Hi community!
I've had a (rarely) recurring issue with my axoloti live set-up during my otherwise super happy years of giggin' with it, and I think it's just about time to address it.
Basically, one or more of the axolotis in my 3/4 axos setup sometimes freeze during performance, and I'm pretty sure it's related to current instabilty in the amplifiers they're connected to. The axos are powered via a separate 12v battery, and the amps are 2 high quality AER acoustic amps (so change the amps is not an option 
), but the thing happens when the washing machine starts (at home, not too bad) or coffee machine (during pub concerts, rare but embarrassing to say the least). I'm fairly ignorant in electronics so I'm asking for help!! What could I do to reduce such unpleasant events?
Electrical instabilty causing axoloti to freeze (maybe...)
Hey I'm quite an ignorant on this topic too but one thing comes to my mind: Are your boards in a shielded enclosure with ground connected to the shielding?
Hi, looper friend
no, they're not... I never felt it was necessary because I never had noise or interference. Actually they're pretty brutally screwed to the bottom of a plastic box and all the cables always connected coming out from a hole... so it could also be the right time to get a hammond aluminum box and make a more refined job.
Even so my (poor) understanding is that this kind of shielding is good against RMI, and this should not be case, because it never happens when I play with headphones disconnected from the amps. I was thinking more of something like a DI box with ground lifted between last board and amp, but I'm shooting in the darkness as I don't know what I'm talking about really..
Hmmm in that case I would just try all the options available. I use plastic or wood enclosures too but I cover the inside with copper or aluminium foil and connect the ground the the shielding.
A di box is also a good thing to try I guess... but it's odd that your boards completely freezes. I mean I had lot's of problems with unwanted noise on multi axolti board + preamp + midi controller applications. The thing that solve this for me was seperating the grounds of the power supplies with this baby https://www.ebay.de/i/283061974099?chn=ps. This has the advantage that I can run the whole setup with 12v coming from a battery wich makes the system even more independent of external noise.
I'm already powering the axos from a 12v battery (that's the reason I think the problem comes from the amp - wich are connected to the main), but they're daisy chained. As a cheap experiment i'll try to shield the existing box with copper foil and ground it. BTW that powersupply look very interesting,and very busker-friendly as well!
hmm, my gut feeling tells me that you will actually have more issues, when you power the boards from battery and connect them to an amp that is connected to mains. a sudden drift off the ground (coffee machine, handdryer) could well lead to some issues that could vanish if the boards were also powered by mains power. i have no proof for this though
I'll try to test this next time I'll a do washing machine at home, the fact is that the freeze occurred only maybe 10 times in 2+ years... so I can't be sure. But I definitely will find a proper power supply and try to use it for a while. What do you think about daisy chaining 3 boards vs separate or isolated power supply as @Blindsmyth suggested? Thank you both for your time...
or could it be some object? i once used a combination of two community objects that froze the axoloti 1 out of 10 times...
i think it was a beatslicer with a bytebeat object
I don't think so, I can see some correlation between washing machine and freezes, although we're a bit on the black magic realm... and except some of your octave objects and @rbrt loopers I'm entirely vanilla
Hello, I looked at the specifications of AER amps and couldn't see whether they have EMI filters fitted on their electrical inlet (they look expensive!) If it's the washing machine, coffee machine, hand dryer etc causing problems, it might be Electro Magnetic Interference coming through the mains and back through the line to the Axoloties from their motors. A sudden high voltage spike can upset microprocessors.
You could try getting a mains EMI filter to plug in between the amps and the mains.
For example: Mains EMI Filter
Thank you for taking the time to look into that! They're expensive indeed, but you never know... they might have overlooked the mains filtering. I already have a multiplug with a EMI filter inside somewhere, I'll try it. I had even forgot that those things existed, thank you.
So I've tried the following:
- as @lokki suggested, using a PSU instead of the battery - even worst, I can get a board to freeze (curiously always the same one) one out ten or so times I turn on an electric heater
- as @UHF suggested, using an EMI filter, and it seems to work.
I hadn't time yet to do a shielding as @Blindsmyth suggested, and although I doubt will work for this specific issue is a good upgrade to the whole system, added to my to do list...
As I'm trying to find a reliable fix to this sparse but annoying issue I found this https://www.radialeng.com/product/stagebug-sb6
They always talk only about noise and ground loops in the description, do you think it could also work for my problem?
As for now I'll always bring a multi plug with Emi filters with me, but I'd like to reduce in every single way the chance of the problem untimely appearing during peeformances.
in that case, wouldn't a d.i. box between the AER and the axoloti solve the problem as well?
That's what I'm asking... I only have a shitty 15€ DI and my setup is stereo, and also the aer alpha plus has a mic input which sounds very different from the instrument input so I can't really test out the whole system. (Keep in mind this is a rare occurrence, I basically will have to see what happens in months to be quite sure) So before buying something I'd like to have more informed opinions. The transformer isolator I linked should work as an unbalanced DI (I might be very wrong though...) Please help guys! 
Hello. Ok, you're getting EMI in the form of transient pulses from high current switching of motors and heaters and the filter seems to work. These are high frequency and a mains filter is designed to deal with them. A DI box is mostly for mains hum and ground loops, it might filter transient pulses but they're not really designed to and will possibly just allow them through.
A cheaper fix might be a ferrite bead around the audio cable, like on video cables. If you look around the house, you may find one that can be unclipped from another cable. I think the mains filter should be the first line of defence though on all mains connected equipment if you're going out to various venues to perform - also on mains PSUs to the Axoloti.
Thanks a lot for all the info, I guess I'll go for abundance... so I'll filter the mains as my primary resource, and then add the ferrite beads between last board in the chain and the amp, and whenever I'll have 140 extra euros I'll get also that radial Isolator.
You can get clip on ferrite beads from amazon. https://www.amazon.de/Entst%C3%B6rfilter-Ferritfilter-Ferritkern-Klappferrit-Kabel-Clip/dp/B07JC4GX6S/ref=sr_1_4?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&keywords=ferrite+bead&qid=1557526465&s=gateway&sr=8-4 I use them on all my usb and (dc) power cables. I didn't know they can help on audio connections too. I always thought they would audible filter off high end of your signal
Extra-late comeback: due to major changes in my live setup I've gone for two boards with isolated power from a multi-powersupply instead of three boards daisy-chained and suddenly everything was fine. I couldn't recreate the freezes no matter what I tried. Hooray and thanks anyone for the help!