Tube amp

About a month ago now, with the help of my friend Erik I finished the Firefly tube amp project. About 30% of the parts came from stuff that me and Erik had laying around, ( Knobs, pots, the case, metal scraps for the tube holders.) The power and output transformers were ordered online by Erik and I believe cost not more then $12 for the 2 of them. The power caps came from some weird tube modules that I picked up at the surplus store. They seemed to work just fine dispite their age. The hammered grey paint did wonders for the gutted aluminum case which I also picked up at the surplus store. I decided to try mounting the tubes sideways in order to keep everything inside the case. Turned out wonderful. Heat is not an issue at all, everything runs very cool. The botton of the case was pre-drilled for the old patch bay that was there before. That helped when deciding to mount things inside that case. The lid was also predrilled but after painting it the holes look kind of cool.

The Gibson style knobs look awesome. Left is the volume and the rightone is resonance.

The hardest part was soldering the tube sockets, but nothing impossible.

Things seemed to have layed out very well inside.

The amp sounds great, nice and clean at low volumes , smooth and distorted cranked way up. The output is not too high but does make for a decent practice amp or a preamp for warming that digital sound.

Projects Projects Projects.

Sometimes I wish that I could just ditch everything else that I have to do and just enjoy making wierd sounding instruments for living. However that will most likelly never happen. My latest projects include.

SN76477 exploration. I scored 11 of those chips from some company in china.

Planning on building a few basic synth modules of those. Also been working with some XR2206 function generator ICs.

Achieving crazy waveforms from a cheap playskool keyboard with the help of some ICs. Stay tuned for finished projects.

The patch bay touch and tell is almost finished, I just have to get a few good connections on there to make sure that I’m maximizing my bending. Paint looks pretty good, and the lot of ICs is just for flossin’.
Many things need to happen this weekend including getting some projects caped off. Pictures of my Tube amp should be up as well sometime. –Alex

New projects will be posted soon

In my sparetime I got to clean the shop area. Finally purchased a drill press with a set of unibits. My next investment would have to be an oscilloscope, $55 at Rockwell surplus, can’t really go wrong for that much. The Talking Teacher toy is gonna be sweet 5 patches, 3 switches and a pot. Custom paint. Gonna be slick. Pictures will be up soon.

Keepin busy

Circuit bending is fun, but I wish I wasn’t so busy fixing virus and spyware infested windows boxes for people who don’t have a clue. Oh well, making money, gotta pay billz!!!! I started working on a Caleco Talking teacher. Pretty sweet to bend. There is alot of glitches and random garbled up sounds. Combinations of bends even cause to spaz out randomlly. I am testing the idea of a patchbay with that one. Unfortunatelly I made some nasty plug holes, they are not the best. So now I’m looking to buy a drill press, I’m done fussing with the drill and scissors. Drill press is the way of the future. Things will look hella well done. I also starter building a Firefly tube amp with the help of my friend. Jolly good times. I’ve been too busy to even go to the Goodwills. Maybe tonite I can swing by one. The circuit bending group on yahoo has been very active. Some topics that make it in there are not always directlly related, but its fun to read still.

Patch bays

I stopped at the Rockwell Surplus store today during lunch to pick up some patchbay hardware. I got a bunch of plugs and connectors. 3 aluminum cases and a few toggle switches. The downside is that the lady charged me $10 for that stuff, what a rip off. Still I did get a ton of stuff that would make for a couple of cool breakout boxes. The SK-5 is gonna have a decent size patch bay. Pictures coming soon. New toy bends posted in the EctoOne bends section.

Good Monday

Today worked out pretty well, I stopped at the Goodwill on the Westside of CR and found a TI Super Speack and Spell. I also picked up Coleco Talking teacher. My total was $4. Pretty good deal. The Super Speack and Spell looks more digital then the previous models. Never to less I read that its bendable. The talking teacher will have to be added to my pile of stuff to bend. Seems how I got 2 of them now. He He He. I think I’m gonna take pics of all that stuff and just for show.


The blog is comming along nice. I added a few links and some cool ebay search features. Anytime anyone needs to check a price on SK-1s or Concertmates, they can just follow the auction links. I’ll add some other relevant links soon as well.

I went to the Rockwell Surplus Store at noon today. They didn’t have much, but I knew what I was looking for. I scored 14 toggle switches for 1$. Plus I got some audio connectors and sweet ass lightbulbs. They had a few things to make patch bays out of, so maybe next week I’ll consider getting some of those connectors.

I did manage to get a Concertmate 400 ( Casio SK-5 ) from ebay tonite. $13 plus $12 shipping, so 25 total, which isnt bad, considering the keyboard is in MINT shape with a box, and a Realistic gig bag. Can’t wait to start bending that one. I think I’ll use an external switch box for that, considering an abundance of those at the RSS.

By the way, here is a link of a person who played at the Nexus, called The Engeneer.

First post.

Welcome to the circuit bending blog for Cedar Rapids Iowa, I noticed that there are atleast 2 other people who are interested in this scene and live in Iowa. Of course I will do my best to get them aware of this blog, and have them involved in representing the local circuit benders. Comments are open to anyone, no need to register. Circuit bending comments only though. I’ll try and post related links when I can. Please contact me at with any comments or requests. Thanks. –Alex

Circuit Bending Events Custom Instruments DIY Tips and Tricks. Cassette Tape and Record Full Albums I converted on YouTube. My eBay Auctions and Special Projects.