Very basic behavior with signals…

Jan 30, 2009 at 8:34am

Very basic behavior with signals…

I am confused why this occurs: If I have a signal path that splits into 2 for some sort of different processing on each and then use a [gate~] to switch between them, why do I get no output when they both (the active and non-active signals) connected to the outlet? Seems like a very basic thing I must be missing.

In the attached small patcher, I get no output from the outlet at all unless I delete the patch cable going from the unused [tapout] to the outlet.

Hope that makes some sense, thank you,

– Pasted Max Patch, click to expand. –
Jan 30, 2009 at 9:17am

So this isn’t working for you ? :

– Pasted Max Patch, click to expand. –
Jan 31, 2009 at 12:07am

It’s weird to me…
I replaced the [ezdac~] in your patch with an outlet, and made it a subpatcher in another document.
Your patch works when there is a slider between the 2 outputs and the 1 outlet, as when you sent it to me. But if I take the slider away just patch the [gate~] and [tapout] directly to the outlet, there is no signal coming out the outlet, even when at least one of the objects is getting there. Probing confirms this.

It seems to happen this way a little erratically (or at least I don’t know what’s triggering it), but try putting a 1 in the num box to the [gate~].

Does that help explain anything?

Thanks a lot,

– Pasted Max Patch, click to expand. –
Jan 31, 2009 at 8:13am

I’m sorry Brian, but I got the expected behaviour with the last patch you sent, i.e. no sound with -1, and sound with either 0 or 1 in the number box.
I don’t think the problem is comming from gate~. You can try gate~.maxhelp to confirm.
have you check the DSP status? is the patch above the only one open? No error in the max window? Have you try to remove the pattr objects? Is max the 5.0.5 version?

Jan 31, 2009 at 8:58pm

Hmmm…I did check the points you mentioned (am running 5.0.5). But I’m starting to think this is a problem with the probing feature. It seems to occur when the patch in question is a sub-patch. This signal is seen in the patch cord just before the outlet, but back in the parent patch, probing displays 0. just after the outlet. However, I connected a [number~] box and it does show signal in the right places, as expected.

Can you reproduce this odd behavior with probing?

Many thanks for your time & effort,

Jan 31, 2009 at 9:57pm

Ok! I reproduce it. (so using the first patch you post as a subpatch).
So when i turn on the ezdac~ in the top patch, I got some sound, but the probe shows a zero signal (when the gate’s number box of the subpatch is set to 0, cause if I set this number box to 1, the probe shows the signal).
So I think you’re right it’s probably a bug from the probe…

However, with either 0 or 1 I got the sound. Don’t you??

Feb 1, 2009 at 4:15am

Feb 1, 2009 at 5:38am

Really? You’re not getting 0. when probing on the outlet of the parent patch? I can reproduce that pretty reliably. To be honest, I hadn’t been at the stage of listening too much, just trying to get signal from one place to another, but probably should have more. Sure, I know if I wanted to hear a delay a [cycle~] would not be the way…Since this is a model of a fairly complex digital mixing console, the routing was my first concern and the delay itself was a detail. I was relying on probing to be a quick way to ‘hear’ stuff along the way, just so I know signal is getting from one point to another. All the rest still to come.

Many thanks,

Feb 1, 2009 at 7:48am

Feb 1, 2009 at 8:25am

Me too, but in this case it’s about whether probing is working as expected. So if you do probe, does it match what you hear, both in the patch & subpatch. If not, is this expected for some reason or a bug?

Feb 13, 2009 at 6:04am

Just to inform anyone who might be wondering or run into this, I wrote to C74 about it and they responded:



I’ve done a little research and essentially, this is just a basic limitation (or feature, depending). The merge of the two signals at the outlet inside the subpatchers is the problem.

An easy way around this is to add the signals before the subpatcher output, like this:

– Pasted Max Patch, click to expand. –

I know its a little confusing, and should be better documented, something i’m looking into.

All the best,

Cycling ’74


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