Axe-Fx III - Why use SPDIF?

You have the AxeFX usb connected to your Mac? If so, choose the AxeFX as the input/output device, not the Scarlett. Then Input 5 will be your dry signal. Inputs 1&2 will be the wet signal.

Output will go to your AxeFX. If instead you want the output to go to the Scarlett, create an aggregate device that combines the Scarlett and the AxeFX and choose that aggregate as your I/O device.
I don't know if this will work when Scarlett is connected. I tried it like that before and there were problems with system preferences and which device handled sounds. Also, sometimes I would get processed signal through axe FX like delay and flanger on skype calls.

I'm trying to hire someone to help me connect the cables and set the right signal flow... Not sure what to do here...
 
I don't know if this will work when Scarlett is connected. I tried it like that before and there were problems with system preferences and which device handled sounds. Also, sometimes I would get processed signal through axe FX like delay and flanger on skype calls.

I'm trying to hire someone to help me connect the cables and set the right signal flow... Not sure what to do here...

I think you're making this way more complicated than it needs to be. I don't see where you need SPDIF or the Scarlett for your simple needs. Just connect your AxeFX to your computer with a USB cable and connect your monitors to your AxeFX output 1. That's all the cabling you need. Choose the AxeFX in system preferences and your DAW as your sound output device and you'll be able to hear your computer audio.

You can make things more complicated later if your needs grow or you become more comfortable with configuring things, but this simple setup is a complete guitar recording rig.
 
Last edited:
The audio interface also has a XLR input for my mic.

Additionally, there were some limitations and issues using the Axe-Fx as the main audio device. I can't recall the details, but using Axe-FX as the main sound device.

Will I be able to plug my guitar into Axe-FX, run that to into Logic, then simultaneously run a dry signal from the Axe-Fx SPDIF into the Scarlett, into Logic? (see diagram)
Code:
Guitar ⭢  [Axe FX II] → USB ⮂ ══════════════╗
               ↓↑                            ║
             S/PDIF                          ║
               ↓↑                            ⮃
           [Scarlett 18i8 2nd gen] ⭢ USB ⭢ Mac
 
Last edited:
Will I be able to plug my guitar into Axe-FX, run that to into Logic, then simultaneously run a dry signal from the Axe-Fx SPDIF into the Scarlett, into Logic? (see diagram)

The SPDIF is unnecessary in that scenario. That's the beauty of using USB. It carries both the wet (processed) and the dry (DI) inputs from the AxeFX. There's no additional cabling necessary. And you can always create an aggregate device later if you want to use both the AxeFX and the Scarlett as inputs and/or outputs simultaneously.

FWIW, this thread started with the question “Why use SPDIF?” Aside from one answer with a rare case of multiple digital devices running at different sample rates (!), I haven’t seen anyone answer why you might want to use SPDIF when recording. SPDIF can be used when recording of course, but I believe its primary purpose in the AxeFX is for when you need a digital output at a live performance.
 
Last edited:
The SPDIF is unnecessary in that scenario.
How do I do what I want?

How do I plug my guitar into Axe-FX to run a dry signal to one track in Logic and a wet signal to another? WITH the Scarlett as the computer's audio device; WITHOUT reconfiguring any hardware or any hardware settings to accommodate mic input or any outputs.

I want to record electric guitar, acoustic guitar, voice, and possibly another analog instrument.

There;s got to be some audio engineers on this forum who can and who will, for a reasonable price, help me with this over Zoom.
 
That’s a very common situation. Just create an aggregate device, using the Audio/MIDI app, that combines the AxeFX and the Scarlett into a single virtual device. It’s possible to do this another way, with SPDIF, but it’s a little convoluted, as evidenced by the difficulty you had in getting it to work.

There should probably be some discussion of connecting the AxeFX III to a computer in the owners manual, like there was for the AxeFX II.
 
"Use an aggregate device" might be one of the steps in the solution you're imagining...

But try to imagine from the my point of view: How can I plug my guitar into Axe-FX, record a dry signal to one track in Logic and, simultaneously, monitor and record a wet signal to another track in logic? Again, I want to do this WITH the Scarlett as the computer's audio device; WITHOUT reconfiguring any hardware or any hardware settings to accommodate mic input or any outputs.

