Connecting guitar to Focusrite 2i4 to make it be heard in loudspeakers

theodorn

Had a friend on a visit, we wanted to see if we could plug her acoustic guitar (not electric) to my Focusrite Scarlett 2i4. She bought a guitar amp for it, and it works fine, but I wanted to see if I could hook the guitar up to Focusrite, and make it be heard in my loudspeakers.

The Focusrite is connected to an amplifier, and it in turn is connected to four loudspeakers. All my virtual libraries work without problems on this setup, with my Casio PX-5S as the MIDI controller. I have been able to connect the Casio directly to the Focusrite, but then I need to use both of the XLR inputs. Which is more of a hassle, and I prefer VSTis anyway, so I never do that.

I connected the guitar to the leftmost XLR input, and switched to INSTR (instead of LINE), but no sound whatsoever. Am I missing something? Do I need to create a track in Reaper or any DAW, to get the guitar to sound? I do not intend to record, not at this point. Any and all suggestions for a solution are welcome.

HZPiano

theodorn to see if we could plug her acoustic guitar (not electric) to my Focusrite Scarlett 2i4.

Hello,

A lot of good input has already been given. Just to make sure, I'd like to add:

Because it's an acoustic guitar, it will probably have a piezo pickup. Piezo pickups have an utterly high impedance and produce an utterly tiny wee signal, which is why instrument level inputs often cannot use their signal. It's just way too weak.

So if this is indeed a piezo-equipped guitar:

If the guitar doesn't have its own preamp, you will need a suitable one inbetween the guitar and the Focusrite.

If the guitar does have its own preamp (like a Fishman or similar) it is usually battery powered and has controls for volume/gain and a basic or more advanced tone control. Check the battery and the controls. In such configuration, the Focusrite needs to be switched to "instrument level" on the input you use.

Sometimes (but more rarely), these built-in preamps are and/or can be powered by phantom power, in which case things may get a little more complicated in making the proper connection. And the Focusrite should then be able to deliver phantom power, which I don't know whether it does.

Hope this gives some more clues to get things going.

Cheers and happy connections,

David B

I would plug the guitar directly into the 2i4 and then go either to your speakers (if they are powered) or to your amp then to speakers.

I've owned a 2i4 (gave it to my son) and now I use a 2i2 for vocals and guitar. I also run my N1X outputs to it and then run the 2i2 to studio monitors to supplement the onboard speakers of my N1X. It works great.

Why are you going through the amp? Are there some effects on the amp that you want to use in the signal chain?

Here is a little guitar and Focusrite action. I recorded this a couple of years ago.

https://youtu.be/wRC2e5SK4Ss

God Bless,
David

theodorn

Thanks a little busy now, will reply in more detail tomorrow.

CyberGene

Not sure about the 2i4 but I have the 2i2 and it has a direct monitor button that would route the input directly to the output without the need to go through a DAW.

Frédéric L

The 2i4 has a knob which permits to mix what you monitor (analog inputs vs. DAW).

theodorn

Thanks for replies, thought I'd start with posting a picture of the 2i4.

theodorn

Found a smaller picture, than the original one. David, that's a great cover of this beautiful praise song, and it just so happens we are doing this to play, and maybe later record, worship music.

I just talked to a guy who was roadie for a band for 20 something years, and he says I have to go through the guitar amp first, if I connect the guitar straight to the Focusrite, I might damage it. However, that's no problem, we'll try that when we meet next week.

Cybergene, I almost never use the direct monitor output, always the big monitor volume knob, but are you saying I have to use the direct monitoring output?

For the record, I have an amplifier and four speakers, which are not powered (by themselves), they need the amp.

CyberGene

theodorn Cybergene, I almost never use the direct monitor output, always the big monitor volume knob, but are you saying I have to use the direct monitoring output?

I see a knob above the “direct monitor” text which should balance between input and playback. Twist it entirely towards “input” and that should give you direct routing from the audio input to your speakers without going through any software (DAW). The other option “playback” is where you listen to what your computer outputs (including re-routing the incoming audio back in case you have configured your DAW for that). For a guitar use the mono switch.

