Pre-Amp Update

2017-09-07 00:00:58 +0000 - Written by Carl Burks

Last night I opened up the preamp and began to make some changes. Before I started I took an old Kodak printer apart with the intent of harvesting a power plug. It looked like right size for a typical guitar pedal so I took it apart.

Kodak print board - Bobcat board

Kodak print board - Bobcat board

If you look carefully at the board the bottom shows the power plug next to the metal USB plug. Lots of interesting things on this board. Looks like a realtime clock I might harvest later. As it turns out the power plug was the wrong size, but I plan on revisting the board to pull off a few parts. That crystal might be useful as well.

I looked through my parts bin and found some RCA connectors and thought it would be a really good thing to have a clean signal going into the mixer before it routes around the pedal board. Also having an RCA aux in doesn't hurt either. I fired up the drill and put some appropriately sized holes for the power, RCA, and a switch because I intended on making the Darlington pair optional. I plugged soldered the power to a 9v connector backwards so I could plug it into the battery lead and remove it to plug in the battery if needed. I realized then that the power was the wrong size. I left the hole because I plan on adding power at a later date. I need to start checking the components first. I pulled out the old transistor and replaced it with two. I liked how it sounded and decided to make the switch toggle one of the resistors to make the signal louder. After that I swapped the resistor with a fast switching RGB LED after switching it out I tested it and was surprised to hear what sounded like a synthizer, the LED was too noisy and I replaced it with a standard red LED.

Preamp - Labeled

Preamp - Labeled

Preamp

Preamp

Preamp - top

Preamp - top

Preamp - Side Shot

Preamp - Side Shot

Preamp - Other Side Shot

Preamp - Other Side Shot