Maths Unity Signal Out Solid?

c0nsumer · Post by **c0nsumer** » Mon Apr 10, 2017 5:38 pm

I was attempting to use the Unity Signal OUT on a Maths (#14 on page 6) to control rotate on a 4ms RCD and when connected directly, the Unity LED on the Maths went solid and didn't seem to do anything.

If I connected it through a buffered Mult then the Maths cycled properly and the RCD appropriately rotated through.

Can any of you help me understand why this happens?

YouTube · Post by **luketeaford** » Mon Apr 10, 2017 6:08 pm

Interesting -- what are the settings of your Maths channel that you're taking the unity output from?

I can only create the behavior you're describing if Maths is cycling so slowly or so quickly that it appears to be a static positive unipolar voltage. I don't have an RCD to test with but maybe it takes less voltage than Maths output (which is maybe 10V) and if the RCD expects 5V, that would appear to keep it static.

I'm not sure how a buffered mult could have to do with it unless of course you were plugged into a different output in the first scenario? Curious to learn the answer to this myself.

BaloErets · Post by **BaloErets** » Mon Apr 10, 2017 6:25 pm

I have both and will give it a go tonight and report back tomorrow.

Any chance you remember where about you had your attack/decay set at?

EDIT; Right could probably check the manual patch for that info. My bad.

sackley · Post by **sackley** » Mon Apr 10, 2017 6:41 pm

Maybe a voltage range issue? Maths unity outs are 0-8v, RCD rotate in expects 0-5v. Don't know why it wouldn't work though, I'd expect it to "clip" the extended range (6-8v) instead of not responding...

Edit: You could try using the ch.1 variable out (0-10v) and sweep the knob to test what happens when approaching the 5v limit.

c0nsumer · Post by **c0nsumer** » Mon Apr 10, 2017 8:58 pm

[video][/video]

Thanks for the help/ideas everyone. Here's a clip I recorded of the problem.

Attack and decay are both at 12 o'clock, response curve is linear.

If I plug into the Channel 1 output in the unity out LED stays cycling, even when sweeping the knob all across its range.

YouTube · Post by **luketeaford** » Mon Apr 10, 2017 9:15 pm

Wow -- that is weird to me. I have seen people say before that Maths Trigger input can put a clock out of it. I have had a clock double by putting it on the Make Noise CV bus (this is OR behavior, not surprising), but it is a new concept that the RCD would go solid like that and whatever the buffered mult is doing is interesting to me too.

I hope someone can answer this question

c0nsumer · Post by **c0nsumer** » Mon Apr 10, 2017 9:42 pm

One other weird thing I just noticed... I tried to use the unity output to increment the RCD and that caused the solid-LED issue as well. EOR and EOC work fine, though.

Very weird.

c0nsumer · Post by **c0nsumer** » Tue Apr 11, 2017 7:54 am

I emailed both 4ms and Make Noise this morning asking for suggestions. Hopefully they'll have some ideas other than just running it through a mult...

makenoise · Post by **makenoise** » Tue Apr 11, 2017 8:45 am

The RCD input is very low impedance (I have no idea why). The MATHS Unity out is VERY low impedance in an effort to preserve 1V/ Octave signals when processing them. If you just use the OTHER MATHS output for that channel it will work fine. Typically in a modular synthesizer inputs are HIGH impedance and thus you would not encounter this problem. I have no idea why the RCD has such low impedance on input, but that is why I also have same signal coming from a buffered output on MATHS.

T

c0nsumer · Post by **c0nsumer** » Tue Apr 11, 2017 9:17 am

makenoise wrote:The RCD input is very low impedance (I have no idea why). The MATHS Unity out is VERY low impedance in an effort to preserve 1V/ Octave signals when processing them. If you just use the OTHER MATHS output for that channel it will work fine. Typically in a modular synthesizer inputs are HIGH impedance and thus you would not encounter this problem. I have no idea why the RCD has such low impedance on input, but that is why I also have same signal coming from a buffered output on MATHS.

T

Thank you very much. I think I'm going to give the RCD input path a look and see what it'd take to change the impedance.

c0nsumer · Post by **c0nsumer** » Tue Apr 11, 2017 3:46 pm

So, I also received a response from 4ms who suggested that I may have a grounding issue with the jacks and suggested that I check the solder points around that part of the board.

I know the soldering is good, but it got me thinking about the rotate jack specifically. In the kit instructions (link, step 8) one is instructed to ignore or break off the ground tab from the rotate jack. This is shown in the images at the top of page 6. (I remember triple-checking it because leaving a connector floating seemed not right.)

I wonder if this is part of the problem? I guess it could get ground via the faceplate, but I can't imagine that's the best way to do it... I replied to 4ms asking about this and if I should tie that floating contact to ground, but maybe I'll just give it a go...

southberry · Post by **southberry** » Tue Apr 11, 2017 5:31 pm

I had the same problem / behaviour when I tried (once) to reset my Radio Music with the MATHS Unity out.

neonmercury1 · Post by **neonmercury1** » Fri Jul 21, 2017 7:39 pm

interesting. i had this same bug. thanks tony for illuminating .

Footkerchief · Post by **Footkerchief** » Fri Jul 21, 2017 10:26 pm

This is a widely reported issue with Maths:
viewtopic.php?t=134834

MUFF WIGGLER

MUFF WIGGLER

Maths Unity Signal Out Solid?

Maths Unity Signal Out Solid?