Of course you should still use the big monitor knob to set the output volume. The small direct monitor knob is only used for setting a balance between input and playback, in most cases it should either be fully left (your case) or fully right (when you play software instruments, etc).

David B

theodorn I just talked to a guy who was roadie for a band for 20 something years, and he says I have to go through the guitar amp first, if I connect the guitar straight to the Focusrite, I might damage it.

I don't see how since the forcusrite is deigned for that purpose. It has two inputs that can handle instrument or line level signals. From their manual:

The only reason I can see why you would want to go through the amp is if you want to use it as an effects processor or to otherwise color the tone of the guitar. I unusually go from my guitar into a Boss VE8 for chorus and delay and then into the 2i2 for recording.

However, here is a recording of just my acoustic guitar plugged straight into the forcusrite. It's a totally dry guitar and vocal signal. Nothing blew up. 😀

https://youtu.be/4NaNCElbeZg

God Bless,
David

theodorn

Ok, now I see it, the one northwest of the big monitor knob, probably what Frédéric L was referring to. I'll make use of it the next time we connect everything. I also intend to connect a microphone, to the other XLR/combo input. The dream scenario is to mix the guitar, microphone, and some piano VST(s).

theodorn

Sorry for a late reply, I thought so exactly, that the Focusrite is designed for this stuff, plugging in an acoustic guitar. I suspect my friend doesn't know about audio interfaces, since they were hardly around when he was working in the business, and thinks they are something else. I was thinking of connecting the guitar and the mic just as shown in the picture.

theodorn

Thank you HZPiano, great info. I believe the guitar has a pickup behind the 6.25mm input, but I have no idea if it is piezo or anything else. It does not have a preamp, but we have a guitar amp for it, which should according to your words, be the link between the guitar and my amplified speaker system. The Focusrite has phantom power, that's the 48V button, right?

HZPiano

theodorn The Focusrite has phantom power, that's the 48V button, right?

Yes, that's the one 🙂.

Cheers,

HZPiano

theodorn we have a guitar amp for it, which should according to your words, be the link between the guitar and my amplified speaker system.

Well, if you mean going from that amplifier into the Focusrite, then please be very careful, and make sure you know exactly what kind of signal is coming out of the amplifier. You don't want to unknowingly damage your Focusrite's input(s).

If in any doubt, you could use a DI Box*) between the guitar amplifier and the Focusrite to obtain a safer ("impedance matched") connection.

Cheers and happy careful experimenting,

*) Such as:

https://www.thomann.de/intl/behringer_di100_ultra_di.htm

theodorn

Oh I see, I wasn't clear when I was describing my setup, the chain is like this (or rather, will be most likely):

Guitar --> Guitar amp --> INSTR combo input Focusrite --> Onkyo amplifier --> Loudspeakers.

The amplifier + speakers is of course nothing new, millions of people have that. Then I'm taking in the computer audio through the USB input on the back of the Focusrite 2i4 - no rocket science there either.🙂

The question remains, can I cut the guitar amp out of the chain above, but I can't if the signal from the guitar (pickup) is too low, or what?

HZPiano

theodorn

The guitar will only work straight into the Focusrite's instrument-level input if either:

It has coil pickups like any odd electric guitar
It uses an internal microphone instead of a pickup;
Or it has a piezo pickup (often invisibly embedded under the bridge) and its own preamp.

A piezo-equipped guitar without any built-in preamp needs an external one with a piezo specific input between it and the Focusrite.

If the guitar amplifier you have there now has an input that is suitable to plug a piezo signal in, it might serve the role of preamp if it also has an output that is on either instrument level or line level. However if it outputs a signal hotter than these (such as a speaker driving signal) it may present a danger to your Focusrite. In that case, you can put a DI Box between the guitar amp's output and the Focusrite's input to manage that.

It'd be better if we knew exactly what guitar and pickup you are dealing with, otherwise all of this gets too speculative/theoretical.

Cheers and happy connections,