Because you say "[t]here should probably be some discussion of connecting the AxeFX III to a computer in the owners manual, like there was for the AxeFX II," that shows that you are not reading carefully but instead talking past me.

Again, I am using Axe-Fx II.

Again, here is a diagram of my cable connections:
Code:
Guitar ⭢  [Axe FX II] → USB ⮂ ══════════════╗
               ↓↑                            ║
             S/PDIF                          ║
               ↓↑                            ⮃
           [Scarlett 18i8 2nd gen] ⭢ USB ⭢ Mac
I may have gotten you wrong, but it kind of comes off as "it's easy and you can just RTM." Well, it's not easy for me. I don't get it and I need a teacher. If someone has the time and patience for me, that'd be great and I can compensate a little $.
 
Again, I am using Axe-Fx II.

I assumed that was a typo. You are posting in the AxeFX III forum.

In any case, my instructions should work for the AxeFX II as well. And I am definitely not saying that you should RTM. That's why I provided instructions for you to follow. I only jumped into this thread because you were having difficulty getting the SPDIF approach to work, so I provided instructions for an alternative, and I believe easier, approach to solving your problem. But if you need hands-on help, hopefully someone here can help you.
 
How do you physically connect S/PDIF to the Focusrite?

My Axe-FX S/PDIF connectors are RCA but the Scarlett's is Toslink. Sweetwater couldn't find a cable product to connect the two. What can I do?

I want to reamp Axe-FX in Logic.

My system:
Macbook Pro, 2015 2.5 GHz Quad-Core Intel Core i7 Macbook Pro. Catalina
Logic Pro X 10.4.8
DKFH
Axe FX II
Scarlett 1818
Headphones/KRK Rokit
I'm fairly certain my Scarlett 18i20 (Gen 3) has S/PDIF IN and Out RCA connections in addition to the optical connections. Am I missing something or did previous generations have Toslink only perhaps?
 
You can’t capture the stereo wet and DI signal at the same time using SPDIF. It’s only a stereo feed. To do that use the USB connection.
If you use input and output of SPDIF on the Axe to an audio interfaces in and out, you can capture a DI and wet signals, at least that is what I gathered from reading the manual. Am I missing something?
 
If you use input and output of SPDIF on the Axe to an audio interfaces in and out, you can capture a DI and wet signals, at least that is what I gathered from reading the manual. Am I missing something?
You're resurrecting a very old thread, so I don't know if anybody is still looking for any answers to questions after all this time :).

However, if you're looking for information about using spdif, see the recording guide. That has info to help you learn if you'd be better off using usb or spdif, and if using spdif, how to record wet and DI for re-amping:

https://forum.fractalaudio.com/threads/axe-fx-for-the-recording-musician.177592/
 
You're resurrecting a very old thread, so I don't know if anybody is still looking for any answers to questions after all this time :).

However, if you're looking for information about using spdif, see the recording guide. That has info to help you learn if you'd be better off using usb or spdif, and if using spdif, how to record wet and DI for re-amping:

https://forum.fractalaudio.com/threads/axe-fx-for-the-recording-musician.177592
Are you saying that I said is wrong when recording with windows, guitar in to FM9T SPDIF in and out, in to an audio interface, that I can't record wet and DI?

I was just correcting what I think is a mistake, at least when recording on windows 11. Not looking for answers I thought I was providing them, though I could be mistaken, your thread is nice and I did read it months ago, I'm not going to plug my guitar into my recording device to use SPDIF, I plug my guitar into the FM9T and use SPDIF, I'm not using an APPLE Product, I'm using windows.
 
If you use input and output of SPDIF on the Axe to an audio interfaces in and out, you can capture a DI and wet signals, at least that is what I gathered from reading the manual.

