have a working one they don’t mind probing and posting the voltages for IC1 at least?

 

[Dan M]

1 1.3
2 0.6
3 3.6
4 3.6
5 4.8
6 0
7 4.8
8 3.6

9 1.3
10 0.5
11 3.6
12 3.6
13 4.8
14 9.0
15 4.8
16 3.6

What did you measure? Do I win a prize?

 

[Quirkey]

OK! Finally had time to get back to this tonight. @Dan M my readings are completely off from yours which makes me thing something is wrong with my power section and maybe not the LM13700s ...

1 0.65
2 0.85
3 0.85
4 0.75
5 0
6 0
7 0
8 0.2
9 0.3
10 0.15
11 8.8
12 0.15
13 0.85
14 0.85
15 0.15
16 0.08

 

[Dan M]

Wait, 14 and 3 should match. And 11 should be V+.

I must have transposed the right side when I wrote them down:
16 1.3
15 0.5
14 3.6
13 3.6
12 4.8
11 9.0
10 4.8
9 3.6

So your power looks ok on pin 11.
Pin 6 is ground, you could check that for continuity to another ground point.

Your Vb on pin 14 and 3 should be Va X (R44 / (R44+R43)). Which should be 3.52 since your voltage source is 8.8.
8.8 x (10/(10+15)) = 3.52

I would start by tracing the power section, specifically the components leading to Vb.

 

[Quirkey]

Yeah, I'm banging my head a little bit - I tried replacing R43 (15K) and same result on the output voltage there. Not seeing any obvious shorts either but it's got to be something around there, right?

 

[Dan M]

Do you have 8.8V and 3.5V on the legs of R43?

 

[Quirkey]

No, its 8.8V and 0.95V

 

[szukalski]

Run a signal through it for a few minutes, do the ICs get warm and then hot to touch?

That was an effect I saw with the out-of-spec (let's not call them counterfeit just yet) ones I experienced in a compressor.

 

[Dan M]

If you remove the ICs from their sockets, and you still have 0.95 V in that part of the circuit, there is something else wrong. (Wrong resistor value, open/cold solder joint, short).

IC2 Pins 14 and 3 should also be at Vb around 3.5-3.6 volts. But I’m guessing they are also 0.85 since your Vb is broken at the voltage splitter R43 and 44.

I would check those voltages on the board with the ICs removed, and go from there