Most convenient output for on-stage use?

#1

I plan to use the Axoloti on stage.

To minimize hassle while setting up, I'd like to come prepared with whatever connections are least likely to surprise the sound guys.

What I usually see is lots of XLR ports/cables carrying balanced microphone-level signals (and DI's to feed guitars etc into those).

Bringing the Axoloti's stereo line level signal back down to microphone-level seems a bit silly (or is it?). On the other hand, I wouldn't want to shock a sound guy by providing a line-level signal when he's expecting a microphone-level one. What kinds of levels do stage piano's and such provide on their various output ports? I can't quite tell from their spec sheets.

As probably obvious I'm far from an expert in these things - curious to hear your thoughts!

#2

Converting Axoloti Core's unbalanced outputs to balanced signals on XLR using a DI box is best practice, eliminating ground loops, interference from light dimmers and crosstalk.

A DI box does not necessarily attenuate the signal. Serious microphone inputs can deal with line level signals too, when the lowest gain on the gain pot is not low enough, there is a "pad" switch to attenuate the input on the mixer.

Without DI box, and just a stereo jack to dual unbalanced XLR cable, the sound guy may accidentally switch +48V phantom power on on you channels, that could damage Axoloti Core.

#3

Thanks for the quick and detailed reply!

Aah, evidently I was misunderstanding how a DI box operates.

Ah that's good to know! Especially as some mixers only allow switching +48V on and off for all channels at once... so that danger is real.

So summarizing, my best bet would be to bring a short(ish) stereo-jack-to-2-unbalanced-mono-jacks Y-cable, plug the stereo jack into the 'out' side of the Axoloti and the unbalanced mono-jack into the 'instrument' side of the DI box (which could be either active or passive), and then pass the XLR output from the DI to the mixer as usual. Am I understanding things right?

#4

Yes, correct.

The phantom power danger is real for many devices with a line output.

#5

The trusty 802xvlz 3 can put the axoloti on the two mic inserts, getting anything up to a nice clean audio quality AND it has balanced outputs so you can plug direct into a clubs snake. You also get three other stereo channels to work with and a aux send. Radial Makes a nice stereo DI for about the same price as a used Mackie.

#6

If you're even a little handy with a soldering iron (it's a very simple project) you might want to try making a passive DI (aka a transformer in a box with two plugs). I made a couple using salvaged DuKane mic transformers that aren't nearly as nice as the transformers in the article and it's still easily the best sounding DI I've ever used.

EDIT: I used a pair of salvaged DuKane 3a55 octal-plug style transformers, last I checked they ran around $25usd on eBay. Nice thing is they have a couple different taps on the low impedence side, so you can switch between 150 and 250 ohms to get slightly different coloration.

#7

For anyone who is still interested in this problem, I have an alternate solution that doesn't require the use of transformers:

Two steps:
1. Block the possibility of 48V Phantom power [of which is DC] using a simple circuit or more simply just with capacitors oriented as a high-pass filter [dc couple or whatever it's called].
Here is a link to a PDF with a more advanced phantom power blocker:
https://www.gearslutz.com/board/geekslutz-forum/218352-phantom-power-blocker.html

  1. Attenuate the line level to a suitable mic level with resistors.
    See information here: http://www.epanorama.net/circuits/line_to_mic.html
#8

As a live sound engineer I would automatically throw a pair of DI boxes in between the axo and the desk.
As Johannes says it prevents a whole load of environmental factors from interfering with the sound.