Aion Helios (Rat) issues

[yuka42]

Hello all!  I've built the Helios and have had what seems to be intermittent issues with it.

It distorts. Awesomely. But the switch does nothing to change the sound from the three settings. I built it with all the trimmings (sweep, softness trimmer, 914's, and led's in the softness path). On occasion it seems to work and the led's light up when switched in and you can hear tone changes. But only on occasion. Most of the time it has no affect on the sound and the leds Dont light up.

I've run a audio probe and am getting signal on both diode paths (when selected). And both reach ground. The switch is also functional. 

I will continue my detective work and post voltages tomorrow.

In the meantime...any ideas? 

[GGBB]

Sounds like the switch has gone bad or the 914s are stuck always connected. By "switch is functional" do you mean that the common/center lug doesn't connect to either of the other two when in the middle position, and no audio on the diodes when not selected?

[yuka42]

Yes. I will test again to verify (and ease my own brain).  No audio on opposite side when switched.  Tested with an audio probe. Then I removed the switch and tested with a dmm, then reinstalled. I will triple check that though cause my thought process was a bit muddled at the time. It seemed to be functioning though...yet no change in audio with the switch.  ill get voltages for you asap.

Thanks for the reply!

[yuka42]

Okay. Just tested switch again in the circuit and when in the middle position I'm reading like 24-30 megs on either side. That's no good correct?  Should be zip? 

[GGBB]

Should be zip, but I'm not sure that explains your problem.

[yuka42]

Alright. Well I ended up swapping out the switch and meticulously going through the whole board last night. So far so good it seems to be working. Love this pedal. I geeked out for a bit swapping diodes in the second track, D9J, D9D, LED's, and the 1N270 all in Symmetrical. I went with the 1N270's cause they seemed slightly brighter and smoother. I do have some OA1160's I'll try as well eventually.

Hopefully it's good. For good. Haha. Thanks for the help.

[banjerpickin]

Anytime I've had a problem with the diode switch on an Aion board, it's 'cause I put too much heat on the switch and damaged it.  Easy to do with those big pads on the board.  I found the best way to install them is to the fill in the center pad with solder first, heat it up, and push the center lug through.  Then you can carefully fill in the other pads around the edges and try to minimize applying direct heat to the lugs.

I'll bet switching out the switch (heh) fixed your problem.