The definitive SLIM PHATTY + patchbay thread

The Moog Forum Little Phatty & Slim Phatty Forum
1

Since there doesn’t seem to be a thread that definitively covers this topic, I thought I’d start one on hopes of figuring it out, and to help other people as a reference.

The SP is made to be rackmounted, but all of the inputs are not easily accessible this way. I am putting mine in a rack with a Patchbay (behringer ultrapatch) that allows each channel/pair to be switched to one of four configurations: normal, half normal, open, or parallel.

Here are the SP’s rear mounted 1/4 jacks:

Headphones out
Audio out
Audio in

I think I am accurate in saying that all 3 of these should be fine connected via TS patch cables to channels on the patchbay set to “open.”

CV/gate inputs:
Pitch in
Filter in
Volume in
Gate in

The 3 CV inputs, I believe, should be connected to the patchbay via TRS cables, but I am unclear what the channels should be set to so that essentially we are not interrupting or altering any functionality of the SP unless we plug something into the corresponding channel on the patchbay.

As for the gate input, I’m not sure what type of patch cable is needed to connect to the patchbay, channel setting, etc.

Basically, I just want to bring the jacks to the patchbay in a manner that the SP performs normally when noting is plugged into the cv inputs on the patchbay.

Moog tech support told me that it should be possible just by selecting the right channel modes on the patchbay, but they couldn’t specifically give me the correct settings.

If someone here has done this and can share your setup, I would be very grateful.

2

I’ve got mine in a patchbay and have had mixed results with the CV inputs. The gate input doesn’t work for sure in normalled or pass through mode. Seems like a couple work fine, but I’ll have to look again to be sure which ones. The audio I/O works fine though.
I’ll be following this thread for sure because I’ve been wondering the same on the CV stuff.
Adam
www.thesolutionmusic.com

3

Hey there,

This is my 3x Phatty Poly Chain/Semi-Modular - with patchbay, dual CP-251’s and rack line mixer:

I colour-coded each Phatty for labelling purposes on the patchbay and mixer - LP with CV Output Mod = Orange, bottom SP = Red, & top SP = Purple, as shown on the key on the top SP’s left rack ear (my father is a signmaker so he printed the vinyl and digitally-printed text for me).

For the Audio Ins and Audio Outs I used standard TS cables, but for Headphone Outs (stereo) and all the CV’s (including Gates), I used TRS cables (this allows expression pedal usage both direct into the patchbay, and via interconnection with the CP-251’s).

I have my patchbay set to pass-thru mode (each front jack matches it’s corresponding jack on the back).

The Gate Input & Volume Input CV’s are the two CV’s which need to be tamed in a patchbay setup:

  • The Gate will always be open when connected to the patchbay
  • The Volume will be set to zero, as the Phatty expects a CV signal to raise the volume

I use TRS dummy plugs (TRS jack heads with no cable - purchased from an electrical store) as shown (GI = Gate Inputs and VI = Volume Inputs - they’re soldered differently):

The Gate Input dummy plugs have the Tip shorted to the Sleeve, and the Volume Input dummy plugs have the Tip shorted to the Ring (remember to label them somehow to tell them apart!) as shown below:

You can test which contacts to short for yourself, by setting up the Phatty to a nice volume, and inserting a TRS cable into the Gate Input or Volume Input. Then you can short the other end of the cable with wire to confirm which contacts need shorting to complete the circuit for that CV Input.

This process allows the Phattys to run normally, without being externally patched. When you want to patch something into the Gate or Volume Inputs, you simply remove the dummy plug and insert the external voltage source.

There are probably other ways of solving this problem (using a normalled patchbay configuration perhaps), but I thought I would share what works well for me! :smiley:

P.S. For the Little Phatty’s CV Outputs, as you’d expect, no dummy plug solution was required - they can all be left plugged in to the patchbay without effecting the operation of the Little Phatty.

I hope this helps!

Regards,
David Smyth
NZ

4

Wow thanks for the info on the dummy plugs. I had pretty much given up on the gate and volume CV. Awesome setup too. I color coded my patch bays too, it makes it so much easier to use.


Untitled by TheSolutionMusic, on Flickr

I just moved so I’m in the middle of setting up the new studio. It’s coming together though. Excited to make some new dummy plugs now!


