Good Day for the Circuit Bent Auctions




Looking at the Circuit Bent Items on eBay, I came across some good looking stuff. One is a whacked out keyboard with Video synth capabilities and a load of patch points. Right below that is a MIDIfied Major toy with the keypad setup to send MIDI notes out. Internal tone generator works as well, although that is not MIDI. Next up is a 5 Oscillator box/synth. Sounds are pretty neat, I really love the case though, wonder what it was originally. Last but not least is a circuit bent AM/FM radio. Not sure what it really sounds like, but I have a pretty good idea that its just a feedback circuit of some sort.

Attack of the 9090 clones


www.introspectiv.org has some interesting info on building a 9090 clone.

9090 User Guide | pdf
74kb | date : 16/11/02
9090 Parts list | pdf
29kb | date : 5/Jan/04
9090 Wiring guide | pdf
86kb | date : 14/10/02
9090 Board layouts | pdf
237kb | date : 14/10/02
9090 Schematics | pdf
203kb | date : 10/6/02

There is a complete part list plus board layouts and useful links to other clone sites. It does look to be fairly complicated but the interesting part is the schematics for each individual drum sound.

EA-1 probbing deeper

One of the main ICs located on the board turns out to be H8S/2350 microcontroller.
Taken from the website of Renesas Technology.

“The H8S/2350 Group is a group of high-performance microcontrollers with the internal 32-bit H8S/2000 CPU core, and a set of on-chip supporting functions required for system configuration.

The H8S/2000 CPU can execute basic instructions in one state, and is provided with sixteen 16-bit general registers with a 32-bit internal configuration, and a concise and optimized instruction set. The CPU can handle a 16 Mbyte linear address space (architecturally 4 Gbytes). Programs based on the high-level language C can also be run efficiently.
The address space is divided into eight areas. The data bus width and access states can be selected for each of these areas, and various kinds of memory can be connected fast and easily.
On-chip memory consists of large-capacity ROM (H8S/2351 only) and RAM.
On-chip supporting functions include a 16-bit timer pulse unit (TPU), programmable pulse generator (PPG), watchdog timer (WDT), serial communication interface (SCI), A/D converter, D/A converter, and I/O ports.
In addition, an on-chip DMA controller (DMAC) and data transfer controller (DTC) are provided, enabling high-speed data transfer without CPU intervention.
Use of the H8S/2350 Group enables easy implementation of compact, high-performance systems capable of processing large volumes of data.”

C language with a serial interface, now we are talking!
From further reading it seems like this chip is perfect for music applications. However for some interesting bedtime reading refer to the full Chip Document located Here.

Get Lofi Gallery

Being back from vacation I’ve been out of the loop. So the update today is gonna consist of a new feature added to the site, a long awaited Gallery!

I do take alot of pictures while circuit bending and modding. So this should be great for keeping those. The first Gallery is alot Electribe EA-1 board pictures some of which were discussed in the previous post. The gallery is also perma-linked on the leftside, enjoy.

EA-1, ER-1 in disguise?

As it were, noone on the net has put up any inside pictures of either ER-1 or EA-1. So taking the matter in my own hands I carefuly taken my EA-1 appart to snag some images. With this information bending/modifying of these units may be possible.

Just from looking at the makings on the board it appears to be that ER-1 and EA-1 are very simular, and as a matter of fact possibly even interchangable! As seen in one of the images the ER-1 and EA-1 functions are separated by a single jumper on the board.

The extra output can been spotted by looking at the outside case.
By comparing the difference in knobs and the emply spots on the board. It appears that the waveform pot is missing from the EA-1 board. This would definatelly open up alot of potential in EA-1 giving it more then just saw, square, and ramp. The second missing knob is located in the place of the Delay depth spot on ER-1.

From one of the main DSP chips there is a wealth of jumpers leading to the memory chip located just above. Those jumpers are not used. I was told that the sound engine is the same as MS-2000. The same source was also right on the two DSP chips located inside of the unit.

My conclusion:
It is not unheard of for companies to use the same boards and chipsets on different instruments and equipment. The other day I was reading about modding DVD players to make them better and adding Cartridge slots to the ATARI FLASHBACK 2.0. So I guess anything is possible, even modding EA-1 into an ER-1 or vise versa.

The next step is to aquire an ER-1 for more board shots. If my theory is true then all the parts present of EA-1 will be missing from the ER-1. Ofcourse there are the control interface differences, however those could be overcome with MIDI control, somehow.

Favorite Budget Synth/Sequencer. EA-1

Thats right!!! Korg’s EA-1 is awesome. For the price it can’t be beat $60-100 on eBay. This has to be the best deal around. MkI and MkII versions may have some extra bells and whistles, but who needs those. It really reminds me of the MS-2000. I wonder if they are the same engine, better sequencer by far is in EA-1. The delay is virtually identical sounding.

Now the real question is can this be Bent? Probably. Board pictures will be up soon.

More I/O boards

USB Experiment Interface board
This is a deal that you seriously can’t beat. About $30 for an 5 Digital Input, 8 Digital Output, 2 Analogue Ins and Outs. USB with a Dynamic Link Library to write software for. Seems to be windows only however. Avaliable via English Maplin Electronic site. Link to the product here. Free shipping in UK to boot!

I/O Board from Wiring.org.co


Thanks to Hernando Barragan we now have what looks to be a very simple to use I/O board with a USB interface. The Project is called Wiring. (website) The board features 40 Digital I/O pins. 8 Analog inputs for measuring resistance and such as well as 6 Analog outputs!!
The code looks to be strait C++ with calls to the Serial port. Priced at $60 this is gonna be a hot seller. Shipping may be pricey still better then any thing else on the DIY market right now.
Tip via the Benders list.

Pathways To Music

The Birth Of Electronic Music Part I by Nick Rossi and published by a Keyboard Publication has been digitized from the original slide and vinyl circa 1971. The QuickTime files are avaliable for Educational purposes only and should serve as a basic rough guide to the historical aspect of early electronic music. As far as I can tell Keyboard Publication/New Haven is not anywhere to be found online. The closest reference to Nick Rossi is here. I know that is not the right Nick because they were born the same year as the publication. This slide show is the only one in existence as far as I can tell. It was located in a middle school library before it got thrown out and retrieved back by my Professor. Use it as you will, just don’t sell it or take Nick Rossi’s credit.


Large Size ( 40mb )


Small Size ( 8mb )
Quicktime Files.

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.