Connecting Instruments to an Audio Interface

Question

My plan is as follows: I have a Yamaha CP300 stage piano, a Yamaha silent violin and a microphone. I want to be able to record the original sounds from the instruments with e.g. Garageband. Im using a MacBook Pro.

The stage piano has following outputs: (Jacks L+R / XLR L+R) Violin has stereo jack and mic has XLR.

I've been checking several audio interfaces like Line 6. In the shop they told me that this would not be my best choice. Now I am looking to Scarlett stuff. The thing is that they have several (stereo?) jacks as input for guitars. If there are two inputs for guitars, do I need to connect each output channel from CP300 to a single guitar input? How does this work?
I am confused because (A) on most interfaces there is only a guitar symbol, and (B) I do not understand how to combine both my output channels to a single guitar input. Can perhaps someone shed a light on this, that would be great!

Answer 1

Your question is a bit confusing, but I will answer by showing you an example.

Your Instruments:

• CP300 Piano - Line Outs = 2 x XLR / 2 x 1⁄4 inch(Phone) Jack
• Silent Violin - Line Out = 1 x mono 1/4 inch TRS(balanced phone) Jack (a guess?)
• Microphone - Mic Level = 1 x XLR

So let's look at a scarlet interface:

Scarlett 2i2 (User Guide - 2nd Gen) - (Record one at a time)

This is a simple Audio interface. Looking at the user guide, the XLR inputs are Mic-level only. Meaning you could not connect your piano to this XLR connector. However, they are combo inputs, meaning they also have a phone jack input at the centre. There is also a line/instrument switch for connecting a line level device(e.g. keyboard) or an instrument-level device(e.g. guitar) to this phone socket.
So how would you connect to this?

• CP300
  Your CP300 could be connected in one of two ways:

  1. CP300 Phone Jack Left <--(via 1/4 inch (mono/TR) Phone lead)--> Combo 1(Line) Phone Jack (Unbalanced)
     CP300 Phone Jack Right <--(via 1/4 inch (mono/TR) Phone lead)--> Combo 2(Line) Phone Jack (Unbalanced)

  2. CP300 XLR Left <--(via XLR to 1/4 inch (TRS) Phone lead)--> Combo 1(Line) Phone Jack (Balanced)
     CP300 XLR Right <--(via XLR to 1/4 inch (TRS) Phone lead)--> Combo 2(Line) Phone Jack (Balanced)

• Silent Violin
  I'm not sure if this has a line-level or instrument level / balanced or unbalanced output. Read the documentation, and you can be sure to use the best connection.
• Microphone
  Plug the XLR connector into combo 1 XLR.

Scarlett 6i6 (User Guide - 2nd Gen) (Record all simultaneously)

If you want to connect all devices simultaneously, then you simply need more inputs in the Audio Interface. The 6i6 provides these extra inputs.

---

The guitar symbol you talk about is just to show you that an instrument can be connected(rather than a Mic). Whether the input is instrument or line-level, you would have to read the documentation to find out. Each input represents a single channel, so for stereo instruments, you have to utilize two of these mono inputs.

I am not recommending you buy any of these devices I have referred to, they were just the first ones I came across.

Info on Input Levels