The Beginning of Rock On Audio

2008-07-29T09:02:00.000-07:00

Greetings fellow rockers! Here is the story of how I developed my monitor system. After years of using a low-end wireless system and constantly having batteries die during shows, I finally thought of the following method:

I made my first prototype using a two channel microphone cable and a generic headphone amp. After this taste of success, I set out to make my own headphone amp. I drew up a new design that looked like this:

With this new setup, I could have a single connector at each end of my cable. It would be much easier to manage. My dream headphone amp (which would later become the "ROCK BOX") looked like this. Notice how on the right side it has just ONE port for both the monitor and guitar signals

After I had begun designing the first model, I went to some engineering companies to see how much it would cost to have this thing made. Well, I found out pretty quickly that it isn't cheap to do this. One company in Denver quoted me 20,000 JUST FOR DESIGN! I couldn't believe it, and after talking with five different companies, I did what I should have done in the first place... I ripped open a few headphone amps and tried to understand their guts.

I wanted my headphone amp to include a speaker-line input. This way I could take a patch out of a passive speaker (be it a stage floor monitor or a main). It would provide a really easy way to access the monitor mix. So I went and bought a little box called the "Headphone TAP" made by ART. It takes a speaker line signal and brings it down to a headphone level - exactly what I needed - perfect! I took it apart and rigged up the following prototype. It ain't that pretty, and it picked up a lot of random radio stations, but it worked!

Next, I found an online tutorial on how to build a headphone amp from scratch. Soon enough, my prototype grew into this:

And so we reach the part of my story when I found the glorious tutorials at Sparkfun. It was here that I learned how to lay out a PCB and order prototypes. If you are new to electronics or already designing projects, then this is the place to go. My first few boards required a lot of fixes, but I quickly learned from my mistakes.

The next few pictures are from a weekend when we made the first big run! Here we are in the garage!

Here we have one end of the cables attached to a pole that is attached the back wall of my garage. Over the pole you can see the black compressed expandable jacket. It will later be slid over the twisted cable.

The best part of making cables is when you run the drill at full speed!

Here's a ton of them lying in on the floor, ready to be cut, stripped, melted, yanked, and terminated - That's what she said!

And that's how it all happened. I am currently working on a new model that will include a limiter (and if I can stay up late enough, EQ and reverb). Rock On!

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