LFO modulated simple VCF abram, May 23, 2014 this is a rough draft of a circuit i’ve been working on based of the Simple VCF circuit floating out there. a big thanks to the original author for that. i’m sure there are some mistakes in here. it’s an odd one for sure, but it works on the breadboard…. Continue Reading
solid-state tremolo for tube amps… abram, May 19, 2013July 27, 2020 i’ve have a CBS-era Fender Bantam Bass in for repair that looks like a bowl of spaghetti inside the chassis. it’s a slew of yellow wire spread from one side to the other that resembles the web of a drunken spider. the amp has been modified to include a tremolo,… Continue Reading
simple LFO circuits… abram, June 8, 2012 i was reading over this thread on diystompboxes.com about building an analog LFO circuit for some wild noise idea i’ve got brewing in the back of my head. i started messing around with some of the schematics on there and got a drifting saw wave out of it after a… Continue Reading
TDA2040-based amp schematic with EQ… abram, June 4, 2012 well here’s the first draft of the simplest medium powered solid state design i could muster. TL082 can easily be substituted with a TL072 which is probably better anyhow (i just have all these TL082s laying around). the power supply i’m using more like 14-15V. both ICs should easily be… Continue Reading
TDA2040 Instrument Amplifier abram, March 27, 2012March 27, 2012 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… Continue Reading
SCHEMATIC: TL082 9V Active EQ… abram, March 7, 2012March 7, 2012 an experimental EQ circuit based of the TL082 datasheet. i modified it to use a 9V battery, but could probably still use some work in terms of efficiency… as most things. nothing is ever finished really. the mid portion has a pretty high quiescence. fine tuning, of course, can be… Continue Reading
SPICE: ngSpice plot test… abram, March 5, 2012March 5, 2012 nothing too special here. i’ve been practicing my SPICE skills and attempting to work with a single-supply active EQ circuit based on the TL082. further research of this chip has pointed out that the TL072 is better for audio applications, but it seems that the differences are pretty minuscule. here’s… Continue Reading
Mellotronium revised… abram, February 20, 2012March 5, 2012 here’s an update on the new additions/approach to the Mellotronium. i’m attempting to redo the SD card routines once i get the functionality added. using the SD library just doesn’t work right when reading byte values at 8kHz. i’ve looked into the WaveHC library with the most success, but had… Continue Reading