Arduino Micro Incorporated in Guitar Amp PCB

Hello all, I wanted to share this PCB I just designed for a guitar amplifier. This board houses the circuitry for three main features of the amp: digital reverb, switchable effects loop, and a buffered line out.

I have incorporated an Arduino Micro into the board to handle a few different functions. The Micro is used to toggle between reverb presets in the DSP, as well as turning the reverb off (via a relay). This is controlled from the front panel of the amplifier. It is also used to switch the effects loop in and out of the circuit via the second relay. The way this works is when a cable is plugged into the "send" jack of the effects loop, the loop is turned on. I'm also utilizing the 3.3v regulator to power an indicator LED. :)

I'm pretty new to Arduino, having just started with it in the past month. I'm loving the platform!

Why do you need the Arduino?

xchip: Why do you need the Arduino?

The arduino provides an interface with the black box that is on the board.

Nice job Cwild! I am a big fan of anything guitar related so, it is nice to see some new ideas!

Thanks, cyclegadget! :slight_smile:

Why do you need the Arduino?

It certainly isn’t the most robust application, but it is useful here.

The DSP I’m using has 16 presets, but I am only using 3 of them. If I were to use a rotary encoder to control it, I would have to cycle through all the presets sequentially–which I don’t want. The Arduino allows me to call the 3 presets I’m wanting to use (and turn the reverb off) with a simple 4 position rotary switch. It also allows for the effects loop switching all in one shot. There are also some ground noise issues that the Arduino eliminates vs. an analog alternative.

It is entirely possible to do all the same things with analog circuitry, but using the Arduino makes it simpler, takes up less real estate, and requires less components.