[sdiy] SOMA Lyra-8 vibrato stopped working

Adam Inglis 21pointy at tpg.com.au
Fri Mar 8 00:34:30 CET 2019

What test gear do you have Joe?
If you’ve been fiddling and something has stopped working, might be good just to do some continuity tests around the connectors and those boards.

However, the pitch of the VCO must be seeing some voltage from the vibrato circuit - maybe the LFO has failed? Does the LFO work as it should on any other part of the synth, say, the filter?

> On 8 Mar 2019, at 8:10 AM, frey at radioles.com wrote:
> Hello, I modified my Lyra-8 by adding switches to the touch contacts so I could have a single oscillator work when switched on. I did this without modifying the pcbs only wiring the switches in parallel with the contacts bolted to pads on the pcb. 
>  However, somehow in removing the pcbs to install the switches I have caused the vibrato switch to stop working. When I flip the vibrato switch on, the Lyra audio output frequency shifts upward but never back down and does not oscillate as a vibrato should. 
>  I have found on one of the pcbs a connector header that runs from board to board marked vib and if I trace it back I come to an IC CD4039. I mention this to see if it is a clue for some of you with experience troubleshooting what I should look for that may be malfunctioning. Should I see an oscillating voltage here or what?
>  Any advice would be most helpful. JoeF.
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