There are now many high quality commercial adapters on the market which enable you to attach your guitar to your iPhone, so it is no longer necessary to put together a cable yourself. I will be testing as many adapters as I can get my hands on so watch this space for a run down!
In the meantime, when choosing a cable look first and foremost at the build quality. Low quality cables tend to lack decent shielding and this can result in cross-talk problems.
Cross-talk occurs when the high volume signal coming from the output induces a signal in the microphone input cable. This can be a problem when the microphone wire and headphone wires run next to each other and have inadequate shielding. You'll notice if your cable is suffering from cross-talk when using loud effects such as distortion where it will sound like feedback, or when using the Delay effect when it will sound like an echo (even when the 'Feedback' dial is turned to 0). RiotFX now comes with a setting to help eliminate cross-talk, but the best solution is to find a great quality adapter in the first place!
Due to the ready availability of guitar adapters, along with decreasing availability of the parts required to easily build your own cable, I no longer recommend building your own.
RiotFX 1.7 is now available!
New & Updated Dynamic Range Effects
Added Compressor & Noise Gate, and improved Expander!
Dynamic range effects now feature a decibel meter around the threshold knob, which enables simple and accurate threshold setting.
A great, in-depth review of our guitar effects app has been written by ScareBear. Check it out!
RiotFX for iPhone Review