Sonoma Wire Works GuitarJack Model 2 – User Report

GuitarJack is an audio interface for iPhone and iPad that allows the user to connect a wide range of instruments, microphones, and other audio hardware to the iPhone, iPad and iPod touch. This user report takes a look at the latest GuitarJack Model 2 (GJ2), which is designed to be compatible with iPhone 4, iPad 2, iPad, iPod touch (2nd, 3rd and 4th gen.). I tested the unit with an iPhone 4S running iOS 5.01. GJ2 has a broad range of functionality, so make sure to visit the company’s website for full details.

Physical Design

The physical design of GJ2 is impressive right out of the box. The unit is housed in a beautiful, sturdy anodized aluminum case. The jacks are high quality.

The unit plugs directly to the 30 pin connector of your phone, or with an optional accessory cable allowing the user to decouple the iPhone/iPad from the GJ2. Although having the GJ2 connected directly to the phone works fine, it does impact your ability to easily reposition your phone if you need better/different access to the screen. For example,

GuitarTone and TaylorEQ (free apps that come with the unit) are locked in vertical display aspect, whereas Garage Band is locked in landscape. Additionally, the connection between the GJ2 and the phone is easily separated, so you need to use care when repositioning. An optional extender cable is available through Sonoma, as well as other sources that they list on their website. Also worth noting, you won’t be able to charge your phone while connected.


The sound quality of the GJ2 is very good. Using the 30 pin connector allows for better frequency response, and lower latency than connection via the iPhone’s 1/8 inch headphone connector. Additionally, the GJ2’s control panel provides a broad range of adjustment for different input levels. You can boost or pad as necessary to achieve perfect level from a variety of sources without clipping — nice! GJ2‘s control panel also allows you to adjust the mix between its two inputs, which is useful when using them simultaneously.

GJ2 accepts microphones as an input source for both the 1/4, and 1/8 inch stereo mic/line inputs. While direct connection of mics is possible, you will need a stereo mic with an 1/8 stereo jack, or a mono mic with a 1/4 mono connector to achieve that. For other types (mono studio mics such as Shure SM57 or SM58), I highly recommend a visit to the FAQ section of the company’s website for details on required adaptors and software setup. While checking the FAQ, make sure to read the info on simultaneous input of guitar and mic. Also noteworthy, you can monitor both channels simultaneously; however, you’re only able to record two channels simultaneously when using Sonoma’s recording apps for iPhone and iPad (FourTrack/StudioTrack).

GJ2 also works as an input for third party apps such as Garage Band. I tested GJ2 with Garage Band and CLEARTUNE with no problems. It’s worth noting that the GJ2 control panel is only accessible through its apps (GuitarTone and TaylorEQ, for example). What this means (with regard to use with third party apps) is that you have to do your input setup via one of Sonoma’s apps (or supported apps), then exit and enter the desired third party app. When you do this, you do not retain the sound effect (such as GuitarTone amp modeling or TaylorEQ setting) for use in your third party app.

Also important to know is that (currently) when the GJ2 is plugged into your phone, connectivity to all networking (WiFi, 3G) is interrupted. Once you’ve disconnected GJ2 from your phone, it won’t automatically reconnect without placing the phone in airplane mode for ten seconds, and then turning airplane mode off. According to Sonoma wireworks, this is an Apple iOS issue.


In summary, Sonoma Wire Works GJ2 is a well made (in the USA) product. The design, construction and performance are all excellent. GJ2 is easy to get up and running, but make sure to visit the company’s website for full details on achieving setups with mics that require adaptors. In the arena of audio interface options for iPhone and iPad, GJ2 is an excellent choice.

Leave a Reply