Multiple Simultaneous USB Inputs?


Just got a hold of Hypno a week or so ago, and have been digging into everything. Really loving it so far.

One question I’ve not been able to find an answer to (but which may well be somewhere obvious, so apologies if that is the case) is:

Is it possible to have multiple USB input devices active at once?

e.g. Could I have a USB stick connected at the same time as a webcam, with one assigned to A and one assigned to B? I suspect that this isn’t possible, but wanted to confirm (and have it all Googleable/searchable for other folks looking).

Thanks a lot, and I apologise in advance for my future dumb questions!

You can use a USB hub to have multiple USB sources plugged in at once, but Hypno can only run one of them at a time, and the active input will be copied to both A and B channels.
From the manual:
When both a USB Drive and UVC live input are plugged in, the Video Index can live switch
between the two types of inputs (the left CCW position of the video index control selects the
live input).

1 Like

Awesome, thanks! That’s as I suspected, but good to have it confirmed.

Hi there,

Thinking this is the right thread to post my question, but apologies if it veers off topic.

@sleepy circuits: do you know if the current eurorack versions of Hypno with a Pi 3 A+ will work with a passive USB hub to the single USB A 2.0 input for inputting simultaneously: midi over USB (korg nanokontrol 2 or keystep pro), usb stick with video loops, and live video over USB via a HDMI capture card?

Thinking of using something like this hub 4-Port USB 2.0 Hub - Sabrent
Is it ‘dangerous’ to try?

I’ve been scouring the forum, and the answer seems to me to be a bit inconclusive.

Looking at the video input thread and suggested accessory thread, it looks like the hub should be powered. But all of this advice is for the older version of Hypno with micro usb on the front panel.

And looking at this thread, it seems like a passive hub like the sabrent might indeed work. Getting at that juicy modulation - #3 by slippage

Would be awesome if there is enough bandwidth/power in the usb 2.0 on the Pi 3 A+ to get those three inputs with a passive hub, since it would make it much easier to make a diy usb breakout with multiple inputs. But of course don’t want to risk frying the Hypno.

Many thanks!

I don’t have any specific technical knowledge here about Hypno etc, but since it appears that the rack mounted Hypno draws power from the Euro PSU, I would definitely not recommend using a passive USB hub. I doubt it would fry anything, but it seems like there would be complications in terms of what’s being drawn from the Euro power, and the impact that might have on other modules. It seems easily avoided with a powered hub!

Thanks a lot! Yeah, makes sense, was just hoping to avoid an extra power plug if possible but probably not worth the potential issues.

Hey Niels, welcome to the forum!

All the current drawn when using the rack will be from that 12V rail in your system. You should be alright pulling about .5A @ 5V off the passive hub assuming your rack has some overhead on that 12v rail as it probably does.

This should be plenty for the 3 accessories unless your midi controller + capture card has some sort of freaky high current draw, I have been doing this sort of setup for a while without consequences.

Just don’t charge anything off of that hub.


I sail close to the wind with my power. Ha. I’ve had issues in the past with certain modules spiking when turning them on (digital ones usually), because they suck up a bunch of power at the start then settle in afterwards. Good to know that it should work fine in theory though!

1 Like

Hi Ron,

Thanks for the welcome! And thanks for the response, that is super encouraging.

I’ve got three sections of 1A (tip top mantis), so with some careful wiring it should be possible then.

@Stephen: always good to know there is plenty of wind to sail close to, ha.


1 Like

One of the things I have just discovered is that the Hypno only takes one midi input source. I can’t have a vcmc and a nanokeys or digitakt functioning at the same time.

I realize this may be a limitation of only being on midi channel 16. Is there a way around this? I’d really like to gave some parameters controlled by a vcmc and other parameters controlled elsewhere.

I ordered the Mezzz as well and now I am concerned that I won’t be able to use the mezzz and another controller at the same time either. This sucks, as I need to be able to jump through patches with keys, have reactivity with my vcmc, and have control with my mezzz.

1 Like

Thanks for your note this is a good observation and I agree, gonna try to fix this by the next patch

Really looking forward to the fixes you’e bringing in the new version.

Do you have a current patch log of fixes? I’d be curious to see what you’ve completed so far :slight_smile: Some of these bugs have impacted performance options for me, and with how often I am doing events, these fixes will open up my options dramatically.

Two inputs at the same time would be life-changing.

1 Like