Connecting Mother 32 KB Out to Sub 37 Pitch CV

by **Durr GaGa** » Thu Jan 17, 2019 1:46 pm

Hi Folks,

I have both a Mother 32 (M32) and a Subsequent 37 (S37)

Having determined in another thread that I can connect my two synthesisers together, I have come up against a problem that is probably of my own making but here goes!

If I connect the VC Mix (output) of the M32 to the Pitch CV (input) on my S37 and press a key on the Sub keyboard, I can control the pitch using the VC Mix so I know that the cable and Pitch CV are working fine.

However, if I patch the KB Out on the M32 to the Pitch CV on the S37, there is no change in pitch. I have checked that there is a voltage change on the KB Out using an oscilloscope both on and off 'load' and am getting a clear voltage change amounting to 1 volt per octave.

Am I missing something?

Any help would be gratefully received.

Thanks

Steve

by **Hugh Robjohns** » Thu Jan 17, 2019 2:01 pm

Do you need to send a gate signal as well as the pitch CV to open the amp/filter?

Also, check the CV mapping (Global menu 2.1) to make sure the control voltage is going where you think it is!

H

by **Durr GaGa** » Thu Jan 17, 2019 6:57 pm

Hi Hugh,

Thank you for responding.

Do you need to send a gate signal as well as the pitch CV to open the amp/filter?

As the VC Mix works fine if I hold a key down on the Sub 37, this would seem to be opening the amp/filter and is in line with the manual but I will research this aspect further.

Also, check the CV mapping (Global menu 2.1) to make sure the control voltage is going where you think it is!

Thank you for this, I have now checked the CV mapping in Global menu 2.1 and the Pitch CV is set to 'default' so I believe it is working correctly.

I have also tried running a sequence on the Sub 37 and then pressing a key on the Mother 32 but this has no effect although, yet again, an output from the Mix CV changes the sequence's pitch.

All a bit perplexing at the moment as I know the voltage from the Mother 32 is changing in sensible steps and I know that the Pitch CV connection on the Sub 37 is working!

This will teach me to run before I can walk!

Thanks again for your input.

Steve

by **Durr GaGa** » Fri Jan 18, 2019 9:42 am

I have now solved the mystery!!

Like so many issues, the solution is so obvious when you know the answer! This is all to do with the Mother 32 having a pitch CV running from -5v to +5v whereas the CV input to the Sub 37 and Subsequent 37 works from 0v to +5v.

Using octaves above 4 on the Mother 32 supplies positive voltages which correctly adjust the pitch of the Sub 37.

I now need to find a voltage converter to give me a little more flexibility and believe that the Erica Synths MScale module may do what is required but I am going to try and find a DIY solution first as I am several steps away from going down the Eurorack path!

by **Hugh Robjohns** » Fri Jan 18, 2019 12:32 pm

Doh!

Yes, of course -- I should have thought of that. Sorry. Glad you sussed it though.

H

by **Durr GaGa** » Fri Jan 18, 2019 5:43 pm

Thanks, Hugh, I can't take the credit for discovering the reason for the problem as I found the missing piece of information on line but thank you all for your input.

Regards,

Steve

by **Ben Asaro** » Wed Jan 23, 2019 7:24 pm

A Precision Adder will do the trick as well, but you should just spring for a Disting; it's the best friend your modular, or semi-modular could have!

by **Durr GaGa** » Thu Jan 24, 2019 11:44 am

Thank you Ben, what an amazing device - I don't think I've ever seen so much functionality in one small module!

Regards,

Steve

by **Ben Asaro** » Thu Jan 24, 2019 1:27 pm

Durr GaGa wrote:Thank you Ben, what an amazing device - I don't think I've ever seen so much functionality in one small module!

Regards,

Steve

Yes, it’s an incredible piece of kit that seems to have new functionality added all the time. What I love about it, besides the versatility, is that you can try just about every type of module available and then purchase a dedicated module if needed. The Disting has ended up costing me thousands lol!

by **Durr GaGa** » Fri Jan 25, 2019 12:44 pm

What I love about it, besides the versatility, is that you can try just about every type of module available and then purchase a dedicated module if needed. The Disting has ended up costing me thousands lol!

Ben, you're selling me on this .............

..... on a more serious note (oops, pun) though, I can see how useful this could be for sending me in the right direction to get the modules I really want.

Before I get onto that carousel though, I really must work harder on getting up to speed with what I already have as I am still a newbie nearly a year after buying my first bit of kit ... :frown:

by **Ben Asaro** » Fri Jan 25, 2019 1:23 pm

That is absolutely the best way to do it! Take you time and get to know each piece before you move on. My modular has been a very slow moving process. I started with a Mother-32, then added a second oscillator, then made that second oscillator into a complete voice, etc etc.

SOUND ON SOUND

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Connecting Mother 32 KB Out to Sub 37 Pitch CV