Adventure in Soundland

These two things are the initial Vitamin S cargo. I’d done lots of other effects, but these two were the more appropriate for soundscape type stuff. The one on the left is a T.M.K. (too many knobs) which was designed by Tim Escobedo and is one tl072 opamp with a myriad of interconnections.

As you can see it’s got lots going on and is capable of anything from straight boost to self oscillating sonic mayhem… I like it!
To the right is my version of the synthstick, minus the stick which I gave to Felix Delux (after he built the synth stick oscillator as his first electronics project), which is two oscillators in the one enclosure with one as a drone and the other as the “melody maker”. I’ve got to go back into this as I didn’t use a summing mixer to mix the two signals and as a consequence it’s very tricky to get them going together. Just three resistors and it’ll work but I haven’t gotten around to even now.
The stick I gave to Felix was kinda hard to use, though he figured out a way very quickly, and I’ll eventually make another one as soon as I go through all Mum’s dead VCR tapes to find one with the 1 megaohm resistance per metre.
A link to the Synth stick page is at the bottom (haven’t learnt enough html to stop a link in the middle linking to everything underneath)

This is my little sound amplifying baby, which gets mic’d up for the PA at Vit S, and serves as my monitor and a monitor for those I’m playing with, and was originally built into a conventional wooden box, but that was kinda boring so out came the kitchen aluminium… well actually theres a tellus vacuum cleaner upper body for the speaker.
The amp itself is a class A transistor amp using two old RCA transistors I found at Radio Spares in Upper Queen St years ago. They spec’d out to be equivalents to 2N3055′s so in they went. I liked them because they have the old RCA logo on the top which can just be seen through the rust where they’re sitting at the top on their heat sink, which gets very hot as it is class A.
The amp design came from a book I bought off the net by Kevin O’connor who runs London Power and makes tubes amps in London, Ontario, Canada. The Books called “Tonnes of Tone” and is a local printer bound and photo copied type book thats just chock full of the stuff a guitar player needs to make for themselves. Amps, tube and SS, preamps, reverbs and tremelo’s, mostly tube but a smattering of SS stuff as well. I got it for the tubes which was why I started electronics but built the Hood amp, the one I’m discussing here is called that in the book, ’cause it was easy.

‘Cause it’s class A, which means that the output transistors are biased at half the supply and swing from the suppy to ground, these babies run really hot and do not suffer from crossover distortion which can be a problem with garden variety class AB amps. They run hot, never resting as it were, but they are very good at creating even first harmonic distortion, tube or transistor, and thats a real plus for an output amp. The original spec’d supply voltage was 54VDC but I’m sure I eventually found a transformer to give me 65-70VDC but I can’t remember as it’s been so long since I opened it up plus I wasn’t so good in those early days about documenting what I was doing.

This is the page from the book with my notes on it. If you make it make sure you get a big heatsink for the transistors… works like a very inefficient heater in a small room.
The amp itself is fed with a preamp and baxandall tone control from an early book I had from Jaycar which I can’t, right now, remember the name of (I’ve lost my original copy) but it was by R.A. Penfold, who is a hero to many in the FX fraternity. Jaycar used to bring in a bunch of stuff published by Babani Books of the U.K. and was, and still are, very useful. Recently I got an updated copy of the book from Whitcoulls for about $15.00 which was essentially the same book but the old opamps, TL072′s and 5534′s, had been changed to more modern types plus it included a beginners section on resistance, capacitance, etc and how to build stuff. “Audio Amplifier projects “. I googled it!
So guitar preamp, bax stack and Hoody. On/off switch plays up but apart from that it’s solid as a rock and it sounds good… and I’m a real fan of tubes!

Garden variety Jaycar ceramic magnet paper cone and rubber suspended 12″ speaker. Not an alnico, ribbed paper minimal suspension speaker but it still sounds good. Maybe it likes me!

This is my kinda first Vit S stringed instrument, the celljo or banlo, because it’s cello strings over a drumhead. The neck and body are cherry and the fretboard is packing crate rosewood style timber. It’s got a small duo preamp with a piezo on the underface of the head and an electret condensor mic mounted on the drum body. I gotta go back in and change some stuff as the piezo’s the stronger but it feedbacks too easily and maybe should be on the body and the electrets not strong enough and needs to be in a better position to add voice to the mix. I did this little pre on the run one mnday afternoon so I don’t think I even documented it. Just scavenged the electret schematic from a Paia drum trigger and the piezo from somewhere else which I can’t even remember though it’s most probably jfets due to the high input impedance required by piezo’s to make them sing the bass.

The head is a tamborine type, sans jingly bits, I picked up for about a tenner at a music shop and the bridge support is a milkshake shaker top. The actual bridge is an old ebony piano key that is rounded on the bottom so it can be used as a vibrato.

Joe Strummer said two chords were enough… two strings is enough for me!

This is the 1 hour preamp. maybe two hours. I’ll do a schematic when I go in next.