Yes, works perfectly. You just arm 2 tracks when recording: your interface's hi-z input (mono) and spdif input (mono/stereo).
  • guitar connected to interface's guitar / hi-z input
  • use interface's control software to route that to interface's SPDIF out
  • connect my interface's spdif output to axefx's spdif input
  • set axefx's input to digital (I change this to analog when playing live)
  • set axefx's digital input to spdif (as opposed to AES). This setting never changes for me.
  • connect axefx's spdif output to my interface's spdif input
  • Use my interface's gain to make sure the level hitting the axefx input is identical with spdif or the front/rear inputs.
It sounds a little complicated but once you get it working it has several benefits over USB audio or XLR to interface:
  • No workarounds required for latency issues (very common when using the axe as an interface)
  • no messing with aggregate devices on mac
  • monitors and headphones work when the axefx is off without patching
  • much more flexible routing with interface's control software
  • less patching
    • I leave a guitar cable permanently connected to interface instead of patching it every time I take the axefx out of the house or on the road
    • when I get home all I have to connect to my axefx rack are: power, SPDIF I/O, USB (for axe-edit), and the FC12 XLR, all of which are bundled together and stay in the studio
  • frees up 2 mic pres / line inputs on my interface i.e. no patching required when I want to record mics or other instruments with my interface
 
Last edited:
Are you saying that I said is wrong when recording with windows, guitar in to FM9T SPDIF in and out, in to an audio interface, that I can't record wet and DI?

I was just correcting what I think is a mistake, at least when recording on windows 11. Not looking for answers I thought I was providing them, though I could be mistaken, your thread is nice and I did read it months ago, I'm not going to plug my guitar into my recording device to use SPDIF, I plug my guitar into the FM9T and use SPDIF, I'm not using an APPLE Product, I'm using windows.
It's entirely possible I was wrong, yes.
 
Are you saying that I said is wrong when recording with windows, guitar in to FM9T SPDIF in and out, in to an audio interface, that I can't record wet and DI?

I was just correcting what I think is a mistake, at least when recording on windows 11. Not looking for answers I thought I was providing them, though I could be mistaken, your thread is nice and I did read it months ago, I'm not going to plug my guitar into my recording device to use SPDIF, I plug my guitar into the FM9T and use SPDIF, I'm not using an APPLE Product, I'm using windows.

I don't believe I said anybody was right or wrong. I was just providing the instructions for how to do it. You'll find the instructions for how to record DI and stereo wet via spdif in configuration #5 here:

https://forum.fractalaudio.com/threads/axe-fx-for-the-recording-musician.177592
 
Yes, works perfectly. You just arm 2 tracks when recording: your interface's hi-z input (mono) and spdif input (mono/stereo).
  • guitar connected to interface's guitar / hi-z input
  • use interface's control software to route that to interface's SPDIF out
  • connect my interface's spdif output to axefx's spdif input
  • set axefx's input to digital (I change this to analog when playing live)
  • set axefx's digital input to spdif (as opposed to AES). This setting never changes for me.
  • connect axefx's spdif output to my interface's spdif input
  • Use my interface's gain to make sure the level hitting the axefx input is identical with spdif or the front/rear inputs.
It sounds a little complicated but once you get it working it has several benefits over USB audio or XLR to interface:
  • No workarounds required for latency issues (very common when using the axe as an interface)
  • no messing with aggregate devices on mac
  • monitors and headphones work when the axefx is off without patching
  • much more flexible routing with interface's control software
  • less patching
    • I leave a guitar cable permanently connected to interface instead of patching it every time I take the axefx out of the house or on the road
    • when I get home all I have to connect to my axefx rack are: power, SPDIF I/O, USB (for axe-edit), and the FC12 XLR, all of which are bundled together and stay in the studio
  • frees up 2 mic pres / line inputs on my interface i.e. no patching required when I want to record mics or other instruments with my interface
That is a sick write up my man!
 
It's entirely possible I was wrong, yes.

I don't believe I said anybody was right or wrong. I was just providing the instructions for how to do it. You'll find the instructions for how to record DI and stereo wet via spdif in configuration #5 here:

https://forum.fractalaudio.com/threads/axe-fx-for-the-recording-musician.177592
Ah cool. I wasn't wrong. I was fairly certain the SPDIF line only carried a single, stereo signal. Neat trick though using your interface to capture the dry guitar signal @GlennO !
 
Back
Top Bottom