Author Topic: So... how would I switch between 2 effects with midi?  (Read 3270 times)

Willypp

So... how would I switch between 2 effects with midi?
« on: August 16, 2021, 09:24:47 AM »
So, what I want to do, is have 2 effects in a box, and use either the MS-3's CTRL OUT or midi to switch between them.

How would I use the CTLOUT out to do this (it's probably the easiest way) - and what do I need in the pedal to accept the CTLOUT?






Digital Larry

Re: So... how would I switch between 2 effects with midi?
« Reply #1 on: August 16, 2021, 12:47:23 PM »
Generally speaking, I'd think you'd need a flip flop to toggle the state every time you get a pulse and then the 0/1 output of that would drive an analog Mux, either some JFET arrangement or something like (old school) CMOS 4051 family.  Certain circuit details left out for the time being since we're just discussing ideas.
Digital Larry
Want to quickly design your own effects patches for the Spin FV-1 DSP chip?
https://github.com/HolyCityAudio/SpinCAD-Designer

niektb

Re: So... how would I switch between 2 effects with midi?
« Reply #2 on: August 17, 2021, 03:40:44 AM »
Or a little microcontroller (think ATTiny) in combination with analog switch ICs, or relays if you want to go more sophisticated :P

FiveseveN

Re: So... how would I switch between 2 effects with midi?
« Reply #3 on: August 17, 2021, 04:14:55 AM »
Am I not reading the image correctly? Why would he need pulse counters or a microcontroller when there's a latching mode provided?

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what do I need in the pedal to accept the CTLOUT?
In latch mode, the signal should be a constant voltage (probably 5 V, maybe 3.3 V) when on and grounded when off. Probably not hefty enough to drive a relay directly.
Also there's two of them (rip and ring), so you can bypass your two effects independently if that's useful. What's your preferred electronic bypass method (relays, JFET, CMOS)?
Does the circuit sound better when oriented to magnetic north under a pyramid?

ElectricDruid

Re: So... how would I switch between 2 effects with midi?
« Reply #4 on: August 17, 2021, 04:33:55 PM »
+1 what FiveSeven said. It's got a Latch mode, so you've got an output that's either High or Low if you use that mode. Saves the flip-flop.

A relay is maybe simplest, but CMOS switches or JFETs would work too. Since the CTLOUT probably can't supply much juice and is probably only 5V (or even 3.3V) you should use a transistor relay driver. There's a ton of examples of this all over this site.

Willypp

Re: So... how would I switch between 2 effects with midi?
« Reply #5 on: August 17, 2021, 08:16:50 PM »
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Also there's two of them (rip and ring), so you can bypass your two effects independently if that's useful

The plan is to switch between clean and dirty preamps.  I'm thinking I'll use the second one to switch out gain and volume pots on the dirty preamp for a second channel.  Alternatively, I could set upo

I've hooked up a multimeter to the CTLOUT and as far as I can tell it's not sending any voltages, just opening and closing a circuit so I'm guessing I can simply hook it up to the momentary switch lugs to fire a relay.

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What's your preferred electronic bypass method
I've never done this before but I've found a few relay layouts that Think I can adapt to this.

FiveseveN

Re: So... how would I switch between 2 effects with midi?
« Reply #6 on: August 18, 2021, 12:40:24 AM »
as far as I can tell it's not sending any voltages, just opening and closing a circuit
Yeah, that makes more sense for amp channel switching. The info was there, just well hidden on page 27 of the "Parameter Guide", not the user manual where I was looking.



Still no word on how much current and voltage it can handle. Is there an audible click when CTLOUT changes states?

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the momentary switch lugs
Which switch would that be now? Are these preamps commercial units with their own unknown switching systems? If they're operated by momentary controls we're back to pulse mode.
The more details you give us, the faster the road to a solution.
Does the circuit sound better when oriented to magnetic north under a pyramid?

niektb

Re: So... how would I switch between 2 effects with midi?
« Reply #7 on: August 18, 2021, 03:02:28 AM »
Am I not reading the image correctly? Why would he need pulse counters or a microcontroller when there's a latching mode provided?
[...]
Hmm yes  you're right, I understood it as though the TopicStarter might want midi as an option. And thought it would also be useful to support something different than a MS-3 :)
But that's not what the TopicStarter asked for  ::)

Willypp

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Still no word on how much current and voltage it can handle. Is there an audible click when CTLOUT changes states

No click noise from the MS-3 itself.  I'm not measuring any voltage out of it, just a closed/open state.

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I understood it as though the TopicStarter might want midi as an option

Midi switching was an idea, but I think it's outside my paygrade a touch.

ElectricDruid

No click noise from the MS-3 itself.  I'm not measuring any voltage out of it, just a closed/open state.

So how are you measuring it? Using a continuity meter? I don't see how a voltmeter would give you just a closed/open state - I'd expect a high voltage (this could be any one of a number of common things, or something pretty random) and a low voltage (0v or very close to it).

The amount of current that could be drawn is another story entirely, but I suggest we don't push that and just treat it like a delicate logic output!

Tom

PS: Once you've got this thing working with the MS3'S CTLOUT, all you have to do to add MIDI is get enough Arduino code together to turn whichever MIDI message you're interested in into a pulse like the CTLOUT. That's not actually that hard since there are useful Arduino libraries that do the grunt-work. Plus about a thousand people have already done it before you, and many of those have left traces all over the interwebz, so you can nick their good ideas!