DCO as sub source

Ho Again

I can’t hear anything when I try t use the DCO as a source. I was wondering if I am using it correctly and had a good play with the VCO range & detune pots with the sub at full but this has no effect. It all works fine when using the other two positions.

Any ideas ?

Thanks

HI, could someone help me out with this please.

In either of the top 2 positions the sub osc works as expected but when I switch it to DCO I hear no effect when increasing the sub level pot.

Maybe I have the patch set up wrong, can some one give me an idea of how to set up a patch to test.

Thanks

This is on my Anushri BTW

You said you played with the VCO range, but in my experience it def needs to be past 25% to hear much from the DCO. That it the only time I have not been able to get a sound out is 0-25% vco range.

Past that, it may be a soldering issues, in which I do not know the exact place to have you look, oliver will know for sure.

does the sync switch affect your sound in any direction?

I have the VCO range passed 25%.

The sync is definitely working so must be a solder thing. I did re solder the switch.

Thanks both,

I have opened her up and had a listen with a probe. The -12 & -24 inputs to the sub switch are making it fine. The DCO is not.

I have had a listen to test point U and the DCO is definitely there so I just need a little help working out the path from there to the sub input switch.

I feel like I should be able to do this myself but am just staring at the schematics, would really appreciate a bit of guidance with this.

Thanks

from where you hear the sound follow the copper trace to the next component in the chain towards the switch. if there is no sound at some point check the soldering or component.

Have you soldered J12 on the control board (that’s a 3.5mm jack)?

The signal goes from point U to the matching pin on the control board 2x8 connector (J16). From there it is routed to pin 3 of the jack J12. It is then routed to the switch only when nothing is plugged in the jack J12.

Thanks Oliver.

There was a bad joint on J15 stopping the DCO getting through, re soldered and fixed. I hope all faults are now solved.

Now to make some music ! and look at the Eurorack stuff :slight_smile:

Many many thanks :slight_smile:

Hi, back again, sorry !

Something is very intermittent on the board and the DCO keeps coming and going (its gone now). It is always present on J16.

Is it straight from J16 to J12 ? which pin is no 3 ?

The one that corresponds to the “point U” label on the image in the troubleshooting section.

I mean the pin on the jack socket ?

The signal is always present on the corresponding pin of U but isn’t making it to any of the pins on J12.

OK so have looked at this again calmly I have been confusing J 15 and J16 in my text, apologies I always mean J15.

Oliver you say

“The signal goes from point U to the matching pin on the control board 2x8 connector (J16). From there it is routed to pin 3 of the jack J12. It is then routed to the switch only when nothing is plugged in the jack J12”

Do you mean J15 ? as this seems to be where U come up to the control board.

Test point U seems to go through the sync switch (I lose it then) and then ultimately to J12 then to to pin 3 of sw 7 yes ?

Had another little play but no go. The VCO makes it to the sub switch so everything is good from there in.

The DCO does not make it, neither does audio inserted into the aux audio in jack socket on the top. The bottom pin of J12 buzzes out to pin 3 of the sub switch so all good there.

I’m going to need a bit more help please.

Note to my self and bump.

External audio through the rear panel is much louder than audio into the top socket. Is this normal ?

Yes, because the rear input accepts line levels, while the external input on the front panel accepts modular levels.

OK so, switch filter everything downstream from there works fine. As does the sync FM and also external audio input.

Does the DCO get into the sub selection circuit from test point U or from somewhere else ?

Looks like test point U just feeds the sync FM etc to me ?

Here is a doc that show what works & what doesn’t. I’m suspecting a bad solder point somewhere before the rear external audio input that is stopping the DCO making connection… Here is a super basic diagram of what works & doesn’t although I doubt you need that.

OK so found a dodgy solder point on the underneath of pin 5 J16 where the audio / DCO comes from.

“The signal goes from point U to the matching pin on the control board 2x8 connector (J16). From there it is routed to pin 3 of the jack J12. It is then routed to the switch only when nothing is plugged in the jack J12.”

Oliver this sentence confused the hell out of me point U comes up on J15 not J16 and was a bit of a red herring.

Anyway all fixed now, thanks again for the help and an amazing synth !