Aion's Neurotron (Ring Stinger) sawtooth waveshape : low volume, no modulation.

[eh la bas ma]

Hello,

I built the Neurotron recently, from a musikding's kit.

https://aionfx.com/app/files/docs/neurotron_documentation.pdf
https://aionfx.com/app/files/docs/lovetone-ring-stinger-manual.pdf

Based on what i could listen in the utube demos, it sounds like everything is working on my build (VCO, LFO, etc) except the sawtooth waveshape.

According to Lovetone's original manual, Triangle waveshape should be lower in volume compared to the other waveshapes. It's not really the case on my build, Triangle works but the level is quite the same as the other waveshapes.

However, sawtooth waveshape is lower in volume, and i can't hear any effect. Drive, Timbre and Blend affect the signal, but not the other controls.
When VCO waveshape is set on sawtooth, the LFO isn't working neither. LFO works on 3 waveshape positions out of 4.
In other words, when sawtooth is selected, ring modulation stops, LFO stops, and the output volume decrease significantly. Everything sounds fine with the other settings, as far as i can tell with this strange effect...

I should add that i used the same markers on the enclosure as in the drill template p.17, so i guess i am not confusing sawtooth and triangle...

I tried to reflow the waveshape rotary switch pads (main board and sub-pcb) and all the suspicious pads i could find, but no luck so far.

I'd like to do some continuity tests or some audio probing to narrow it down, but i am a bit confused with the schematics :


The most difficult and useful question for me is : what is the signal path when we are set on sawtooth waveshape ?

I am lost with this wave shaper schematics, the rotary switch routing is quite confusing for me...

Edit : surely the 4 waveshapes are B1, B2, B3 and B4... I wonder which one could be the sawtooth ?

Every observations and suggestions are welcome !