Aion Fuzz Phobos debugging

[ercinese]

Hi there,
my first time posting here.

I just finish to build an Aion Phobos (Tonebender MKIII clone) and the pedal doesn't work.
I can't hear any noise when engaged.
I noticed 2 weird things that I never encountered in my past builds.
1- LED blinks when on.
2- The inverter TC1044 overheats immediately (I can't touch it).

Does anybody have an idea of what the issue could be?
I tried another 1044 and nothing changed.
transistors work, I have tested them in another fuzz.
If I remove the 1044 still no sound but the LED is on without blinking i can hear a bit of noise turning the pots for the transistors bias.

Any tip is very welcomed.

Thanks!

[duck_arse]

ercinese - welcome to the forum.

it sounds as if you have shorted or overloaded the output of the charge pump in some manner, but without a circuit diagram and photos of your build, we can't tell if something is wrong value, missing or backwards. also, we need the information as described in the "DEBUGGING - what to do when it doesn't work" thread. I believe it is a sticky at the top of the topics page, somewhere.

[ercinese]

Hi duck_arse

thanks, I was pretty sure I was doing it wrong that's why I specified it was my first post.

[eh la bas ma]

hello,

I have some problem with this circuit as well.

I am building the Sola sound version with BZX 85C12 diode for D1 (1N4742) and 1N4148 for D2 (1N270).

https://aionelectronics.com/wp-content/uploads/2015/05/aion-phobos-tonebender-buzzaround-documentation.pdf

Bypass is Ok, but the signal disappear when I engage the pedal.

Moreover, voltage readings on Q1, Q2, Q3 are in mV and no - symbol.

Looking at TC1044, i read :

1 = 9.45V     8 = 9.45V
2 = 9.45V       7 = 7.38V
3 = 0mV        6 = 6.04V
4 = 2.233V     5 = 332 mV

Instructions :
"Omit these and use a standard 1N4001 for D1 if you want to either (1) use NPN transistors, or (2) power the circuit with an isolated supply and reverse the DC jack wiring. Both of these are outside the scope of this documentation—in other words: if you don't know how, don't try!—but in either case you will want to jumper the pads marked NPN up near the top of the PCB"

  I am using one AC 125 and two AC 122 "gruen" transistor, I think it's PNP .

I did the DC input wiring as usual and left it unchanged.

As the circuit didn't work very well the first time I activated it, I tried to place a jumper on the NPN pads.

While these pads were bridged, I used a standard 9v power supply as always. Now NPN pads are clear and unbridged, and I am using the same center negative power supply .

Maybe I did something wrong with the voltage inverter circuit that could damage transistors or else ?

[duck_arse]

c'mon eh la, you know the rules - show us some photos! of your built board please.

your charge pump isn't making -9V. I have no experience in these things, so can't say why or why not. are you using any tantalum caps on the board, and are they the right way round, if yes?

are you doing buzzaround or mkIII, and have you that pad linked correctly?

you are using PNP's and an external DC supply, and you have an isolated DC jack? and wired centre negative? your 9V45 would suggest that much is correct. from what I read in the docs - DON'T link the NPN pads !!

don't worry about your transistors just yet. if socketed, remove them from the board, give the charge pump another test with them out, but it might be that IC is kacktus. or backwards tantalums.

[eh la bas ma]

hi,

I have already posted pictures here :

https://www.diystompboxes.com/smfforum/index.php?topic=124566.msg1182235#msg1182235

[bluebunny]

hi,

I have already posted pictures here :

https://www.diystompboxes.com/smfforum/index.php?topic=124566.msg1182235#msg1182235

Don't resurrect an old thread when you already have your own, current thread open!  This will confuse folks...

[eh la bas ma]

I didn't get any fruitful answers on the first post.

A month later, i had to do something. Resurrection was the general idea .

I guessed I shouldn't have started a new subject because this old one is about the same topic .

I will replace the IC 1044 with a new one and report back.

[duck_arse]

hi,

I have already posted pictures here :

https://www.diystompboxes.com/smfforum/index.php?topic=124566.msg1182235#msg1182235

I'm two for two this thread. that's fine - just ignore my post above.

[eh la bas ma]

It's working ! it was the 1044 IC that was faulty. iI replaced it and everything is ok now.

wAOW it sounds great ! just what I needed to finish some agitated tune .

Many thanks.

Justin