Aionfx Halo Deluxe very low sound

[Gritdog]

Just built this pedal (Cornish P1 clone).

It bypasses fine (and I have it set to the have the buffer on so I assume that is working ok). But when I turn it on I get almost no sound. LED lights up but barely audible.

It’s a poor build (think my brain is also on holiday…) but before I rewire the whole thing again, I thought I would see if anything jumps out as potential issues / solutions.

Issues that I thought about but am not sure whether they will be causing this are:
- exposed wires where they join the foot switch PCB (I could probably add some solder there).
- output wire is quite tight (I didn’t cut it long enough).
- I forgot to clip the pots and toggle switch after I soldered them onto the pcb so the ends of the jugs slightly stick out from the solder.
- wonder if I fried the power jack. I couldn’t get the wire connected and the solder iron slightly melted a little bit of the plastic.
- on the power jack the solder from the lug to which the green wire is attached slows down the lug and touches the yellow plastic section. I didn’t think this would be an issue as it’s not touching any other lugs of the jack.

Thanks!

 

[jwin615]

A dim LED would indicate a likely short of power to ground or a weak PSU. Check all your power wires for bridges and stray strands as well as the board itself.

 

[Gritdog]

Th

A dim LED would indicate a likely short of power to ground or a weak PSU. Check all your power wires for bridges and stray strands as well as the board itself.

Thanks, sorry though I meant the LED lights up but the sound from the pedal is barely audible.

 

[Feral Feline]

Nonetheless, jwin615's advice is solid, regardless of the LED.

Close visual inspection of solder joints, looking for cold solder joints (for example excess solder, a blob, that either the component or PCB pad —both— didn't get hot enough heat to have the solder adhere to both component and pad — remove excess with copper-braid or a solder-pump.
Reflow anything that looks starved for solder.
Look for whisps/whiskers that connect to places they shouldn't.


Re-examine all your resistors, match their colour-code and position on the schematic to their place on the board to ensure you don't have a 390k where a 390Ω should go. A transistor that needs 390Ω on its emitter to turn on won't turn on if a 390k is in place — don't ask me how I know.
So the same can happen along the signal path. Too large a resistor and your signal will be weak.

Some resistors read front to back the opposite of a higher/lower resistance — easy to mix up, for example a

brown black black red brown = 10k​

vs

brown red black black brown = 120Ω​

So unless you're measuring the resistor with a DMM prior to installation, and instead relying on the colour-bands to populate the PCB... You might inadvertently insert the wrong value.

After checking all the resistor values are correct, re-examine all the caps, ascertain they are correct, too.


Do you have an audio-probe? EASY-peasy to make one (a 100n cap, some wire and a jack...) and then trace the audio path until you find the weak point, and then examine the components and solder-joints around that point.



Oh, and jam one of your DMMs probes into the power jack and the other on the first component it should be connected to: in your case, the Halo, + should connect to D1, and GND ... well just put one probe on the jack's pin and the other probe on any other ground point on the PCB. (DMM set to continuity BEEP, or if you don't have a BEEP-mode, set it to DIODE-mode and look for a zero-Ω reading such as "OOO").