• PT2399 build…

    this is an older build now, but i wanted to post it while i’ve been on the subject to record the process. believe it or not, i still have some work to do on this one. i used a TL082 as a buffer for the mixing circuit. getting the gain set to my taste has…

  • MOSFET overdrive…

    a forced contract job for Ryan of Falcon Scott. he’s been having some issues finding an overdrive suitable to his hollow-body guitar. i just got a lot of BS170s and thought this might do the trick. the distortion is pretty squared off on the oscilloscope and crunchy. the left pot is post volume while the…

  • ngSpice: single frequency FM modulated signal generation

    ever wanted to see how that 2N2222 might hold up as a linear RF amplifier? here’s a handy feature of ngSpice that i found recently. i’m rather new to ngSpice and at first was somewhat frustrated by its differences from other SPICE variants. however, i’ve earned a deep appreciation for it and its integration with…

  • LM386-based “Esteli” demo by Alex Wilson

    an older video, but one i’ve been wanting to post for some time. this is Alex Wilson of Son Cats playing on one of the several cigar-box amps i’ve constructed. this one, in particular, had one of the best sounds during the more work-with-what-is-available days. i thought the video was a great demo of an…

  • MOSFET vs. BJT

    a good rule of thumb pulled from this forum thread (http://www.electro-tech-online.com/general-electronics-chat/39339-mosfet-vs-bjt.html): Need a switch to be fully-on fully-off and carry lots of current -MOSFET Need a switch that needs to have lowish capacitance – BIPOLAR Need a cheap, dirty 2 or 3 component current source – BIPOLAR Need a low voltage/noise amplifier – BIPOLAR Need…

  • Arduino: Mellotronium loops…

    a little improvisation i did after improving the LFO phase modulation and arpeggiator functions of the Mellotronium: an ATMega328P-based mirco-synthesizer. there are plenty of improvements to be made, but it’s surprising how much you can make of these microcontrollers do. combined with a Roland RC-50, it’s music composition on the fly. you’ll have to excuse…

  • Mellontronium vs. the Sun…

    the micro-synthesizer is getting fitted to draw it’s power from the sun via a 6V 200mA solar cell. it’s pretty impressive what the sun along with a cheap collection of photovoltaic cells can do.

  • TDA2040 Instrument Amplifier

    the need for small and portable amplifiers has arisen mainly by a desire to come up with some sort of all-purpose busking amplifier. here is the first screen shot of the output from the preamp section. the entire amplifier is powering an Eminence Beta-12LTA off of a mere 6V. don’t ask me how. it took…

  • ARDUINO: Setting up a Gentoo development environment…

    if you’re reading this post, most likely you’re having issues with setting up Crossdev as mentioned on the arduino.cc site. i tried countless times to configure my system for AVR compiling that way, but it always failed compiling avr-libc and would never compile avr-g++ no matter how i applied the USE flags. in short, i…