Nuts and Volts - May 2014

The Teensy from PJRC.com is a complete USB-based microcontroller development system in a very small footprint. With support for three UARTs, I2C, SPI, and one-wire devices, Coridium’s BASIC makes it easy to integrate a variety of peripherals into a project. For commercial users, licensing is available, as well as customization that can include Ethernet web, ftp, mail, and UDP support.

DIY ELECTRONIC AMP

KITS

Boxed Kit Amps introduces two new DIY electronics kits: the SoloG Pocket Guitar Amp Kit and the Case Free Gobo Stereo Amp Kit. Both kits boast easy-to-follow step-by-step instructions.

The pocket guitar amp retails for US$25 and is a learn-to-solder kit or a quick fun build for a more experienced maker. It's suitable for any age qualified to handle a soldering iron. There are only through-hole components and the only wiring is to the battery holder.

This guitar amp will fit in a back pocket and can be used with either headphones or speakers, or plug it into a regular amp to add another groovy effect.

The SoloG is Boxed Kit's take on the venerable

"Smokey" amp. It uses a genuine JRC386D op-amp just like the original. This is buffered by a JFET-based emitter follower to get clean powerful tube-like sound like the famous "Ruby" amp, but the similarity ends there.

Instead of a redundant "volume" control or any sound shaping, Boxed takes advantage of the guitar's volume and tone knobs. A red LED on the pocket amp acts as a clipping indicator for the gain control, and it's backed by a couple of Si diodes (it wouldn't be an audio circuit without at least one 1N4148). Using the LED, musicians can adjust the gain so there's no clipping, or can crank it. The Case Free Gobo Stereo Amp Kit is a Class AB chip amp kit that lowers the bar and the cost for anyone wanting to build their own high-quality stereo amp. Assemble the Gobo's high-end audio-grade components, build a case, and show off the warm, retro sounding custom analog-based chip amp design.

The Case Free Gobo kit lists for US$170 and includes: • Easy-to-follow instructions crafted with the beginner in mind, rich with high-quality photos.

• The popular op-amp LM1875 which is easy to use, stable, and provides excellent performance.

• Hand-routed amp boards designed with the shortest possible paths and smooth lines.

• A power board with oversized capacities and flexible options.

• Professional-grade toroidal audio transformer engineered specifically for audio applications — cool running, quiet, and efficient-boasting minimal interference from stray signals.

•High-quality audio grade capacitors and resistors.

• Bling in the form of an anodized aluminum knob, stainless steel hardware, and gold plated connectors.

MANUAL ESP/PSI TESTER

The manual ESP/PSI tester kit now available from Images SI is an interesting human-input random number generator (RNG) device that can be used to check ESP/PSI, and the mind's ability to influence (PK) and forecast random events.

The ESP tester utilizes a momentary contact switch that a user presses to generate true random numbers. The PIC16F88 in the ESP tester is spinning at approximately