TREE

The target of this project was the design of a small portable mixer supplied by a 9V PP3 battery, keeping high quality performance. The mixer is formed assembling three main modules that can be varied in number and/or disposition to suit everyone needs. The three main modules are: Input Amplifier Module: a low noise circuit equipped with a variable voltage-gain (10 - 100) preset, primarily intended as high quality microphone input, also suitable for low-level line input. Tone Control Module: a three-band (Bass, Middle, Treble) tone control circuit providing unity-gain when its controls are set to flat frequency response. It can be inserted after one or more Input Amplifier Modules and/or after the Main Mixer Amplifiers. Main Mixer Amplifier Module: a stereo circuit incorporating two virtual-earth mixers and showing the connection of one Main Fader and one Pan-Pot. The image below shows a Block diagram of the entire mixer featuring four Input Amplifier Modules followed by four in-out...

Although electricity is a ubiquitous and there are times when it is not possible at all to connect your equipment to an electrical outlet. The purpose of the KIWI-Powered U-passes is to provide energy to any type of mobile device. You can connect this device to any source of energy, including the car’s cigarette lighter, USB port, an outlet or even solar power through photovoltaic cells leaflets. Once loaded, it has the ability to store this energy for at least 6 months. Finally, in terms of connectors, this Swiss Army knife of the batteries can be connected to virtually any device. From phones, to MP3 players or any other gadget. In terms of capacity, the KIWI U-Powered masi can get loads of 1000 and has the ability to charge 2000mAh. The price was another pleasant surprise is which is less than $ 50 USD.

This small amplifier was intended to be used in conjunction with an electric guitar to do some low power monitoring, mainly for practice, either via an incorporated small loudspeaker or headphones. The complete circuit, loudspeaker, batteries, input and output jacks can be encased in a small box having the dimensions of a packet of cigarettes, or it could be fitted also into a real packet of cigarettes like some ready-made units available on the market. This design can be used in three different ways: Mini Portable Guitar Amplifier Max output power:  1.5W @ 9V supply - 8 Ohm load; 60mW @ 3V supply - 8 Ohm load Frequency response:  Flat from 20Hz to 20kHz Total harmonic distortion @ 100mW output:  0.2% Max input voltage @ 3V supply:  8mV RMS Minimum input voltage for Fuzz-box operation:  18mV RMS @ 3V supply Current consumption @ 400mW and 9V supply:  200mA Current consumption @ 250mW and 9V supply:  150mA Current consumption @ 60mW and 3V supply: ...