Serge CGS 116 ADSR CV & Pots

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: Joe., lisa, luketeaford, Kent

Post Reply
michel07
Learning to Wiggle
Posts: 23
Joined: Mon Jul 13, 2015 9:44 am
Location: france

Serge CGS 116 ADSR CV & Pots

Post by michel07 » Wed Mar 25, 2020 6:30 am

Hi there,
As I can't leave my house, I try to fix issues on my DIY modules.
MY CGS 116 is weird.
The module works because I can do all shapes possibles but some pots are reverted and also CV inputs.
I checked several times the wiring and it's like indicated on Ken stone's instructions.
I report here how differents controls act:

Delay pot Reverted
Attack pot Reverted (shortest attack with pot FCW) / CV reverted (need negative voltage to vary)
Decay pot does nothing / CV OK
Sustain pot OK / CV OK
Release pot reverted / CV OK
All CV input : Reverted

If you have any ideas about what is wrong...
Thanks
Best
Ben

tardishead
Wiggling with Experience
Posts: 302
Joined: Sat Aug 03, 2013 3:00 pm
Location: London

Re: Serge CGS 116 ADSR CV & Pots

Post by tardishead » Wed Mar 25, 2020 7:24 am

I’ve just built the new Elby version which works
The pots should be voltage dividers between +12v and GND
Sounds like you may have connected to -12v by mistake
I did not build mine with the matched transistors
Can someone tell me if that might cause any issues - possibly inconsistent timing due to temperature variations?

User avatar
the bad producer
Super Deluxe Wiggler
Posts: 2528
Joined: Tue Mar 17, 2009 8:43 am
Location: Clapton Pond

Re: Serge CGS 116 ADSR CV & Pots

Post by the bad producer » Wed Mar 25, 2020 7:46 am

Yes, the wiring is weird, if wired as per Ken's page the Attack is inverted etc, also CV etc, you can change the pot wiring so it makes sense to you.

Tardishead - Serge said on FB don't bother 'matching them well' which I found rather amusing!

michel07
Learning to Wiggle
Posts: 23
Joined: Mon Jul 13, 2015 9:44 am
Location: france

Re: Serge CGS 116 ADSR CV & Pots

Post by michel07 » Wed Mar 25, 2020 8:20 am

Ok, great! I'll reverse connections.
And for the non-working Decay Pot? The CV input works, I checked and the pot center leg is well connected to the same point than the CV input via 2 differents resistors (82k & 110k).
Thanks

michel07
Learning to Wiggle
Posts: 23
Joined: Mon Jul 13, 2015 9:44 am
Location: france

Re: Serge CGS 116 ADSR CV & Pots

Post by michel07 » Wed Mar 25, 2020 9:45 am

The decay pot was dead, simple fix...
Thanks for your replies, everything works great now, except for the need of negative CV for the attack... it's strange

User avatar
the bad producer
Super Deluxe Wiggler
Posts: 2528
Joined: Tue Mar 17, 2009 8:43 am
Location: Clapton Pond

Re: Serge CGS 116 ADSR CV & Pots

Post by the bad producer » Wed Mar 25, 2020 9:48 am

Great! Yes, it is odd the attack, but I think in that sense maybe the pot acts as an offset?

michel07
Learning to Wiggle
Posts: 23
Joined: Mon Jul 13, 2015 9:44 am
Location: france

Re: Serge CGS 116 ADSR CV & Pots

Post by michel07 » Wed Mar 25, 2020 10:23 am

yes, you're right, I'll use it in this way.
about something else the bad producer, I don't understand how do you wire your serge phaser panel
The upper part is just a 2 input mixer? and at the bottom feedback pot is to send it back to phaser's input?
But you may don't want to share your building techniques... sorry if I ask to much

User avatar
the bad producer
Super Deluxe Wiggler
Posts: 2528
Joined: Tue Mar 17, 2009 8:43 am
Location: Clapton Pond

Re: Serge CGS 116 ADSR CV & Pots

Post by the bad producer » Wed Mar 25, 2020 10:47 am

Ah yes indeed I should post the wiring, but basically on the phaser PCB there are two mixers, one is the mixer at top of panel, the other I use to mix inputs. Input to phaser goes to mixer first, output of mixer goes to input of phaser, feedback pot is amount of phaser output going in the the mixer, does that make sense? I’ll try and get diagram up soon!

michel07
Learning to Wiggle
Posts: 23
Joined: Mon Jul 13, 2015 9:44 am
Location: france

Re: Serge CGS 116 ADSR CV & Pots

Post by michel07 » Wed Mar 25, 2020 1:08 pm

Yes,
I think I understand... I'll try it.
I also modded and wired my VCF 73 as you suggested and it's great!!
For me it's sounds better than my VCFQ R*S version...

User avatar
the bad producer
Super Deluxe Wiggler
Posts: 2528
Joined: Tue Mar 17, 2009 8:43 am
Location: Clapton Pond

Re: Serge CGS 116 ADSR CV & Pots

Post by the bad producer » Thu Mar 26, 2020 7:09 am

Great - a bit OT but just uploaded Phaser wiring to here:

http://www.loudestwarning.co.uk/portfolio/serge-phaser/

michel07
Learning to Wiggle
Posts: 23
Joined: Mon Jul 13, 2015 9:44 am
Location: france

Re: Serge CGS 116 ADSR CV & Pots

Post by michel07 » Thu Mar 26, 2020 8:22 am

Awesome, thanks a lot!
About ordering questions, where can I write to you?

User avatar
the bad producer
Super Deluxe Wiggler
Posts: 2528
Joined: Tue Mar 17, 2009 8:43 am
Location: Clapton Pond

Re: Serge CGS 116 ADSR CV & Pots

Post by the bad producer » Thu Mar 26, 2020 1:31 pm

You can send a PM here and go from there!

Post Reply

Return to “Music Tech DIY”