Untitled by TheSolutionMusic, on Flickr

Adam
http://www.thesolutionmusic.com

5

Thanks for the kind words, I remember seeing the construction of your setup when you linked to your facebook album a while back - Looks awesome! I’m in the process of setting up another rack with a Minitaur, MF-102, MF-104M (when it finally arrives) and one other Fooger (to fill the 3-fooger rack kit) - I can’t wait for some serious Fooger patching - Looks like you’ve got that side of things well covered! :mrgreen:

I agree about colour coding, I’d definitely get lost without it!

Regards,
David.
NZ

6

I don’t want to have to mess with dummy plugs if there is a way to configure the patchbay to not need them, via normalling, etc.

Has anyone figured it out? Even Moog tech support couldn’t give me an answer.

7

Well theoretically you should be able to configure it normalled and plug the dummy plug to the top rear jack and the SP on the rear bottom jack. Then when you plug something into the front bottom jack it would break the connection to the dummy plug. I’d have to try it to be sure of course.
Adam
www.thesolutionmusic.com

8

After giving up on trying to figure out normalling, etc, I went the dummy plug route. Works great for the gate, but not working for Volume. if I short the tip to ring on the cable itself, it works, but not via the patch bay. Any suggestions?

9

What patchbay are you using?
Does the patchbay support stereo (TRS) signals?
Are you using TRS cables to connect the Phatty CV’s to the patchbay?

10

Behringer TRS balanced patchbay. Jacks are set to “open”. I guess I need to test on an open channel just to make sure it isn’t shot.

11

I should also mention that running a cv signal through the patchbay works - but the dummy plug does not.

12

Interesting.. What I was getting at with the TRS stuff is that if one of the components (a cable, patchbay, dummy plug etc.) isn’t TRS, then that component cannot distinguish between the ring and the sleeve signals (they will both be running into the sleeve). This is the only cause I can think of immediately, but if all your components are TRS, perhaps it’s some other problem.. Is your dummy plug TRS also?

Testing that patchbay open channel sounds like a good idea.

The other thing I would check is if the soldered connection is not touching the sleeve contact inside the dummy plug.

Hope you solve this thing soon!

Regards,
David.
NZ

13

Patchbay is TRS, Cable is TRS, phono plug is TRS. Have tried 2 phono plugs with the same results - wondering if I need to try another brand. This is weird. If I short tip to ring on the end of the cable itself outside of the patch bay, it works, but as soon as I plug into the patch bay, the dummy plug doesn’t work. If I plug in a CV source to the corresponding jack on the bay, it controls volume as it should. The dummy plug seems to be the culprit, but no idea why. Gat dummy plug works fine.

ARRRGGGGGGHHHH!

14

I’m sorry to hear you are still having trouble. :cry:

What about inserting the dummy plug directly into the Phatty’s Volume CV Input?
That should indicate if the dummy plug is to blame in any way.

If that turns out to work direct into the Phatty, is it possible that the “open” patchbay configuration you’re using only allows a signal to travel in one direction?
All I know about the configuration I use (pass-thru) is that each front jack matches it’s corresponding back jack, and it seems to pass the signal both ways fine - whether our configurations are different, I do not know.

From searching in google images:

  • Is this how yours is set up?
  • Do the arrows actually matter? Because I always thought if the signal could travel one way, it could also travel in the other direction through the same path?

Anyone feel free to correct me or add some useful insight..

David.
NZ

15

good point on inserting the dummy plug into the volume CV jack - that works, so there’s something with the patchbay itself. Time to pull it out of the rack and experiment with the different settings, althought strangely enough it works fine with the other CVs in open mode.

16

Hey guys,

Is there somewhere I can buy the dummy plugs you guys are talking about, preferably already soldered to the correct setup for pitch and gate? I am way to overwhelmed with other things to spend the time learning how to solder and such, but I have a cp 251 that is just collecting dust because my Minitaur and my Slim are racked and it’s a pain to get back there for constant patching.
If there is nowhere to buy them, would any one be interested in making some for a reasonable fee?

Thank you

17

Doubtful that they’re available “ready to go” ~

They’re just 1/4" TRS phone plugs, available through just about any electronics store.
This would be one of the easiest soldering jobs you’re likely to run across, since all you’re doing is soldering jumpers between 2 of the 3 connectors inside the plug.

1/4" plugs are generally pretty easy to work with - plenty of room to work with the connectors, and just about any hook-up wire would work.

If you’re going to work with analog synths, soldering skills would be handy to have, and soldering 1/4" dummy plugs would be a really easy way to learn…

Also, it might be helpful if you post your location info in your profile ~
There might be a forum member close by that could help you out.

Randy