Planning live performance hardware. Is this realistic to do with zynthian?

[Kame]

Hi everyone,

I’m quite new to zynthian and raspberry hacking, I hope I put my post into the correct category.

I want to build a combined sampler and effect machine for live performances. Could you give me some hints if you think this is archivable with Zynthian?

I want (besides the touchscreen and 4 rotary encoders):

• 4 analog Inputs (incl. preAmp for mics)
• 2 analog Outputs
• additional controllers (fader and rotary encoders)
• triggering samples (from a piezo or maybe even with circuit closing)

Diagramm

I would very much appreciate any tips (or criticism) as this is to be my first more complex electronic instrument.

Thanks
Kame

[riban]

Hi @Kame! Welcome to our wonderful community.

Anything is possible!

You will need a multiple inputs sound card. The Beringer USB devices work well. A couple of us have the 1820 which works very nicely.

You can use a MIDI controller to provide extra rotary/slider controls.

There is an expansion board available that extends the GPI. This may be suitable to interface with external triggers but you will have to build an interface that handles levels, filtering, debounce, etc.

[Kame]

Hi @riban,

thanks a lot for the warm welcome!

I already have a Behringer FCA1616 but ideally, I would like to have all inputs in one box and above all be battery-powered (if needed). I saw your reply here: Zynthian "Mobile" - #12 by riban
We sometimes play in places without electricity, these are more experimental sound art places than concert spaces.

Maybe I’ll start with the classic Zynthian Box (battery-powered) and try to play some live performances with it. After that, I can try to expand the setup with a trigger system (incl. interface) and more analog inputs.

Thanks again!
Kame

[wyleu]

Battery power is a subject in itself. I’ve tried with USB battery packs but I’ve settled on using 20volt power drill battery packs which is adjutably supplied to the pi and ancillaries with led display equipped buck converters. Don’t forget to put a line fuse in the battery supply and a mechanism to turn off the supply when the voltage drops below a preset level so you don’t simply flatten the battery so a leve lwhere it won’t recharge properly. I will probably do a thread on my experiences in this area after I’ve completed a couple of events with the rig. If you are simply looking for playback of midi or sounds consider the hifiberry amps as they allow the whole device to be powered with one 18volt supply or a battery pack and provide 60watts of amplification into the bargain.

Also have a look at Power over Ethernet. It is a interesting approach for multi pi rigs and its all available as pre made parts.

[Kame]

Thanks @wyleu

Drill battery packs sound smart, I will be following you to see how it evolves.

@wyleu

If you are simply looking for playback of midi or sounds…

No, we want to do real-time effect processing.

@wyleu

Power over Ethernet

Will check out!

Thanks for sharing all the knowledge!

Now I just need to wait till the Kit is available again

[wyleu]

Free forming with zynthian is considerably easier in the USB world than it is with cards on the Pi GPIO connector. But power supplies are the real problem. easy to get to a sea of wall warts and extension leads with hum and goodness knows what else.
Your Behringer kit can be driven off a buck converter from the Battery Pack with a separate Buck converter driving the Pi & it’s 5 volt USB world. The 7" touchscreens fit nicely into this world but you have to provide a case of some sort for them and that is an exercise in logistics all of it’s own. But is worth considering as a device to loose into a 19" inch rack That’s kind of how I’m going…

Tablets and VNC let you get a look into the zynth world without having to muck around with 7" touchcreens and make really nice Read only reassurance panels espcially with the new audo mixer interface…

I don’t know if you plan to do the pa from batteries, but you can get to 200watts with small class ds that will run from battery packs (fuse etc)
The modification or manufacture of clips to interface with the battery pack requires a certain deft hand and sadly it doesn’t mount into 19" rack very nicely. It’s the sort of thing people with 3D printer can address but it’s an issue but the battery pack to clip works as a decent low voltage isolator.

Notice the lack of an inline fuse here!! Don’t do this!!

You can get into some big currents so good fuses and wires are to be preferred but sadly most of the low voltage connectors are ghastly horrible barrel connectors and you can only go so far, but as its stage based in need to be rugged.

[Kame]

Thanks!

@wyleu

Your Behringer kit can be driven off a buck converter from the Battery Pack with a separate Buck converter driving the Pi & it’s 5 volt USB world.

Good Idea. Maybe I just get a more compact Tascam US-4x4HR for additional mic or instrument inputs…

@wyleu

if you plan to do the pa from batteries

For now, we will just use some cheap JBL / Anker speakers. Probably we get more wild in the future

@riban

There is an expansion board available that extends the GPI. This may be suitable to interface with external triggers but you will have to build an interface that handles levels, filtering, debounce, etc.

I am not sure if this is possible but I would like to measure if a current flows between a glove and a pair of pants? The fabric could be either conductive or wet (depending on the performance). If the glove touches the pants (the circuit is closed) a sample is triggered. Is this something I could archive with the expansion board? I think I know how to filter the signal with PD or other software.

[wyleu]

@Kame

I am not sure if this is possible but I would like to measure if a current flows between a glove and a pair of pants? The fabric could be either conductive or wet (depending on the performance). If the glove touches the pants (the circuit is closed) a sample is triggered. Is this something I could archive with the expansion board? I think I know how to filter the signal with PD or other software.

There is a dangerous undercurrent of MIDI Goulashes developing here…

Disturbingly it’s possible… @Baggypants where’s the watch…?

[riban]

@Kame

current flows between a glove and a pair of pants

I don’t see why this can’t be done. You would probably want to connect one end to a GPI with pull-up resistor, input limiting resistor and some form of filter to reject noise. You could then tie the other end to ground and do something, looking for a sustained period of low signal (debounce) to trigger an event.

[wyleu]

Battery provision and bluetooth MIDI would seem one way out. How much weight can the performer carry if taped to the middle of the back or in a belt pack?

[Kame]

I ordered my Zythian today, I’m very curious! I also ordered the expansion box for the future wet pants sample pad

@wyleu

Battery provision and bluetooth MIDI would seem one way out.

For now, I don’t mind just wiring the performer, just to keep complexity low in the beginning.